Format

Send to

Choose Destination
See comment in PubMed Commons below
Neuroimage. 2014 Jan 15;85 Pt 2:844-52. doi: 10.1016/j.neuroimage.2013.07.006. Epub 2013 Jul 16.

Repeated stimuli elicit diminished high-gamma electrocorticographic responses.

Author information

1
School of Biomedical Engineering, Science & Health Systems, Drexel University, Philadelphia, PA 19104, USA.

Abstract

In the phenomenon of repetition suppression (RS), when a person views a stimulus, the neural activity involved in processing that item is relatively diminished if that stimulus had been previously viewed. Previous noninvasive imaging studies mapped the prevalence of RS for different stimulus types to identify brain regions involved in representing a range of cognitive information. However, these noninvasive findings are challenging to interpret because they do not provide information on how RS relates to the brain's electrophysiological activity. We examined the electrophysiological basis of RS directly using brain recordings from implanted electrocorticographic (ECoG) electrodes in neurosurgical patients. Patients performed a memory task during ECoG recording and we identified high-gamma signals (65-128 Hz) that distinguished the neuronal representation of specific memory items. We then compared the neural representation of each item between novel and repeated viewings. This revealed the presence of RS, in which the neuronal representation of a repeated item had a significantly decreased amplitude and duration compared with novel stimuli. Furthermore, the magnitude of RS was greatest for the stimuli that initially elicited the largest activation at each site. These results have implications for understanding the neural basis of RS and human memory by showing that individual cortical sites exhibit the largest RS for the stimuli that they most actively represent.

KEYWORDS:

Electrocorticography; Gamma band; Repetition suppression

PMID:
23867555
PMCID:
PMC3859728
DOI:
10.1016/j.neuroimage.2013.07.006
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Support Center