1
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Srokova S, Aktas ANZ, Koen JD, Rugg MD. Dissociative Effects of Age on Neural Differentiation at the Category and Item Levels. J Neurosci 2024; 44:e0959232023. [PMID: 38050137 PMCID: PMC10860568 DOI: 10.1523/jneurosci.0959-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 10/07/2023] [Accepted: 11/22/2023] [Indexed: 12/06/2023] Open
Abstract
Increasing age is associated with age-related neural dedifferentiation, a reduction in the selectivity of neural representations, which has been proposed to contribute to cognitive decline in older age. Recent findings indicate that when operationalized in terms of selectivity for different perceptual categories, age-related neural dedifferentiation and the apparent age-invariant association of neural selectivity with cognitive performance are largely restricted to the cortical regions typically recruited during scene processing. It is currently unknown whether this category-level dissociation extends to metrics of neural selectivity defined at the level of individual stimulus items. Here, we examined neural selectivity at the category and item levels using multivoxel pattern similarity analysis (PSA) of fMRI data. Healthy young and older male and female adults viewed images of objects and scenes. Some items were presented singly, while others were either repeated or followed by a "similar lure." In agreement with recent findings, category-level PSA revealed robustly lower differentiation in older than in younger adults in scene-selective, but not object-selective, cortical regions. By contrast, at the item level, robust age-related declines in neural differentiation were evident for both stimulus categories. Additionally, we identified an age-invariant association between category-level scene selectivity in the parahippocampal place area and subsequent memory performance, but no such association was evident for item-level metrics. Lastly, category- and item-level neural metrics were uncorrelated. Thus, the present findings suggest that age-related category- and item-level dedifferentiation depend on distinct neural mechanisms.
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Affiliation(s)
- Sabina Srokova
- Center for Vital Longevity, University of Texas at Dallas, Dallas, Texas 75235
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas 75080
| | - Ayse N Z Aktas
- Center for Vital Longevity, University of Texas at Dallas, Dallas, Texas 75235
| | - Joshua D Koen
- Department of Psychology, University of Notre Dame, Notre Dame, Indiana 46556
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, Texas 75235
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas 75080
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2
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Abstract
A longstanding question in memory research is whether recognition is supported by more than one mnemonic process. Dual-process models distinguish recollection of episodic detail from familiarity, while single-process models explain recognition in terms of one process that varies in strength. Dual process models have drawn support from findings that recollection and familiarity elicit distinct electroencephalographic event-related potentials (ERPs): a mid-frontal ERP effect that occurs at around 300-500 ms post-stimulus onset and is often larger for familiarity than recollection contrasts, and a parietal ERP effect that occurs at around 500-800 ms and is larger for recollection than familiarity contrasts. We sought to adjudicate between dual- and single-process models by investigating whether the dissociation between these two ERP effects is reliable over studies. We extracted effect sizes from 41 experiments that had used Remember-Know, source memory, and associative memory paradigms (1,000 participants). Meta-analysis revealed a strong interaction between ERP effect and mnemonic process of the form predicted by dual-process models. Although neither ERP effect was significantly process-selective taken alone, a moderator analysis revealed a larger mid-frontal effect for familiarity than recollection contrasts in studies using the Remember-Know paradigm. Mega-analysis of raw data from six studies further showed significant process-selectivity for both mid-frontal and parietal ERPs in the predicted time windows. On balance, the findings favor dual- over single-process theories of recognition memory, but point to a need to promote sharing of raw data.
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Affiliation(s)
- Simon Kwon
- Department of Psychology, University of Edinburgh, Edinburgh, UK
- Department of Psychology, University of Cambridge, Cambridge, UK
- Department of Psychiatry, Brigham and Women's Hospital, Boston, MA, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
- School of Psychology, University of East Anglia, Norwich, UK
| | - Ronny Wiegand
- Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Tim Curran
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Alexa M Morcom
- Department of Psychology, University of Edinburgh, Edinburgh, UK.
- School of Psychology, University of Sussex, Brighton, UK.
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3
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Hou M, de Chastelaine M, Rugg MD. Age differences in the neural correlates of recollection: transient versus sustained fMRI effects. Neurobiol Aging 2023; 131:132-143. [PMID: 37633119 PMCID: PMC10528128 DOI: 10.1016/j.neurobiolaging.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/28/2023] [Accepted: 07/02/2023] [Indexed: 08/28/2023]
Abstract
Prior functional magnetic resonance imaging findings in young adults indicate that recollection-sensitive neural regions dissociate according to the time courses of their respective recollection effects. Here, we examined whether such dissociations are also evident in older adults. Young and older participants encoded a series of word-image pairs, judging which of the denoted objects was the smaller. At the test, participants judged whether each of a series of test words was old or new. If a word was old, the requirement was to recall the associated image and maintain it over a variable delay period. Older adults demonstrated significantly lower associative memory performance than young adults. Transient recollection effects were identified in the left hippocampus, medial prefrontal cortex, and posterior cingulate, while sustained effects were widespread across left lateral cortex and were also evident in the bilateral striatum. Except for those in the left insula, all effects were age-invariant. These findings suggest that both transient and sustained recollection effects are largely stable across much of the healthy adult life span.
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Affiliation(s)
- Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA.
| | - Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA
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4
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de Chastelaine M, Horne ED, Hou M, Rugg MD. Relationships between age, fMRI correlates of familiarity and familiarity-based memory performance under single and dual task conditions. Neuropsychologia 2023; 189:108670. [PMID: 37633516 PMCID: PMC10591814 DOI: 10.1016/j.neuropsychologia.2023.108670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 08/28/2023]
Abstract
Using fMRI, we investigated the effects of age and divided attention on the neural correlates of familiarity and their relationship with memory performance. At study, word pairs were visually presented to young and older participants under the requirement to make a relational judgment on each pair. Participants were then scanned while undertaking an associative recognition test under single and dual (auditory tone detection) task conditions. The test items comprised studied, rearranged (words from different studied pairs) and new word pairs. fMRI familiarity effects were operationalized as greater activity elicited by studied pairs incorrectly identified as 'rearranged' than by correctly rejected new pairs. The reverse contrast was employed to identify 'novelty' effects. Behavioral familiarity estimates were equivalent across age groups and task conditions. Robust fMRI familiarity effects were identified in several regions, including medial and superior lateral parietal cortex, dorsal medial and left lateral prefrontal cortex, and bilateral caudate. fMRI novelty effects were identified in the anterior medial temporal lobe. Both familiarity and novelty effects were largely age-invariant and did not vary, or varied minimally, according to task condition. In addition, the familiarity effects correlated positively with a behavioral estimate of familiarity strength irrespective of age. These findings extend a previous report from our laboratory, and converge with prior behavioral reports, in demonstrating that the factors of age and divided attention have little impact on behavioral and neural estimates of familiarity.
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Affiliation(s)
- Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas, Dallas, TX, USA.
| | - Erin D Horne
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas, Dallas, TX, USA
| | - Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas, Dallas, TX, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas, Dallas, TX, USA
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5
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Koen JD, Lewis L, Rugg MD, Clementz BA, Keshavan MS, Pearlson GD, Sweeney JA, Tamminga CA, Ivleva EI. Supervised machine learning classification of psychosis biotypes based on brain structure: findings from the Bipolar-Schizophrenia network for intermediate phenotypes (B-SNIP). Sci Rep 2023; 13:12980. [PMID: 37563219 PMCID: PMC10415369 DOI: 10.1038/s41598-023-38101-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/03/2023] [Indexed: 08/12/2023] Open
Abstract
Traditional diagnostic formulations of psychotic disorders have low correspondence with underlying disease neurobiology. This has led to a growing interest in using brain-based biomarkers to capture biologically-informed psychosis constructs. Building upon our prior work on the B-SNIP Psychosis Biotypes, we aimed to examine whether structural MRI (an independent biomarker not used in the Biotype development) can effectively classify the Biotypes. Whole brain voxel-wise grey matter density (GMD) maps from T1-weighted images were used to train and test (using repeated randomized train/test splits) binary L2-penalized logistic regression models to discriminate psychosis cases (n = 557) from healthy controls (CON, n = 251). A total of six models were evaluated across two psychosis categorization schemes: (i) three Biotypes (B1, B2, B3) and (ii) three DSM diagnoses (schizophrenia (SZ), schizoaffective (SAD) and bipolar (BD) disorders). Above-chance classification accuracies were observed in all Biotype (B1 = 0.70, B2 = 0.65, and B3 = 0.56) and diagnosis (SZ = 0.64, SAD = 0.64, and BD = 0.59) models. However, the only model that showed evidence of specificity was B1, i.e., the model was able to discriminate B1 vs. CON and did not misclassify other psychosis cases (B2 or B3) as B1 at rates above nominal chance. The GMD-based classifier evidence for B1 showed a negative association with an estimate of premorbid general intellectual ability, regardless of group membership, i.e. psychosis or CON. Our findings indicate that, complimentary to clinical diagnoses, the B-SNIP Psychosis Biotypes may offer a promising approach to capture specific aspects of psychosis neurobiology.
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Affiliation(s)
- Joshua D Koen
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA.
- Department of Psychology, University of Notre Dame, Notre Dame, IN, 46556, USA.
| | - Leslie Lewis
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA
- UT Southwestern Medical Center, Dallas, TX, USA
- University of East Anglia, Norwich, UK
| | | | | | - Godfrey D Pearlson
- Institute of Living, Hartford Hospital, Hartford, CT, USA
- Yale School of Medicine, New Haven, CT, USA
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6
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de Chastelaine M, Horne ED, Hou M, Rugg MD. Relationships between age, fMRI correlates of familiarity and familiarity-based memory performance under single and dual task conditions. bioRxiv 2023:2023.05.26.542526. [PMID: 37398000 PMCID: PMC10312430 DOI: 10.1101/2023.05.26.542526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Using fMRI, we investigated the effects of age and divided attention on the neural correlates of familiarity and their relationship with memory performance. At study, word pairs were visually presented to young and older participants under the requirement to make a relational judgment on each pair. Participants were then scanned while undertaking an associative recognition test under single and dual (auditory tone detection) task conditions. The test items comprised studied, rearranged (words from different studied pairs) and new word pairs. fMRI familiarity effects were operationalized as greater activity elicited by studied pairs incorrectly identified as 'rearranged' than by correctly rejected new pairs. The reverse contrast was employed to identify 'novelty' effects. Behavioral familiarity estimates were equivalent across age groups and task conditions. Robust fMRI familiarity effects were identified in several regions, including medial and superior lateral parietal cortex, dorsal medial and left lateral prefrontal cortex, and bilateral caudate. fMRI novelty effects were identified in the anterior medial temporal lobe. Both familiarity and novelty effects were age-invariant and did not vary according to task condition. In addition, the familiarity effects correlated positively with a behavioral estimate of familiarity strength irrespective of age. These findings extend a previous report from our laboratory, and converge with prior behavioral reports, in demonstrating that the factors of age and divided attention have minimal impact on behavioral and neural estimates of familiarity.
