451
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Campo P, Garrido MI, Moran RJ, Maestú F, García-Morales I, Gil-Nagel A, del Pozo F, Dolan RJ, Friston KJ. Remote effects of hippocampal sclerosis on effective connectivity during working memory encoding: a case of connectional diaschisis? Cereb Cortex 2011; 22:1225-36. [PMID: 21810779 PMCID: PMC3357177 DOI: 10.1093/cercor/bhr201] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Accumulating evidence suggests a role for the medial temporal lobe (MTL) in working memory (WM). However, little is known concerning its functional interactions with other cortical regions in the distributed neural network subserving WM. To reveal these, we availed of subjects with MTL damage and characterized changes in effective connectivity while subjects engaged in WM task. Specifically, we compared dynamic causal models, extracted from magnetoencephalographic recordings during verbal WM encoding, in temporal lobe epilepsy patients (with left hippocampal sclerosis) and controls. Bayesian model comparison indicated that the best model (across subjects) evidenced bilateral, forward, and backward connections, coupling inferior temporal cortex (ITC), inferior frontal cortex (IFC), and MTL. MTL damage weakened backward connections from left MTL to left ITC, a decrease accompanied by strengthening of (bidirectional) connections between IFC and MTL in the contralesional hemisphere. These findings provide novel evidence concerning functional interactions between nodes of this fundamental cognitive network and sheds light on how these interactions are modified as a result of focal damage to MTL. The findings highlight that a reduced (top-down) influence of the MTL on ipsilateral language regions is accompanied by enhanced reciprocal coupling in the undamaged hemisphere providing a first demonstration of "connectional diaschisis."
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Affiliation(s)
- Pablo Campo
- Department of Basic Psychology, Autonoma University of Madrid, 28049 Madrid, Spain
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452
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Allen P, Seal ML, Valli I, Fusar-Poli P, Perlini C, Day F, Wood SJ, Williams SC, McGuire PK. Altered prefrontal and hippocampal function during verbal encoding and recognition in people with prodromal symptoms of psychosis. Schizophr Bull 2011; 37:746-56. [PMID: 19933712 PMCID: PMC3122294 DOI: 10.1093/schbul/sbp113] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Despite robust evidence of hippocampal abnormalities in schizophrenia, it is unclear whether hippocampal dysfunction predates the onset of psychosis. We used functional magnetic resonance imaging to investigate hippocampal function in subjects with an at-risk mental state (ARMS). Eighteen subjects meeting criteria for an ARMS and 22 healthy controls, matched for age, gender, and premorbid IQ, were scanned while performing a version of the Deese-Roediger-McDermott false memory task. During an encoding phase, subjects read lists of words aloud. Following a delay, they were presented with 24 target words, 24 semantically related lure words, and 24 novel words and required to indicate if each had been presented before. Behaviorally, the ARMS group made more false alarm responses for novel words than controls (P = .04) and had a lower discrimination accuracy for target words (P = .02). During encoding, ARMS subjects showed less activation than healthy controls in the left middle frontal gyrus, the bilateral medial frontal gyri, and the left parahippocampal gyrus. Correct recognition relative to false alarms was associated with differential engagement of the hippocampus bilaterally in healthy controls, but this difference was absent in the ARMS group. The ARMS was associated with altered function in the medial temporal cortex, as well as in the prefrontal regions, during both verbal encoding and recognition. These neurofunctional differences were associated with diminished recognition performance and may reflect the greatly increased risk of psychosis associated with the ARMS.
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Affiliation(s)
- Paul Allen
- Section of Neuroimaging, Division of Psychological Medicine, Institute of Psychiatry, London, UK.
| | - Marc L. Seal
- Melbourne Neuropsychiatry Centre, University of Melbourne, Australia
| | - Isabel Valli
- Section of Neuroimaging, Division of Psychological Medicine, Institute of Psychiatry, London, UK
| | - Paolo Fusar-Poli
- Section of Neuroimaging, Division of Psychological Medicine, Institute of Psychiatry, London, UK
| | - Cinzia Perlini
- Section of Neuroimaging, Division of Psychological Medicine, Institute of Psychiatry, London, UK,Department of Medicine and Public Health, Section of Psychiatry and Clinical Psychology, University of Verona, Italy,Inter-University Centre for Behavioural Neurosciences (ICBN), University of Verona, Italy
| | - Fern Day
- Section of Neuroimaging, Division of Psychological Medicine, Institute of Psychiatry, London, UK
| | - Stephen J. Wood
- Melbourne Neuropsychiatry Centre, University of Melbourne, Australia
| | | | - Philip K. McGuire
- Section of Neuroimaging, Division of Psychological Medicine, Institute of Psychiatry, London, UK
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453
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Abstract
Rostrolateral prefrontal cortex (RLPFC) plays a key role in our ability to postpone the execution of intended behaviors until after another activity has been performed. However, it is poorly understood in computational terms. One crucial question is whether RLPFC represents the content of delayed intentions or plays a nonspecific role. In this human functional magnetic resonance imaging study (n = 32), RLPFC was active while participants stored delayed intentions during a distracting ongoing task. Multivariate analysis showed that the intended cue for future action and the intended behavior could be decoded from distinct posterior brain regions. However, the content of intentions could not be decoded from RLPFC itself. Functional connectivity analysis showed that RLPFC increased its coupling with content-representing regions during intention storage. Furthermore, trials with relatively high RLPFC activity were associated with enhanced decoding. Thus, RLPFC may enable realization of delayed intentions via interactions with posterior brain regions, which represent their content.
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454
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Kühn AB, Schubotz RI. Temporally remote destabilization of prediction after rare breaches of expectancy. Hum Brain Mapp 2011; 33:1812-20. [PMID: 21674697 DOI: 10.1002/hbm.21325] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 02/04/2011] [Accepted: 03/10/2011] [Indexed: 11/05/2022] Open
Abstract
While neural signatures of breaches of expectancy and their immediate effects have been investigated, thus far, temporally more remote effects have been neglected. The present fMRI study explored neural correlates of temporally remote destabilization of prediction following rare breaches of expectancy with a mean delay of 14 s. We hypothesized temporally remote destabilization to be reflected either in an attenuation of areas related to long-term memory or in an increase of lateral fronto-parietal loops related to the encoding of new stimuli. Monitoring a deterministic 24-digit sequence, subjects were asked to indicate occasional sequential omissions by key press. Temporally remote destabilization of prediction was expected to be revealed by contrasting sequential events whose equivalent was omitted in the preceding sequential run n-1 (destabilized events) with sequential events without such history (nondestabilized events). Temporally remote destabilization of prediction was reflected in an attenuation of activity in the dorsal frontomedian cortex (Brodmann Area (BA) 9) bilaterally. Moreover, activation of the left medial BA 9 was enhanced by contrasting nondestabilized events with breaches. The decrease of dorsal frontomedian activation in the case of destabilized events might be interpreted as a top-down modulation on perception causing a less expectation-restricted encoding of the current stimulus and hence enabling the adaptation of expectation and prediction in the long run.
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Affiliation(s)
- Anne B Kühn
- Motor Cognition Group, Max Planck Institute for Neurological Research, Gleueler Straße 50, 50931 Cologne, Germany.
