Pupillary Stroop effects

We recorded the pupil diameters of participants performing the words’ color-naming Stroop task (i.e., naming the color of a word that names a color). Non-color words were used as baseline to firmly establish the effects of semantic relatedness induced by color word distractors. We replicated the classic Stroop effects of color congruency and color incongruency with pupillary diameter recordings: relative to non-color words, pupil diameters increased for color distractors that differed from color responses, while they reduced for color distractors that were identical to color responses. Analyses of the time courses of pupil responses revealed further differences between color-congruent and color-incongruent distractors, with the latter inducing a steep increase of pupil size and the former a relatively lower increase. Consistent with previous findings that have demonstrated that pupil size increases as task demands rise, the present results indicate that pupillometry is a robust measure of Stroop interference, and it represents a valuable addition to the cognitive scientist’s toolbox

The hidden effect of hearing acuity on speech recall, and compensatory effects of self-paced listening

OBJECTIVE: The purpose of this research was to determine whether negative effects of hearing loss on recall accuracy for spoken narratives can be mitigated by allowing listeners to control the rate of speech input. DESIGN: Paragraph-length narratives were presented for recall under two listening conditions in a within-participants design: presentation without interruption (continuous) at an average speech-rate of 150 words per minute; and presentation interrupted at periodic intervals at which participants were allowed to pause before initiating the next segment (self-paced). STUDY SAMPLE: Participants were 24 adults ranging from 21 to 33 years of age. Half had age-normal hearing acuity and half had mild-to-moderate hearing loss. The two groups were comparable for age, years of formal education, and vocabulary. RESULTS: When narrative passages were presented continuously, without interruption, participants with hearing loss recalled significantly fewer story elements, both main ideas and narrative details, than those with age-normal hearing. The recall difference was eliminated when the two groups were allowed to self-pace the speech input. CONCLUSION: Results support the hypothesis that the listening effort associated with reduced hearing acuity can slow processing operations and increase demands on working memory, with consequent negative effects on accuracy of narrative recall