Integral bias in the cognitive processing of emotionally linked pictures.

It is well established that human cognitive processes are subject to systematic biases associated with particular emotional states. But how do these cognitive biases arise? This question was addressed by means of a pictorial Stroop task which allowed the development of such a bias to be assessed. In each of two experiments, spider-phobic participants were significantly impaired at naming the colours of phobia-related pictures relative to those of control pictures. Investigation of the magnitude of this effect for participants of different ages allowed two contrasting hypotheses concerning the development of such biases to be compared. The integral bias hypothesis asserts that the effects of emotion on cognition reflect integral links between emotional states and cognitive mechanisms, links that are not arbitrary but instead are fixed constituents of our mental architecture. In contrast, the inferred bias hypothesis asserts that these effects arise as a consequence of the gradual establishment of associations between particular emotional states and particular patterns of cognitive behaviour. It was found that the magnitude of the observed bias remained approximately constant irrespective either of the ages of participants or of the directly estimated durations of their phobias. This fixed relation provides strong support for the integral bias explanation of the cognitive effects of an emotional disturbance. Finally, the evolutionary context in which integral links between emotion and cognition may arise is discussed