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Hasan SM, Huq MS, Chowdury AZ, Baajour S, Kopchick J, Robison AJ, Thakkar KN, Haddad L, Amirsadri A, Thomas P, Khatib D, Rajan U, Stanley JA, Diwadkar VA. Learning without contingencies: A loss of synergy between memory and reward circuits in schizophrenia. Schizophr Res 2023; 258:21-35. [PMID: 37467677 PMCID: PMC10521382 DOI: 10.1016/j.schres.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 02/09/2023] [Accepted: 06/11/2023] [Indexed: 07/21/2023]
Abstract
Motivational deficits in schizophrenia may interact with foundational cognitive processes including learning and memory to induce impaired cognitive proficiency. If such a loss of synergy exists, it is likely to be underpinned by a loss of synchrony between the brains learning and reward sub-networks. Moreover, this loss should be observed even during tasks devoid of explicit reward contingencies given that such tasks are better models of real world performance than those with artificial contingencies. Here we applied undirected functional connectivity (uFC) analyses to fMRI data acquired while participants engaged in an associative learning task without contingencies or feedback. uFC was estimated and inter-group differences (between schizophrenia patients and controls, n = 54 total, n = 28 patients) were assessed within and between reward (VTA and NAcc) and learning/memory (Basal Ganglia, DPFC, Hippocampus, Parahippocampus, Occipital Lobe) sub-networks. The task paradigm itself alternated between Encoding, Consolidation, and Retrieval conditions, and uFC differences were quantified for each of the conditions. Significantly reduced uFC dominated the connectivity profiles of patients across all conditions. More pertinent to our motivations, these reductions were observed within and across classes of sub-networks (reward-related and learning/memory related). We suggest that disrupted functional connectivity between reward and learning sub-networks may drive many of the performance deficits that characterize schizophrenia. Thus, cognitive deficits in schizophrenia may in fact be underpinned by a loss of synergy between reward-sensitivity and cognitive processes.
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Affiliation(s)
- Sazid M Hasan
- Oakland University William Beaumont School of Medicine, USA
| | - Munajj S Huq
- Michigan State University, College of Osteopathic Medicine, USA
| | - Asadur Z Chowdury
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA
| | - Shahira Baajour
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA
| | - John Kopchick
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA
| | - A J Robison
- Dept. of Physiology, Michigan State University, USA
| | | | - Luay Haddad
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA
| | - Alireza Amirsadri
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA
| | - Patricia Thomas
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA
| | - Dalal Khatib
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA
| | - Usha Rajan
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA
| | - Jeffrey A Stanley
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA
| | - Vaibhav A Diwadkar
- Dept. of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, USA.
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Merchie A, Gomot M. Habituation, Adaptation and Prediction Processes in Neurodevelopmental Disorders: A Comprehensive Review. Brain Sci 2023; 13:1110. [PMID: 37509040 PMCID: PMC10377027 DOI: 10.3390/brainsci13071110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/12/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
Habituation, the simplest form of learning preserved across species and evolution, is characterized by a response decrease as a stimulus is repeated. This adaptive function has been shown to be altered in some psychiatric and neurodevelopmental disorders such as autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD) or schizophrenia. At the brain level, habituation is characterized by a decrease in neural activity as a stimulation is repeated, referred to as neural adaptation. This phenomenon influences the ability to make predictions and to detect change, two processes altered in some neurodevelopmental and psychiatric disorders. In this comprehensive review, the objectives are to characterize habituation, neural adaptation, and prediction throughout typical development and in neurodevelopmental disorders; and to evaluate their implication in symptomatology, specifically in sensitivity to change or need for sameness. A summary of the different approaches to investigate adaptation will be proposed, in which we report the contribution of animal studies as well as electrophysiological studies in humans to understanding of underlying neuronal mechanisms.
