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1.
PLoS Biol ; 22(7): e3002721, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39008524

RESUMEN

The abundance of distractors in the world poses a major challenge to our brain's limited processing capacity, but little is known about how selective attention modulates stimulus representations in the brain to reduce interference and support durable target memory. Here, we collected functional magnetic resonance imaging (fMRI) data in a selective attention task in which target and distractor pictures of different visual categories were simultaneously presented. Participants were asked to selectively process the target according to the effective cue, either before the encoding period (i.e., perceptual attention) or the maintenance period (i.e., reflective attention). On the next day, participants were asked to perform a memory recognition task in the scanner in which the targets, distractors, and novel items were presented in a pseudorandom order. Behavioral results showed that perceptual attention was better at enhancing target memory and reducing distractor memory than reflective attention, although the overall memory capacity (memory for both target and distractor) was comparable. Using multiple-voxel pattern analysis of the neural data, we found more robust target representation and weaker distractor representation in working memory for perceptual attention than for reflective attention. Interestingly, perceptual attention partially shifted the regions involved in maintaining the target representation from the visual cortex to the parietal cortex. Furthermore, the targets and distractors simultaneously presented in the perceptual attention condition showed reduced pattern similarity in the parietal cortex during retrieval compared to items not presented together. This neural pattern repulsion positively correlated with individuals' recognition of both targets and distractors. These results emphasize the critical role of selective attention in transforming memory representations to reduce interference and improve long-term memory performance.


Asunto(s)
Atención , Imagen por Resonancia Magnética , Memoria a Largo Plazo , Memoria a Corto Plazo , Lóbulo Parietal , Humanos , Atención/fisiología , Lóbulo Parietal/fisiología , Masculino , Memoria a Corto Plazo/fisiología , Femenino , Memoria a Largo Plazo/fisiología , Adulto , Adulto Joven , Objetivos , Mapeo Encefálico , Estimulación Luminosa/métodos , Percepción Visual/fisiología
2.
Proc Natl Acad Sci U S A ; 120(35): e2308951120, 2023 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-37603733

RESUMEN

Individuals generally form their unique memories from shared experiences, yet the neural representational mechanisms underlying this subjectiveness of memory are poorly understood. The current study addressed this important question from the cross-subject neural representational perspective, leveraging a large functional magnetic resonance imaging dataset (n = 415) of a face-name associative memory task. We found that individuals' memory abilities were predicted by their synchronization to the group-averaged, canonical trial-by-trial activation level and, to a lesser degree, by their similarity to the group-averaged representational patterns during encoding. More importantly, the memory content shared between pairs of participants could be predicted by their shared local neural activation pattern, particularly in the angular gyrus and ventromedial prefrontal cortex, even after controlling for differences in memory abilities. These results uncover neural representational mechanisms for individualized memory and underscore the constructive nature of episodic memory.


Asunto(s)
Memoria Episódica , Humanos , Corteza Prefrontal/diagnóstico por imagen , Lóbulo Parietal
3.
Cereb Cortex ; 34(2)2024 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-38183183

RESUMEN

Elucidating the neural mechanisms of general cognitive ability (GCA) is an important mission of cognitive neuroscience. Recent large-sample cohort studies measured GCA through multiple cognitive tasks and explored its neural basis, but they did not investigate how task number, factor models, and neural data type affect the estimation of GCA and its neural correlates. To address these issues, we tested 1,605 Chinese young adults with 19 cognitive tasks and Raven's Advanced Progressive Matrices (RAPM) and collected resting state and n-back task fMRI data from a subsample of 683 individuals. Results showed that GCA could be reliably estimated by multiple tasks. Increasing task number enhances both reliability and validity of GCA estimates and reliably strengthens their correlations with brain data. The Spearman model and hierarchical bifactor model yield similar GCA estimates. The bifactor model has better model fit and stronger correlation with RAPM but explains less variance and shows weaker correlations with brain data than does the Spearman model. Notably, the n-back task-based functional connectivity patterns outperform resting-state fMRI in predicting GCA. These results suggest that GCA derived from a multitude of cognitive tasks serves as a valid measure of general intelligence and that its neural correlates could be better characterized by task fMRI than resting-state fMRI data.


Asunto(s)
Mapeo Encefálico , Encéfalo , Adulto Joven , Humanos , Reproducibilidad de los Resultados , Vías Nerviosas , Encéfalo/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Cognición
4.
Artículo en Inglés | MEDLINE | ID: mdl-38226770

RESUMEN

Research has suggested that daily cognitive reappraisal and mindfulness are differentially associated with emotional experience. Nevertheless, the different relationship between these two emotion regulation strategies and emotional experience remains unexplored amidst the COVID-19 pandemic, when people were facing unprecedented challenges and disruptions in their everyday lives. The current study aimed to examine the potential unidirectional or bidirectional relations between two strategies and daily emotional experience during the COVID-19 pandemic and whether the associations between the two strategies and emotional experience varied. A total of 184 college students participated in this study. Daily positive reappraisal, mindful attention and awareness (MAA), positive and negative affect, and COVID-19-related stress were assessed utilizing experience sampling method (three times a day for 14 consecutive days). Results suggested that the directionality of the link between the two strategies and daily emotional experience differed. The links between positive reappraisal and positive affect, negative affect, and COVID-19-related stress were transactional. However, a unidirectional relation was observed between positive affect and subsequent MAA. The study provided support for the contextual perspective of emotion regulation by demonstrating that the efficacy of regulation strategies is contingent upon the context. The identification of optimal conditions for effective strategies remains a crucial area for future research.

5.
Sci Adv ; 8(16): eabm3829, 2022 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-35442734

RESUMEN

Episodic memory enables humans to encode and later vividly retrieve information about our rich experiences, yet the neural representations that support this mental capacity are poorly understood. Using a large fMRI dataset (n = 468) of face-name associative memory tasks and principal component analysis to examine neural representational dimensionality (RD), we found that the human brain maintained a high-dimensional representation of faces through hierarchical representation within and beyond the face-selective regions. Critically, greater RD was associated with better subsequent memory performance both within and across participants, and this association was specific to episodic memory but not general cognitive abilities. Furthermore, the frontoparietal activities could suppress the shared low-dimensional fluctuations and reduce the correlations of local neural responses, resulting in greater RD. RD was not associated with the degree of item-specific pattern similarity, and it made complementary contributions to episodic memory. These results provide a mechanistic understanding of the role of RD in supporting accurate episodic memory.

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