Asymmetric coding of reward prediction errors in human insula and dorsomedial prefrontal cortex

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Дек. 21, 2023

Abstract The signed value and unsigned salience of reward prediction errors (RPEs) are critical to understanding reinforcement learning (RL) cognitive control. Dorsomedial prefrontal cortex (dMPFC) insula (INS) key regions for integrating surprise information, but conflicting evidence both activity has led multiple proposals the nature RPE representations in these brain areas. Recently developed RL models allow neurons respond differently positive negative RPEs. Here, we use intracranially recorded high frequency (HFA) test whether this flexible asymmetric coding strategy captures diversity human INS dMPFC. At region level, found a bias towards RPEs areas which paralleled behavioral adaptation. local spatially interleaved neural populations responding valence-specific Furthermore, directional connectivity estimates revealed leading role communicating These findings support across distinct intermingled as core principle processing inform theories dMPFC

Язык: Английский

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Long-term, multi-event surprise correlates with enhanced autobiographical memory

Nature Human Behaviour, Год журнала: 2023, Номер 7(12), С. 2152 - 2168

Опубликована: Июнь 15, 2023

Язык: Английский

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Event segmentation promotes the reorganization of emotional memory

Опубликована: Май 16, 2024

Event boundaries help structure the content of episodic memories by segmenting continuous experiences into discrete events. may also serve to preserve meaningful information within an event, thereby actively separating important from interfering representations imposed past and future Here, we tested hypothesis that event organize emotional memory based on changing dynamics as events unfold. We developed a novel threat-reversal learning task whereby participants encoded trial-unique exemplars two semantic categories across three phases: preconditioning, fear-acquisition, reversal. Shock contingencies were established for one category during acquisition (CS+) then switched other reversal (CS-). Importantly, was either separated perceptible boundary (experiment 1) or occurred immediately after acquisition, with no context shift 2). In surprise recognition test next day, performance tracked contingences encoding in experiment 1, such selectively recognized more threat-associated CS+ before (retroactive) but this pattern reversed toward CS- By contrast, encoding—without between conditioning reversal—exhibited undifferentiated both following Further analyses highlight nuanced effects reversing conditioned fear, updating mnemonic generalization, biasing temporal source memory. These findings suggest provide anchor points distinctly information, adaptively structuring our experiences.

Язык: Английский

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Learning depends on the information conveyed by temporal relationships between events and is reflected in the dopamine response to cues

Science Advances, Год журнала: 2024, Номер 10(36)

Опубликована: Сен. 6, 2024

Contemporary theories guiding the search for neural mechanisms of learning and memory assume that associative results from temporal pairing cues reinforcers resulting in coincident activation associated neurons, strengthening their synaptic connection. While enduring, this framework has limitations: Temporal pairing-based models do not fit with many experimental observations cannot be used to make quantitative predictions about behavior. Here, we present behavioral data support an alternative, information-theoretic conception: The amount information provide timing reward delivery predicts Furthermore, approach accounts rate depth both inhibitory excitatory across paradigms species. We also show dopamine release ventral striatum reflects cue-predicted changes reinforcement rates consistent subjects understanding relationships between task events. Our reshape conceptual biological learning.

Язык: Английский

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Decoding Salience: A Functional Magnetic Resonance Imaging Investigation of Reward and Contextual Unexpectedness in Memory Encoding and Retrieval

Human Brain Mapping, Год журнала: 2025, Номер 46(1)

Опубликована: Янв. 1, 2025

ABSTRACT The present study investigated the neuromodulatory substrates of salience processing and its impact on memory encoding behaviour, with a specific focus two distinct types salience: reward contextual unexpectedness. 46 Participants performed novel task paradigm modulating these aspects independently allowing for investigating their interactive effects while undergoing high‐resolution fMRI. By using advanced image techniques tailored to examine midbrain brainstem nuclei high precision, our additionally aimed elucidate differential activation patterns in subcortical response reward‐associated contextually unexpected stimuli, including pathways involving particular dopaminergic modulation. We observed involvement ventral striatum, substantia nigra (SN) caudate nucleus, as well functional specialisation within subregions cingulate cortex types. Moreover, SN could be identified. Dorsal areas preferentially processed related stimulus (of both unexpectedness), were involved salience‐related (for unexpectedness only). These specialisations are line different projection dorsal brain supporting attention memory, respectively. disentangling types, we hope further consolidate understanding structures' roles behavioural responses salient events.

Язык: Английский

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