Absolute coding of stimulus novelty in the human substantia nigra/VTA.
369 - 379.
Novelty exploration can enhance hippocampal plasticity in animals through dopaminergic neuromodulation arising in the substantia nigra/ventral tegmental area (SN/VTA). This enhancement can outlast the exploration phase by several minutes. Currently, little is known about dopaminergic novelty processing and its relationship to hippocampal function in humans. In two functional magnetic resonance imaging (fMRI) studies, SN/VTA activations in humans were indeed driven by stimulus novelty rather than other forms of stimulus salience such as rareness, negative emotional valence, or targetness of familiar stimuli, whereas hippocampal responses were less selective. SN/VTA novelty responses were scaled according to absolute rather than relative novelty in a given context, unlike adaptive SN/VTA responses recently reported for reward outcome in animal studies. Finally, novelty enhanced learning and perirhinal/parahippocampal processing of familiar items presented in the same context. Thus, the human SN/VTA can code absolute stimulus novelty and might contribute to enhancing learning in the context of novelty.
|Title:||Absolute coding of stimulus novelty in the human substantia nigra/VTA|
|Keywords:||LONG-TERM POTENTIATION, EVENT-RELATED FMRI, MEMORY FORMATION, DOPAMINERGIC MIDBRAIN, RECOGNITION MEMORY, HUMAN HIPPOCAMPAL, VISUAL-STIMULI, DENTATE GYRUS, SHORT-LATENCY, REWARD|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Psychology and Language Sciences (Division of) > Institute of Cognitive Neuroscience
UCL > School of Life and Medical Sciences > Faculty of Life Sciences
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