Format

Send to

Choose Destination
Nat Neurosci. 2015 Jul;18(7):1041-50. doi: 10.1038/nn.4041. Epub 2015 Jun 8.

Representation of retrieval confidence by single neurons in the human medial temporal lobe.

Author information

1
1] Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, California, USA. [2] Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, California, USA. [3] Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA. [4] Computation &Neural Systems Program, California Institute of Technology, Pasadena, California, USA. [5] Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA.
2
1] Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, California, USA. [2] Computation &Neural Systems Program, California Institute of Technology, Pasadena, California, USA.
3
1] Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, California, USA. [2] Departement de Biologie, Ecole Normale Superieure de Cachan, Cachan, France.
4
1] Computation &Neural Systems Program, California Institute of Technology, Pasadena, California, USA. [2] Division of Humanities and Social Science, California Institute of Technology, Pasadena, California, USA.
5
Department of Neurosurgery, Huntington Memorial Hospital, Pasadena, California, USA.
6
Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, California, USA.
7
Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, California, USA.

Abstract

Memory-based decisions are often accompanied by an assessment of choice certainty, but the mechanisms of such confidence judgments remain unknown. We studied the response of 1,065 individual neurons in the human hippocampus and amygdala while neurosurgical patients made memory retrieval decisions together with a confidence judgment. Combining behavioral, neuronal and computational analysis, we identified a population of memory-selective (MS) neurons whose activity signaled stimulus familiarity and confidence, as assessed by subjective report. In contrast, the activity of visually selective (VS) neurons was not sensitive to memory strength. The groups further differed in response latency, tuning and extracellular waveforms. The information provided by MS neurons was sufficient for a race model to decide stimulus familiarity and retrieval confidence. Together, our results indicate a trial-by-trial relationship between a specific group of neurons and declared memory strength in humans. We suggest that VS and MS neurons are a substrate for declarative memories.

PMID:
26053402
PMCID:
PMC4482779
DOI:
10.1038/nn.4041
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center