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Vishnu P. Murty
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Journal Articles
Publisher: Journals Gateway
Journal of Cognitive Neuroscience (2024) 36 (11): 2432–2441.
Published: 01 November 2024
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View articletitled, Threat Impairs the Organization of Memory Around Motivational Context
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for article titled, Threat Impairs the Organization of Memory Around Motivational Context
Previous work highlighted a critical role for top–down goals in shifting memory organization, namely, through studying the downstream influences of event segmentation and task switching on free recall. Here, we extend these frameworks into the realm of motivation, by comparing how threat motivation influences memory organization by capturing free recall dynamics. In Study 1, we manipulated individuals' motivation to successfully encode information by the threat of exposure to aversive sounds for forgetting. In Study 2, we conducted a parallel study manipulating motivation via instruction rather than threat, allowing us to examine changes directly related to threat motivation. Our findings showed that motivation to avoid threat broadly enhances memory for items presented within a threatening context, regardless of whether items were directly associated with the threat or not. Concurrently, these memory enhancements coincide with a decrease in the organization of memory around motivationally relevant features. These results highlight the importance of considering motivational valence when conceptualizing memory organization within adaptive memory frameworks.
Journal Articles
Publisher: Journals Gateway
Journal of Cognitive Neuroscience (2024) 36 (11): 2299–2301.
Published: 01 November 2024
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Journal Articles
Publisher: Journals Gateway
Journal of Cognitive Neuroscience (2024) 36 (3): 415–434.
Published: 01 March 2024
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View articletitled, Representational Dissimilarity of Faces and Places during a Working Memory Task is Associated with Subsequent Recognition Memory during Development
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for article titled, Representational Dissimilarity of Faces and Places during a Working Memory Task is Associated with Subsequent Recognition Memory during Development
Nearly 50 years of research has focused on faces as a special visual category, especially during development. Yet it remains unclear how spatial patterns of neural similarity of faces and places relate to how information processing supports subsequent recognition of items from these categories. The current study uses representational similarity analysis and functional imaging data from 9- and 10-year-old youth during an emotional n -back task from the Adolescent Brain and Cognitive Development Study 3.0 data release to relate spatial patterns of neural similarity during working memory to subsequent out-of-scanner performance on a recognition memory task. Specifically, we examine how similarities in representations within face categories (neutral, happy, and fearful faces) and representations between visual categories (faces and places) relate to subsequent recognition memory of these visual categories. Although working memory performance was higher for faces than places, subsequent recognition memory was greater for places than faces. Representational similarity analysis revealed category-specific patterns in face-and place-sensitive brain regions (fusiform gyrus, parahippocampal gyrus) compared with a nonsensitive visual region (pericalcarine cortex). Similarity within face categories and dissimilarity between face and place categories in the parahippocampus was related to better recognition of places from the n -back task. Conversely, in the fusiform, similarity within face categories and their relative dissimilarity from places was associated with better recognition of new faces, but not old faces. These findings highlight how the representational distinctiveness of visual categories influence what information is subsequently prioritized in recognition memory during development.
Journal Articles
Publisher: Journals Gateway
Journal of Cognitive Neuroscience (2024) 36 (2): 362–376.
Published: 01 February 2024
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View articletitled, Motivation as a Lens for Understanding Information-seeking Behaviors
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for article titled, Motivation as a Lens for Understanding Information-seeking Behaviors
Most prior research characterizes information-seeking behaviors as serving utilitarian purposes, such as whether the obtained information can help solve practical problems. However, information-seeking behaviors are sensitive to different contexts (i.e., threat vs. curiosity), despite having equivalent utility. Furthermore, these search behaviors can be modulated by individuals' life history and personality traits. Yet the emphasis on utilitarian utility has precluded the development of a unified model, which explains when and how individuals actively seek information. To account for this variability and flexibility, we propose a unified information-seeking framework that examines information-seeking through the lens of motivation. This unified model accounts for integration across individuals' internal goal states and the salient features of the environment to influence information-seeking behavior. We propose that information-seeking is determined by motivation for information, invigorated either by instrumental utility or hedonic utility, wherein one's personal or environmental context moderates this relationship. Furthermore, we speculate that the final common denominator in guiding information-seeking is the engagement of different neuromodulatory circuits centered on dopaminergic and noradrenergic tone. Our framework provides a unified framework for information-seeking behaviors and generates several testable predictions for future studies.
Journal Articles
Publisher: Journals Gateway
Journal of Cognitive Neuroscience (2023) 35 (9): 1446–1462.
