TY - JOUR
T1 - Working memory component processes
T2 - Isolating BOLD signal changes
AU - Motes, Michael A.
AU - Rypma, Bart
N1 - Funding Information:
The project described was supported by grant number AG029523 from NIH and grant number VA549-P-0027 from the United States Veteran's Administration . Its contents are solely the responsibility of the authors and do not necessarily represent the official views of NIH or the Veteran's Administration. The authors thank Ehsan Shokri Kojori for helpful comments on the manuscript.
PY - 2010/1/15
Y1 - 2010/1/15
N2 - The chronology of the component processes subserving working memory (WM) and hemodynamic response lags has hindered the use of fMRI for exploring neural substrates of WM. In the present study, however, participants completed full trials that involved encoding two or six letters, maintaining the memory set over a delay, and then deciding whether a probe was in the memory set or not. Additionally, they completed encode-only, encode-and-maintain, and encode-and-decide partial trials intermixed with the full trials. The inclusion of partial trials allowed for the isolation of BOLD signal changes to the different trial periods. The results showed that only lateral and medial prefrontal cortex regions differentially responded to the 2- and 6-letter memory sets over the trial periods, showing greater activation to 6-letter sets during the encode and maintain trial periods. Thus, the data showed the differential involvement of PFC in the encoding and maintenance of supra- and sub-capacity memory sets and show the efficacy of using fMRI partial trial methods to study WM component processes.
AB - The chronology of the component processes subserving working memory (WM) and hemodynamic response lags has hindered the use of fMRI for exploring neural substrates of WM. In the present study, however, participants completed full trials that involved encoding two or six letters, maintaining the memory set over a delay, and then deciding whether a probe was in the memory set or not. Additionally, they completed encode-only, encode-and-maintain, and encode-and-decide partial trials intermixed with the full trials. The inclusion of partial trials allowed for the isolation of BOLD signal changes to the different trial periods. The results showed that only lateral and medial prefrontal cortex regions differentially responded to the 2- and 6-letter memory sets over the trial periods, showing greater activation to 6-letter sets during the encode and maintain trial periods. Thus, the data showed the differential involvement of PFC in the encoding and maintenance of supra- and sub-capacity memory sets and show the efficacy of using fMRI partial trial methods to study WM component processes.
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U2 - 10.1016/j.neuroimage.2009.08.054
DO - 10.1016/j.neuroimage.2009.08.054
M3 - Article
C2 - 19732840
AN - SCOPUS:70749095212
SN - 1053-8119
VL - 49
SP - 1933
EP - 1941
JO - NeuroImage
JF - NeuroImage
IS - 2
ER -