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Affiliation(s)
| | - Marie Gomot
- UMR 1253 iBrain, Université de Tours, INSERM, 37000 Tours, France
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McHugo M, Avery S, Armstrong K, Rogers BP, Vandekar SN, Woodward ND, Blackford JU, Heckers S. Anterior hippocampal dysfunction in early psychosis: a 2-year follow-up study. Psychol Med 2023; 53:160-169. [PMID: 33875028 PMCID: PMC8919704 DOI: 10.1017/s0033291721001318] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Cross-sectional studies indicate that hippocampal function is abnormal across stages of psychosis. Neural theories of psychosis pathophysiology suggest that dysfunction worsens with illness stage. Here, we test the hypothesis that hippocampal function is impaired in the early stage of psychosis and declines further over the next 2 years. METHODS We measured hippocampal function over 2 years using a scene processing task in 147 participants (76 individuals in the early stage of a non-affective psychotic disorder and 71 demographically similar healthy control individuals). Two-year follow-up was completed in 97 individuals (50 early psychosis, 47 healthy control). Voxelwise longitudinal analysis of activation in response to scenes was carried out within a hippocampal region of interest to test for group differences at baseline and a group by time interaction. RESULTS At baseline, we observed lower anterior hippocampal activation in the early psychosis group relative to the healthy control group. Contrary to our hypothesis, hippocampal activation remained consistent and did not show the predicted decline over 2 years in the early psychosis group. Healthy controls showed a modest reduction in hippocampal activation after 2 years. CONCLUSIONS The results of this study suggest that hippocampal dysfunction in early psychosis does not worsen over 2 years and highlight the need for longer-term longitudinal studies.
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Affiliation(s)
- Maureen McHugo
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Suzanne Avery
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kristan Armstrong
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Baxter P. Rogers
- Vanderbilt University Institute of Imaging Sciences, Nashville, TN, USA
| | - Simon N. Vandekar
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Neil D. Woodward
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jennifer Urbano Blackford
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Research and Development, Tennessee Valley Healthcare System, United States Department of Veteran Affairs
| | - Stephan Heckers
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
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Walker VG. Elder's life course theory and person-centered research: A lens for conducting ethical nursing research and mental health nursing practice with older adults aging with the diagnosis of schizophrenia. J Psychiatr Ment Health Nurs 2022; 29:904-914. [PMID: 35020244 DOI: 10.1111/jpm.12819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 12/17/2021] [Accepted: 01/07/2022] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Older adults diagnosed with schizophrenia are a vulnerable population owing to the manifestations of their illness, which can include decreased reality orientation, paranoia, hallucinations and delusions. This paper presents ethical principles of vulnerability, veracity, non-maleficence and autonomy for person-centered care in mental health nursing research and practice, focused with the lens of Elder's life course theory (LCT). AIM To present Elder's LCT as an ethical lens for person-centered care as nurses engage with older adults aging with the diagnosis of schizophrenia in clinical practice and/or research. METHOD Four ethical principles fundamental to nursing research and mental health practice are presented, with Elder's LCT as a theoretical lens for person-centered care. RESULTS A model for ethical research and mental health practice with older adults diagnosed with schizophrenia. DISCUSSION Nursing research and mental health nursing practice with an ethical LCT lens for person-centered can help nurses envision, explore and generate interventions to address the special needs of older adults aging with schizophrenia. IMPLICATIONS FOR PRACTICE The use of a LCT lens for person-centered care can encourage nurses in research and mental health practice to seek information collaboratively with older adults diagnosed with schizophrenia in a thoughtful, ethical manner, to inform the improvement of their health outcomes and health policy.
