To Go or Not to Go: Exploring brain activation during response inhibition reading tasks

Abstract

Objective: Response inhibition is an understudied component of reading that aids in the selection of appropriate responses amidst complicated tasks. Our objective was to explore the contribution of brain regions associated with response inhibition processing in reading tasks that vary in difficulty of response inhibition. Method: Participants (N = 15) completed two go/no-go reading tasks while in a functional magnetic resonance imaging (fMRI) scanner, with the instructions to “name aloud the letter strings that spell a real word.” For the minimal response inhibition condition, the foils, which are stimuli that should not be repsonded to, were nonwords with unfamiliar spelling and sound (e.g., “bink”). For the maximal response inhibition condition, the foils were pseudohomophones with unfamiliar spelling but familiar sound (e.g., “pynt”). The following brain regions associated with decision-making processes were analyzed: the anterior cingulate cortex (ACC), the dorsomedial prefrontal cortex (DMPFC), the inferior frontal gyrus (IFG), the middle temporal gyrus (MTG), the middle occipital gyrus (MOG), and the posterior insula (PI). Results: Significant differences in activation within the nonword task were found for the DMPFC and the PI (the ACC approached significance). Significant differences in activation within the pseudohomophone task were found for the ACC, the MTG, and the PI. The IFG was found to be greatly activated for all words that had familiar phonemes (sounds). The MOG was found to be activated across all tasks. Conclusion: We provide evidence for differential response inhibition processing in the decision-making network during reading tasks. This work is a necessary step in better understanding response inhibition ability for individuals with and without reading impairments.