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7
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Srokova S, Aktas ANZ, Koen JD, Rugg MD. Dissociative effects of age on neural differentiation at the category and item level. bioRxiv 2023:2023.05.24.542148. [PMID: 37293054 PMCID: PMC10245847 DOI: 10.1101/2023.05.24.542148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Increasing age is associated with age-related neural dedifferentiation, a reduction in the selectivity of neural representations which has been proposed to contribute to cognitive decline in older age. Recent findings indicate that when operationalized in terms of selectivity for different perceptual categories, age-related neural dedifferentiation, and the apparent age-invariant association of neural selectivity with cognitive performance, are largely restricted to the cortical regions typically recruited during scene processing. It is currently unknown whether this category-level dissociation extends to metrics of neural selectivity defined at the level of individual stimulus items. Here, we examined neural selectivity at the category and item levels using multivoxel pattern similarity analysis (PSA) of fMRI data. Healthy young and older male and female adults viewed images of objects and scenes. Some items were presented singly, while others were either repeated or followed by a 'similar lure'. Consistent with recent findings, category-level PSA revealed robustly lower differentiation in older than younger adults in scene-selective, but not object-selective, cortical regions. By contrast, at the item level, robust age-related declines in neural differentiation were evident for both stimulus categories. Moreover, we identified an age-invariant association between category-level scene-selectivity in the parahippocampal place area and subsequent memory performance, but no such association was evident for item-level metrics. Lastly, category and item-level neural metrics were uncorrelated. Thus, the present findings suggest that age-related category- and item-level dedifferentiation depend on distinct neural mechanisms.
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Affiliation(s)
- Sabina Srokova
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX 75235
- School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080
| | - Ayse N. Z. Aktas
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX 75235
| | - Joshua D. Koen
- Department of Psychology, University of Notre Dame, IN, 90 Corbett Family Hall, Notre Dame, IN 46556
| | - Michael D. Rugg
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX 75235
- School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080
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8
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de Chastelaine M, Srokova S, Hou M, Kidwai A, Kafafi SS, Racenstein ML, Rugg MD. Cortical thickness, gray matter volume, and cognitive performance: a crosssectional study of the moderating effects of age on their interrelationships. Cereb Cortex 2023; 33:6474-6485. [PMID: 36627250 PMCID: PMC10183746 DOI: 10.1093/cercor/bhac518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 01/12/2023] Open
Abstract
In a sample comprising younger, middle-aged, and older cognitively healthy adults (N = 375), we examined associations between mean cortical thickness, gray matter volume (GMV), and performance in 4 cognitive domains-memory, speed, fluency, and crystallized intelligence. In almost all cases, the associations were moderated significantly by age, with the strongest associations in the older age group. An exception to this pattern was identified in a younger adult subgroup aged <23 years when a negative association between cognitive performance and cortical thickness was identified. Other than for speed, all associations between structural metrics and performance in specific cognitive domains were fully mediated by mean cognitive ability. Cortical thickness and GMV explained unique fractions of the variance in mean cognitive ability, speed, and fluency. In no case, however, did the amount of variance jointly explained by the 2 metrics exceed 7% of the total variance. These findings suggest that cortical thickness and GMV are distinct correlates of domain-general cognitive ability, that the strength and, for cortical thickness, the direction of these associations are moderated by age, and that these structural metrics offer only limited insights into the determinants of individual differences in cognitive performance across the adult lifespan.
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Affiliation(s)
- Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, 1600, Viceroy Drive, Suite 800, Dallas, TX 75235, United States
| | - Sabina Srokova
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, 1600, Viceroy Drive, Suite 800, Dallas, TX 75235, United States
| | - Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, 1600, Viceroy Drive, Suite 800, Dallas, TX 75235, United States
| | - Ambereen Kidwai
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, 1600, Viceroy Drive, Suite 800, Dallas, TX 75235, United States
| | - Seham S Kafafi
- Department of Psychology, University of Notre Dame, Notre Dame, IN 46556, United States
| | - Melanie L Racenstein
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, 1600, Viceroy Drive, Suite 800, Dallas, TX 75235, United States
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, 1600, Viceroy Drive, Suite 800, Dallas, TX 75235, United States
- School of Psychology, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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9
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Hou M, de Chastelaine M, Rugg MD. The effects of age on neural correlates of recollection: transient versus sustained fMRI effects. bioRxiv 2023:2023.04.12.536508. [PMID: 37090506 PMCID: PMC10120722 DOI: 10.1101/2023.04.12.536508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Prior fMRI findings in young adults indicate that recollection-sensitive neural regions dissociate according to the time courses of their respective recollection effects. Here, we examined whether such dissociations are also evident in older adults. Young and older participants encoded a series of word-object image pairs, judging which of the denoted objects was the smaller. At test, participants first judged whether a test word was old or new. For items judged old, they were required to recall the associated image and hold it in mind across a variable delay period. A post-delay cue denoted which of three judgments should be made on the retrieved image. Older adults demonstrated significantly lower associative memory performance than young adults. Replicating prior findings, transient recollection effects were identified in the left hippocampus, medial prefrontal cortex and posterior cingulate, while sustained effects were widespread across left lateral cortex and were also evident in the bilateral striatum. With the exception of those in the left insula, all effects were age-invariant. These findings add to the evidence that recollection-related BOLD effects in different neural regions can be temporally dissociated. Additionally, the findings suggest that both transient and sustained recollection effects are largely stable across much of the healthy adult lifespan.
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10
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Hill PF, de Chastelaine M, Rugg MD. Patterns of retrieval-related cortico-striatal connectivity are stable across the adult lifespan. Cereb Cortex 2023; 33:4542-4552. [PMID: 36124666 PMCID: PMC10110447 DOI: 10.1093/cercor/bhac360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 11/14/2022] Open
Abstract
Memory retrieval effects in the striatum are well documented and robust across experimental paradigms. However, the functional significance of these effects, and whether they are moderated by age, remains unclear. We used functional magnetic resonance imaging paired with an associative recognition task to examine retrieval effects in the striatum in a sample of healthy young, middle-aged, and older adults. We identified anatomically segregated patterns of enhanced striatal blood oxygen level-dependent (BOLD) activity during recollection- and familiarity-based memory judgments. Successful recollection was associated with enhanced BOLD activity in bilateral putamen and nucleus accumbens, and neither of these effects were reliably moderated by age. Familiarity effects were evident in the head of the caudate nucleus bilaterally, and these effects were attenuated in middle-aged and older adults. Using psychophysiological interaction analyses, we observed a monitoring-related increase in functional connectivity between the caudate and regions of the frontoparietal control network, and between the putamen and bilateral retrosplenial cortex and intraparietal sulcus. In all instances, monitoring-related increases in cortico-striatal connectivity were unmoderated by age. These results suggest that the striatum, and the caudate in particular, couples with the frontoparietal control network to support top-down retrieval-monitoring operations, and that the strength of these inter-regional interactions is preserved in later life.
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Affiliation(s)
- Paul F Hill
- Psychology Department, University of Arizona, Tucson, AZ 85721, United States
| | | | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX 75235, United States
- School of Psychology, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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11
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Liu ES, Hou M, Koen JD, Rugg MD. Effects of age on the neural correlates of encoding source and item information: An fMRI study. Neuropsychologia 2022; 177:108415. [PMID: 36343706 PMCID: PMC9729408 DOI: 10.1016/j.neuropsychologia.2022.108415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 09/27/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022]
Abstract
The effects of age on encoding-related neural activity predictive of accurate item and source memory judgments were examined with fMRI, with an a priori focus of the inferior frontal gyrus (IFG) and hippocampus. During a scanned study phase, young and older adults viewed a series of pictures of objects and made one of two judgments on each object. At test, which occurred outside of the scanner, an 'old/new' judgment on each test item was followed, for those items endorsed old, by a source judgment querying the study task. Neural activity predictive of accurate subsequent item and source memory judgments was identified in bilateral IFG, several other cortical regions and bilateral hippocampus. Cortical effects were graded in the young group (source > item > miss) but predicted item memory only in the older group. Hippocampal effects exclusively predicted source memory, and the magnitude of these effects did not reliably differ between the age groups. In the older group only, IFG and hippocampal encoding effects were positively correlated across participants with memory performance. Similar findings were evident in the extra-IFG regions demonstrating encoding effects. With the exception of the age-dependent relationship identified for hippocampal encoding effects, the present findings are broadly consistent with those from prior aging studies that employed verbal memoranda and tests of associative recognition. Thus, they extend these prior findings to include non-verbal materials and a different operationalization of episodic recollection. Additionally, the present findings suggest that the sensitivity in older adults of IFG encoding effects to subsequent memory performance reflects a more general tendency for cortical encoding effects to predict memory performance in this age group.
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Affiliation(s)
- E Song Liu
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, USA
| | - Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, USA.
| | - Joshua D Koen
- Department of Psychology, University of Notre Dame, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, USA; School of Psychology, University of East Anglia, UK
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12
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Thakral PP, Yu SS, Rugg MD. Sensitivity of the hippocampus to objective but not subjective episodic memory judgments. Cogn Neurosci 2022; 13:165-170. [PMID: 35148666 DOI: 10.1080/17588928.2022.2033713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We assessed whether neural activity in the hippocampus dissociates according to whether memory test items elicit a subjective sense of recollection or accurate retrieval of contextual information. We reanalyzed a previously acquired dataset from a study in which participants made both objective (source memory for spatial context) and subjective (Remember-Know) judgments for each test item. Results indicated that the hippocampus was exclusively sensitive to the amount of contextual information retrieved, such that accurate source memory judgments were associated with greater activity than inaccurate judgments, regardless of Remember/Know status. The findings add to the evidence that the hippocampus is insensitive to the subjective experience of recollection, but supports retrieval of contextual information.