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455
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Executive function mediates effects of white matter hyperintensities on episodic memory. Neuropsychologia 2011; 49:2817-24. [PMID: 21689669 DOI: 10.1016/j.neuropsychologia.2011.06.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 05/18/2011] [Accepted: 06/02/2011] [Indexed: 11/21/2022]
Abstract
This study examined the relationship between white matter hyperintensities (WMH) and executive functioning on episodic memory in a group of older adults who were cognitively normal or diagnosed with MCI or dementia. Volumetric magnetic resonance imaging (MRI) measures of total brain volume, white matter hyperintensity volume, and hippocampal volume along with age, education, and gender were evaluated as predictors of episodic memory. WMH were found to influence both episodic memory and executive functioning independently of other variables. The influence WMH on episodic memory was mediated by executive functioning and was completely eliminated when the interaction between executive functioning and hippocampal volume was entered in the regression model. The results indicate that executive functioning mediates the effects of WMH on episodic memory but that executive functioning and hippocampal volume can also interact such that executive functioning can exacerbate or ameliorate the influence of hippocampal volume on episodic memory.
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456
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Loureiro M, Lecourtier L, Engeln M, Lopez J, Cosquer B, Geiger K, Kelche C, Cassel JC, Pereira de Vasconcelos A. The ventral hippocampus is necessary for expressing a spatial memory. Brain Struct Funct 2011; 217:93-106. [PMID: 21667304 DOI: 10.1007/s00429-011-0332-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 05/21/2011] [Indexed: 10/18/2022]
Abstract
Current views posit the dorsal hippocampus (DHipp) as contributing to spatial memory processes. Conversely, the ventral hippocampus (VHipp) modulates stress, emotions and affects. Arguments supporting this segregation include differences in (i) connectivity: the DHipp is connected with the entorhinal cortex which receives visuospatial neocortical inputs; the VHipp is connected with both the amygdala and hypothalamus, (ii) electrophysiological characteristics: there is a larger proportion of place cells in the DHipp than in the VHipp, and an increasing dorsoventral gradient in the size of place fields, suggesting less refined spatial coding in the VHipp, and (iii) consequences of lesions: spatial memory is altered after DHipp lesions, less dramatically, sometimes not, after VHipp lesions. Using reversible inactivation, we report in rats, that lidocaine infusions into the DHipp or VHipp right before a probe trial impair retrieval performance in a water-maze task. This impairment was found at two post-acquisition delays compatible with recent memory (1 and 5 days). Pre-training blockade of the VHipp did not prevent task acquisition and drug-free retrieval, on the contrary to pre-training blockade of DHipp, which altered performance in a subsequent drug-free probe trial. Complementary experiments excluded possible locomotor, sensorimotor, motivational or anxiety-related biases from data interpretation. Our conclusion is that a spatial memory can be acquired with the DHipp, less efficiently with the VHipp, and that the retrieval of such a memory and/or the expression of its representation engages the dorsoventral axis of the hippocampus when the task has been learnt with an entirely functional hippocampus.
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Affiliation(s)
- Michael Loureiro
- Laboratoire d'Imagerie et de Neurosciences Cognitives, UMR 7237, Université de Strasbourg, CNRS, IFR 37 des Neurosciences, GDR CNRS 2905 Neuromem, 12 rue Goethe, 67000 Strasbourg, France
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457
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Episodic retrieval and the cortical binding of relational activity. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2011; 11:277-91. [DOI: 10.3758/s13415-011-0031-4] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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458
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Brambilla P, Cerruti S, Bellani M, Perlini C, Ferro A, Marinelli V, Giusto D, Tomelleri L, Rambaldelli G, Tansella M, Diwadkar VA. Shared impairment in associative learning in schizophrenia and bipolar disorder. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:1093-9. [PMID: 21420463 DOI: 10.1016/j.pnpbp.2011.03.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 03/09/2011] [Accepted: 03/09/2011] [Indexed: 11/28/2022]
Abstract
BACKGROUND Schizophrenia (SCZ) and bipolar disorder (BD) share some cognitive commonalities. However, the role of associative learning, which is a cornerstone of human cognition mainly relying on hippocampus, has been under-investigated. We assessed behavioral performance during associative learning in a group of SCZ, BD and healthy controls (HC). METHODS Nineteen patients with SCZ (36 ± 8.1 years; 13 males, 6 females; all Caucasians), 14 patients with BD (41 ± 9.6 years; 5 males, 9 females; all Caucasians) and 45 HC (27.7 ± 6.9 years; 18 males, 27 females; all Caucasians) were studied. Learning was assessed using an established object-location paired-associative learning paradigm. Subjects learned associations between nine equi-familiar common objects and locations in a nine-location grid. Performance data were analyzed in a repeated measures analysis of variance with time (repeated) and group as factors. RESULTS Learning curves (performance = (1-e(-k x time)) fitted to average performance data in the three groups revealed lower learning rates in SCZ and BD (k = 0.17 and k = 0.34) than HC (k = 0.78). Significant effects of group (F = 11.05, p < 0.001) and time (F = 122.06, p < 0.001) on learning performance were observed. CONCLUSIONS Our study showed that associative learning is impaired in both SCZ and BD, being potentially not affected by medication. Future studies should investigate the neural substrates of learning deficits in SCZ and BD, particularly focusing on hippocampus function and glutamatergic transmission.
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Affiliation(s)
- Paolo Brambilla
- DISM, Inter-University Centre for Behavioural Neurosciences, University of Udine, Udine, Italy.
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459
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Primate prefrontal neurons encode the association of paired visual stimuli during the pair-association task. Brain Cogn 2011; 76:58-69. [DOI: 10.1016/j.bandc.2011.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 02/24/2011] [Accepted: 03/05/2011] [Indexed: 11/24/2022]
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460
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Aggleton JP, Dumont JR, Warburton EC. Unraveling the contributions of the diencephalon to recognition memory: a review. Learn Mem 2011; 18:384-400. [PMID: 21597044 PMCID: PMC3101772 DOI: 10.1101/lm.1884611] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 03/13/2011] [Indexed: 11/24/2022]
Abstract
Both clinical investigations and studies with animals reveal nuclei within the diencephalon that are vital for recognition memory (the judgment of prior occurrence). This review seeks to identify these nuclei and to consider why they might be important for recognition memory. Despite the lack of clinical cases with circumscribed pathology within the diencephalon and apparent species differences, convergent evidence from a variety of sources implicates a subgroup of medial diencephalic nuclei. It is supposed that the key functional interactions of this subgroup of diencephalic nuclei are with the medial temporal lobe, the prefrontal cortex, and with cingulate regions. In addition, some of the clinical evidence most readily supports dual-process models of recognition, which assume two independent cognitive processes (recollective-based and familiarity-based) that combine to direct recognition judgments. From this array of information a "multi-effect multi-nuclei" model is proposed, in which the mammillary bodies and the anterior thalamic nuclei are of preeminent importance for recollective-based recognition. The medial dorsal thalamic nucleus is thought to contribute to familiarity-based recognition, but this nucleus, along with various midline and intralaminar thalamic nuclei, is also assumed to have broader, indirect effects upon both recollective-based and familiarity-based recognition.
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Affiliation(s)
- John P Aggleton
- School of Psychology, Cardiff University, Cardiff, CF10 3AT, Wales, United Kingdom.
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461
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Dulas MR, Duarte A. The effects of aging on material-independent and material-dependent neural correlates of source memory retrieval. Cereb Cortex 2011; 22:37-50. [PMID: 21616984 DOI: 10.1093/cercor/bhr056] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Age-related declines in source memory have been observed for various stimuli and associated details. These impairments may be related to alterations in brain regions contributing to source memory via material-independent processes and/or regions specialized for processing specific materials. Using event-related functional magnetic resonance imaging, we investigate the effects of aging on source memory and associated neural activity for words and objects. Source accuracy was equally impaired in older adults for both materials. Imaging data revealed both groups recruited similar networks of regions to support source memory accuracy irrespective of material, including parietal and prefrontal cortices (PFC) and the hippocampus. Age-related decreases in material-independent activity linked to postretrieval monitoring were observed in right lateral PFC. Additionally, age-related increases in source accuracy effects were shown in perirhinal cortex, which were positively correlated with performance in older adults, potentially reflecting functional compensation. In addition to group differences in material-independent regions, age-related crossover interactions for material-dependent source memory effects were observed in regions selectively engaged by objects. These results suggest that older adults' source memory impairments reflect alterations in regions making material-independent contributions to source memory retrieval, primarily the lateral PFC, but may be further impacted by changes in regions sensitive to particular materials.
