Temporal sequence of hemispheric network activation during semantic processing: a functional network connectivity analysis.

Full Abstract

To explore the temporal sequence of, and the relationship between, the left and right hemispheres (LH and RH) during semantic memory (SM) processing we identified the neural networks involved in the performance of functional MRI semantic object retrieval task (SORT) using group independent component analysis (ICA) in 47 healthy individuals. SORT requires participants to determine whether word pairs describing object features combine to retrieve an object. Functional network connectivity (FNC) was used to assess the correlations between components' time courses. Results showed that semantic left and right hemisphere networks comprise two independent ICA components. The components' time courses were highly correlated and RH activation preceded that of the LH. Moreover, this correlation was significantly stronger in better vs. poorer performers of the SORT. These results indicate an early activation of the RH that is closely followed by activation of the LH, to facilitate performance during word retrieval from SM.

Author information

Author/s: Assaf, Michal (M); Jagannathan, Kanchana (K); Calhoun, Vince (V); Kraut, Michael (M); Hart, John (J); Pearlson, Godfrey (G);

Affiliation: Olin Neuropsychiatry Research Center, Institute of Living, Hartford Hospital, Hartford, CT, United States. massaf(-atsign-)harthosp.org

Grants: R01 MH-52886 (Agency:NIMH NIH HHS) ; R01 MH-60504 (Agency:NIMH NIH HHS) ; R01 MH43775 (Agency:NIMH NIH HHS) ; R01EB-000840 (Agency:NIBIB NIH HHS)

Journal and publication information

Publication Type: Journal Article; Research Support, N.I.H., Extramural

Journal: Brain and cognition (Brain Cogn), published in United States. (Language: eng)

Reference: 2009-Jul; vol 70 (issue 2) : pp 238-46

Dates: Created 2009/04/27; Completed 2009/06/18;

PMID: 19307050, status: MEDLINE (last retrieval date: 6/18/2009, IMS Date: 18 Jun 2009 00:00:00)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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