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Affiliation(s)
- Preston P Thakral
- Department of Psychology and Neuroscience, Boston College, Chestnut Hill, MA, USA
| | - Sarah S Yu
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Tx, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Tx, USA.,School of Psychology, University of East Anglia, Norwich, UK
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13
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Hou M, Horne ED, de Chastelaine M, Rugg MD. Divided attention at retrieval does not influence neural correlates of recollection in young or older adults. Neuroimage 2022; 250:118918. [PMID: 35051582 PMCID: PMC8885896 DOI: 10.1016/j.neuroimage.2022.118918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/12/2022] [Accepted: 01/15/2022] [Indexed: 01/23/2023] Open
Abstract
Age-related decline in episodic memory has been partially attributed to older adults' reduced domain general processing resources. In the present study, we examined the effects of divided attention (DA) - a manipulation assumed to further deplete the already limited processing resources of older adults - on the neural correlates of recollection in young and older adults. Participants underwent fMRI scanning while they performed an associative recognition test in single and dual (tone detection) task conditions. Recollection effects were operationalized as greater BOLD activity elicited by test pairs correctly endorsed as 'intact' than pairs correctly or incorrectly endorsed as 'rearranged'. Detrimental effects of DA on associative recognition performance were identified in older but not young adults. The magnitudes of recollection effects did not differ between the single and dual (tone detection) tasks in either age group. Across the task conditions, age-invariant recollection effects were evident in most members of the core recollection network. However, while young adults demonstrated robust recollection effects in left angular gyrus, angular gyrus effects were undetectable in the older adults in either task condition. With the possible exception of this result, the findings suggest that DA did not influence processes supporting the retrieval and representation of associative information in either young or older adults, and converge with prior behavioral findings to suggest that episodic retrieval operations are little affected by DA.
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Affiliation(s)
- Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA.
| | - Erin D Horne
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA; Center for BrainHealth and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA
| | - Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA; School of Psychology, University of East Anglia, Norwich NR4 7TJ, UK
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14
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Koen JD, Hauck N, Rugg MD. The hippocampus shows an own-age bias during unfamiliar face viewing. Eur J Neurosci 2021; 54:7876-7885. [PMID: 34755395 DOI: 10.1111/ejn.15523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/01/2021] [Accepted: 11/05/2021] [Indexed: 11/28/2022]
Abstract
The present study investigated the neural correlates of the own-age bias for face recognition in a repetition suppression paradigm. Healthy young and older adults viewed upright and inverted unfamiliar faces. Some of the upright faces were repeated following one of two delays (lag 0 or lag 11). Repetition suppression effects were observed in bilateral fusiform cortex. However, there were no significant effects indicating an own-age bias in repetition suppression. The absence of these effects is arguably inconsistent with perceptual expertise accounts of own-age biases in face processing. By contrast, the right anterior hippocampus showed an own-age bias (greater activity for own-age compared to other-age faces) when viewing an unfamiliar face for the first time. Given the importance of the hippocampus for episodic memory encoding, we conjecture that the increased hippocampal activity for own-age relative to other-age faces reflects differential engagement of neural processes supporting the episodic encoding of faces and might provide insight into the neural underpinnings of own-age biases in face recognition memory.
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Affiliation(s)
- Joshua D Koen
- Department of Psychology, University of Notre Dame, Notre Dame, Indiana, USA
| | - Nedra Hauck
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas, USA.,School of Psychology, University of East Anglia, Norwich, UK
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15
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Hill PF, Horne ED, Koen JD, Rugg MD. Transcranial magnetic stimulation of right dorsolateral prefrontal cortex does not affect associative retrieval in healthy young or older adults. Neuroimage Rep 2021; 1:100027. [PMID: 35434691 PMCID: PMC9009824 DOI: 10.1016/j.ynirp.2021.100027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We examined whether post-retrieval monitoring processes supporting memory performance are more resource limited in older adults than younger individuals. We predicted that older adults would be more susceptible to an experimental manipulation that reduced the neurocognitive resources available to support post-retrieval monitoring. Young and older adults received transcranial magnetic stimulation (TMS) to the right dorsolateral prefrontal cortex (DLPFC) or a vertex control site during an associative recognition task. The right DLPFC was selected as a TMS target because the region is held to be a key member of a network of regions engaged during retrieval monitoring and is readily accessible to administration of TMS. We predicted that TMS to the right DLPFC would lead to reduced associative recognition accuracy, and that this effect would be more prominent in older adults. The results did not support this prediction. Recognition accuracy was significantly reduced in older adults relative to their younger counterparts, but the magnitude of this age difference was unaffected following TMS to the right DLPFC or vertex. These findings suggest that TMS to the right DLPFC was insufficient to deplete the neurocognitive resources necessary to support post-retrieval monitoring.
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Affiliation(s)
- Paul F Hill
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX 75235
| | - Erin D Horne
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX 75235
| | - Joshua D Koen
- Department of Psychology, University of Notre Dame, Notre Dame, IN 46556
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX 75235
- School of Psychology, University of East Anglica, Norwich NR4 7TJ, UK
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16
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Hou M, Wang TH, Rugg MD. The effects of age on neural correlates of recognition memory: An fMRI study. Brain Cogn 2021; 153:105785. [PMID: 34419811 DOI: 10.1016/j.bandc.2021.105785] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/23/2021] [Accepted: 07/29/2021] [Indexed: 11/19/2022]
Abstract
Studies examining the effects of age on the neural correlates of recognition memory have yielded mixed results. In the present study, we employed a modified remember-know paradigm to compare the fMRI correlates of recollection and familiarity in samples of healthy young and older adults. After studying a series of words, participants underwent fMRI scanning during a test phase in which they responded "remember" to a test word if any qualitative information could be recollected about the study event. When recollection failed, participants signaled how confident they were that the test item had been studied. Young and older adults demonstrated statistically equivalent estimates of recollection and familiarity strength, while recognition memory accuracy was significantly lower in the older adults. Robust, age-invariant fMRI effects were evident in two sets of a priori defined brain regions consistently reported in prior studies to be sensitive to recollection and familiarity respectively. In addition, the magnitudes of 'familiarity-attenuation effects' in perirhinal cortex demonstrated age-invariant correlations with estimates of familiarity strength and memory accuracy, replicating prior findings. Together, the present findings add to the evidence that the neural correlates of recognition memory are largely stable across much of the healthy human adult lifespan.
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Affiliation(s)
- Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA.
| | - Tracy H Wang
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA; School of Psychology, University of East Anglia, Norwich NR4 7TJ, UK
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17
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Hill PF, Seger SE, Yoo HB, King DR, Wang DX, Lega BC, Rugg MD. Distinct Neurophysiological Correlates of the fMRI BOLD Signal in the Hippocampus and Neocortex. J Neurosci 2021; 41:6343-6352. [PMID: 34131036 PMCID: PMC8287995 DOI: 10.1523/jneurosci.0278-21.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/30/2021] [Accepted: 06/02/2021] [Indexed: 11/21/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) is among the foremost methods for mapping human brain function but provides only an indirect measure of underlying neural activity. Recent findings suggest that the neurophysiological correlates of the fMRI blood oxygenation level-dependent (BOLD) signal might be regionally specific. We examined the neurophysiological correlates of the fMRI BOLD signal in the hippocampus and neocortex, where differences in neural architecture might result in a different relationship between the respective signals. Fifteen human neurosurgical patients (10 female, 5 male) implanted with depth electrodes performed a verbal free recall task while electrophysiological activity was recorded simultaneously from hippocampal and neocortical sites. The same patients subsequently performed a similar version of the task during a later fMRI session. Subsequent memory effects (SMEs) were computed for both imaging modalities as patterns of encoding-related brain activity predictive of later free recall. Linear mixed-effects modeling revealed that the relationship between BOLD and gamma-band SMEs was moderated by the lobar location of the recording site. BOLD and high gamma (70-150 Hz) SMEs positively covaried across much of the neocortex. This relationship was reversed in the hippocampus, where a negative correlation between BOLD and high gamma SMEs was evident. We also observed a negative relationship between BOLD and low gamma (30-70 Hz) SMEs in the medial temporal lobe more broadly. These results suggest that the neurophysiological correlates of the BOLD signal in the hippocampus differ from those observed in the neocortex.SIGNIFICANCE STATEMENT The BOLD signal forms the basis of fMRI but provides only an indirect measure of neural activity. Task-related modulation of BOLD signals are typically equated with changes in gamma-band activity; however, relevant empirical evidence comes largely from the neocortex. We examined neurophysiological correlates of the BOLD signal in the hippocampus, where the differing neural architecture might result in a different relationship between the respective signals. We identified a positive relationship between encoding-related changes in BOLD and gamma-band activity in the frontal and parietal cortices. This effect was reversed in the hippocampus, where BOLD and gamma-band effects negatively covaried. These results suggest regional variability in the transfer function between neural activity and the BOLD signal in the hippocampus and neocortex.
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Affiliation(s)
- Paul F Hill
- Center for Vital Longevity, University of Texas at Dallas, Dallas, Texas 75235
| | - Sarah E Seger
- Department of Neurosurgery, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Hye Bin Yoo
- Department of Neurosurgery, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Danielle R King
- Center for Vital Longevity, University of Texas at Dallas, Dallas, Texas 75235
| | - David X Wang
- Department of Electrical and Computer Engineering, Southern Methodist University, Dallas, Texas 75275
| | - Bradley C Lega
- Department of Neurosurgery, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, Texas 75235
- School of Psychology, University of East Anglia, Norwich NR4 7TJ, England
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18
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Hou M, de Chastelaine M, Donley BE, Rugg MD. Specific and general relationships between cortical thickness and cognition in older adults: a longitudinal study. Neurobiol Aging 2021; 102:89-101. [PMID: 33765434 PMCID: PMC8110604 DOI: 10.1016/j.neurobiolaging.2020.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/22/2020] [Accepted: 11/02/2020] [Indexed: 10/23/2022]
Abstract
Prior studies suggest that relationships between regional cortical thickness and domain-specific cognitive performance can be mediated by the relationship between global cortical thickness and domain-general cognition. Whether such findings extend to longitudinal cognitive change remains unclear. Here, we examined the relationships in healthy older adults between cognitive performance, longitudinal cognitive change over 3 years, and cortical thickness at baseline of the left and right inferior frontal gyrus (IFG) and left and right hemispheres. Both right IFG and right hemisphere thickness predicted baseline general cognition and domain-specific cognitive performance. Right IFG thickness was also predictive of longitudinal memory change. However, right IFG thickness was uncorrelated with cognitive performance and memory change after controlling for the mean thickness of other ipsilateral cortical regions. In addition, most identified associations between cortical thickness and specific cognitive domains were nonsignificant after controlling for the variance shared with other cognitive domains. Thus, relationships between right IFG thickness, cognitive performance, and memory change appear to be largely accounted for by more generic relationships between cortical thickness and cognition. This article is part of the Virtual Special Issue titled "COGNITIVE NEUROSCIENCE OF HEALTHY AND PATHOLOGICAL AGING". The full issue can be found on ScienceDirect athttps://www.sciencedirect.com/journal/neurobiology-of-aging/special-issue/105379XPWJP.