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Affiliation(s)
- Michael R Dulas
- School of Psychology, Georgia Institute of Technology, Atlanta, GA 30332-0170, USA.
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462
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O'Neil EB, Protzner AB, McCormick C, McLean DA, Poppenk J, Cate AD, Köhler S. Distinct patterns of functional and effective connectivity between perirhinal cortex and other cortical regions in recognition memory and perceptual discrimination. Cereb Cortex 2011; 22:74-85. [PMID: 21613466 DOI: 10.1093/cercor/bhr075] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Traditionally, the medial temporal lobe (MTL) is thought to be dedicated to declarative memory. Recent evidence challenges this view, suggesting that perirhinal cortex (PrC), which interfaces the MTL with the ventral visual pathway, supports highly integrated object representations in recognition memory and perceptual discrimination. Even with comparable representational demands, perceptual and memory tasks differ in numerous task demands and the subjective experience they evoke. Here, we tested whether such differences are reflected in distinct patterns of connectivity between PrC and other cortical regions, including differential involvement of prefrontal control processes. We examined functional magnetic resonance imaging data for closely matched perceptual and recognition memory tasks for faces that engaged right PrC equivalently. Multivariate seed analyses revealed distinct patterns of interactions: Right ventrolateral prefrontal and posterior cingulate cortices exhibited stronger functional connectivity with PrC in recognition memory; fusiform regions were part of the pattern that displayed stronger functional connectivity with PrC in perceptual discrimination. Structural equation modeling revealed distinct patterns of effective connectivity that allowed us to constrain interpretation of these findings. Overall, they demonstrate that, even when MTL structures show similar involvement in recognition memory and perceptual discrimination, differential neural mechanisms are reflected in the interplay between the MTL and other cortical regions.
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Affiliation(s)
- Edward B O'Neil
- Department of Psychology, University of Western Ontario, London, Ontario, Canada
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463
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464
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Dulas MR, Newsome RN, Duarte A. The effects of aging on ERP correlates of source memory retrieval for self-referential information. Brain Res 2011; 1377:84-100. [DOI: 10.1016/j.brainres.2010.12.087] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 10/07/2010] [Accepted: 12/30/2010] [Indexed: 02/07/2023]
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465
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Weiler J, Suchan B, Koch B, Schwarz M, Daum I. Differential impairment of remembering the past and imagining novel events after thalamic lesions. J Cogn Neurosci 2011; 23:3037-51. [PMID: 21268672 DOI: 10.1162/jocn.2011.21633] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Vividly remembering the past and imagining the future (mental time travel) seem to rely on common neural substrates and mental time travel impairments in patients with brain lesions seem to encompass both temporal domains. However, because future thinking-or more generally imagining novel events-involves the recombination of stored elements into a new event, it requires additional resources that are not shared by episodic memory. We aimed to demonstrate this asymmetry in an event generation task administered to two patients with lesions in the medial dorsal thalamus. Because of the dense connection with pFC, this nucleus of the thalamus is implicated in executive aspects of memory (strategic retrieval), which are presumably more important for future thinking than for episodic memory. Compared with groups of healthy matched control participants, both patients could only produce novel events with extensive help of the experimenter (prompting) in the absence of episodic memory problems. Impairments were most pronounced for imagining personal fictitious and impersonal events. More precisely, the patients' descriptions of novel events lacked content and spatio-temporal relations. The observed impairment is unlikely to trace back to disturbances in self-projection, scene construction, or time concept and could be explained by a recombination deficit. Thus, although memory and the imagination of novel events are tightly linked, they also partly rely on different processes.
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466
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Labile or stable: opposing consequences for memory when reactivated during waking and sleep. Nat Neurosci 2011; 14:381-6. [PMID: 21258327 DOI: 10.1038/nn.2744] [Citation(s) in RCA: 236] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/22/2010] [Indexed: 01/18/2023]
Abstract
Memory consolidation is a dynamic process. Reconsolidation theory assumes that reactivation during wakefulness transiently destabilizes memories, requiring them to reconsolidate in order to persist. Memory reactivation also occurs during slow-wave sleep (SWS) and is assumed to underlie the consolidating effect of sleep. Here, we tested whether the same principle of transient destabilization applies to memory reactivation during SWS. We reactivated memories in humans by presenting associated odor cues either during SWS or wakefulness. Reactivation was followed by an interference task to probe memory stability. As we expected, reactivation during waking destabilized memories. In contrast, reactivation during SWS immediately stabilized memories, thereby directly increasing their resistance to interference. Functional magnetic resonance imaging revealed that reactivation during SWS mainly activated hippocampal and posterior cortical regions, whereas reactivation during wakefulness primarily activated prefrontal cortical areas. Our results show that reactivation of memory serves distinct functions depending on the brain state of wakefulness or sleep.
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467
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St Jacques PL, Rubin DC, Cabeza R. Age-related effects on the neural correlates of autobiographical memory retrieval. Neurobiol Aging 2010; 33:1298-310. [PMID: 21190759 DOI: 10.1016/j.neurobiolaging.2010.11.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 11/03/2010] [Accepted: 11/05/2010] [Indexed: 11/26/2022]
Abstract
Older adults recall less episodically rich autobiographical memories (AM), however, the neural basis of this effect is not clear. Using functional MRI, we examined the effects of age during search and elaboration phases of AM retrieval. Our results suggest that the age-related attenuation in the episodic richness of AMs is associated with difficulty in the strategic retrieval processes underlying recovery of information during elaboration. First, age effects on AM activity were more pronounced during elaboration than search, with older adults showing less sustained recruitment of the hippocampus and ventrolateral prefrontal cortex (VLPFC) for less episodically rich AMs. Second, there was an age-related reduction in the modulation of top-down coupling of the VLPFC on the hippocampus for episodically rich AMs. In sum, the present study shows that changes in the sustained response and coupling of the hippocampus and prefrontal cortex (PFC) underlie age-related reductions in episodic richness of the personal past.
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Affiliation(s)
- Peggy L St Jacques
- Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, USA.
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468
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Kida T, Inui K, Tanaka E, Kakigi R. Dynamics of within-, inter-, and cross-modal attentional modulation. J Neurophysiol 2010; 105:674-86. [PMID: 21148089 DOI: 10.1152/jn.00807.2009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Numerous studies have demonstrated effects of spatial attention within single sensory modalities (within-modal spatial attention) and the effect of directing attention to one sense compared with the other senses (intermodal attention) on cortical neuronal activity. Furthermore, recent studies have been revealing that the effects of spatial attention directed to a certain location in a certain sense spread to the other senses at the same location in space (cross-modal spatial attention). The present study used magnetoencephalography to examine the temporal dynamics of the effects of within-modal and cross-modal spatial and intermodal attention on cortical processes responsive to visual stimuli. Visual or tactile stimuli were randomly presented on the left or right side at a random interstimulus interval and subjects directed attention to the left or right when vision or touch was a task-relevant modality. Sensor-space analysis showed that a response around the occipitotemporal region at around 150 ms after visual stimulation was significantly enhanced by within-modal, cross-modal spatial, and intermodal attention. A later response over the right frontal region at around 200 ms was enhanced by within-modal spatial and intermodal attention, but not by cross-modal spatial attention. These effects were estimated to originate from the occipitotemporal and lateral frontal areas, respectively. Thus the results suggest different spatiotemporal dynamics of neural representations of cross-modal attention and intermodal or within-modal attention.
