Assessment of Reaction Time in Congruent and Incongruent Dual Task Stroop Effect in the Elderly

In the psychological refractory period, two stimuli with close asynchronous onset are set and two quick responses are required, which the response to the second stimulus is delayed in these conditions, especially if the stroop stimuli are used. These stimuli require high-capacity information processing. The aim of this study was to evaluate selective attention in the elderly.
In the present quasi-experimental study, 16 healthy older adults (mean age, 67.4±3.2), were selected from railway employees using purposeful sampling. All the participants performed stroop effect dual task. This test included four intervals of 50, 100, 300, and 900 ms between asynchronous onset of the two tasks in both congruent and incongruent conditions. The elderly subjects whose cognitive status score was more than 25 participated in this study.
According to the results of repeated measures ANOVA, there was a significant difference between congruent-congruent and incongruent-incongruent trials in over 50 ms interval. Also, the reaction time of incongruent stimuli had longer response time than congruent stimuli.
The findings of this stydy revealed that functional deficts of the healthy elderly in working memory, cognitive processes, perception, and movement reduce selective attention in the elderly. Moreover, this reduction disrupts the reaction to the incongruent stroop stimuli.