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Newbolds SF, Wenger MJ. Assessing the pattern electroretinogram as a proxy measure for dopamine in the context of iron deficiency. Nutr Neurosci 2024:1-12. [PMID: 38272898 DOI: 10.1080/1028415x.2024.2304943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
OBJECTIVES Animal studies have suggested that dietary iron deficiency (ID) negatively affects dopamine (DA) synthesis and re-uptake, which in turn negatively affects memory and cognition. This study was intended to assess whether the pattern electroretinogram (pattern ERG) could be used as an indirect measure of DA in college-age women with and without ID by determining the extent to which features of the ERG were sensitive to iron status and were related to other indirect measures of DA. METHODS The pattern ERG was measured in 21 iron deficient non-anemic (IDNA) and 21 iron sufficient (IS) women, who also performed a contrast detection and probabilistic selection task, both with concurrent electroencephalography (EEG). Both spontaneous and task-related blink rates were also measured. RESULTS The implicit times of the A- and B-waves were significantly longer for the IDNA than for the IS women. Both the amplitudes and implicit times of the A- and B-waves were significantly correlated with levels of serum ferritin (sFt). Only the amplitude of the A-wave was correlated with spontaneous blink rate. It was possible to accurately identify a woman's iron status solely on the basis of the implicit time of the B-wave. Finally, the implicit times of the ERG features mediated the relationship between iron levels and accuracy in the probabilistic selection task. CONCLUSIONS Results suggest the utility of the pattern ERG in testing the hypothesis that iron deficiency affects DA levels in humans and that this may be one of the mechanisms by which iron deficiency negatively affects cognition.
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Affiliation(s)
- Sarah F Newbolds
- Psychology and Cellular and Behavioral Neurobiology, The University of Oklahoma, Norman, OK, USA
| | - Michael J Wenger
- Psychology and Cellular and Behavioral Neurobiology, The University of Oklahoma, Norman, OK, USA
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2
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Leow LA, Bernheine L, Carroll TJ, Dux PE, Filmer HL. Dopamine Increases Accuracy and Lengthens Deliberation Time in Explicit Motor Skill Learning. eNeuro 2024; 11:ENEURO.0360-23.2023. [PMID: 38238069 PMCID: PMC10849023 DOI: 10.1523/eneuro.0360-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 11/23/2023] [Accepted: 11/28/2023] [Indexed: 01/23/2024] Open
Abstract
Although animal research implicates a central role for dopamine in motor skill learning, a direct causal link has yet to be established in neurotypical humans. Here, we tested if a pharmacological manipulation of dopamine alters motor learning, using a paradigm which engaged explicit, goal-directed strategies. Participants (27 females; 11 males; aged 18-29 years) first consumed either 100 mg of levodopa (n = 19), a dopamine precursor that increases dopamine availability, or placebo (n = 19). Then, during training, participants learnt the explicit strategy of aiming away from presented targets by instructed angles of varying sizes. Targets jumped mid-movement by the instructed aiming angle. Task success was thus contingent upon aiming accuracy and not speed. The effect of the dopamine manipulations on skill learning was assessed during training and after an overnight follow-up. Increasing dopamine availability at training improved aiming accuracy and lengthened reaction times, particularly for larger, more difficult aiming angles, both at training and, importantly, at follow-up, despite prominent session-by-session performance improvements in both accuracy and speed. Exogenous dopamine thus seems to result in a learnt, persistent propensity to better adhere to task goals. Results support the proposal that dopamine is important in engagement of instrumental motivation to optimize adherence to task goals, particularly when learning to execute goal-directed strategies in motor skill learning.