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Affiliation(s)
- Tetsuo Kida
- National Institute for Physiological Sciences, Department of Integrative Physiology, 38 Nishigo-naka, Myodaiji, Okazaki 444-8585, Japan.
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469
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Townsend EL, Richmond JL, Vogel-Farley VK, Thomas K. Medial temporal lobe memory in childhood: developmental transitions. Dev Sci 2010; 13:738-51. [PMID: 20712740 DOI: 10.1111/j.1467-7687.2009.00935.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The medial temporal lobes (MTL) support declarative memory and mature structurally and functionally during the postnatal years in humans. Although recent work has addressed the development of declarative memory in early childhood, less is known about continued development beyond this period of time. The purpose of this investigation was to explore MTL-dependent memory across middle childhood. Children (6 -10 years old) and adults completed two computerized tasks, place learning (PL) and transitive inference (TI), that each examined relational memory, as well as the flexible use of relational learning. Findings suggest that the development of relational memory precedes the development of the ability to use relational knowledge flexibly in novel situations. Implications for the development of underlying brain areas and ideas for future neuroimaging investigations are discussed.
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Affiliation(s)
- Elise L Townsend
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, MGH Institute of Health Professions, Boston, USA.
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470
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Hippocampal brain-network coordination during volitional exploratory behavior enhances learning. Nat Neurosci 2010; 14:115-20. [PMID: 21102449 PMCID: PMC3057495 DOI: 10.1038/nn.2693] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Accepted: 10/06/2010] [Indexed: 11/16/2022]
Abstract
Exploratory behaviors during learning determine what is studied and when, helping to optimize subsequent memory performance. We manipulated how much control subjects had over the position of a moving window through which they studied objects and their locations, in order to elucidate the cognitive and neural determinants of exploratory behaviors. Our behavioral, neuropsychological, and neuroimaging data indicate volitional control benefits memory performance, and is linked to a brain network centered on the hippocampus. Increases in correlated activity between the hippocampus and other areas were associated with specific aspects of memory, suggesting that volitional control optimizes interactions among specialized neural systems via the hippocampus. Memory is therefore an active process intrinsically linked to behavior. Furthermore, brain structures typically seen as passive participants in memory encoding (e.g., the hippocampus) are actually part of an active network that controls behavior dynamically as it unfolds.
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471
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Matre DA, Hernandez-Garcia L, Tran TD, Casey KL. "First pain" in humans: convergent and specific forebrain responses. Mol Pain 2010; 6:81. [PMID: 21083897 PMCID: PMC3000383 DOI: 10.1186/1744-8069-6-81] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 11/17/2010] [Indexed: 11/29/2022] Open
Abstract
Background Brief heat stimuli that excite nociceptors innervated by finely myelinated (Aδ) fibers evoke an initial, sharp, well-localized pain ("first pain") that is distinguishable from the delayed, less intense, more prolonged dull pain attributed to nociceptors innervated by unmyelinated (C) fibers ("second pain"). In the present study, we address the question of whether a brief, noxious heat stimulus that excites cutaneous Aδ fibers activates a distinct set of forebrain structures preferentially in addition to those with similar responses to converging input from C fibers. Heat stimuli at two temperatures were applied to the dorsum of the left hand of healthy volunteers in a functional brain imaging (fMRI) paradigm and responses analyzed in a set of volumes of interest (VOI). Results Brief 41°C stimuli were painless and evoked only C fiber responses, but 51°C stimuli were at pain threshold and preferentially evoked Aδ fiber responses. Most VOI responded to both intensities of stimulation. However, within volumes of interest, a contrast analysis and comparison of BOLD response latencies showed that the bilateral anterior insulae, the contralateral hippocampus, and the ipsilateral posterior insula were preferentially activated by painful heat stimulation that excited Aδ fibers. Conclusions These findings show that two sets of forebrain structures mediate the initial sharp pain evoked by brief cutaneous heat stimulation: those responding preferentially to the brief stimulation of Aδ heat nociceptors and those with similar responses to converging inputs from the painless stimulation of C fibers. Our results suggest a unique and specific physiological basis, at the forebrain level, for the "first pain" sensation that has long been attributed to Aδ fiber stimulation and support the concept that both specific and convergent mechanisms act concurrently to mediate pain.
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Affiliation(s)
- Dagfinn A Matre
- Dept. of Work-related Musculoskeletal Disorders, National Institute of Occupational Health, Oslo, Norway.
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472
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Rattenborg NC, Martinez-Gonzalez D, Roth TC, Pravosudov VV. Hippocampal memory consolidation during sleep: a comparison of mammals and birds. Biol Rev Camb Philos Soc 2010; 86:658-91. [PMID: 21070585 DOI: 10.1111/j.1469-185x.2010.00165.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The transition from wakefulness to sleep is marked by pronounced changes in brain activity. The brain rhythms that characterize the two main types of mammalian sleep, slow-wave sleep (SWS) and rapid eye movement (REM) sleep, are thought to be involved in the functions of sleep. In particular, recent theories suggest that the synchronous slow-oscillation of neocortical neuronal membrane potentials, the defining feature of SWS, is involved in processing information acquired during wakefulness. According to the Standard Model of memory consolidation, during wakefulness the hippocampus receives input from neocortical regions involved in the initial encoding of an experience and binds this information into a coherent memory trace that is then transferred to the neocortex during SWS where it is stored and integrated within preexisting memory traces. Evidence suggests that this process selectively involves direct connections from the hippocampus to the prefrontal cortex (PFC), a multimodal, high-order association region implicated in coordinating the storage and recall of remote memories in the neocortex. The slow-oscillation is thought to orchestrate the transfer of information from the hippocampus by temporally coupling hippocampal sharp-wave/ripples (SWRs) and thalamocortical spindles. SWRs are synchronous bursts of hippocampal activity, during which waking neuronal firing patterns are reactivated in the hippocampus and neocortex in a coordinated manner. Thalamocortical spindles are brief 7-14 Hz oscillations that may facilitate the encoding of information reactivated during SWRs. By temporally coupling the readout of information from the hippocampus with conditions conducive to encoding in the neocortex, the slow-oscillation is thought to mediate the transfer of information from the hippocampus to the neocortex. Although several lines of evidence are consistent with this function for mammalian SWS, it is unclear whether SWS serves a similar function in birds, the only taxonomic group other than mammals to exhibit SWS and REM sleep. Based on our review of research on avian sleep, neuroanatomy, and memory, although involved in some forms of memory consolidation, avian sleep does not appear to be involved in transferring hippocampal memories to other brain regions. Despite exhibiting the slow-oscillation, SWRs and spindles have not been found in birds. Moreover, although birds independently evolved a brain region--the caudolateral nidopallium (NCL)--involved in performing high-order cognitive functions similar to those performed by the PFC, direct connections between the NCL and hippocampus have not been found in birds, and evidence for the transfer of information from the hippocampus to the NCL or other extra-hippocampal regions is lacking. Although based on the absence of evidence for various traits, collectively, these findings suggest that unlike mammalian SWS, avian SWS may not be involved in transferring memories from the hippocampus. Furthermore, it suggests that the slow-oscillation, the defining feature of mammalian and avian SWS, may serve a more general function independent of that related to coordinating the transfer of information from the hippocampus to the PFC in mammals. Given that SWS is homeostatically regulated (a process intimately related to the slow-oscillation) in mammals and birds, functional hypotheses linked to this process may apply to both taxonomic groups.
