RT Journal Article
SR Electronic
T1 The Dynamic Nature of Top-Down Signals Originating from Prefrontal Cortex: A Combined fMRI–TMS Study
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 15458
OP 15466
DO 10.1523/JNEUROSCI.0627-12.2012
VO 32
IS 44
A1 Taraz G. Lee
A1 Mark D'Esposito
YR 2012
UL http://www.jneurosci.org/content/32/44/15458.abstract
AB The prefrontal cortex (PFC) is proposed to be the source of top-down signals that can modulate extrastriate visual processing in accordance with behavioral goals, yet little direct causal evidence for this hypothesis exists. Using theta burst transcranial magnetic stimulation, we disrupted PFC function in human participants before performing a working memory task during fMRI scanning. PFC disruption decreased the tuning of extrastriate cortex responses, coinciding with decrements in working memory performance. We also found that activity in the homologous PFC region in the nonstimulated hemisphere predicted performance following disruption. Specifically, those participants with greater homologous PFC activity and greater connectivity between this region and extrastriate cortex were the most resistant to PFC disruption. These findings provide evidence for a compensatory mechanism following insults to the brain, and insight into the dynamic nature of top-down signals originating from the PFC.