A forced-attention dichotic listening fMRI study on 113 subjects.

We report fMRI and behavioral data from 113 subjects on attention and cognitive control using a variant of the classic dichotic listening paradigm with pairwise presentations of consonant-vowel syllables. The syllable stimuli were presented in a block-design while subjects were in the MR scanner. The subjects were instructed to pay attention to and report either the left or right ear stimulus. The hypothesis was that paying attention to the left ear stimulus (FL condition) induces a cognitive conflict, requiring cognitive control processes, not seen when paying attention to the right ear stimulus (FR condition), due to the perceptual salience of the right ear stimulus in a dichotic situation. The FL condition resulted in distinct activations in the left inferior prefrontal gyrus and caudate nucleus, while the right inferior frontal gyrus and caudate were activated in both the FL and FR conditions, and in a non-instructed (NF) baseline condition.