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Affiliation(s)
- Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA.
| | - Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA
| | - Brian E Donley
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA; School of Psychology, University of East Anglia, Norwich, UK
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19
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Elward RL, Rugg MD, Vargha-Khadem F. When the brain, but not the person, remembers: Cortical reinstatement is modulated by retrieval goal in developmental amnesia. Neuropsychologia 2021; 154:107788. [PMID: 33587931 PMCID: PMC7967023 DOI: 10.1016/j.neuropsychologia.2021.107788] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 01/18/2021] [Accepted: 02/08/2021] [Indexed: 11/16/2022]
Abstract
Developmental amnesia (DA) is associated with early hippocampal damage and subsequent episodic amnesia emerging in childhood alongside age-appropriate development of semantic knowledge. We employed fMRI to assess whether patients with DA show evidence of 'cortical reinstatement', a neural correlate of episodic memory, despite their amnesia. At study, 23 participants (5 patients) were presented with words overlaid on a scene or a scrambled image for later recognition. Scene reinstatement was indexed by scene memory effects (greater activity for previously presented words paired with a scene rather than scrambled images) that overlapped with scene perception effects. Patients with DA demonstrated scene reinstatement effects in the parahippocampal and retrosplenial cortex that were equivalent to those shown by healthy controls. Behaviourally, however, patients with DA showed markedly impaired scene memory. The data indicate that reinstatement can occur despite hippocampal damage, but that cortical reinstatement is insufficient to support accurate memory performance. Furthermore, scene reinstatement effects were diminished during a retrieval task in which scene information was not relevant for accurate responding, indicating that strategic mnemonic processes operate normally in DA. The data suggest that cortical reinstatement of trial-specific contextual information is decoupled from the experience of recollection in the presence of severe hippocampal atrophy.
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Affiliation(s)
- Rachael L Elward
- UCL Great Ormond Street Institute for Child Health, London, UK; London South Bank University, London, UK
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, USA; School of Psychology, University of East Anglia, UK
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20
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Sweeney-Reed CM, Buentjen L, Voges J, Schmitt FC, Zaehle T, Kam JWY, Kaufmann J, Heinze HJ, Hinrichs H, Knight RT, Rugg MD. The role of the anterior nuclei of the thalamus in human memory processing. Neurosci Biobehav Rev 2021; 126:146-158. [PMID: 33737103 DOI: 10.1016/j.neubiorev.2021.02.046] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 12/13/2022]
Abstract
Extensive neuroanatomical connectivity between the anterior thalamic nuclei (ATN) and hippocampus and neocortex renders them well-placed for a role in memory processing, and animal, lesion, and neuroimaging studies support such a notion. The deep location and small size of the ATN have precluded their real-time electrophysiological investigation during human memory processing. However, ATN electrophysiological recordings from patients receiving electrodes implanted for deep brain stimulation for pharmacoresistant focal epilepsy have enabled high temporal resolution study of ATN activity. Theta frequency synchronization of ATN and neocortical oscillations during successful memory encoding, enhanced phase alignment, and coupling between ATN local gamma frequency activity and frontal neocortical and ATN theta oscillations provide evidence of an active role for the ATN in memory encoding, potentially integrating information from widespread neocortical sources. Greater coupling of a broader gamma frequency range with theta oscillations at rest than during memory encoding provides additional support for the hypothesis that the ATN play a role in selecting local, task-relevant high frequency activity associated with particular features of a memory trace.
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Affiliation(s)
- Catherine M Sweeney-Reed
- Neurocybernetics and Rehabilitation, Dept. of Neurology, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany.
| | - Lars Buentjen
- Dept. of Stereotactic Neurosurgery, Otto-von-Guericke University, Magdeburg, Germany
| | - Jürgen Voges
- Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany; Dept. of Stereotactic Neurosurgery, Otto-von-Guericke University, Magdeburg, Germany
| | | | - Tino Zaehle
- Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany; Dept. of Neurology, Otto-von-Guericke University, Magdeburg, Germany
| | - Julia W Y Kam
- Department of Psychology, University of Calgary, Calgary, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Canada; Helen Wills Neuroscience Institute, University of California - Berkeley, Berkeley, CA, USA
| | - Jörn Kaufmann
- Dept. of Neurology, Otto-von-Guericke University, Magdeburg, Germany
| | - Hans-Jochen Heinze
- Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany; Dept. of Neurology, Otto-von-Guericke University, Magdeburg, Germany; Dept. of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Hermann Hinrichs
- Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany; Dept. of Neurology, Otto-von-Guericke University, Magdeburg, Germany; Dept. of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Robert T Knight
- Helen Wills Neuroscience Institute, University of California - Berkeley, Berkeley, CA, USA; Department of Psychology, University of California, Berkeley, Berkeley, CA, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas, Dallas, TX, USA
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21
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Srokova S, Hill PF, Elward RL, Rugg MD. Effects of age on goal-dependent modulation of episodic memory retrieval. Neurobiol Aging 2021; 102:73-88. [PMID: 33765433 DOI: 10.1016/j.neurobiolaging.2021.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 10/22/2022]
Abstract
Retrieval gating refers to the ability to modulate the retrieval of features of a single memory episode according to behavioral goals. Recent findings demonstrate that younger adults engage retrieval gating by attenuating the representation of task-irrelevant features of an episode. Here, we examine whether retrieval gating varies with age. Younger and older adults incidentally encoded words superimposed over scenes or scrambled backgrounds that were displayed in one of three spatial locations. Participants subsequently underwent fMRI as they completed two memory tasks: the background task, which tested memory for the word's background, and the location task, testing memory for the word's location. Employing univariate and multivariate approaches, we demonstrated that younger, but not older adults, exhibited attenuated reinstatement of scene information when it was goal-irrelevant (during the location task). Additionally, in younger adults only, the strength of scene reinstatement in the parahippocampal place area during the background task was related to item and source memory performance. Together, these findings point to an age-related decline in the ability to engage retrieval gating.
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Affiliation(s)
- Sabina Srokova
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA.
| | - Paul F Hill
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Rachael L Elward
- School of Applied Sciences, Division of Psychology, London South Bank University, London, UK
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA; School of Psychology, University of East Anglia, Norwich, UK; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
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22
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Liu ES, Koen JD, Rugg MD. Effects of Age on Prestimulus Neural Activity Predictive of Successful Memory Encoding: An fMRI Study. Cereb Cortex 2021; 31:917-932. [PMID: 32959047 DOI: 10.1093/cercor/bhaa265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/17/2020] [Accepted: 08/13/2020] [Indexed: 11/13/2022] Open
Abstract
Prestimulus subsequent memory effects (SMEs)-differences in neural activity preceding the onset of study items that are predictive of later memory performance-have consistently been reported in young adults. The present functional magnetic resonance imaging experiment investigated potential age-related differences in prestimulus SMEs. During study, healthy young and older participants made one of two semantic judgments on images, with the judgment signaled by a preceding cue. In test phase, participants first made an item recognition judgment and, for each item judged old, a source memory judgment. Age-invariant prestimulus SMEs were observed in left dorsomedial prefrontal cortex, left hippocampus, and right subgenual cortex. In each case, the effects reflected lower blood oxygen level dependent signal for later recognized items, regardless of source accuracy, than for unrecognized items. A similar age-invariant pattern was observed in left orbitofrontal cortex, but this effect was specific to items attracting a correct source response compared to unrecognized items. In contrast, the left angular gyrus and fusiform cortex demonstrated negative prestimulus SMEs that were exclusive to young participants. The findings indicate that age differences in prestimulus SMEs are regionally specific and suggest that prestimulus SMEs reflect multiple cognitive processes, only some of which are vulnerable to advancing age.
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Affiliation(s)
- E Song Liu
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX 75235, USA.,School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Joshua D Koen
- Department of Psychology, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX 75235, USA.,School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA.,School of Psychology, University of East Anglia, Norwich NR4 7TJ, UK
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23
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Horne ED, de Chastelaine M, Rugg MD. Neural correlates of post-retrieval monitoring in older adults are preserved under divided attention, but are decoupled from memory performance. Neurobiol Aging 2020; 97:106-119. [PMID: 33190122 DOI: 10.1016/j.neurobiolaging.2020.10.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 09/01/2020] [Accepted: 10/12/2020] [Indexed: 11/26/2022]
Abstract
Post-retrieval monitoring is associated with engagement of anterior cingulate and dorsolateral prefrontal cortex. Recent fMRI studies reported age-invariant monitoring effects in these regions and an age-invariant correlation between these effects and memory performance. The present study examined monitoring effects during associative recognition (difference in activity elicited by 'rearranged' and 'intact' test pairs) under single and dual (tone detection) task conditions in young and older adults (Ns = 28 per group). It was predicted that, for the older adults only, dual tasking would attenuate memory performance and monitoring effects and weaken their correlation. Consistent with this prediction, in the older group imposition of the secondary task led to lower memory performance and elimination of the relationship between monitoring effects and performance. However, the size of the effects did not differ between single and dual task conditions. The findings suggest that the decline in older adults' memory performance in the dual task condition resulted not from impaired monitoring, but from a different cause that also weakened the dependence of performance on monitoring.
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Affiliation(s)
- Erin D Horne
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA; Center for BrainHealth, University of Texas at Dallas, Dallas, TX, USA.
| | | | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA; School of Psychology, University of East Anglia, Norwich, UK
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24
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Tan RJ, Rugg MD, Lega BC. Direct brain recordings identify hippocampal and cortical networks that distinguish successful versus failed episodic memory retrieval. Neuropsychologia 2020; 147:107595. [PMID: 32871132 PMCID: PMC7554101 DOI: 10.1016/j.neuropsychologia.2020.107595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 08/06/2020] [Accepted: 08/26/2020] [Indexed: 12/14/2022]
Abstract
Human data collected using noninvasive imaging techniques have established the importance of parietal regions towards episodic memory retrieval, including the angular gyrus and posterior cingulate cortex. Such regions comprise part of a putative core episodic retrieval network. In free recall, comparisons between contextually appropriate and inappropriate recall events (i.e. prior list intrusions) provide the opportunity to study memory retrieval networks supporting veridical recall, and existing findings predict that differences in electrical activity in these brain regions should be identified according to the accuracy of recall. However, prior iEEG studies, utilizing principally subdural grid electrodes, have not fully characterized brain activity in parietal regions during memory retrieval and have not examined connectivity between core recollection areas and the hippocampus or prefrontal cortex. Here, we employed a data set obtained from 100 human patients implanted with stereo EEG electrodes for seizure mapping purposes as they performed a free recall task. This data set allowed us to separately analyze activity in midline versus lateral parietal brain regions, and in anterior versus posterior hippocampus, to identify areas in which retrieval-related activity predicted the recollection of a correct versus an incorrect memory. With the wide coverage afforded by the stereo EEG approach, we were also able to examine interregional connectivity. Our key findings were that differences in gamma band activity in the angular gyrus, precuneus, posterior temporal cortex, and posterior (more than anterior) hippocampus discriminated accurate versus inaccurate recall as well as active retrieval versus memory search. The left angular gyrus exhibited a significant power decrease preceding list intrusions as well as unique phase-amplitude coupling properties, whereas the prefrontal cortex was unique in exhibiting a power increase during list intrusions. Analysis of connectivity revealed significant hemispheric asymmetry, with relatively sparse left-sided functional connections compared to the right hemisphere. One exception to this finding was elevated connectivity between the prefrontal cortex and left angular gyrus. This finding is interpreted as evidence for the engagement of prefrontal cortex in memory monitoring and mnemonic decision-making.
