Gating by inhibition during top-down control of willed attention

ABSTRACT

In natural settings, the control of attention may be influenced both by external information as well as internal decision-making processes driven by intent (e.g. free will). In past studies of spatial attention, we and others have developed experimental paradigms that permit individuals to choose where to direct their attention on a trial-by-trial basis in the absence of instructive external cues – we term this willed attention. Here we investigate the electrophysiological correlates of willed attention by recording EEG activity when subjects decided to focus covert attention on one of two lateralized target locations versus when they decided to maintain attention at fixation. Independent of the direction of attention, decisions to attend, relative to decisions not to attend, resulted in significant increases in both frontal theta (4–7 Hz) power and central alpha (8–13 Hz) power. We found that focusing spatial attention, as indexed by occipital alpha lateralization was predicted across subjects by the decision-related alpha increases over central scalp regions, but not changes in frontal theta power. This finding is interpreted in terms of the Gating by Inhibition model, where the central alpha EEG signals reflect cortical inhibition of decision processes that lead to the expression of willed attention.

KEYWORDS:

• Attention
• decision-making
• alpha
• theta
• inhibition
• EEG

Acknowledgments

We thank Sharon Coffey Corina and Alexander Morales for their assistance, and are grateful also to the administrative and technical staff of the Center for Mind and Brain for their support. This research was supported by grants from NSF (BCS 1339049) and NIMH (MH117991) to JJB and GRM.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Mechanisms of Willed Attention [NSF (BCS 1339049)].