Confusion of fear and surprise: a test of the perceptual-attentional limitation hypothesis with eye movement monitoring.

Of the basic emotional facial expressions, fear is typically less accurately recognised as a result of being confused with surprise. According to the perceptual-attentional limitation hypothesis, the difficulty in recognising fear could be attributed to the similar visual configuration with surprise. In effect, they share more muscle movements than they possess distinctive ones. The main goal of the current study was to test the perceptual-attentional limitation hypothesis in the recognition of fear and surprise using eye movement recording and by manipulating the distinctiveness between expressions. Results revealed that when the brow lowerer is the only distinctive feature between expressions, accuracy is lower, participants spend more time looking at stimuli and they make more comparisons between expressions than when stimuli include the lip stretcher. These results not only support the perceptual-attentional limitation hypothesis but extend its definition by suggesting that it is not solely the number of distinctive features that is important but also their qualitative value.