Publication Date


Degree Program

Department of Psychology

Degree Type

Master of Arts


Two studies were performed to investigate the effects of age and practice on Stroop inhibition. The first experiment examined the influence of age on the ability to ignore the meaning of words on Stroop items. Fifteen younger and 15 older adults were asked to name the color of congruent, incongruent, and control items appearing on a computer screen. Participants' interference and facilitation scores, error rates, and color and word process dissociation estimates were computed. The results indicate that older adults experienced more interference and facilitation than the younger adults and produced more errors than the younger adults on items where the meaning of the word and the color of the item did not match. Likewise, the process dissociation measures showed higher word estimates for older adults. Altogether these findings are indicative of a breakdown in older adults' inhibitory processes. The second study examined the effects of practice on older and younger adults' ability to inhibit word reading in the Stroop. Twelve younger and 12 older adults were assigned to each of two list conditions. Participants in the mostly congruent list condition received 140 items, 100 of which were congruent, 20 of which were incongruent and 20 of which were control. Participants in the mostly incongruent condition also received 140 trials, 100 of which where incongruent, 20 of which were congruent and 20 of which were control. The mostly incongruent list thus provided more practice in ignoring word meaning. Once again Stroop facilitation and interference scores, error rates, and process dissociation measures were computed. The results indicated that the mostly congruent list produced more facilitation and interference than the mostly incongruent list and that older adults again had higher facilitation and interference scores than younger adults. However, there was no evidence in the latency data that older adults benefitted less from practice than their younger counterparts. The process dissociation estimates demonstrated that older adults had higher word process estimates than the younger participants but that their color process estimates were similar to those of the younger adults. In addition, the mostly incongruent list produced lower word estimates and higher color estimates than the mostly congruent list. Moreover, this pattern did not differ across list types from that of the younger adults, again suggesting a similar benefit from practice for the two age groups. Taken together, these two studies suggest that while older adults are poorer at inhibitory skills, they do benefit from practice.


Cognition and Perception | Psychology