Faculty Collaboration Database

Single Neuron Coding of Identity in the Human Hippocampal Formation. Curr Biol 2020 Mar 23;30(6):1152-1159.e3

Date

03/07/2020

Pubmed ID

32142694

Pubmed Central ID

PMC7103760

DOI

10.1016/j.cub.2020.01.035

Scopus ID

2-s2.0-85081668717 (requires institutional sign-in at Scopus site)   39 Citations

Abstract

Experimental findings show the ubiquitous presence of graded responses and tuning curves in the neocortex, particularly in visual areas [1-15]. Among these, inferotemporal-cortex (IT) neurons respond to complex visual stimuli, but differences in the neurons' responses can be used to distinguish the stimuli eliciting the responses [8, 9, 16-18]. The IT projects directly to the medial temporal lobe (MTL) [19], where neurons respond selectively to different pictures of specific persons and even to their written and spoken names [20-22]. However, it is not clear whether this is done through a graded coding, as in the neocortex, or a truly invariant code, in which the response-eliciting stimuli cannot be distinguished from each other. To address this issue, we recorded single neurons during the repeated presentation of different stimuli (pictures and written and spoken names) corresponding to the same persons. Using statistical tests and a decoding approach, we found that only in a minority of cases can the different pictures of a given person be distinguished from the neurons' responses and that in a larger proportion of cases, the responses to the pictures were different to the ones to the written and spoken names. We argue that MTL neurons tend to lack a representation of sensory features (particularly within a sensory modality), which can be advantageous for the memory function attributed to this area [23-25], and that a full representation of memories is given by a combination of mostly invariant coding in the MTL with a representation of sensory features in the neocortex.

Author List

Rey HG, Gori B, Chaure FJ, Collavini S, Blenkmann AO, Seoane P, Seoane E, Kochen S, Quian Quiroga R

Author

Hernan Gonzalo Rey PhD Assistant Professor in the Neurosurgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adult
Argentina
Brain Mapping
Hippocampus
Humans
Male
Middle Aged
Neocortex
Neurons
Pattern Recognition, Visual
Single-Cell Analysis
Temporal Lobe
Young Adult