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Affiliation(s)
- Li-Ann Leow
- School of Psychology, The University of Queensland, St Lucia, 4072, Australia
- Centre for Sensorimotor Performance, School of Human Movement & Nutrition Sciences, St Lucia, 4067, Australia
| | - Lena Bernheine
- Centre for Sensorimotor Performance, School of Human Movement & Nutrition Sciences, St Lucia, 4067, Australia
- School of Sport Science Faculty of Sport Governance and Event Management, University of Bayreuth, 95447 Bayreuth, Germany
| | - Timothy J Carroll
- Centre for Sensorimotor Performance, School of Human Movement & Nutrition Sciences, St Lucia, 4067, Australia
| | - Paul E Dux
- School of Psychology, The University of Queensland, St Lucia, 4072, Australia
| | - Hannah L Filmer
- School of Psychology, The University of Queensland, St Lucia, 4072, Australia
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3
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Williams JC, Zheng ZJ, Tubiolo PN, Luceno JR, Gil RB, Girgis RR, Slifstein M, Abi-Dargham A, Van Snellenberg JX. Medial Prefrontal Cortex Dysfunction Mediates Working Memory Deficits in Patients With Schizophrenia. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2023; 3:990-1002. [PMID: 37881571 PMCID: PMC10593895 DOI: 10.1016/j.bpsgos.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/04/2022] [Accepted: 10/11/2022] [Indexed: 02/18/2023] Open
Abstract
Background Schizophrenia (SCZ) is marked by working memory (WM) deficits, which predict poor functional outcome. While most functional magnetic resonance imaging studies of WM in SCZ have focused on the dorsolateral prefrontal cortex (PFC), some recent work suggests that the medial PFC (mPFC) may play a role. We investigated whether task-evoked mPFC deactivation is associated with WM performance and whether it mediates deficits in SCZ. In addition, we investigated associations between mPFC deactivation and cortical dopamine release. Methods Patients with SCZ (n = 41) and healthy control participants (HCs) (n = 40) performed a visual object n-back task during functional magnetic resonance imaging. Dopamine release capacity in mPFC was quantified with [11C]FLB457 in a subset of participants (9 SCZ, 14 HCs) using an amphetamine challenge. Correlations between task-evoked deactivation and performance were assessed in mPFC and dorsolateral PFC masks and were further examined for relationships with diagnosis and dopamine release. Results mPFC deactivation was associated with WM task performance, but dorsolateral PFC activation was not. Deactivation in the mPFC was reduced in patients with SCZ relative to HCs and mediated the relationship between diagnosis and WM performance. In addition, mPFC deactivation was significantly and inversely associated with dopamine release capacity across groups and in HCs alone, but not in patients. Conclusions Reduced WM task-evoked mPFC deactivation is a mediator of, and potential substrate for, WM impairment in SCZ, although our study design does not rule out the possibility that these findings could relate to cognition in general rather than WM specifically. We further present preliminary evidence of an inverse association between deactivation during WM tasks and dopamine release capacity in the mPFC.
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Affiliation(s)
- John C. Williams
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Zu Jie Zheng
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
| | - Philip N. Tubiolo
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Jacob R. Luceno
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
| | - Roberto B. Gil
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, Presbyterian/Columbia University Irving Medical Center, New York, New York
- New York State Psychiatric Institute, New York, New York
| | - Ragy R. Girgis
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, Presbyterian/Columbia University Irving Medical Center, New York, New York
- New York State Psychiatric Institute, New York, New York
| | - Mark Slifstein
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, Presbyterian/Columbia University Irving Medical Center, New York, New York
- New York State Psychiatric Institute, New York, New York
| | - Anissa Abi-Dargham
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, Presbyterian/Columbia University Irving Medical Center, New York, New York
- New York State Psychiatric Institute, New York, New York
| | - Jared X. Van Snellenberg
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, Presbyterian/Columbia University Irving Medical Center, New York, New York
- New York State Psychiatric Institute, New York, New York
- Department of Psychology, Stony Brook University, Stony Brook, New York
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4
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A ventral stream-prefrontal cortex processing cascade enables working memory gating dynamics. Commun Biol 2022; 5:1086. [PMID: 36224253 PMCID: PMC9556714 DOI: 10.1038/s42003-022-04048-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 09/29/2022] [Indexed: 11/09/2022] Open
Abstract
The representation of incoming information, goals and the flexible processing of these are required for cognitive control. Efficient mechanisms are needed to decide when it is important that novel information enters working memory (WM) and when these WM 'gates' have to be closed. Compared to neural foundations of maintaining information in WM, considerably less is known about what neural mechanisms underlie the representational dynamics during WM gating. Using different EEG analysis methods, we trace the path of mental representations along the human cortex during WM gate opening and closing. We show temporally nested representational dynamics during WM gate opening and closing depending on multiple independent neural activity profiles. These activity profiles are attributable to a ventral stream-prefrontal cortex processing cascade. The representational dynamics start in the ventral stream during WM gate opening and WM gate closing before prefrontal cortical regions are modulated. A regional specific activity profile is shown within the prefrontal cortex depending on whether WM gates are opened or closed, matching overarching concepts of prefrontal cortex functions. The study closes an essential conceptual gap detailing the neural dynamics underlying how mental representations drive the WM gate to open or close to enable WM functions such as updating and maintenance.