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Affiliation(s)
- Ryan Joseph Tan
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX 75390, USA.
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX 75390, USA
| | - Bradley C Lega
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX 75390, USA
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25
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Abstract
Episodic memory performance declines with increasing age. It has sometimes been reported that this decline is more marked when episodic recollection is estimated by "objective" measures such as source memory performance than when it is estimated by "subjective" measures such as the "Remember/Know" procedure. Here, our main goal was to directly contrast recollection estimates derived from these procedures in the same samples of young and older participants (24 adults per age group, within-subjects manipulation of test procedure). Following identical study phases in which words were paired with either faces or scenes, participants' memories were assessed in separate test blocks using either Remember/Know or source memory procedures. Contrary to several prior reports, the deleterious effects of age on recollection estimates did not differ according to test type. Thus, we found no evidence that age differentially impacts subjective and objective recollection estimates. Additionally, and consistent with prior findings, effects of age on estimates of familiarity-driven recognition were small and non-significant.
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Affiliation(s)
- Saad A Alghamdi
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA.,School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA.,Department of Psychology, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX, USA.,School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA.,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.,School of Psychology, University of East Anglia, Norwich, UK
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26
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Hill PF, King DR, Rugg MD. Age Differences In Retrieval-Related Reinstatement Reflect Age-Related Dedifferentiation At Encoding. Cereb Cortex 2020; 31:106-122. [PMID: 32829396 DOI: 10.1093/cercor/bhaa210] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 12/15/2022] Open
Abstract
Age-related reductions in neural selectivity have been linked to cognitive decline. We examined whether age differences in the strength of retrieval-related cortical reinstatement could be explained by analogous differences in neural selectivity at encoding, and whether reinstatement was associated with memory performance in an age-dependent or an age-independent manner. Young and older adults underwent fMRI as they encoded words paired with images of faces or scenes. During a subsequent scanned memory test participants judged whether test words were studied or unstudied and, for words judged studied, also made a source memory judgment about the associated image category. Using multi-voxel pattern similarity analyses, we identified robust evidence for reduced scene reinstatement in older relative to younger adults. This decline was however largely explained by age differences in neural differentiation at encoding; moreover, a similar relationship between neural selectivity at encoding and retrieval was evident in young participants. The results suggest that, regardless of age, the selectivity with which events are neurally processed at the time of encoding can determine the strength of retrieval-related cortical reinstatement.
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Affiliation(s)
- Paul F Hill
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX 75235.,School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080
| | - Danielle R King
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX 75235.,School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX 75235.,School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080.,Department of Psychiatry, University of Texas Southwestern Medical Center, 6363 Forest Park Rd 7th floor suite 749, Dallas TX 75235.,School of Psychology, University of East Anglia, Norwich NR4 7TJ, UK
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27
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Hou M, de Chastelaine M, Jayakumar M, Donley BE, Rugg MD. Recollection-related hippocampal fMRI effects predict longitudinal memory change in healthy older adults. Neuropsychologia 2020; 146:107537. [PMID: 32569610 DOI: 10.1016/j.neuropsychologia.2020.107537] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 06/11/2020] [Accepted: 06/12/2020] [Indexed: 02/07/2023]
Abstract
Prior fMRI studies have reported relationships between memory-related activity in the hippocampus and in-scanner memory performance, but whether such activity is predictive of longitudinal memory change remains unclear. Here, we administered a neuropsychological test battery to a sample of cognitively healthy older adults on three occasions, the second and third sessions occurring one month and three years after the first session. Structural and functional MRI data were acquired between the first two sessions. The fMRI data were derived from an associative recognition procedure and allowed estimation of hippocampal effects associated with both successful associative encoding and successful associative recognition (recollection). Baseline memory performance and memory change were evaluated using memory component scores derived from a principal components analysis of the neuropsychological test scores. Across participants, right hippocampal encoding effects correlated significantly with baseline memory performance after controlling for chronological age. Additionally, both left and right hippocampal associative recognition effects correlated negatively with longitudinal memory decline after controlling for age, and the relationship with the left hippocampal effect remained after also controlling for left hippocampal volume. Thus, in cognitively healthy older adults, the magnitude of hippocampal recollection effects appears to be a robust predictor of future memory change.
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Affiliation(s)
- Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA.
| | - Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Manasi Jayakumar
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Brian E Donley
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA; School of Psychology, University of East Anglia, Norwich, NR4 7TJ, UK
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28
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Reifegerste J, Veríssimo J, Rugg MD, Pullman MY, Babcock L, Glei DA, Weinstein M, Goldman N, Ullman MT. Early-life education may help bolster declarative memory in old age, especially for women. Neuropsychol Dev Cogn B Aging Neuropsychol Cogn 2020; 28:218-252. [PMID: 32501778 DOI: 10.1080/13825585.2020.1736497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Although declarative memory declines with age, sex and education might moderate these weaknesses. We investigated effects of sex and education on nonverbal declarative (recognition) memory in 704 older adults (aged 58-98, 0-17 years of education). Items were drawings of real and made-up objects. Age negatively impacted declarative memory, though this age effect was moderated by sex and object-type: it was steeper for males than females, but only for real objects. Education was positively associated with memory, but also interacted with sex and object-type: education benefited women more than men (countering the age effects, especially for women), and remembering real more than made-up objects. The findings suggest that nonverbal memory in older adults is associated negatively with age but positively with education; both effects are modulated by sex, and by whether learning relates to preexisting or new information. The study suggests downstream benefits from education, especially for girls.
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Affiliation(s)
- Jana Reifegerste
- Department of Neuroscience, Georgetown University , Washington, DC, USA.,Westfälische Wilhelms-Universität Münster, Institute for Psychology , Münster, Germany.,Potsdam Research Institute for Multilingualism, University of Potsdam , Potsdam, Germany
| | - João Veríssimo
- Potsdam Research Institute for Multilingualism, University of Potsdam , Potsdam, Germany
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas , TX, USA.,School of Psychology, University of East Anglia , Norwich, UK
| | | | - Laura Babcock
- Department of Neuroscience, Karolinska Institutet , Stockholm, Sweden
| | - Dana A Glei
- Center for Population and Health, Georgetown University , Washington, DC, USA
| | - Maxine Weinstein
- Center for Population and Health, Georgetown University , Washington, DC, USA
| | - Noreen Goldman
- Office of Population Research, Princeton University , New Jersey, USA
| | - Michael T Ullman
- Department of Neuroscience, Georgetown University , Washington, DC, USA
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29
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Renoult L, Rugg MD. An historical perspective on Endel Tulving's episodic-semantic distinction. Neuropsychologia 2020; 139:107366. [PMID: 32007511 DOI: 10.1016/j.neuropsychologia.2020.107366] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 01/09/2020] [Accepted: 01/29/2020] [Indexed: 10/25/2022]
Abstract
The distinction between episodic and semantic memory, proposed by Endel Tulving in 1972, remains a key concept in contemporary Cognitive Neuroscience. Here we review how this distinction evolved in Tulving's writings over the years. Crucially, from 1972 onward, he argued that the two forms of memory were inter-dependent and that their interaction was an essential feature of normal episodic memory function. Moreover, later elaborations of the theory clearly proposed that these interactions formed the basis of normal declarative memory functioning. A later but crucial aspect of Tulving's contribution was his stress on the importance of subjective experience, which, according to him, "should be the ultimate object of interest, the central aspect of remembering that is to be explained and understood". We relate these and his numerous other ideas to current perspectives about the organization and function of human memory.
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Affiliation(s)
- Louis Renoult
- School of Psychology, University of East Anglia, Norwich, UK.
| | - Michael D Rugg
- School of Psychology, University of East Anglia, Norwich, UK; Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas, Dallas, USA
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30
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Renoult L, Irish M, Moscovitch M, Rugg MD. From Knowing to Remembering: The Semantic–Episodic Distinction. Trends Cogn Sci 2019; 23:1041-1057. [DOI: 10.1016/j.tics.2019.09.008] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/09/2019] [Accepted: 09/29/2019] [Indexed: 01/02/2023]
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31
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Hill PF, King DR, Lega BC, Rugg MD. Comparison of fMRI correlates of successful episodic memory encoding in temporal lobe epilepsy patients and healthy controls. Neuroimage 2019; 207:116397. [PMID: 31770638 PMCID: PMC7238288 DOI: 10.1016/j.neuroimage.2019.116397] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 10/23/2019] [Accepted: 11/22/2019] [Indexed: 12/30/2022] Open
Abstract
Intra-cranial electroencephalographic brain recordings (iEEG) provide a powerful tool for investigating the neural processes supporting episodic memory encoding and form the basis of experimental therapies aimed at improving memory dysfunction. However, given the invasiveness of iEEG, investigations are constrained to patients with drug-resistant epilepsy for whom such recordings are clinically indicated. Particularly in the case of temporal lobe epilepsy (TLE), neuropathology and the possibility of functional reorganization are potential constraints on the generalizability of intra-cerebral findings and pose challenges to the development of therapies for memory disorders stemming from other etiologies. Here, samples of TLE (N = 16; all of whom had undergone iEEG) and age-matched healthy control (N = 19) participants underwent fMRI as they studied lists of concrete nouns. fMRI BOLDresponses elicited by the study words were segregated according to subsequent performance on tests of delayed free recall and recognition memory. Subsequent memory effects predictive of both successful recall and recognition memory were evident in several neural regions, most prominently in the left inferior frontal gyrus, and did not demonstrate any group differences. Behaviorally, the groups did not differ in overall recall performance or in the strength of temporal contiguity effects. However, group differences in serial position effects and false alarm rates were evident during the free recall and recognition memory tasks, respectively. Despite these behavioral differences, neuropathology associated with temporal lobe epilepsy was apparently insufficient to give rise to detectable differences in the functional neuroanatomy of episodic memory encoding relative to neurologically healthy controls. The findings provide reassurance that iEEG findings derived from experimental paradigms similar to those employed here generalize to the neurotypical population.