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Affiliation(s)
- Niels C Rattenborg
- Max Planck Institute for Ornithology, Sleep and Flight Group, Eberhard-Gwinner-Strasse, 82319, Seewiesen, Germany.
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473
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Kalpouzos G, Eriksson J, Sjölie D, Molin J, Nyberg L. Neurocognitive systems related to real-world prospective memory. PLoS One 2010; 5:e13304. [PMID: 20949046 PMCID: PMC2951914 DOI: 10.1371/journal.pone.0013304] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 09/10/2010] [Indexed: 11/19/2022] Open
Abstract
Background Prospective memory (PM) denotes the ability to remember to perform actions in the future. It has been argued that standard laboratory paradigms fail to capture core aspects of PM. Methodology/Principal Findings We combined functional MRI, virtual reality, eye-tracking and verbal reports to explore the dynamic allocation of neurocognitive processes during a naturalistic PM task where individuals performed errands in a realistic model of their residential town. Based on eye movement data and verbal reports, we modeled PM as an iterative loop of five sustained and transient phases: intention maintenance before target detection (TD), TD, intention maintenance after TD, action, and switching, the latter representing the activation of a new intention in mind. The fMRI analyses revealed continuous engagement of a top-down fronto-parietal network throughout the entire task, likely subserving goal maintenance in mind. In addition, a shift was observed from a perceptual (occipital) system while searching for places to go, to a mnemonic (temporo-parietal, fronto-hippocampal) system for remembering what actions to perform after TD. Updating of the top-down fronto-parietal network occurred at both TD and switching, the latter likely also being characterized by frontopolar activity. Conclusion/Significance Taken together, these findings show how brain systems complementary interact during real-world PM, and support a more complete model of PM that can be applied to naturalistic PM tasks and that we named PROspective MEmory DYnamic (PROMEDY) model because of its dynamics on both multi-phase iteration and the interactions of distinct neurocognitive networks.
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Affiliation(s)
- Grégoria Kalpouzos
- Physiology Section, Department of Integrative Medical Biology, Umeå University, Umeå, Sweden.
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474
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Engvig A, Fjell AM, Westlye LT, Moberget T, Sundseth Ø, Larsen VA, Walhovd KB. Effects of memory training on cortical thickness in the elderly. Neuroimage 2010; 52:1667-76. [DOI: 10.1016/j.neuroimage.2010.05.041] [Citation(s) in RCA: 261] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 05/10/2010] [Accepted: 05/17/2010] [Indexed: 12/16/2022] Open
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475
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Locus coeruleus stimulation and noradrenergic modulation of hippocampo-prefrontal cortex long-term potentiation. Int J Neuropsychopharmacol 2010; 13:1219-31. [PMID: 20128952 DOI: 10.1017/s1461145709991131] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Stimulation of the subiculum/CA1 of the hippocampal formation evokes monosynaptic field potentials in the prefrontal cortex (PFC). High-frequency stimulation of the hippocampus (HPC) can induce long-term potentiation (LTP) in this hippocampo-prefrontal cortical (hippo-PFC) pathway. Previous studies have shown that dopamine and serotonin modulate hippo-PFC LTP. Here, we investigated whether the locus coeruleus (LC) and noradrenaline (NA) can modulate LTP in the rat hippo-PFC pathway. Stimulation of the LC in combination with stimulation of the HPC increased hippo-PFC LTP. Infusion of lidocaine into the LC reduced hippo-PFC LTP. Administration of the noradrenaline reuptake inhibitor, nisoxetine or the alpha2 adrenoceptor antagonist, idazoxan prior to high-frequency stimulation of the HPC enhanced hippo-LTP. In contrast, administration of clonidine, an alpha2 adrenoceptor agonist, impaired hippo-PFC LTP. Partial noradrenergic (NAergic) lesioning with DSP-4 also impaired hippo-PFC LTP. In conclusion, the LC and NAergic mechanisms modulate hippo-PFC LTP.
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476
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Innocenti I, Giovannelli F, Cincotta M, Feurra M, Polizzotto NR, Bianco G, Cappa SF, Rossi S. Event-related rTMS at encoding affects differently deep and shallow memory traces. Neuroimage 2010; 53:325-30. [DOI: 10.1016/j.neuroimage.2010.06.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 05/25/2010] [Accepted: 06/04/2010] [Indexed: 11/16/2022] Open
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477
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Kim H. Neural activity that predicts subsequent memory and forgetting: a meta-analysis of 74 fMRI studies. Neuroimage 2010; 54:2446-61. [PMID: 20869446 DOI: 10.1016/j.neuroimage.2010.09.045] [Citation(s) in RCA: 411] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2010] [Revised: 07/30/2010] [Accepted: 09/17/2010] [Indexed: 10/19/2022] Open
Abstract
The present study performed a quantitative meta-analysis of functional MRI studies that used a subsequent memory approach. The meta-analysis considered both subsequent memory (SM; remembered>forgotten) and subsequent forgetting (SF; forgotten>remembered) effects, restricting the data used to that concerning visual information encoding in healthy young adults. The meta-analysis of SM effects indicated that they most consistently associated with five neural regions: left inferior frontal cortex (IFC), bilateral fusiform cortex, bilateral hippocampal formation, bilateral premotor cortex (PMC), and bilateral posterior parietal cortex (PPC). Direct comparisons of the SM effects between the studies using verbal versus pictorial material and item-memory versus associative-memory tasks yielded three main sets of findings. First, the left IFC exhibited greater SM effects during verbal material than pictorial material encoding, whereas the fusiform cortex exhibited greater SM effects during pictorial material rather than verbal material encoding. Second, bilateral hippocampal regions showed greater SM effects during pictorial material encoding compared to verbal material encoding. Furthermore, the left hippocampal region showed greater SM effects during pictorial-associative versus pictorial-item encoding. Third, bilateral PMC and PPC regions, which may support attention during encoding, exhibited greater SM effects during item encoding than during associative encoding. The meta-analysis of SF effects indicated they associated mostly with default-mode network regions, including the anterior and posterior midline cortex, the bilateral temporoparietal junction, and the bilateral superior frontal cortex. Recurrent activity oscillations between the task-positive and task-negative/default-mode networks may account for trial-to-trial variability in participants' encoding performances, which is a fundamental source of both SM and SF effects. Taken together, these findings clarify the neural activity that supports successful encoding, as well as the neural activity that leads to encoding failure.
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Affiliation(s)
- Hongkeun Kim
- Department of Rehabilitation Psychology, Daegu University, Gyeongsan, South Korea.
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478
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Wang L, Metzak PD, Honer WG, Woodward TS. Impaired efficiency of functional networks underlying episodic memory-for-context in schizophrenia. J Neurosci 2010; 30:13171-9. [PMID: 20881136 PMCID: PMC6633526 DOI: 10.1523/jneurosci.3514-10.2010] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 08/09/2010] [Indexed: 11/21/2022] Open
Abstract
Memory for context and episodic memory have been identified as primary contributors to cognitive impairments in schizophrenia. This study examined neural networks involved in episodic memory-for-context in schizophrenia using a multimodal strategy including a graph theoretical approach, combined with an assessment of the contribution of structural impairments to disruption in the efficiency of functional brain networks. Twenty-three patients with schizophrenia and 33 healthy controls performed an episodic memory-for-context task while undergoing functional magnetic resonance imaging scanning. Graph theory was used to characterize the small-world properties of functional connections between activated regions, and a morphometric analysis was used to investigate schizophrenia-related structural deficits. Similar functional activations were identified in the two groups; however, although small-world properties were present in the topological organization of the functional networks in both groups, significant reductions in local, but not global, efficiency were observed in the schizophrenia group. Several key network "hub" regions related to recollection, such as the bilateral dorsal anterior cingulate gyrus, showed reduced gray matter volume in schizophrenia patients. These findings suggest that loss of gray matter volume may contribute to local inefficiencies in the architecture of the network underlying memory-for-context in schizophrenia.