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5
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Wenger MJ, Murray Kolb LE, Scott SP, Boy E, Haas JD. Modeling relationships between iron status, behavior, and brain electrophysiology: evidence from a randomized study involving a biofortified grain in Indian adolescents. BMC Public Health 2022; 22:1299. [PMID: 35794587 PMCID: PMC9260997 DOI: 10.1186/s12889-022-13612-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 06/08/2022] [Indexed: 11/10/2022] Open
Abstract
Background Iron deficiency (ID) and iron deficiency anemia (IDA) are highly-prevalent nutrient deficiencies and have been shown to have a range of negative effects on cognition and brain function. Human intervention studies including measures at three levels—blood, brain, and behavior—are rare and our objective was to model the relationships among measures at these three levels in school-going Indian adolescents. Methods Male and female adolescents in rural India were screened for ID/IDA. Subjects consumed 2 meals/day for 6 months; half were randomly assigned to consume meals made from a standard grain (pearl millet) and half consumed meals made from an iron biofortified pearl millet (BPM). Prior to and then at the conclusion of the feeding trial, they completed a set of cognitive tests with concurrent electroencephalography (EEG). Results Overall, serum ferritin (sFt) levels improved over the course of the study. Ten of 21 possible measures of cognition showed improvements from baseline (BL) to endline (EL) that were larger for those consuming BPM than for those consuming the comparison pearl millet (CPM). Critically, the best model for the relationship between change in iron status and change in cognition had change in brain measures as a mediating factor, with both change in serum ferritin as a primary predictor and change in hemoglobin as a moderator. Conclusions A dietary intervention involving a biofortified staple grain was shown to be efficacious in improving blood iron biomarkers, behavioral measures of cognition, and EEG measures of brain function. Modeling the relationships among these variables strongly suggests multiple mechanisms by which blood iron level affects brain function and cognition. Trial registration Registered at ClinicalTrials.gov, NCT02152150, 02 June 2014. Supplementary Information The online version contains supplementary material available at (10.1186/s12889-022-13612-z).
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Affiliation(s)
- Michael J Wenger
- Department of Psychology, Cellular and Behavioral Neurobiology, The University of Oklahoma, Norman, OK, USA. .,Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
| | | | - Samuel P Scott
- Poverty Health and Nutrition Division, International Food Policy Research Institute, Washington, DC, USA
| | - Erick Boy
- HarvestPlus, International Food Policy Research Institute, Washington, DC, USA
| | - Jere D Haas
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA
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6
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Caffeine and attentional control: improved and impaired performance in healthy older adults and Parkinson's disease according to task demands. Psychopharmacology (Berl) 2022; 239:605-619. [PMID: 35006304 PMCID: PMC8799544 DOI: 10.1007/s00213-021-06054-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 12/28/2021] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Caffeine is frequently consumed to boost goal-directed attention. These procognitive effects may occur due to the adenosine-mediated enhancement of monoamines, such as dopamine, after caffeine administration. As such, caffeine's beneficial effects may be altered in conditions such as Parkinson's disease (PD). However, whether caffeine improves cognition, and at what cost, has not been experimentally established in patients with neurodegenerative disease. METHODS Single-dose trials to probe cognitive effects of caffeine are often confounded by short-term caffeine abstinence which conflates caffeine's effects with treatment of withdrawal. Using a placebo controlled, blinded, randomised trial design, we assessed the effect of 100 mg of caffeine across well-established tasks (Choice reaction time, Stroop Task and Rapid Serial Visual Presentation Task; RSVP) that probe different aspects of attention in PD patients (n = 24) and controls (n = 44). Critically, participants withdrew from caffeine for a week prior to testing to eliminate the possibility that withdrawal reversal explained any cognitive benefit. RESULTS Caffeine administration was found to reduce the overall number of errors in patients and controls on the Stroop (p = .018, η2p = .086) and Choice reaction time (p < . 0001, η2p = .588) tasks, but there was no specific effect of caffeine on ignoring irrelevant information in the Stroop task. On the RSVP task, caffeine improved dual item accuracy (p = .037) but impaired single item accuracy (p = .044). Across all tasks, there was little evidence that caffeine has different effects in PD participants and controls. CONCLUSION When removing withdrawal effects as a factor, we demonstrate caffeine has beneficial effects on selective attention but is a double-edge sword for visual temporal attention and would need careful targeting to be clinically useful.
