Comparing the Effect of Interference on an Emotional Stroop Task in Older Adults with and without Alzheimer's Disease.

BACKGROUND

Impairments in the ability to recognize facial affective expressions may lead to social dysfunction and difficulties with interpersonal communication.

OBJECTIVE

The objective was to compare the attentional responses on a Stroop emotional task using words and faces by testing whether the two stimuli differ in the degree of interference they produce in patients with Alzheimer's disease (AD).

METHODS

There were 75 participants: 25 healthy older adults, 25 with mild AD, and 25 with moderate AD. A variation of the classic emotional Stroop test was administered. This task combined emotional words (happy or sad) superimposed on facial expressions (happy or sad), where the words were either incongruent or congruent with the emotion expressed by the face stimuli.

RESULTS

Facilitation was shown on negative words in healthy older adults, and significant effects were obtained for condition, valence, group, and the condition x group interaction. Although less interference was observed on negative stimuli, the fastest reaction times were found for congruent positive stimuli. The effect of interference in healthy older adults is similar in both conditions. However, in the AD groups, there is less interference on the words task than on the faces task.

CONCLUSION

The more complex nature of faces, as opposed to the over-learning and automaticity of words, may explain the higher interference in AD patients in the faces condition. In patients with AD, words can be a better method for recognizing emotions than affective facial expressions.