Stress induces a functional asymmetry in an emotional attention task.

Anxiety is associated with an attentional bias towards angry faces. This effect is most pronounced when the face is presented in the left visual hemifield (LVHF), suggestive of a right hemisphere involvement. Little is known about the modulation of this attentional bias in situations of acute stress. In the current study 38 male participants were randomly allocated to a stress (Trier Social Stress Test; TSST) or a non-stressful control condition. Afterwards they performed an emotional dot-probe paradigm. Stress induced negative affect and a rise in salivary cortisol. Stress caused a pattern of functional asymmetry in the short stimulus onset asynchrony (SOA) interval, which was absent in the control group. Stressed participants responded faster to angry faces presented to the LVHF, but responded faster to happy faces presented to the right VHF. This could suggest that stress influences interhemispheric transfer of information that is relevant for emotion processing.