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Affiliation(s)
- Paul F Hill
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX, 75235, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, USA.
| | - Danielle R King
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX, 75235, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, USA
| | - Bradley C Lega
- Department of Neurosurgery, University of Texas Southwestern Medical Center, 5303 Harry Hines Blvd 6th Floor Suite 108, Dallas, TX, 75390, USA
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX, 75235, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, 6363 Forest Park Rd 7th Floor Suite 749, Dallas, TX, 75235, USA
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32
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Abstract
Many cognitive abilities decline with age even in the absence of detectable pathology. Recent evidence indicates that age-related neural dedifferentiation, operationalized in terms of neural selectivity, may contribute to this decline. We review here work exploring the relationship between neural dedifferentiation, cognition, and age. Compelling evidence for age effects on neural selectivity comes from both non-human animal and human research. However, current data suggest that age does not moderate the observed relationships between neural dedifferentiation and cognitive performance. We propose that functionally significant variance in measures of neural dedifferentiation reflects both age-dependent and age-independent factors. We further propose that the effects of age on neural dedifferentiation do not exclusively reflect detrimental consequences of aging.
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Affiliation(s)
- Joshua D Koen
- Department of Psychology, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Michael D Rugg
- Center for Vital Longevity, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75235, USA
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33
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Thakral PP, Wang TH, Rugg MD. Effects of age on across-participant variability of cortical reinstatement effects. Neuroimage 2019; 191:162-175. [PMID: 30731244 DOI: 10.1016/j.neuroimage.2019.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/03/2019] [Accepted: 02/04/2019] [Indexed: 10/27/2022] Open
Abstract
Using functional magnetic resonance imaging data, we assessed whether across-participant variability of content-selective retrieval-related neural activity differs with age. We addressed this question by employing across-participant multi-voxel pattern analysis (MVPA), predicting that increasing age would be associated with reduced variability of retrieval-related cortical reinstatement across participants. During study, 24 young and 24 older participants viewed objects and concrete words. Test items comprised studied words, names of studied objects, and unstudied words. Participants judged whether the items were recollected, familiar, or new by making 'Remember', 'Know' and 'New' responses, respectively. MVPA was conducted on each region belonging to the 'core recollection network', dorsolateral prefrontal cortex, and a previously identified content-selective voxel set. A leave-one-participant-out classification approach was employed whereby a classifier was trained on a subset of participants and tested on the data from a yoked pair of held-out participants. Classifiers were trained on the study phase data to discriminate the study trials as a function of content (picture or word). The classifiers were then applied to the test phase data to discriminate studied test words according to their study condition. In all of the examined regions, classifier performance demonstrated little or no sensitivity to age and, for the test data, was robustly above chance. Thus, there was little evidence to support the hypothesis that across-participant variability of retrieval-related cortical reinstatement differs with age. The findings extend prior evidence by demonstrating that content-selective cortical reinstatement is sufficiently invariant to support across-participant multi-voxel classification across the healthy adult lifespan.
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Affiliation(s)
| | - Tracy H Wang
- Department of Psychology, University of Texas at Austin, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, USA
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34
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Lin JJ, Umbach G, Rugg MD, Lega B. Gamma oscillations during episodic memory processing provide evidence for functional specialization in the longitudinal axis of the human hippocampus. Hippocampus 2018; 29:68-72. [PMID: 30394594 DOI: 10.1002/hipo.23016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/04/2018] [Accepted: 07/18/2018] [Indexed: 11/11/2022]
Abstract
The question of whether the anterior and posterior hippocampus serve different or complementary functional roles during episodic memory processing has been motivated by noteworthy findings in rodent experiments and from noninvasive studies in humans. Researchers have synthesized these data to postulate several models of functional specialization, However, the issue has not been explored in detail using direct brain recordings. We recently published evidence that theta power increases during episodic memory encoding occur in the posterior hippocampus in humans. In our current investigation we analyzed an expanded data set of 32 epilepsy patients undergoing stereo EEG seizure mapping surgery with electrodes precisely targeted to the anterior and posterior hippocampus simultaneously who performed an episodic memory task. Using a repeated measures design, we looked for an interaction between encoding versus retrieval differences in gamma oscillatory power and anterior versus posterior hippocampal location. Our findings are consistent with a recently articulated model (the HERNET model) favoring posterior hippocampal activation during retrieval related processing. We also tested for encoding versus retrieval differences in the preferred gamma frequency band (high versus low gamma oscillations) motivated by published rodent data.
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Affiliation(s)
- Jui-Jui Lin
- Department of Neurological Surgery, University of Texas-Southwestern Medical Center, Dallas, Texas
| | - Gray Umbach
- Department of Neurological Surgery, University of Texas-Southwestern Medical Center, Dallas, Texas
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, Texas
| | - Bradley Lega
- Department of Neurological Surgery, University of Texas-Southwestern Medical Center, Dallas, Texas
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35
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Cabeza R, Albert M, Belleville S, Craik FIM, Duarte A, Grady CL, Lindenberger U, Nyberg L, Park DC, Reuter-Lorenz PA, Rugg MD, Steffener J, Rajah MN. Maintenance, reserve and compensation: the cognitive neuroscience of healthy ageing. Nat Rev Neurosci 2018; 19:701-710. [PMID: 30305711 PMCID: PMC6472256 DOI: 10.1038/s41583-018-0068-2] [Citation(s) in RCA: 536] [Impact Index Per Article: 89.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cognitive ageing research examines the cognitive abilities that are preserved and/or those that decline with advanced age. There is great individual variability in cognitive ageing trajectories. Some older adults show little decline in cognitive ability compared with young adults and are thus termed 'optimally ageing'. By contrast, others exhibit substantial cognitive decline and may develop dementia. Human neuroimaging research has led to a number of important advances in our understanding of the neural mechanisms underlying these two outcomes. However, interpreting the age-related changes and differences in brain structure, activation and functional connectivity that this research reveals is an ongoing challenge. Ambiguous terminology is a major source of difficulty in this venture. Three terms in particular - compensation, maintenance and reserve - have been used in a number of different ways, and researchers continue to disagree about the kinds of evidence or patterns of results that are required to interpret findings related to these concepts. As such inconsistencies can impede progress in both theoretical and empirical research, here, we aim to clarify and propose consensual definitions of these terms.
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Affiliation(s)
- Roberto Cabeza
- Center for Cognitive Neuroscience, Department of Psychology and Neuroscience, Duke University, Durham, NC, USA.
| | - Marilyn Albert
- Departments of Psychiatry and Neurology, John Hopkins University, Baltimore, MD, USA
| | - Sylvie Belleville
- Research Center of the Institut Universitaire de Gériatrie de Montréal, Montreal, Quebec, Canada
| | - Fergus I M Craik
- Rotman Research Institute, Baycrest Health Sciences, Toronto, Ontario, Canada
| | - Audrey Duarte
- School of Psychology, Georgia Tech, Atlanta, GA, USA
| | - Cheryl L Grady
- Rotman Research Institute, Baycrest Health Sciences, Toronto, Ontario, Canada
| | - Ulman Lindenberger
- Max Planck Institute for Human Development and Max Planck UCL Centre for Computational Psychiatry and Ageing Research, Berlin, Germany
| | - Lars Nyberg
- Departments of Radiation Sciences and Integrated Medical Biology, UFBI, Umeå University, Umeå, Sweden
| | - Denise C Park
- Center for Vital Longevity, University of Texas, Dallas, TX, USA
| | | | - Michael D Rugg
- Center for Vital Longevity, University of Texas, Dallas, TX, USA
| | - Jason Steffener
- Interdisciplinary School of Health Sciences, University of Ottawa, Ottowa, Ontario, Canada
| | - M Natasha Rajah
- Departments of Psychiatry & Psychology, McGill University and Douglas Hospital Research Centre, Montreal, Quebec, Canada
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36
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Cabeza R, Albert M, Belleville S, Craik FIM, Duarte A, Grady CL, Lindenberger U, Nyberg L, Park DC, Reuter-Lorenz PA, Rugg MD, Steffener J, Rajah MN. Maintenance, reserve and compensation: the cognitive neuroscience of healthy ageing. Nat Rev Neurosci 2018. [PMID: 30305711 DOI: 10.1038/s41583-018-0068-2.] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cognitive ageing research examines the cognitive abilities that are preserved and/or those that decline with advanced age. There is great individual variability in cognitive ageing trajectories. Some older adults show little decline in cognitive ability compared with young adults and are thus termed 'optimally ageing'. By contrast, others exhibit substantial cognitive decline and may develop dementia. Human neuroimaging research has led to a number of important advances in our understanding of the neural mechanisms underlying these two outcomes. However, interpreting the age-related changes and differences in brain structure, activation and functional connectivity that this research reveals is an ongoing challenge. Ambiguous terminology is a major source of difficulty in this venture. Three terms in particular - compensation, maintenance and reserve - have been used in a number of different ways, and researchers continue to disagree about the kinds of evidence or patterns of results that are required to interpret findings related to these concepts. As such inconsistencies can impede progress in both theoretical and empirical research, here, we aim to clarify and propose consensual definitions of these terms.
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Affiliation(s)
- Roberto Cabeza
- Center for Cognitive Neuroscience, Department of Psychology and Neuroscience, Duke University, Durham, NC, USA.
| | - Marilyn Albert
- Departments of Psychiatry and Neurology, John Hopkins University, Baltimore, MD, USA
| | - Sylvie Belleville
- Research Center of the Institut Universitaire de Gériatrie de Montréal, Montreal, Quebec, Canada
| | - Fergus I M Craik
- Rotman Research Institute, Baycrest Health Sciences, Toronto, Ontario, Canada
| | - Audrey Duarte
- School of Psychology, Georgia Tech, Atlanta, GA, USA
| | - Cheryl L Grady
- Rotman Research Institute, Baycrest Health Sciences, Toronto, Ontario, Canada
| | - Ulman Lindenberger
- Max Planck Institute for Human Development and Max Planck UCL Centre for Computational Psychiatry and Ageing Research, Berlin, Germany
| | - Lars Nyberg
- Departments of Radiation Sciences and Integrated Medical Biology, UFBI, Umeå University, Umeå, Sweden
| | - Denise C Park
- Center for Vital Longevity, University of Texas, Dallas, TX, USA
| | | | - Michael D Rugg
- Center for Vital Longevity, University of Texas, Dallas, TX, USA
| | - Jason Steffener
- Interdisciplinary School of Health Sciences, University of Ottawa, Ottowa, Ontario, Canada
| | - M Natasha Rajah
- Departments of Psychiatry & Psychology, McGill University and Douglas Hospital Research Centre, Montreal, Quebec, Canada
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Koen JD, Thakral PP, Rugg MD. Transcranial magnetic stimulation of the left angular gyrus during encoding does not impair associative memory performance. Cogn Neurosci 2018; 9:127-138. [PMID: 29870300 DOI: 10.1080/17588928.2018.1484723] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
The left angular gyrus (AG) is thought to play a critical role in episodic retrieval and has been implicated in the recollection of specific details of prior episodes. Motivated by recent fMRI studies in which it was reported that elevated neural activity in left AG during study is predictive of subsequent associative memory, the present study investigated whether the region plays a causal role in associative memory encoding. Participants underwent online transcranial magnetic stimulation (TMS) while encoding word pairs prior to an associative memory test. We predicted that TMS to left AG during encoding would result in reduced subsequent memory accuracy, especially for estimates of recollection. The results did not support this prediction: estimates of both recollection and familiarity-driven recognition were essentially identical for words pairs encoded during TMS to left AG relative to a vertex control site. These results suggest that the left AG may not play a necessary role in associative memory encoding. TMS to left AG did however affect confidence for incorrect 'intact' judgments to rearranged pairs and incorrect 'rearranged' judgments to intact pairs. These findings suggest that the left AG supports encoding processes that contribute to aspects of subjective mnemonic experience.
