Our bias towards negative interpretation of ambiguous faces

Neta and Whalen make some interesting observations (on the usual cadre of undergraduate psychology students usually involved in such studies), showing that we have a 'better be safe than sorry' strategy in responding to ambiguous expressions of surprise that could signal either a negative or positive situation.  We pick the negative interpretation, and our background bias towards being positive or negative biases this effect.:

Low-spatial-frequency (LSF) visual information is processed in an elemental fashion before a finer analysis of high-spatial-frequency information. Further, the amygdala is particularly responsive to LSF information contained within negative (e.g., fearful) facial expressions. In a separate line of research, it has been shown that surprised facial expressions are ambiguous in that they can be interpreted as either negatively or positively valenced. More negative interpretations of surprise are associated with increased ventral amygdala activity. In this report, we show that LSF presentations of surprised expressions bias the interpretation of surprised expressions in a negative direction, a finding suggesting that negative interpretations are first and fast during the resolution of ambiguous valence.