TY - JOUR
T1 - Intracranial EEG Correlates of Expectancy and Memory Formation in the Human Hippocampus and Nucleus Accumbens
AU - Axmacher, Nikolai
AU - Cohen, Michael X.
AU - Fell, Juergen
AU - Haupt, Sven
AU - Dümpelmann, Matthias
AU - Elger, Christian E.
AU - Schlaepfer, Thomas E.
AU - Lenartz, Doris
AU - Sturm, Volker
AU - Ranganath, Charan
PY - 2010/2/25
Y1 - 2010/2/25
N2 - The human brain is adept at anticipating upcoming events, but in a rapidly changing world, it is essential to detect and encode events that violate these expectancies. Unexpected events are more likely to be remembered than predictable events, but the underlying neural mechanisms for these effects remain unclear. We report intracranial EEG recordings from the hippocampus of epilepsy patients, and from the nucleus accumbens of depression patients. We found that unexpected stimuli enhance an early (187 ms) and a late (482 ms) hippocampal potential, and that the late potential is associated with successful memory encoding for these stimuli. Recordings from the nucleus accumbens revealed a late potential (peak at 475 ms), which increases in magnitude during unexpected items, but no subsequent memory effect and no early component. These results are consistent with the hypothesis that activity in a loop involving the hippocampus and the nucleus accumbens promotes encoding of unexpected events.
AB - The human brain is adept at anticipating upcoming events, but in a rapidly changing world, it is essential to detect and encode events that violate these expectancies. Unexpected events are more likely to be remembered than predictable events, but the underlying neural mechanisms for these effects remain unclear. We report intracranial EEG recordings from the hippocampus of epilepsy patients, and from the nucleus accumbens of depression patients. We found that unexpected stimuli enhance an early (187 ms) and a late (482 ms) hippocampal potential, and that the late potential is associated with successful memory encoding for these stimuli. Recordings from the nucleus accumbens revealed a late potential (peak at 475 ms), which increases in magnitude during unexpected items, but no subsequent memory effect and no early component. These results are consistent with the hypothesis that activity in a loop involving the hippocampus and the nucleus accumbens promotes encoding of unexpected events.
KW - HUMDISEASE
KW - SYSNEURO
UR - http://www.scopus.com/inward/record.url?scp=76849100736&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=76849100736&partnerID=8YFLogxK
U2 - 10.1016/j.neuron.2010.02.006
DO - 10.1016/j.neuron.2010.02.006
M3 - Article
C2 - 20188658
AN - SCOPUS:76849100736
VL - 65
SP - 541
EP - 549
JO - Neuron
JF - Neuron
SN - 0896-6273
IS - 4
ER -