Psychological Medicine

Original Articles

Electrophysiological evidence of attentional biases in social anxiety disorder

E. M. Muellera1a2, S. G. Hofmanna1, D. L. Santessoa2, A. E. Meureta3, S. Bitrana1 and D. A. Pizzagallia2 c1

a1 Department of Psychology, Boston University, Boston, MA, USA

a2 Department of Psychology, Harvard University, Cambridge, MA, USA

a3 Department of Psychology, Southern Methodist University, Dallas, TX, USA


Background Previous studies investigating attentional biases in social anxiety disorder (SAD) have yielded mixed results. Recent event-related potential (ERP) studies using the dot-probe paradigm in non-anxious participants have shown that the P1 component is sensitive to visuospatial attention towards emotional faces. We used a dot-probe task in conjunction with high-density ERPs and source localization to investigate attentional biases in SAD.

Method Twelve SAD and 15 control participants performed a modified dot-probe task using angry–neutral and happy–neutral face pairs. The P1 component elicited by face pairs was analyzed to test the hypothesis that SAD participants would display early hypervigilance to threat-related cues. The P1 component to probes replacing angry, happy or neutral faces was used to evaluate whether SAD participants show either sustained hypervigilance or decreased visual processing of threat-related cues at later processing stages.

Results Compared to controls, SAD participants showed relatively (a) potentiated P1 amplitudes and fusiform gyrus (FG) activation to angry–neutral versus happy–neutral face pairs; (b) decreased P1 amplitudes to probes replacing emotional (angry and happy) versus neutral faces; and (c) higher sensitivity (d′) to probes following angry–neutral versus happy–neutral face pairs. SAD participants also showed significantly shorter reaction times (RTs) to probes replacing angry versus happy faces, but no group differences emerged for RT.

Conclusions The results provide electrophysiological support for early hypervigilance to angry faces in SAD with involvement of the FG, and reduced visual processing of emotionally salient locations at later stages of information processing, which might be a manifestation of attentional avoidance.

(Received March 26 2008)

(Revised October 10 2008)

(Accepted October 23 2008)

(Online publication December 15 2008)


c1 Address for correspondence: D. A. Pizzagalli, Ph.D., Department of Psychology, Harvard University, 1220 William James Hall, 33 Kirkland Street, Cambridge, MA 02138, USA. (Email:


The present findings were presented in preliminary form at the conference ‘Tagung experimentell arbeitender Psychologen 2008’ (TeaP) in Marburg, Germany, 3–5 March 2008.