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Affiliation(s)
- Liang Wang
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 2A1, Canada, and
- BC Mental Health and Addictions Research Institute, Vancouver, British Columbia V5Z 4H4, Canada
| | - Paul D. Metzak
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 2A1, Canada, and
- BC Mental Health and Addictions Research Institute, Vancouver, British Columbia V5Z 4H4, Canada
| | - William G. Honer
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 2A1, Canada, and
- BC Mental Health and Addictions Research Institute, Vancouver, British Columbia V5Z 4H4, Canada
| | - Todd S. Woodward
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 2A1, Canada, and
- BC Mental Health and Addictions Research Institute, Vancouver, British Columbia V5Z 4H4, Canada
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479
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Orientation to learning context modulates retrieval processing for unrecognized words. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s11434-010-4102-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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480
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The role of the prefrontal cortex in familiarity and recollection processes during verbal and non-verbal recognition memory: An rTMS study. Neuroimage 2010; 52:348-57. [DOI: 10.1016/j.neuroimage.2010.04.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 03/30/2010] [Accepted: 04/04/2010] [Indexed: 10/19/2022] Open
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481
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Effects of handedness and saccadic bilateral eye movements on components of autobiographical recollection. Brain Cogn 2010; 73:93-101. [DOI: 10.1016/j.bandc.2010.03.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Revised: 03/17/2010] [Accepted: 03/18/2010] [Indexed: 11/16/2022]
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482
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Sergerie K, Armony JL, Menear M, Sutton H, Lepage M. Influence of emotional expression on memory recognition bias in schizophrenia as revealed by fMRI. Schizophr Bull 2010; 36:800-10. [PMID: 19176471 PMCID: PMC2894593 DOI: 10.1093/schbul/sbn172] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We recently showed that, in healthy individuals, emotional expression influences memory for faces both in terms of accuracy and, critically, in memory response bias (tendency to classify stimuli as previously seen or not, regardless of whether this was the case). Although schizophrenia has been shown to be associated with deficit in episodic memory and emotional processing, the relation between these processes in this population remains unclear. Here, we used our previously validated paradigm to directly investigate the modulation of emotion on memory recognition. Twenty patients with schizophrenia and matched healthy controls completed functional magnetic resonance imaging (fMRI) study of recognition memory of happy, sad, and neutral faces. Brain activity associated with the response bias was obtained by correlating this measure with the contrast subjective old (ie, hits and false alarms) minus subjective new (misses and correct rejections) for sad and happy expressions. Although patients exhibited an overall lower memory performance than controls, they showed the same effects of emotion on memory, both in terms of accuracy and bias. For sad faces, the similar behavioral pattern between groups was mirrored by a largely overlapping neural network, mostly involved in familiarity-based judgments (eg, parahippocampal gyrus). In contrast, controls activated a much larger set of regions for happy faces, including areas thought to underlie recollection-based memory retrieval (eg, superior frontal gyrus and hippocampus) and in novelty detection (eg, amygdala). This study demonstrates that, despite an overall lower memory accuracy, emotional memory is intact in schizophrenia, although emotion-specific differences in brain activation exist, possibly reflecting different strategies.
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Affiliation(s)
| | | | | | | | - Martin Lepage
- To whom correspondence should be addressed; Douglas Mental Health University Institute, 6875 LaSalle Boulevard, F.B.C. Pavilion, Verdun, Quebec H4H 1R3, Canada; tel: +1-514-761-6131, ext. 4393, fax: +1-514-888-4064, e-mail:
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483
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Rossi S, Innocenti I, Polizzotto NR, Feurra M, De Capua A, Ulivelli M, Bartalini S, Cappa SF. Temporal Dynamics of Memory Trace Formation in the Human Prefrontal Cortex. Cereb Cortex 2010; 21:368-73. [DOI: 10.1093/cercor/bhq103] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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484
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Abstract
The neural substrates of memory for when events occurred are not well described. One reason for this is that the paradigms used to date have permitted isolation of only some of the relevant memory processes. In this experiment, functional magnetic resonance imaging was used to identify for the first time brain regions that support two distinct bases upon which "when" judgments can be made. Seventeen human participants (6 male) completed a continuous recognition memory task where the interval between presentation and re-presentation of words varied between 5 and 25 intervening words (the lag). The task on each trial was to distinguish repeated words from those presented for the first time, and to indicate the lag for repeated words. The inferior parietal lobe showed greater activation for shorter lag judgments, regardless of judgment accuracy. The lingual gyrus, by contrast, was more active for correct than for incorrect lag judgments, regardless of the interval between first and second item presentations. Both of these regions have been linked in previous work to the process of recollection, and the findings described here represent a novel neural dissociation across regions that deploy mnemonic information in fundamentally different ways to support judgments about when events occurred.
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485
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Botzung A, Labar KS, Kragel P, Miles A, Rubin DC. Component Neural Systems for the Creation of Emotional Memories during Free Viewing of a Complex, Real-World Event. Front Hum Neurosci 2010; 4:34. [PMID: 20508750 PMCID: PMC2876881 DOI: 10.3389/fnhum.2010.00034] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Accepted: 04/09/2010] [Indexed: 11/25/2022] Open
Abstract
To investigate the neural systems that contribute to the formation of complex, self-relevant emotional memories, dedicated fans of rival college basketball teams watched a competitive game while undergoing functional magnetic resonance imaging (fMRI). During a subsequent recognition memory task, participants were shown video clips depicting plays of the game, stemming either from previously-viewed game segments (targets) or from non-viewed portions of the same game (foils). After an old–new judgment, participants provided emotional valence and intensity ratings of the clips. A data driven approach was first used to decompose the fMRI signal acquired during free viewing of the game into spatially independent components. Correlations were then calculated between the identified components and post-scanning emotion ratings for successfully encoded targets. Two components were correlated with intensity ratings, including temporal lobe regions implicated in memory and emotional functions, such as the hippocampus and amygdala, as well as a midline fronto-cingulo-parietal network implicated in social cognition and self-relevant processing. These data were supported by a general linear model analysis, which revealed additional valence effects in fronto-striatal-insular regions when plays were divided into positive and negative events according to the fan's perspective. Overall, these findings contribute to our understanding of how emotional factors impact distributed neural systems to successfully encode dynamic, personally-relevant event sequences.
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Affiliation(s)
- Anne Botzung
- Department of Psychology and Neuroscience, Duke University Durham, NC, USA
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486
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Persson J, Kalpouzos G, Nilsson LG, Ryberg M, Nyberg L. Preserved hippocampus activation in normal aging as revealed by fMRI. Hippocampus 2010; 21:753-66. [PMID: 20865729 DOI: 10.1002/hipo.20794] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2010] [Indexed: 11/09/2022]
Abstract
The hippocampus is deteriorated in various pathologies such as Alzheimer's disease (AD) and such deterioration has been linked to memory impairment. By contrast, the structural and functional effects of normal aging on the hippocampus is a matter of debate, with some findings suggesting deterioration and others providing evidence of preservation. This constitutes a crucial question since many investigations on AD are based on the assumption that the deterioration of the hippocampus is the breaking point between normal and pathological aging. A growing number of fMRI studies specifically aimed at investigating hippocampal engagement in various cognitive tasks, notably memory tasks, but the results have been inconclusive. Here, we optimized the episodic face-name paired-associates task in order to test the functioning of the hippocampus in normal aging. Critically, we found no difference in the activation of the hippocampus between the young and a group of older participants. Analysis of individual patterns of activation substantiated this impression. Collectively, these findings provide evidence of preserved hippocampal functioning in normal aging.