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Budson AE, Richman KA, Kensinger EA. Consciousness as a Memory System. Cogn Behav Neurol 2022; 35:263-297. [PMID: 36178498 PMCID: PMC9708083 DOI: 10.1097/wnn.0000000000000319] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 05/03/2022] [Indexed: 01/31/2023]
Abstract
We suggest that there is confusion between why consciousness developed and what additional functions, through continued evolution, it has co-opted. Consider episodic memory. If we believe that episodic memory evolved solely to accurately represent past events, it seems like a terrible system-prone to forgetting and false memories. However, if we believe that episodic memory developed to flexibly and creatively combine and rearrange memories of prior events in order to plan for the future, then it is quite a good system. We argue that consciousness originally developed as part of the episodic memory system-quite likely the part needed to accomplish that flexible recombining of information. We posit further that consciousness was subsequently co-opted to produce other functions that are not directly relevant to memory per se, such as problem-solving, abstract thinking, and language. We suggest that this theory is compatible with many phenomena, such as the slow speed and the after-the-fact order of consciousness, that cannot be explained well by other theories. We believe that our theory may have profound implications for understanding intentional action and consciousness in general. Moreover, we suggest that episodic memory and its associated memory systems of sensory, working, and semantic memory as a whole ought to be considered together as the conscious memory system in that they, together, give rise to the phenomenon of consciousness. Lastly, we suggest that the cerebral cortex is the part of the brain that makes consciousness possible, and that every cortical region contributes to this conscious memory system.
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Affiliation(s)
- Andrew E. Budson
- Center for Translational Cognitive Neuroscience, Veterans Affairs Boston Healthcare System, Boston, Massachusetts
- Alzheimer’s Disease Research Center, Boston University, Boston, Massachusetts
| | - Kenneth A. Richman
- Center for Health Humanities, Massachusetts College of Pharmacy and Health Sciences, Boston, Massachusetts
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Avery SN, McHugo M, Armstrong K, Blackford JU, Woodward ND, Heckers S. Stable habituation deficits in the early stage of psychosis: a 2-year follow-up study. Transl Psychiatry 2021; 11:20. [PMID: 33414431 PMCID: PMC7791099 DOI: 10.1038/s41398-020-01167-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/01/2020] [Accepted: 12/09/2020] [Indexed: 01/29/2023] Open
Abstract
Neural habituation, the decrease in brain response to repeated stimuli, is a fundamental, highly conserved mechanism that acts as an essential filter for our complex sensory environment. Convergent evidence indicates neural habituation is disrupted in both early and chronic stages of schizophrenia, with deficits co-occurring in brain regions that show inhibitory dysfunction. As inhibitory deficits have been proposed to contribute to the onset and progression of illness, habituation may be an important treatment target. However, a crucial first step is clarifying whether habituation deficits progress with illness. In the present study, we measured neural habituation in 138 participants (70 early psychosis patients (<2 years of illness), 68 healthy controls), with 108 participants assessed longitudinally at both baseline and 2-year follow-up. At follow-up, all early psychosis patients met criteria for a schizophrenia spectrum disorder (i.e., schizophreniform disorder, schizophrenia, schizoaffective disorder). Habituation slopes (i.e., rate of fMRI signal change) to repeated images were computed for the anterior hippocampus, occipital cortex, and the fusiform face area. Habituation slopes were entered into a linear mixed model to test for effects of group and time by region. We found that early psychosis patients showed habituation deficits relative to healthy control participants across brain regions, and that these deficits were maintained, but did not worsen, over two years. These results suggest a stable period of habituation deficits in the early stage of schizophrenia.
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Affiliation(s)
- Suzanne N. Avery
- grid.412807.80000 0004 1936 9916Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN USA
| | - Maureen McHugo
- grid.412807.80000 0004 1936 9916Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN USA
| | - Kristan Armstrong
- grid.412807.80000 0004 1936 9916Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN USA
| | - Jennifer Urbano Blackford
- grid.412807.80000 0004 1936 9916Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN USA ,grid.413806.8Research Health Scientist, Research and Development, Department of Veterans Affairs Medical Center, Nashville, TN USA
| | - Neil D. Woodward
- grid.412807.80000 0004 1936 9916Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN USA
| | - Stephan Heckers
- grid.412807.80000 0004 1936 9916Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN USA
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