Jintao Sheng

All Publications

• Top-down attention and Alzheimer's pathology impact cortical selectivity during learning, influencing episodic memory in older adults. bioRxiv : the preprint server for biology Sheng, J., Trelle, A. N., Romero, A., Park, J., Tran, T. T., Sha, S. J., Andreasson, K. I., Wilson, E. N., Mormino, E. C., Wagner, A. D. 2024

  Abstract

  Human aging affects the ability to remember new experiences, in part, because of altered neural function during memory formation. One potential contributor to age-related memory decline is diminished neural selectivity -- i.e., a decline in the differential response of cortical regions to preferred vs. non-preferred stimuli during event perception -- yet the factors driving variability in neural selectivity with age remain unclear. We examined the impact of top-down attention and preclinical Alzheimer's disease (AD) pathology on neural selectivity during memory encoding in 156 cognitively unimpaired older participants who underwent fMRI while performing a word-face and word-scene associative memory task. Neural selectivity in face- and place-selective cortical regions was greater during events that were later remembered compared to forgotten. Critically, neural selectivity during learning positively scaled with memory-related variability in top-down attention, whereas selectivity negatively related to early AD pathology, evidenced by elevated plasma pTau181. Path analysis revealed that neural selectivity at encoding mediated the effects of age, top-down attention, and pTau181 on associative memory. Collectively, these data reveal multiple pathways that contribute to memory differences among older adults -- AD-independent reductions in top-down attention and AD-related pathology alter the precision of cortical representations of events during experience, with consequences for remembering.

  View details for DOI 10.1101/2024.12.04.626911

  View details for PubMedID 39713293

  View details for PubMedCentralID PMC11661099

• Intersubject similarity in neural representations underlies shared episodic memory content PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Sheng, J., Wang, S., Zhang, L., Liu, C., Shi, L., Zhou, Y., Hu, H., Chen, C., Xue, G. 2023; 120 (35): e2308951120

  Abstract

  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.

  View details for DOI 10.1073/pnas.2308951120

  View details for Web of Science ID 001138989500001

  View details for PubMedID 37603733

  View details for PubMedCentralID PMC10466090

• Higher-dimensional neural representations predict better episodic memory SCIENCE ADVANCES Sheng, J., Zhang, L., Liu, C., Liu, J., Feng, J., Zhou, Y., Hu, H., Xue, G. 2022; 8 (16): eabm3829

  Abstract

  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.

  View details for DOI 10.1126/sciadv.abm3829

  View details for Web of Science ID 000786214100024

  View details for PubMedID 35442734

  View details for PubMedCentralID PMC9020666