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Affiliation(s)
- Jonas Persson
- Department of Psychology, Stockholm University, Sweden.
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487
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On the characterization of the spatio-temporal profiles of brain activity associated with face naming and the tip-of-the-tongue state: A magnetoencephalographic (MEG) study. Neuropsychologia 2010; 48:1757-66. [DOI: 10.1016/j.neuropsychologia.2010.02.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 02/22/2010] [Accepted: 02/22/2010] [Indexed: 11/19/2022]
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488
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Schumacher EH, Seymour TL, Schwarb H. Brain activation evidence for response conflict in the exclude recognition task. Brain Res 2010; 1329:113-23. [DOI: 10.1016/j.brainres.2010.03.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 02/26/2010] [Accepted: 03/04/2010] [Indexed: 12/01/2022]
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489
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Dudukovic NM, Preston AR, Archie JJ, Glover GH, Wagner AD. High-resolution fMRI reveals match enhancement and attentional modulation in the human medial temporal lobe. J Cogn Neurosci 2010; 23:670-82. [PMID: 20433244 DOI: 10.1162/jocn.2010.21509] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
A primary function of the medial temporal lobe (MTL) is to signal prior encounter with behaviorally relevant stimuli. MTL match enhancement--increased activation when viewing previously encountered stimuli--has been observed for goal-relevant stimuli in nonhuman primates during delayed-match-to-sample tasks and in humans during more complex relational memory tasks. Match enhancement may alternatively reflect (a) an attentional response to familiar relative to novel stimuli or (b) the retrieval of contextual details surrounding the past encounter with familiar stimuli. To gain leverage on the functional significance of match enhancement in the hippocampus, high-resolution fMRI of human MTL was conducted while participants attended, ignored, or passively viewed face and scene stimuli in the context of a modified delayed-match-to-sample task. On each "attended" trial, two goal-relevant stimuli were encountered before a probe that either matched or mismatched one of the attended stimuli, enabling examination of the consequences of encountering one of the goal-relevant stimuli as a match probe on later memory for the other (nonprobed) goal-relevant stimulus. fMRI revealed that the hippocampus was insensitive to the attentional manipulation, whereas parahippocampal cortex was modulated by scene-directed attention, and perirhinal cortex showed more subtle and general effects of attention. By contrast, all hippocampal subfields demonstrated match enhancement to the probe, and a postscan test revealed more accurate recognition memory for the nonprobed goal-relevant stimulus on match relative to mismatch trials. These data suggest that match enhancement in human hippocampus reflects retrieval of other goal-relevant contextual details surrounding a stimulus's prior encounter.
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490
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Neural correlates of relational reasoning and the symbolic distance effect: involvement of parietal cortex. Neuroscience 2010; 168:138-48. [PMID: 20371271 DOI: 10.1016/j.neuroscience.2010.03.052] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 03/19/2010] [Accepted: 03/24/2010] [Indexed: 10/19/2022]
Abstract
A novel, five-term relational reasoning paradigm was employed during functional magnetic resonance imaging to investigate neural correlates of the symbolic distance effect (SDE). Prior to scanning, participants learned a series of more-than (E>D>C>B>A) or less-than (A<B<C<D<E) ordered premise pairs. During scanning, inferential tests presented the premise pairs, adjacent, mutually entailed tasks (e.g., D<E and B>A) and nonadjacent one-step (A<C, B<D, C<E, C>A, D>B and E>C) and two-step (A<D, B<E, D>A and E>B) combinatorial entailed tasks. In terms of brain activation, the SDE was identified in the inferior frontal cortex, dorsolateral prefrontal cortex, and bilateral parietal cortex with a graded activation pattern from adjacent to one-step and two-step relations. We suggest that this captures the behavioural SDE of increased accuracy and decreased reaction time from adjacent to two-step relations. One-step relations involving endpoints A or E resulted in greater parietal activation compared to one-step relations without endpoints. Novel contrasts found enhanced activation in right parietal and prefrontal cortices during mutually entailed tasks only for participants who had learned all less-than relations. Increased parietal activation was found for one-step tasks that were inconsistent with prior training. Overall, the findings demonstrate a crucial role for parietal cortex during relational reasoning with a spatially ordered array.
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491
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Crespo-Garcia M, Cantero J, Pomyalov A, Boccaletti S, Atienza M. Functional neural networks underlying semantic encoding of associative memories. Neuroimage 2010; 50:1258-70. [DOI: 10.1016/j.neuroimage.2010.01.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Revised: 12/21/2009] [Accepted: 01/06/2010] [Indexed: 10/20/2022] Open
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492
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Zöllig J, Martin M, Kliegel M. Forming intentions successfully: Differential compensational mechanisms of adolescents and old adults. Cortex 2010; 46:575-89. [DOI: 10.1016/j.cortex.2009.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 06/09/2009] [Accepted: 09/25/2009] [Indexed: 10/20/2022]
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493
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Viard A, Lebreton K, Chételat G, Desgranges B, Landeau B, Young A, De La Sayette V, Eustache F, Piolino P. Patterns of hippocampal-neocortical interactions in the retrieval of episodic autobiographical memories across the entire life-span of aged adults. Hippocampus 2010; 20:153-65. [PMID: 19338022 DOI: 10.1002/hipo.20601] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We previously demonstrated that episodic autobiographical memories (EAMs) rely on a network of brain regions comprising the medial temporal lobe (MTL) and distributed neocortical regions regardless of their remoteness. The findings supported the model of memory consolidation, which proposes a permanent role of MTL during EAM retrieval (multiple-trace theory or MTT) rather than a temporary role (standard model). Our present aim was to expand the results by examining the interactions between the MTL and neocortical regions (or MTL-neocortical links) during EAM retrieval with varying retention intervals. We used an experimental paradigm specially designed to engage aged participants in the recollection of EAMs, extracted from five different time-periods, covering their whole life-span, in order to examine correlations between activation in the MTL and neocortical regions. The nature of the memories was checked at debriefing by means of behavioral measures to control the degree of episodicity and properties of memories. Targeted correlational analyses carried out on the MTL, frontal, lateral temporal, and posterior regions revealed strong links between the MTL and neocortex during the retrieval of both recent and remote EAMs, challenging the standard model of memory consolidation and supporting MTT instead. Further confirmation was given by results showing that activation in the left and right hippocampi significantly correlated during the retrieval of both recent and remote memories. Correlations among extra-MTL neocortical regions also emerged for all time-periods, confirming the critical role of the prefrontal, temporal (lateral temporal cortex and temporal pole), precuneus, and posterior cingulate regions in EAM retrieval. Overall, this paper emphasizes the role of a bilateral network of MTL and neocortical areas whose activation correlate during the recollection of rich phenomenological recent and remote EAMs.
