Slow semantic learning in the cerebral cortex, and its relation to the hippocampal episodic memory system

Cerebral Cortex, Journal Year: 2025, Volume and Issue: 35(5)

Published: May 1, 2025

Abstract A key question is how new semantic representations are formed in the human brain and this may benefit from hippocampal episodic memory system. Here, we describe major effective connectivity between system anterior temporal lobe (ATL) humans. Then, present model a theory of be ATL using slow associative learning attractor networks that receive inputs The hypothesis if one category being processed for several seconds, then short-term trace biologically plausible rule will enable all components during time to associated together network. This benefits binding provided by modeled four-layer network view-invariant visual object recognition, followed layer utilizes form categories based on occur close time, or world.

Language: Английский

Egocentric body-axis-related and allocentric clover-like tuning of object vector representations supports human spatial cognition

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: April 21, 2025

1 Abstract Vector-based spatial representation is key for navigation, mapping direction and distance between self environment. Though observed in rodents, its neural basis humans remains unclear. Using high-resolution imaging a novel updating task, we found vectorial representations retrosplenial parahippocampal cortex, extending to parietal entorhinal areas self- object-centered coordinates, respectively. Ego-centric directional signals peaked when the object was behind navigator, while emerged only out of view, suggesting these might act as mnemonic buffers vision-independent mapping. Allocentric formed clover-shaped four-axis pattern aligned common visual feature, with improved navigation accuracy along axes, highlighting their functional relevance human navigation. Rodent parallel single unit recordings indicated clover resulted from average activity neurons allocentric properties, shared, cross-species mechanism. Collectively, our findings demonstrate vector-based population code detectable via fMRI, potentially serving reference axis that anchors objects internal maps, supporting flexible perhaps broader cognition.

Language: Английский

Contingency learning of social cues: neural engagement and emotional modulation by facial expressions

Frontiers in Human Neuroscience, Journal Year: 2025, Volume and Issue: 19

Published: Feb. 21, 2025

Contingency learning-the fundamental process by which associations are formed between events in our experience is as relevant of conditioning it for social interactions, where emotional cues, such facial expressions, signal complex and reciprocal causal dynamics. This study investigates the functional neuroanatomy underlying contingency perception with three type contingent relation (positive, zero, negative) using sad happy expressions stimuli a group neurotypical participants. Employing streaming trial paradigm MRI, we examined how these contingencies engage brain regions involved attention predictive processing. The behavioural results indicated that participants could distinguish different contingencies, regardless stimuli. However, judgment ratings varied across conditions, eliciting weaker compared to moderated perceived causality, especially uncorrelated negative tasks. These findings were primarily linked increased activation frontal regions, including inferior gyrus, middle anterior cingulate cortex. highlight differential cognitive demands neural responses evoked suggestive idea statistical relations violate expectations processed differently than positive relations.

Language: Английский