Presetting an inhibitory state modifies the neural processing of negated action sentences. An ERP study.

It has been proposed that understanding negated action sentences (You don't cut the bread) uses the neural networks of action inhibition. The evidence comes from studies in which affirmative or negative action language immediately preceded a Go/NoGo task. It was found that negation selectively modulates inhibition-related signatures of NoGo trials, supporting the Reusing Inhibition for Negation (RIN) hypothesis. To further explore this hypothesis, this study tested the reverse effects; namely, how presetting an inhibitory state affects the processing of negated action sentences. To this end, Go/NoGo responses preceded sentence reading and EEG activities were recorded throughout the entire trials. ERP results indicate that the presetting of inhibition by the NoGo cue induced a sustained modulation of waveform for negated action sentences relative to affirmative ones, which began shortly after the negation operator onset and remained beyond the action verb onset. Crucially, the estimated sources of such effect were the right inferior frontal gyrus and the left middle frontal gyrus, both relevant regions in the action inhibition circuitry. These results, complemented by previous findings, support the idea that action inhibition and negated action language share neural mechanisms and influence each other, thus confirming and extending the RIN hypothesis.