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Affiliation(s)
- Armelle Viard
- Inserm-EPHE-Université de Caen/Basse-Normandie, Unité U923, GIP Cyceron, CHU Côte de Nacre, Caen, France
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494
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DeVito LM, Lykken C, Kanter BR, Eichenbaum H. Prefrontal cortex: role in acquisition of overlapping associations and transitive inference. Learn Mem 2010; 17:161-7. [PMID: 20189961 DOI: 10.1101/lm.1685710] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
"Transitive inference" refers to the ability to judge from memory the relationships between indirectly related items that compose a hierarchically organized series, and this capacity is considered a fundamental feature of relational memory. Here we explored the role of the prefrontal cortex in transitive inference by examining the performance of mice with selective damage to the medial prefrontal cortex. Damage to the infralimbic and prelimbic regions resulted in significant impairment in the acquisition of a series of overlapping odor discrimination problems, such that animals with prefrontal lesions required twice as many trials to learn compared to sham-operated controls. Following eventually successful acquisition, animals with medial prefrontal lesions were severely impaired on a transitive inference probe test, whereas they performed as well as controls on a test that involved a nontransitive judgment from a novel odor pairing. These results suggest that the prefrontal cortex is part of an integral hippocampal-cortical network essential for relational memory organization.
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Affiliation(s)
- Loren M DeVito
- Center for Memory and Brain, Boston University, Boston, Massachusetts 02215, USA
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495
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496
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Enhancing cognitive control through neurofeedback: A role of gamma-band activity in managing episodic retrieval. Neuroimage 2010; 49:3404-13. [DOI: 10.1016/j.neuroimage.2009.11.023] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 11/05/2009] [Accepted: 11/10/2009] [Indexed: 11/19/2022] Open
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497
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The brain-derived neurotrophic factor Val66Met polymorphism affects memory formation and retrieval of biologically salient stimuli. Neuroimage 2010; 50:1212-8. [PMID: 20097294 DOI: 10.1016/j.neuroimage.2010.01.058] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 01/12/2010] [Accepted: 01/15/2010] [Indexed: 11/22/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is involved in memory and the pathophysiology of various neuropsychiatric disorders. A single nucleotide polymorphism in the human BDNF gene (Val66Met) affects memory, and influences Alzheimer's disease and depression vulnerability in a sex-specific manner. Recent animal studies suggest that BDNF mediates memory for emotional experiences in the amygdala, but it is currently unknown whether BDNF Val66Met influences memory processing in the amygdala. Here, we investigated its effect on the successful encoding and recognition of biologically salient stimuli. Forty-seven healthy volunteers memorized and recognized faces while their brain activity was measured with event-related functional MRI. No significant differences in memory performance were observed between Val homozygotes and Met allele carriers. The imaging results demonstrated BDNF genotype x sex interactions in the amygdala during memory formation, and in the prefrontal cortex and posterior cingulate cortex during memory retrieval. Subsequent tests showed a larger contribution of these brain regions to successful encoding and retrieval in male Met allele carriers than male Val homozygotes, whereas no significant differences were observed in females. These results provide preliminary evidence that the BDNF Val66Met polymorphism influences specific mnemonic operations underlying encoding and retrieval of salient stimuli, and suggest less efficient memory processing in male Met allele carriers. Furthermore, the sex-specific genotype effects may contribute to sex-specific effects of BDNF Val66Met on depression vulnerability.
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498
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Krach S, Jansen A, Krug A, Markov V, Thimm M, Sheldrick AJ, Eggermann T, Zerres K, Stöcker T, Shah NJ, Kircher T. COMT genotype and its role on hippocampal-prefrontal regions in declarative memory. Neuroimage 2010; 53:978-84. [PMID: 20060911 DOI: 10.1016/j.neuroimage.2009.12.090] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 12/03/2009] [Accepted: 12/22/2009] [Indexed: 12/25/2022] Open
Abstract
INTRODUCTION Memory dysfunction is a prominent feature in schizophrenia. Impairments of declarative memory have been consistently linked to alterations especially within hippocampal-prefrontal regions. Due to the high heritability of schizophrenia, susceptibility genes and their modulatory impact on the neural correlates on memory are of major relevance. In the present study the influence of the COMT val(158)met status on the neural correlates of declarative memory was investigated in healthy subjects. METHODS From an initial behavioural sample of 522 healthy individuals (Sheldrick et al., 2008), 84 subjects underwent fMRI scanning while performing a memory encoding and a retrieval task. The COMT val(158)met status was determined for the whole sample and correlated with cortical activation within the group of n=84 individuals. RESULTS There were no effects of COMT status on behavioural performance. For declarative memory processing the number of met alleles predicted circumscribed bilateral insula and anterior hippocampus activations during memory encoding as well as less deactivations within the bilateral posterior parahippocampal gyri during memory retrieval. DISCUSSION Although declarative memory performance was unaffected, the neural correlates within hippocampal-prefrontal regions demonstrate a link between COMT val(158)met carrier status and brain areas associated with declarative memory processing. The study contributes to a better understanding of the role that susceptibility genes might play in the aetiology of schizophrenia.
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Affiliation(s)
- Sören Krach
- Department of Psychiatry and Psychotherapy, Section of Brain Imaging, Philipps-University Marburg, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany.
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499
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Dickerson BC, Eichenbaum H. The episodic memory system: neurocircuitry and disorders. Neuropsychopharmacology 2010; 35:86-104. [PMID: 19776728 PMCID: PMC2882963 DOI: 10.1038/npp.2009.126] [Citation(s) in RCA: 394] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 07/31/2009] [Accepted: 08/01/2009] [Indexed: 11/08/2022]
Abstract
The ability to encode and retrieve our daily personal experiences, called episodic memory, is supported by the circuitry of the medial temporal lobe (MTL), including the hippocampus, which interacts extensively with a number of specific distributed cortical and subcortical structures. In both animals and humans, evidence from anatomical, neuropsychological, and physiological studies indicates that cortical components of this system have key functions in several aspects of perception and cognition, whereas the MTL structures mediate the organization and persistence of the network of memories whose details are stored in those cortical areas. Structures within the MTL, and particularly the hippocampus, have distinct functions in combining information from multiple cortical streams, supporting our ability to encode and retrieve details of events that compose episodic memories. Conversely, selective damage in the hippocampus, MTL, and other structures of the large-scale memory system, or deterioration of these areas in several diseases and disorders, compromises episodic memory. A growing body of evidence is converging on a functional organization of the cortical, subcortical, and MTL structures that support the fundamental features of episodic memory in humans and animals.
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Affiliation(s)
- Bradford C Dickerson
- Department of Neurology, Massachusetts Alzheimer's Disease Research Center, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA.
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500
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Czernochowski D, Mecklinger A, Johansson M. Age-related changes in the control of episodic retrieval: an ERP study of recognition memory in children and adults. Dev Sci 2009; 12:1026-40. [PMID: 19840057 DOI: 10.1111/j.1467-7687.2009.00841.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We examined developmental aspects of the ability to monitor the temporal context of an item's previous occurrence while event-related potentials (ERPs) were recorded. In a continuous recognition task, children between 10 and 12 years and young adults watched a stream of pictures repeated with a lag of 10-15 intervening items and indicated recurrences. In a second run, these already familiar pictures were repeated as non-targets along with new pictures, while subjects were instructed to indicate only recurrences within the run. Young adults were able to maintain high performance levels in both tasks, whereas children had longer response times and committed a large number of false alarms to non-targets. ERPs in both age groups showed similar parietal old/new effects for target repetitions within runs. In addition, adults' ERPs showed similar old/new effects at frontal electrodes for repetitions and non-targets, presumably reflecting assessments of familiarity, whereas for children repeated relative to first presentations were associated with more negative-going waveforms at anterior frontal recording sites. Together, these results suggest a continuing maturation of the brain networks assessing novelty or familiarity. Recollection as indexed by parietal old/new effects appeared similar between young adults and children, but the development of controlled episodic retrieval, resulting in recollection of non-target information, appears to continue well into adolescence.
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Affiliation(s)
- Daniela Czernochowski
- Mathematical and Cognitive Psychology, Heinrich-Heine University, Duesseldorf, Germany.
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