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7
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Zmigrod L, Robbins TW. Dopamine, Cognitive Flexibility, and IQ: Epistatic Catechol-O-MethylTransferase:DRD2 Gene-Gene Interactions Modulate Mental Rigidity. J Cogn Neurosci 2021; 34:153-179. [PMID: 34818409 DOI: 10.1162/jocn_a_01784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Cognitive flexibility has been hypothesized to be neurochemically rooted in dopamine neurotransmission. Nonetheless, underpowered sample sizes and contradictory meta-analytic findings have obscured the role of dopamine genes in cognitive flexibility and neglected potential gene-gene interactions. In this largest neurocognitive-genetic study to date (n = 1400), single nucleotide polymorphisms associated with elevated prefrontal dopamine levels (catechol-O-methyltransferase; rs4680) and diminished striatal dopamine (C957T; rs6277) were both implicated in Wisconsin Card Sorting Test performance. Crucially, however, these genetic effects were only evident in low-IQ participants, suggesting high intelligence compensates for, and eliminates, the effect of dispositional dopamine functioning on flexibility. This interaction between cognitive systems may explain and resolve previous empirical inconsistencies in highly educated participant samples. Moreover, compensatory gene-gene interactions were discovered between catechol-O-methyltransferase and DRD2, such that genotypes conferring either elevated prefrontal dopamine or diminished striatal dopamine-via heightened striatally concentrated D2 dopamine receptor availability-are sufficient for cognitive flexibility, but neither is necessary. The study has therefore revealed a form of epistatic redundancy or substitutability among dopamine systems in shaping adaptable thought and action, thus defining boundary conditions for dopaminergic effects on flexible behavior. These results inform theories of clinical disorders and psychopharmacological interventions and uncover complex fronto-striatal synergies in human flexible cognition.
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8
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A Novel Approach to Learning Models on EEG Data Using Graph Theory Features—A Comparative Study. BIG DATA AND COGNITIVE COMPUTING 2021. [DOI: 10.3390/bdcc5030039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Brain connectivity is studied as a functionally connected network using statistical methods such as measuring correlation or covariance. The non-invasive neuroimaging techniques such as Electroencephalography (EEG) signals are converted to networks by transforming the signals into a Correlation Matrix and analyzing the resulting networks. Here, four learning models, namely, Logistic Regression, Random Forest, Support Vector Machine, and Recurrent Neural Networks (RNN), are implemented on two different types of correlation matrices: Correlation Matrix (static connectivity) and Time-resolved Correlation Matrix (dynamic connectivity), to classify them either on their psychometric assessment or the effect of therapy. These correlation matrices are different from traditional learning techniques in the sense that they incorporate theory-based graph features into the learning models, thus providing novelty to this study. The EEG data used in this study is trail-based/event-related from five different experimental paradigms, of which can be broadly classified as working memory tasks and assessment of emotional states (depression, anxiety, and stress). The classifications based on RNN provided higher accuracy (74–88%) than the other three models (50–78%). Instead of using individual graph features, a Correlation Matrix provides an initial test of the data. When compared with the Time-resolved Correlation Matrix, it offered a 4–5% higher accuracy. The Time-resolved Correlation Matrix is better suited for dynamic studies here; it provides lower accuracy when compared to the Correlation Matrix, a static feature.
