Working memory in adults who stutter using a visual N-back task

Purpose: The purpose of this study was to investigate working memory in adults who do (AWS) and do not (AWNS) stutter using a visual N-back task. Processes involved in an N-back task include encoding, storing, rehearsing, inhibition, temporal ordering, and matching. Methods: Fifteen AWS (11 males, 4 females; M = 23.27 years, SD = 5.68 years) and 15 AWNS (M = 23.47 years, SD = 6.21 years) were asked to monitor series of images and respond by pressing a "yes" button if the image they viewed was the same as the image one, two, or three trials back. Stimuli included images with phonologically similar (i.e., phonological condition) or phonologically dissimilar (i.e., neutral condition) names. Accuracy and manual reaction time (mRT) were analyzed. Results: No difference was found between AWS and AWNS in accuracy. Furthermore, both groups were more accurate and significantly faster in 1- followed by 2- followed by 3-back trials. Finally, AWNS demonstrated faster mRT in the phonological compared to neutral condition, whereas AWS did not. Conclusion: Results from this study suggest different processing mechanisms between AWS and AWNS for visually presented phonologically similar stimuli. Specifically, a phonological priming effect occurred in AWNS but not in AWS, potentially due to reduced spreading activation and organization in the mental lexicon of AWS. However, the lack of differences between AWS and AWNS across all N-back levels does not support deficits in AWS in aspects of working memory targeted through a visual N-back task; but, these results are preliminary and additional research is warranted.