[Discrimination thresholds for recognizing facial emotions: mostly higher among the elderly]

Elderly people have lower ability for recognizing facial emotions than younger people. Previous studies showed that older adults had difficulty in recognizing anger, sadness and fear, but there were no consistent results for happiness, surprise and disgust. Most of these studies used a small number of stimuli, and tabulated the number of correct responses for facial expressions. These characteristics of the task might be the source of the discrepancy in the findings. The present study used a task which measures participants' discrimination thresholds for six basic emotions using psychophysical measurement methods. The results showed that the thresholds for elderly participants (74.8 +/- 6.5 yrs) were significantly higher than for younger participants (20.1 +/- 1.6 yrs) for sadness, surprise, anger, disgust and fear. There was no significant difference for happiness. Since the task that we developed was sufficiently sensitive, it is a useful tool for assessing individuals' ability to perceive emotion.