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Westbrook A, Frank MJ, Cools R. A mosaic of cost-benefit control over cortico-striatal circuitry. Trends Cogn Sci 2021; 25:710-721. [PMID: 34120845 DOI: 10.1016/j.tics.2021.04.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 04/12/2021] [Accepted: 04/15/2021] [Indexed: 12/22/2022]
Abstract
Dopamine contributes to cognitive control through well-established effects in both the striatum and cortex. Although earlier work suggests that dopamine affects cognitive control capacity, more recent work suggests that striatal dopamine may also impact on cognitive motivation. We consider the emerging perspective that striatal dopamine boosts control by making people more sensitive to the benefits versus the costs of cognitive effort, and we discuss how this sensitivity shapes competition between controlled and prepotent actions. We propose that dopamine signaling in distinct cortico-striatal subregions mediates different types of cost-benefit tradeoffs, and also discuss mechanisms for the local control of dopamine release, enabling selectivity among cortico-striatal circuits. In so doing, we show how this cost-benefit mosaic can reconcile seemingly conflicting findings about the impact of dopamine signaling on cognitive control.
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Affiliation(s)
- Andrew Westbrook
- Donders Centre for Cognitive Neuroimaging, Nijmegen, The Netherlands; Department of Psychiatry, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA.
| | - Michael J Frank
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA; Carney Institute for Brain Science, Brown University, Providence, RI, USA
| | - Roshan Cools
- Donders Centre for Cognitive Neuroimaging, Nijmegen, The Netherlands; Department of Psychiatry, Radboud University Medical Center, Nijmegen, The Netherlands
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10
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Lorenc ES, Mallett R, Lewis-Peacock JA. Distraction in Visual Working Memory: Resistance is Not Futile. Trends Cogn Sci 2021; 25:228-239. [PMID: 33397602 PMCID: PMC7878345 DOI: 10.1016/j.tics.2020.12.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 01/19/2023]
Abstract
Over half a century of research focused on understanding how working memory is capacity constrained has overshadowed the fact that it is also remarkably resistant to interference. Protecting goal-relevant information from distraction is a cornerstone of cognitive function that involves a multifaceted collection of control processes and storage mechanisms. Here, we discuss recent advances in cognitive psychology and neuroscience that have produced new insights into the nature of visual working memory and its ability to resist distraction. We propose that distraction resistance should be an explicit component in any model of working memory and that understanding its behavioral and neural correlates is essential for building a comprehensive understanding of real-world memory function.
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Affiliation(s)
- Elizabeth S Lorenc
- Department of Psychology, University of Texas at Austin, Austin, TX 78712, USA.
| | - Remington Mallett
- Department of Psychology, University of Texas at Austin, Austin, TX 78712, USA
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11
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Boonstra EA, van Schouwenburg MR, Seth AK, Bauer M, Zantvoord JB, Kemper EM, Lansink CS, Slagter HA. Conscious perception and the modulatory role of dopamine: no effect of the dopamine D2 agonist cabergoline on visual masking, the attentional blink, and probabilistic discrimination. Psychopharmacology (Berl) 2020; 237:2855-2872. [PMID: 32621073 PMCID: PMC7501106 DOI: 10.1007/s00213-020-05579-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 06/03/2020] [Indexed: 11/02/2022]
Abstract
RATIONALE Conscious perception is thought to depend on global amplification of sensory input. In recent years, striatal dopamine has been proposed to be involved in gating information and conscious access, due to its modulatory influence on thalamocortical connectivity. OBJECTIVES Since much of the evidence that implicates striatal dopamine is correlational, we conducted a double-blind crossover pharmacological study in which we administered cabergoline-a dopamine D2 agonist-and placebo to 30 healthy participants. Under both conditions, we subjected participants to several well-established experimental conscious-perception paradigms, such as backward masking and the attentional blink task. RESULTS We found no evidence in support of an effect of cabergoline on conscious perception: key behavioral and event-related potential (ERP) findings associated with each of these tasks were unaffected by cabergoline. CONCLUSIONS Our results cast doubt on a causal role for dopamine in visual perception. It remains an open possibility that dopamine has causal effects in other tasks, perhaps where perceptual uncertainty is more prominent.
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Affiliation(s)
- E A Boonstra
- Department of Experimental and Applied Psychology, Institute for Brain and Behavior Amsterdam (iBBA) Vrije Universiteit, Amsterdam, Netherlands.