Published: 01 September 2023
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View articletitled, Awake Hippocampal–Cortical Co-reactivation Is Associated with Forgetting
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for article titled, Awake Hippocampal–Cortical Co-reactivation Is Associated with Forgetting
Systems consolidation theories posit that consolidation occurs primarily through a coordinated communication between hippocampus and neocortex [Moscovitch, M., & Gilboa, A. Systems consolidation, transformation and reorganization: Multiple trace theory, trace transformation theory and their competitors. PsyArXiv , 2021; Kumaran, D., Hassabis, D., & McClelland, J. L. What learning systems do intelligent agents need? Complementary learning systems theory updated. Trends in Cognitive Sciences , 20 , 512–534, 2016; McClelland, J. L., & O'Reilly, R. C. Why there are complementary learning systems in the hippocampus and neocortex: Insights from the successes and failures of connectionist models of learning and memory. Psychological Review , 102 , 419–457, 1995]. Recent sleep studies in rodents have shown that hippocampus and visual cortex replay the same information at temporal proximity (“co-replay”; Lansink, C. S., Goltstein, P. M., Lankelma, J. V., McNaughton, B. L., & Pennartz, C. M. A. Hippocampus leads ventral striatum in replay of place-reward information. PLoS Biology , 7 , e1000173, 2009; Peyrache, A., Khamassi, M., Benchenane, K., Wiener, S. I., & Battaglia, F. P. Replay of rule-learning related neural patterns in the prefrontal cortex during sleep. Nature Neuroscience , 12 , 919–926, 2009; Wierzynski, C. M., Lubenov, E. V., Gu, M., & Siapas, A. G. State-dependent spike-timing relationships between hippocampal and prefrontal circuits during sleep. Neuron , 61 , 587–596, 2009; Ji, D., & Wilson, M. A. Coordinated memory replay in the visual cortex and hippocampus during sleep. Nature Neuroscience , 10 , 100–107, 2007). We developed a novel repetition time (TR)-based co-reactivation analysis method to study hippocampal–cortical co-replays in humans using fMRI. Thirty-six young adults completed an image (face or scene) and location paired associate encoding task in the scanner, which were preceded and followed by resting state scans. We identified post-encoding rest TRs (± 1) that showed neural reactivation of each image–location trials in both hippocampus (HPC) and category-selective cortex (fusiform face area [FFA]). This allowed us to characterize temporally proximal coordinated reactivations (“co-reactivations”) between HPC and FFA. Moreover, we found that increased HPC–FFA co-reactivations were associated with incorrectly recognized trials after a 1-week delay ( p = .004). Finally, we found that these HPC–FFA co-reactivations were also associated with trials that were initially correctly recognized immediately after encoding but were later forgotten in 1-day ( p = .043) and 1-week delay period ( p = .031). We discuss these results from a trace transformation perspective [Sekeres, M. J., Winocur, G., & Moscovitch, M. The hippocampus and related neocortical structures in memory transformation. Neuroscience Letters , 680 , 39–53, 2018; Winocur, G., & Moscovitch, M. Memory transformation and systems consolidation. Journal of the International Neuropsychological Society , 17 , 766–780, 2011] and speculate that HPC–FFA co-reactivations may be integrating related events, at the expense of disrupting event-specific details, hence leading to forgetting.
Journal Articles
Publisher: Journals Gateway
Journal of Cognitive Neuroscience (2019) 31 (9): 1308–1317.
Published: 01 September 2019
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View articletitled, Decision-making Increases Episodic Memory via Postencoding Consolidation
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for article titled, Decision-making Increases Episodic Memory via Postencoding Consolidation
The ability for individuals to actively make decisions engages regions within the mesolimbic system and enhances memory for chosen items. In other behavioral contexts, mesolimbic engagement has been shown to enhance episodic memory by supporting consolidation. However, research has yet to investigate how consolidation may support interactions between decision-making and episodic memory. Across two studies, participants encoded items that were covered by occluder screens and could either actively decide which of two items to uncover or an item was preselected by the experimenter. In Study 1, we show that active decision-making reduces forgetting rates across an immediate and 24-hr memory test, a behavioral marker of consolidation. In Study 2, we use functional neuroimaging to characterize putative neural markers of memory consolidation by measuring interactions between the hippocampus and perirhinal cortex (PRC) during a postencoding period that reexposed participants to elements of the decision-making context without exposing them to memoranda. We show that choice-related striatal engagement is associated with increased postencoding hippocampal–PRC interactions. Finally, we show that a previous reported relationship between choice-related striatal engagement and long-term memory is accounted for by these postencoding hippocampal–PRC interactions. Together, these findings support a model by which actively deciding to encode information enhances memory consolidation to preserve episodic memory for outcomes, a process that may be facilitated by reexposure to the original decision-making context.
Journal Articles
Age-related Alterations in Simple Declarative Memory and the Effect of Negative Stimulus Valence
UnavailablePublisher: Journals Gateway
Journal of Cognitive Neuroscience (2009) 21 (10): 1920–1933.
Published: 01 October 2009
Abstract
View articletitled, Age-related Alterations in Simple Declarative Memory and the Effect of Negative Stimulus Valence
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for article titled, Age-related Alterations in Simple Declarative Memory and the Effect of Negative Stimulus Valence
Healthy aging has been shown to modulate the neural circuitry underlying simple declarative memory; however, the functional impact of negative stimulus valence on these changes has not been fully investigated. Using BOLD fMRI, we explored the effects of aging on behavioral performance, neural activity, and functional coupling during the encoding and retrieval of novel aversive and neutral scenes. Behaviorally, there was a main effect of valence with better recognition performance for aversive greater than neutral stimuli in both age groups. There was also a main effect of age with better recognition performance in younger participants compared to older participants. At the imaging level, there was a main effect of valence with increased activity in the medial-temporal lobe (amygdala and hippocampus) during both encoding and retrieval of aversive relative to neutral stimuli. There was also a main effect of age with older participants showing decreased engagement of medial-temporal lobe structures and increased engagement of prefrontal structures during both encoding and retrieval sessions. Interestingly, older participants presented with relatively decreased amygdalar–hippocampal coupling and increased amygdalar–prefrontal coupling when compared to younger participants. Furthermore, older participants showed increased activation in prefrontal cortices and decreased activation in the amygdala when contrasting the retrieval of aversive and neutral scenes. These results suggest that although normal aging is associated with a decline in declarative memory with alterations in the neural activity and connectivity of brain regions underlying simple declarative memory, memory for aversive stimuli is relatively better preserved than for neutral stimuli, possibly through greater compensatory prefrontal cortical activity.