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Affiliation(s)
- Joshua D Koen
- a Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas , Dallas , USA
| | | | - Michael D Rugg
- a Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas , Dallas , USA
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38
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Koen JD, Horne ED, Hauck N, Rugg MD. Age-related Differences in Prestimulus Subsequent Memory Effects Assessed with Event-related Potentials. J Cogn Neurosci 2018; 30:829-850. [PMID: 29488850 DOI: 10.1162/jocn_a_01249] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Prestimulus subsequent memory effects (preSMEs)-differences in neural activity elicited by a task cue at encoding that are predictive of later memory performance-are thought to reflect differential engagement of preparatory processes that benefit episodic memory encoding. We investigated age differences in preSMEs indexed by differences in ERP amplitude just before the onset of a study item. Young and older adults incidentally encoded words for a subsequent memory test. Each study word was preceded by a task cue that signaled a judgment to perform on the word. Words were presented for either a short (300 msec) or long (1000 msec) duration with the aim of placing differential benefits on engaging preparatory processes initiated by the task cue. ERPs associated with subsequent successful and unsuccessful recollection, operationalized here by source memory accuracy, were estimated time-locked to the onset of the task cue. In a late time window (1000-2000 msec after onset of the cue), young adults demonstrated frontally distributed preSMEs for both the short and long study durations, albeit with opposite polarities in the two conditions. This finding suggests that preSMEs in young adults are sensitive to perceived task demands. Although older adults showed no evidence of preSMEs in the same late time window, significant preSMEs were observed in an earlier time window (500-1000 msec) that was invariant with study duration. These results are broadly consistent with the proposal that older adults differ from their younger counterparts in how they engage preparatory processes during memory encoding.
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39
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King DR, de Chastelaine M, Rugg MD. Recollection-related increases in functional connectivity across the healthy adult lifespan. Neurobiol Aging 2018; 62:1-19. [PMID: 29101898 PMCID: PMC5753578 DOI: 10.1016/j.neurobiolaging.2017.09.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 09/20/2017] [Accepted: 09/23/2017] [Indexed: 12/24/2022]
Abstract
In young adults, recollection-sensitive brain regions exhibit enhanced connectivity with a widely distributed set of other regions during successful versus unsuccessful recollection, and the magnitude of connectivity change correlates with individual differences in recollection accuracy. Here, we examined whether recollection-related changes in connectivity and their relationship with performance varied across samples of young, middle-aged, and older adults. Psychophysiological interaction analyses identified recollection-related increases in connectivity both with recollection-sensitive seed regions and among regions distributed throughout the whole brain. The seed-based approach failed to identify age-related differences in recollection-related connectivity change. However, the whole-brain analysis revealed a number of age-related effects. Numerous pairs of regions exhibited a main effect of age on connectivity change, mostly due to decreased change with increasing age. After controlling for recollection accuracy, however, these effects of age were for the most part no longer significant, and those effects that were detected now reflected age-related increases in connectivity change. A subset of pairs of regions also exhibited an age by performance interaction, driven mostly by a weaker relationship between connectivity change and recollection accuracy with increasing age. We conjecture that these effects reflect age-related differences in neuromodulation.
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Affiliation(s)
- Danielle R King
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA.
| | - Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
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40
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Abstract
Two experiments investigated the modulation of event-related potentials (ERPs) by semantic priming and item repetition. In Experiment 1, subjects silently counted occasional non-words against a background of words, a proportion of which were either semantic associates or repetitions of a preceding word. Compared to control items, ERPs to repeated words were distinguished by an early (ca. 200 msec) transient negative-going deflection and a later, topographically widespread and temporally sustained positive-going shift. In contrast, semantically primed words showed a relatively small, topographically and temporally limited positive-going modulation peaking around 500 msec. These data were interpreted as evidence against models of priming and repetition which postulate similar loci for these effects. In Experiment 2, subjects counted occasional words against a background of non-words, some of which were repeated. ERPs to repetitions showed a similar early ERP modulation to that in Experiment 1, and also displayed a later slow positive shift. This latter effect was smaller in magnitude and had a delayed onset in comparison to Experiment 1. It was concluded that the effects of repetition differ as a consequence of whether, prior to their first presentation, items possess a representation in lexical memory.
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Affiliation(s)
- Michael D. Rugg
- MRC Cognitive Neuroscience Research Group, Psychological Laboratory, University of St Andrews, St Andrews, Fife, U.K
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41
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Abstract
With the advent of functional neuroimaging it quickly became apparent that successful episodic memory retrieval was consistently associated with enhanced activity in ventral lateral parietal cortex (VLPC), especially the left angular gyrus. Here, we selectively review recent neuropsychological and functional neuroimaging evidence relevant to the question of the functional significance of this activity. We argue that the balance of the evidence suggests that the angular gyrus supports the representation of retrieved episodic information, and that this likely reflects a more general role for the region in representing multi-modal and multi-domain information.
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Affiliation(s)
- Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, 1600 Viceroy, Dallas, TX, USA.
| | - Danielle R King
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, 1600 Viceroy, Dallas, TX, USA
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42
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Sweeney-Reed CM, Zaehle T, Voges J, Schmitt FC, Buentjen L, Borchardt V, Walter M, Hinrichs H, Heinze HJ, Rugg MD, Knight RT. Anterior Thalamic High Frequency Band Activity Is Coupled with Theta Oscillations at Rest. Front Hum Neurosci 2017; 11:358. [PMID: 28775684 PMCID: PMC5518534 DOI: 10.3389/fnhum.2017.00358] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 06/22/2017] [Indexed: 12/15/2022] Open
Abstract
Cross-frequency coupling (CFC) between slow and fast brain rhythms, in the form of phase–amplitude coupling (PAC), is proposed to enable the coordination of neural oscillatory activity required for cognitive processing. PAC has been identified in the neocortex and mesial temporal regions, varying according to the cognitive task being performed and also at rest. PAC has also been observed in the anterior thalamic nucleus (ATN) during memory processing. The thalamus is active during the resting state and has been proposed to be involved in switching between task-free cognitive states such as rest, in which attention is internally-focused, and externally-focused cognitive states, in which an individual engages with environmental stimuli. It is unknown whether PAC is an ongoing phenomenon during the resting state in the ATN, which is modulated during different cognitive states, or whether it only arises during the performance of specific tasks. We analyzed electrophysiological recordings of ATN activity during rest from seven patients who received thalamic electrodes implanted for treatment of pharmacoresistant focal epilepsy. PAC was identified between theta (4–6 Hz) phase and high frequency band (80–150 Hz) amplitude during rest in all seven patients, which diminished during engagement in tasks involving an external focus of attention. The findings are consistent with the proposal that theta–gamma coupling in the ATN is an ongoing phenomenon, which is modulated by task performance.
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Affiliation(s)
- Catherine M Sweeney-Reed
- Departments of Neurology and Stereotactic Neurosurgery, Otto von Guericke UniversityMagdeburg, Germany
| | - Tino Zaehle
- Departments of Neurology and Stereotactic Neurosurgery, Otto von Guericke UniversityMagdeburg, Germany
| | - Jürgen Voges
- Departments of Neurology and Stereotactic Neurosurgery, Otto von Guericke UniversityMagdeburg, Germany.,Department of Behavioral Neurology, Leibniz Institute for NeurobiologyMagdeburg, Germany
| | - Friedhelm C Schmitt
- Departments of Neurology and Stereotactic Neurosurgery, Otto von Guericke UniversityMagdeburg, Germany
| | - Lars Buentjen
- Departments of Neurology and Stereotactic Neurosurgery, Otto von Guericke UniversityMagdeburg, Germany
| | - Viola Borchardt
- Department of Behavioral Neurology, Leibniz Institute for NeurobiologyMagdeburg, Germany
| | - Martin Walter
- Department of Behavioral Neurology, Leibniz Institute for NeurobiologyMagdeburg, Germany.,Department of Psychiatry, Eberhard Karls UniversityTübingen, Germany
| | - Hermann Hinrichs
- Departments of Neurology and Stereotactic Neurosurgery, Otto von Guericke UniversityMagdeburg, Germany.,Department of Behavioral Neurology, Leibniz Institute for NeurobiologyMagdeburg, Germany.,German Centre for Neurodegenerative Diseases (DZNE), Otto von Guericke UniversityMagdeburg, Germany
| | - Hans-Jochen Heinze
- Departments of Neurology and Stereotactic Neurosurgery, Otto von Guericke UniversityMagdeburg, Germany.,Department of Behavioral Neurology, Leibniz Institute for NeurobiologyMagdeburg, Germany.,German Centre for Neurodegenerative Diseases (DZNE), Otto von Guericke UniversityMagdeburg, Germany
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of TexasDallas, TX, United States
| | - Robert T Knight
- Helen Wills Neuroscience Institute and Department of Psychology, University of California, BerkeleyBerkeley, CA, United States
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43
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Lin JJ, Rugg MD, Das S, Stein J, Rizzuto DS, Kahana MJ, Lega BC. Theta band power increases in the posterior hippocampus predict successful episodic memory encoding in humans. Hippocampus 2017; 27:1040-1053. [PMID: 28608960 DOI: 10.1002/hipo.22751] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/07/2017] [Accepted: 06/08/2017] [Indexed: 12/23/2022]
Abstract
Functional differences in the anterior and posterior hippocampus during episodic memory processing have not been examined in human electrophysiological data. This is in spite of strong evidence for such differences in rodent data, including greater place cell specificity in the dorsal hippocampus, greater sensitivity to the aversive or motivational content of memories in ventral regions, connectivity analyses identifying preferential ventral hippocampal connections with the amygdala, and gene expression analyses identifying a dorsal-ventral gradient. We asked if memory-related oscillatory patterns observed in human hippocampal recordings, including the gamma band and slow-theta (2.5-5 Hz) subsequent memory effects, would exhibit differences along the longitudinal axis and between hemispheres. We took advantage of a new dataset of stereo electroencephalography patients with simultaneous, robotically targeted anterior, and posterior hippocampal electrodes to directly compare oscillatory subsequent memory effects during item encoding. This same data set allowed us to examine left-right connectivity and hemispheric differences in hippocampal oscillatory patterns. Our data suggest that a power increase during successful item encoding in the 2.5-5 Hz slow-theta frequency range preferentially occurs in the posterior hippocampus during the first 1,000 ms after item presentation, while a gamma band power increase is stronger in the dominant hemisphere. This dominant-nondominant pattern in the gamma range appears to reverse during item retrieval, however. Intrahippocampal phase coherence was found to be stronger during successful item encoding. Our phase coherence data are also consistent with existing reports of a traveling wave for theta oscillations propagating along the septotemporal (longitudinal) axis of the human hippocampus. We examine how our findings fit with theories of functional specialization along the hippocampal axis.