- Department of Psychology, University of Amsterdam, Amsterdam Brain and Cognition (ABC), Amsterdam, Netherlands.
| | - M R van Schouwenburg
- Department of Psychology, University of Amsterdam, Amsterdam Brain and Cognition (ABC), Amsterdam, Netherlands
| | - A K Seth
- Department of Informatics Sackler Centre for Consciousness Science, University of Sussex, Brighton, BN1 9QJ, UK
- Canadian Institute for Advanced Research, Azrieli Programme on Brain, Mind, and Consciousness, Toronto, Canada
| | - M Bauer
- School of Psychology, University of Nottingham, Nottingham, UK
| | - J B Zantvoord
- Department of Child and Adolescent Psychiatry, The Bascule, Academic Centre for Child and Adolescent Psychiatry Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - E M Kemper
- Department of Pharmacy, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - C S Lansink
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam Brain and Cognition (ABC), Amsterdam, Netherlands
| | - H A Slagter
- Department of Experimental and Applied Psychology, Institute for Brain and Behavior Amsterdam (iBBA) Vrije Universiteit, Amsterdam, Netherlands
- Department of Psychology, University of Amsterdam, Amsterdam Brain and Cognition (ABC), Amsterdam, Netherlands
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12
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Individual differences in baseline oculometrics: Examining variation in baseline pupil diameter, spontaneous eye blink rate, and fixation stability. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2020; 19:1074-1093. [PMID: 30888645 DOI: 10.3758/s13415-019-00709-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Individual differences in baseline oculometrics (baseline pupil diameter, spontaneous eye blink rate, fixation stability), and their relation with cognitive abilities, personality traits, and self-report assessments were examined. Participants performed a baseline eye measure in which they were instructed to stare at a fixation point onscreen for 5 min. Following the baseline eye measure, participants completed a questionnaire asking what they were thinking about during the baseline eye measure. Participants also completed various cognitive ability measures assessing working memory capacity, attention control, and off-task thinking. Finally, participants completed a number of questionnaires assessing personality, Attention Deficit/Hyperactivity Disorder symptomology, mind wandering, and morningness-eveningness. Overall, the vast majority of correlations with the baseline eye measures were weak and nonsignificant, suggesting that these associations may not be very robust. The results also demonstrated the importance of examining what participants are thinking about during the baseline measure. These results add to the growing body of findings suggesting inconsistent relations between different baseline eye measures and various individual differences constructs.
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13
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Fallon SJ, Kienast A, Muhammed K, Ang YS, Manohar SG, Husain M. Dopamine D2 receptor stimulation modulates the balance between ignoring and updating according to baseline working memory ability. J Psychopharmacol 2019; 33:1254-1263. [PMID: 31526206 DOI: 10.1177/0269881119872190] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Working memory (WM) deficits in neuropsychiatric disorders have often been attributed to altered dopaminergic signalling. Specifically, D2 receptor stimulation is thought to affect the ease with which items can be gated into and out of WM. In addition, this effect has been hypothesised to vary according to baseline WM ability, a putative index of dopamine synthesis levels. Moreover, whether D2 stimulation affects WM vicariously through modulating relatively WM-free cognitive control processes has not been explored. AIMS We examined the effect of administering a dopamine agonist on the ability to ignore or update information in WM. METHOD A single dose of cabergoline (1 mg) was administered to healthy older adult humans in a within-subject, double-blind, placebo-controlled study. In addition, we obtained measures of baseline WM ability and relatively WM-free cognitive control (overcoming response conflict). RESULTS Consistent with predictions, baseline WM ability significantly modulated the effect that drug administration had on the proficiency of ignoring and updating. High-WM individuals were relatively better at ignoring compared to updating after drug administration. Whereas the opposite occurred in low-WM individuals. Although the ability to overcome response conflict was not affected by cabergoline, a negative relationship between the effect the drug had on response conflict performance and ignoring was observed. Thus, both response conflict and ignoring are coupled to dopaminergic stimulation levels. CONCLUSIONS Cumulatively, these results provide evidence that dopamine affects subcomponents of cognitive control in a diverse, antagonistic fashion and that the direction of these effects is dependent upon baseline WM.
