The contribution of the prefrontal cortex to relevancy-based gating of visual and tactile stimuli
Patients with lesions of the prefrontal cortex (PFC) show increased distractibility and impairments in inhibiting cortical responses to irrelevant stimuli. This study was designed to test the role of the PFC in the early modality-specific modulation of event-related potentials (ERPs) generated during a sensory selection task. The task required participants to make a scaled motor response to the amplitudes of visual and tactile stimuli presented individually or concurrently. Task relevance was manipulated and continuous theta burst stimulation (cTBS) was used to transiently inhibit PFC activity to test the contribution of the PFC to modulation of sensory gating. Electroencephalography (EEG) was collected from participants both before and after cTBS was applied. The somatosensory-evoked N70 ERP was shown to be modulated by task relevance before but not after cTBS was applied to the PFC, and downregulating PFC activity through the use of cTBS abolished any relevancy differences in N70 amplitude. In conclusion, this study demonstrated that early modality-specific changes in cortical somatosensory processing are modulated by attention, and that this effect is subserved by prefrontal cortical activity.
KeywordsContinuous theta burst stimulation Prefrontal cortex Task relevance Attentional gating
This work was supported by a research grant to WRS from the National Sciences and Engineering Research Council of Canada (NSERC).
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Conflict of interest
All authors of this paper report no affiliation or involvement in any organization or entity with a financial or non-financial interest in the subject matter or materials discussed in this manuscript.
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