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Affiliation(s)
- Jui-Jui Lin
- Department of Neurological Surgery, University of Texas, Southwestern Medical Center, Dallas, Texas, 75390
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, Texas, 75390
| | - Sandhitsu Das
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Joel Stein
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Daniel S Rizzuto
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Bradley C Lega
- Department of Neurological Surgery, University of Texas, Southwestern Medical Center, Dallas, Texas, 75390
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44
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de Chastelaine M, Mattson JT, Wang TH, Donley BE, Rugg MD. Independent contributions of fMRI familiarity and novelty effects to recognition memory and their stability across the adult lifespan. Neuroimage 2017; 156:340-351. [PMID: 28528847 DOI: 10.1016/j.neuroimage.2017.05.039] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 12/12/2022] Open
Abstract
The impact of age on the neural correlates of familiarity-driven recognition memory has received relatively little attention. Here, the relationships between age, the neural correlates of familiarity, and memory performance were investigated using an associative recognition test in young, middle-aged and older participants. Test items comprised studied, rearranged (items studied on different trials) and new word pairs. fMRI 'familiarity effects' were operationalized as greater activity for studied test pairs incorrectly identified as 'rearranged' than for correctly rejected new pairs. The reverse contrast was employed to identify 'novelty' effects. Estimates of familiarity strength were slightly but significantly lower for the older relative to the younger group. With the exception of one region in dorsal medial prefrontal cortex, fMRI familiarity effects (which were identified in medial and lateral parietal cortex, dorsal medial and left lateral prefrontal cortex, and bilateral caudate among other regions) did not differ significantly with age. Age-invariant 'novelty effects' were identified in the anterior hippocampus and the perirhinal cortex. When entered into the same regression model, familiarity and novelty effects independently predicted familiarity strength across participants, suggesting that the two classes of memory effect reflect functionally distinct mnemonic processes. It is concluded that the neural correlates of familiarity-based memory judgments, and their relationship with familiarity strength, are largely stable across much of the healthy adult lifespan.
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Affiliation(s)
- Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA.
| | | | - Tracy H Wang
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA
| | - Brian E Donley
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX 75235, USA
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45
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Thakral PP, Wang TH, Rugg MD. Decoding the content of recollection within the core recollection network and beyond. Cortex 2016; 91:101-113. [PMID: 28077212 DOI: 10.1016/j.cortex.2016.12.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/12/2016] [Accepted: 12/13/2016] [Indexed: 10/20/2022]
Abstract
Recollection - retrieval of qualitative information about a past event - is associated with enhanced neural activity in a consistent set of neural regions (the 'core recollection network') seemingly regardless of the nature of the recollected content. Here, we employed multi-voxel pattern analysis (MVPA) to assess whether retrieval-related functional magnetic resonance imaging (fMRI) activity in core recollection regions - including the hippocampus, angular gyrus, medial prefrontal cortex, retrosplenial/posterior cingulate cortex, and middle temporal gyrus - contain information about studied content and thus demonstrate retrieval-related 'reinstatement' effects. During study, participants viewed objects and concrete words that were subjected to different encoding tasks. Test items included studied words, the names of studied objects, or unstudied words. Participants judged whether the items were recollected, familiar, or new by making 'remember', 'know', and 'new' responses, respectively. The study history of remembered test items could be reliably decoded using MVPA in most regions, as well as from the dorsolateral prefrontal cortex, a region where univariate recollection effects could not be detected. The findings add to evidence that members of the core recollection network, as well as at least one neural region where mean signal is insensitive to recollection success, carry information about recollected content. Importantly, the study history of recognized items endorsed with a 'know' response could be decoded with equal accuracy. The results thus demonstrate a striking dissociation between mean signal and multi-voxel indices of recollection. Moreover, they converge with prior findings in suggesting that, as it is operationalized by classification-based MVPA, reinstatement is not uniquely a signature of recollection.
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Affiliation(s)
| | - Tracy H Wang
- Department of Psychology, University of Texas at Austin, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, USA
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46
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de Chastelaine M, Mattson JT, Wang TH, Donley BE, Rugg MD. The relationships between age, associative memory performance, and the neural correlates of successful associative memory encoding. Neurobiol Aging 2016; 42:163-76. [PMID: 27143433 DOI: 10.1016/j.neurobiolaging.2016.03.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/09/2016] [Accepted: 03/13/2016] [Indexed: 11/18/2022]
Abstract
Using functional magnetic resonance imaging, subsequent memory effects (greater activity for later remembered than later forgotten study items) predictive of associative encoding were compared across samples of young, middle-aged, and older adults (total N = 136). During scanning, participants studied visually presented word pairs. In a later test phase, they discriminated between studied pairs, "rearranged" pairs (items studied on different trials), and new pairs. Subsequent memory effects were identified by contrasting activity elicited by study pairs that went on to be correctly judged intact or incorrectly judged rearranged. Effects in the hippocampus were age-invariant and positively correlated across participants with associative memory performance. Subsequent memory effects in the right inferior frontal gyrus (IFG) were greater in the older than the young group. In older participants only, both left and, in contrast to prior reports, right IFG subsequent memory effects correlated positively with memory performance. We suggest that the IFG is especially vulnerable to age-related decline in functional integrity and that the relationship between encoding-related activity in right IFG and memory performance depends on the experimental context.
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Affiliation(s)
- Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA.
| | | | - Tracy H Wang
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA
| | - Brian E Donley
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, USA
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47
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Abstract
fMRI was employed to assess whether the contents of recollection vary according to retrieval goal. At study, visually presented words were superimposed on urban or rural scenes or a gray background. The word-background pairs were presented in one of three spatial locations. During a scanned test phase, studied and unstudied words were presented. Two different source memory tasks were randomly interleaved. In the "background" task, the requirement was to judge whether the word had been presented against one of the two classes of scene, as opposed to the alternate class or the gray background. In the "location" task, discrimination was between words presented in one of the two lateral locations and words presented in either of the alternate locations. In both tasks, unstudied words required a separate response. In the background task, words studied against scenes elicited greater activity in parahippocampal and retrosplenial cortex than did words studied against the gray background, consistent with prior reports of scene reinstatement effects. Reinstatement effects were also evident in the location task. Relative to the background task, however, the effects were attenuated in parahippocampal cortex. In other regions, including medial prefrontal and posterior cingulate cortex, activity elicited in the location task by items associated with scenes was lower than that elicited by items presented on the gray background. The findings are interpreted as evidence that contextual retrieval is partially modulated by retrieval goal.
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48
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Abstract
Functional magnetic resonance imaging (fMRI) was employed to examine the effects of a study task manipulation on pre-stimulus activity in the hippocampus predictive of later successful recollection. Eighteen young participants were scanned while making either animacy or syllable judgments on visually presented study words. Cues presented before each word denoted which judgment should be made. Following the study phase, a surprise recognition memory test was administered in which each test item had to be endorsed as "Remembered," "Known," or "New." As expected, "deep" animacy judgments led to better memory for study items than did "shallow" syllable judgments. In both study tasks, pre-stimulus subsequent recollection effects were evident in the interval between the cue and the study item in bilateral anterior hippocampus. However, the direction of the effects differed according to the study task: whereas pre-stimulus hippocampal activity on animacy trials was greater for later recollected items than items judged old on the basis of familiarity (replicating prior findings), these effects reversed for syllable trials. We propose that the direction of pre-stimulus hippocampal subsequent memory effects depends on whether an optimal pre-stimulus task set facilitates study processing that is conducive or unconducive to the formation of contextually rich episodic memories.
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Affiliation(s)
- Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, the University of Texas at Dallas, Dallas, Texas
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, the University of Texas at Dallas, Dallas, Texas
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49
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Abstract
The use of fMRI to inform cognitive theory depends upon the assumption that there is an isomorphic relationship between functional states and brain states. Even if this assumption is accepted, employing fMRI to make cognitive inferences is not straightforward. We discuss these inferential difficulties and describe an example in which fMRI data has had a significant impact on a cognitive theory despite them. The embodied cognition framework states that accessing a conceptual feature engages the same processes that are active when the feature is directly experienced. fMRI studies have consistently found that accessing a feature activates cortical regions slightly anterior to the regions activated when the feature is experienced. We suggest that this neural dissociation between accessing and perceiving a feature is inconsistent with the strong form of embodied cognition theory and that this inconsistency would likely not have been identified without fMRI. We describe how the observation of this forward shift has led to new ways of thinking about perceptual and conceptual representations and the relation between them. Finally, we argue that despite the strong assumptions that are needed to make functional inferences from fMRI, this does not detract from its value as a source of convergent evidence.
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50
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Sweeney-Reed CM, Zaehle T, Voges J, Schmitt FC, Buentjen L, Kopitzki K, Hinrichs H, Heinze HJ, Rugg MD, Knight RT, Richardson-Klavehn A. Thalamic theta phase alignment predicts human memory formation and anterior thalamic cross-frequency coupling. eLife 2015; 4. [PMID: 25993559 PMCID: PMC4459033 DOI: 10.7554/elife.07578] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 05/19/2015] [Indexed: 02/01/2023] Open
Abstract
Previously we reported electrophysiological evidence for a role for the anterior thalamic nucleus (ATN) in human memory formation (Sweeney-Reed et al., 2014). Theta-gamma cross-frequency coupling (CFC) predicted successful memory formation, with the involvement of gamma oscillations suggesting memory-relevant local processing in the ATN. The importance of the theta frequency range in memory processing is well-established, and phase alignment of oscillations is considered to be necessary for synaptic plasticity. We hypothesized that theta phase alignment in the ATN would be necessary for memory encoding. Further analysis of the electrophysiological data reveal that phase alignment in the theta rhythm was greater during successful compared with unsuccessful encoding, and that this alignment was correlated with the CFC. These findings support an active processing role for the ATN during memory formation. DOI:http://dx.doi.org/10.7554/eLife.07578.001
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Affiliation(s)
| | - Tino Zaehle
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany
| | - Jürgen Voges
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany
| | | | - Lars Buentjen
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany
| | - Klaus Kopitzki
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany
| | - Hermann Hinrichs
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany
| | - Hans-Jochen Heinze
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, United States
| | - Robert T Knight
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
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