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Affiliation(s)
- Sean James Fallon
- Department of Experimental Psychology, University of Oxford, Oxford, UK.,Wellcome Trust Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Annika Kienast
- Department of Experimental Psychology, University of Oxford, Oxford, UK.,Wellcome Trust Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Kinan Muhammed
- Department of Experimental Psychology, University of Oxford, Oxford, UK.,Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Yuen-Siang Ang
- Department of Experimental Psychology, University of Oxford, Oxford, UK.,Wellcome Trust Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK.,Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Sanjay G Manohar
- Department of Experimental Psychology, University of Oxford, Oxford, UK.,Wellcome Trust Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Masud Husain
- Department of Experimental Psychology, University of Oxford, Oxford, UK.,Wellcome Trust Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK.,Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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Cools R. Chemistry of the Adaptive Mind: Lessons from Dopamine. Neuron 2019; 104:113-131. [DOI: 10.1016/j.neuron.2019.09.035] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/19/2019] [Accepted: 09/20/2019] [Indexed: 12/21/2022]
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Fallon SJ, Gowell M, Maio MR, Husain M. Dopamine affects short-term memory corruption over time in Parkinson's disease. NPJ Parkinsons Dis 2019; 5:16. [PMID: 31396548 PMCID: PMC6683156 DOI: 10.1038/s41531-019-0088-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 06/25/2019] [Indexed: 11/09/2022] Open
Abstract
Cognitive deficits are a recognised component of Parkinson's disease (PD). However, particularly within the domain of short-term memory, it is unclear whether these impairments are masked, or caused, by patients' dopaminergic medication. The effect of medication on pure maintenance in PD patients has rarely been explored, with most assessments examining maintenance intercalated between other executive tasks. Moreover, few studies have utilised methods that can measure the quality of mental representations, which can enable the decomposition of recall errors into their underlying neurocognitive components. Here, we fill this gap by examining pure maintenance in PD patients in high and low dopaminergic states. Participants had to encode the orientation of two stimuli and reproduce these orientations after a short (2 s) or long (8 s) delay. In addition, we also examined the performance of healthy, age-matched older adults to contextualise these effects and determine whether PD represents an exacerbation of the normal ageing process. Patients showed improved recall OFF compared to ON their dopaminergic medication, but only for long-duration trials. Moreover, PD patients OFF their medication actually performed at a level superior to age-matched controls, indicative of a paradoxical enhancement of memory in the low dopaminergic state. The application of a probabilistic model of response selection suggested that PD patients made fewer misbinding errors in the low, compared with high, dopaminergic state for longer-delay trials. Thus, unexpectedly, the mechanisms that prevent memoranda from being corrupted by misbinding over time appear to be enhanced in PD patients OFF dopaminergic medication. Possible explanations for this paradoxical effect are discussed.
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Affiliation(s)
- Sean James Fallon
- Department of Experimental Psychology, University of Oxford, Oxford, UK
- National Institute for Health Research Bristol Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, Bristol, UK
| | - Matthew Gowell
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Maria Raquel Maio
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Masud Husain
- Department of Experimental Psychology, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
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Olivito L, De Risi M, Russo F, De Leonibus E. Effects of pharmacological inhibition of dopamine receptors on memory load capacity. Behav Brain Res 2018; 359:197-205. [PMID: 30391393 DOI: 10.1016/j.bbr.2018.10.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/30/2018] [Accepted: 10/31/2018] [Indexed: 12/26/2022]
Abstract
Memory capacity (MC) refers to the limited capacity of working memory and is defined as the number of elements that an individual can remember for a short retention interval. MC is impaired in many human pathologies, such as schizophrenia and ageing. Fronto-striatal dopamine regulates working memory, through its action on dopamine D1- and D2-like receptors. Human and rodent studies have suggested that MC is improved by D2 dopamine receptor agonists. Although D1 receptors have been crucially involved in the maintenance of working memory during delay, their role in regulating the capacity of WM remains poorly explored. In this study, we tested the effects of systemic injection of the D1-like and D2-like receptor antagonists, SCH 23390 and Haloperidol respectively, on MC in mice. For this, we used a modified version of the object recognition task, the Different/Identical Objects Task (DOT/IOT), which allows the evaluation of MC in rodents. The results showed a negative interaction between the dose of both drugs and the number of objects that could be remembered. The doses of SCH 23390 and Haloperidol that impaired novel object discrimination in the highest memory load condition were about 4 and 3 time lower, respectively, of those impairing performance in the lowest memory load condition. However, while SCH 23390 specifically impaired memory load capacity, the effects of Haloperidol were associated to impairment in exploratory behaviors. These findings may help to predict the cognitive side effects induced by Haloperidol in healthy subjects.
