The impact of aging and Alzheimers disease on decoding emotion cues from bodily motion.

Abstract

Both healthy aging and dementia cause problems with emotion perception, and the impairment is generally greater for specific emotions (anger, sadness and fear). Most studies to date have focused on static facial photographs of emotions. The current study investigated the effects of healthy aging and Alzheimer's disease (AD) on the ability to decode emotions from bodily motion displayed by point light stimuli. Response biases were controlled to investigate whether these influenced the specificity of impairment in perceiving individual emotions. Study 1 compared healthy young and older adults, and Study 2 people with AD and age-matched controls, on an emotion perception task using point light stimuli. Accuracy and the pattern of errors were investigated. Specific age-related impairments were found in labeling sadness, anger and fear from point light displays. Response biases were also found, and controlling for these biases indicated that older adults were worse at labeling all emotions. People with AD were less accurate than healthy older controls at labeling fear, anger and sadness. After controlling for response biases, AD caused impairment in perceiving all emotions. These results indicate a general age-related impairment in decoding emotions from bodily motion, and a further impairment in this skill in AD. Apparent specificity of deficits in emotion labeling tasks needs to be interpreted cautiously, and correction for response bias should be considered. Problems perceiving emotion cues from biological motion might impair social interaction in older adults, particularly those with dementia.