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Affiliation(s)
- Laura Olivito
- Institute of Genetics and Biophysics (IGB), Naples and Institute of Cellular Biology and Neurobiology (IBCN), National Research Council, Monterotondo (Rome), Italy; Telethon Institute of Genetics and Medicine, Telethon Foundation, Pozzuoli (Naples), Italy
| | - Maria De Risi
- Institute of Genetics and Biophysics (IGB), Naples and Institute of Cellular Biology and Neurobiology (IBCN), National Research Council, Monterotondo (Rome), Italy; Telethon Institute of Genetics and Medicine, Telethon Foundation, Pozzuoli (Naples), Italy; PhD Program in Behavioral Neuroscience, Sapienza University of Rome, Italy
| | - Fabio Russo
- Telethon Institute of Genetics and Medicine, Telethon Foundation, Pozzuoli (Naples), Italy
| | - Elvira De Leonibus
- Institute of Genetics and Biophysics (IGB), Naples and Institute of Cellular Biology and Neurobiology (IBCN), National Research Council, Monterotondo (Rome), Italy; Telethon Institute of Genetics and Medicine, Telethon Foundation, Pozzuoli (Naples), Italy.
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Annerer-Walcher S, Körner C, Benedek M. Eye behavior does not adapt to expected visual distraction during internally directed cognition. PLoS One 2018; 13:e0204963. [PMID: 30265715 PMCID: PMC6161918 DOI: 10.1371/journal.pone.0204963] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 09/16/2018] [Indexed: 11/18/2022] Open
Abstract
When focused on a specific internal task like calculating a multiplication in mind we are able to ignore sensory distraction. This may be achieved by effective perceptual decoupling during internally directed cognition. The present study investigated whether decoupling from external events during internally directed cognition represents an active shielding mechanism that adapts to expected external distraction or a passive/automatic shielding mechanism that is independent of external distraction. Participants performed multiplications in mind (e.g. 26 x 7), a task that required to turn attention inward as soon as the problem was encoded. At the beginning of a block of trials, participants were informed whether or not distractors could appear during the calculation period, thereby potentially allowing them to prepare for the distractors. We tracked their eye behavior as markers of perceptual decoupling and workload. Turning attention inward to calculate the multiplication elicited evidence of perceptual decoupling for five of six eye parameters: blink rate, saccade and microsaccade rate increased, gaze was less constricted to the center, and pupils dilated. Although participants perceived blocks with distractors as more challenging, performance and eye behavior markers of both perceptual decoupling and workload were unaffected. This result supports the notion of perceptual decoupling as an automatic mechanism: focusing inward induces desensitization to external events independent of external distraction.
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Rac-Lubashevsky R, Kessler Y. Oscillatory Correlates of Control over Working Memory Gating and Updating: An EEG Study Using the Reference-back Paradigm. J Cogn Neurosci 2018; 30:1870-1882. [PMID: 30125218 DOI: 10.1162/jocn_a_01326] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Optimal working memory (WM) functioning depends on a control mechanism that balances between maintenance and updating by closing or opening the gate to WM, respectively. Here, we examined the neural oscillation correlates of WM updating and of the control processes involved in gating. The reference-back paradigm was employed to manipulate gate opening, gate closing, and updating independently and examine how the control functions involved in these processes are mapped to oscillatory EEG activity. The results established that different oscillatory patterns were associated with the control process related to gate opening than in gate closing. During the time of gate closing, a relative increase in theta power was observed over midfrontal electrodes. This theta response is a known EEG signature of cognitive control that is proposed here to reflect reactive conflict resolution, achieved by closing the gate when facing irrelevant information. On the other hand, proactive gate opening in preparation for relevant information was associated with an increase in relative delta power over parietal-occipital electrodes. Finally, WM updating was associated with relative increase in delta power over midfrontal electrodes, suggesting a functional role of delta oscillations in WM updating.
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