Kalogeropoulou, F. 1 , Vivas, A. 2 & Woodruff, P. 3
1 South East European Research Centre, Thessaloniki, Greece
2 City College, Thessaloniki, Greece
3 University of Sheffield, UK
Previous research has failed to report significant inhibition of return (IOR) with a single cue procedure in schizophrenia patients (Huey & Wexler,1994). This finding has been attributed to a deficit (Fuentes & Santiago, 1999) in voluntary re-orientating attention to the centre, however this hypothesis has not been tested directly. In this study the target appeared in 60% of the trials in the centre in an otherwise typical single cue IOR procedure (Posner & Cohen, 1984), to encourage endogenous shifting of attention to the center after the cue. In line with Posner and Cohen’s findings early facilitation effects were eliminates in the group of healthy adults. However, facilitation persisted in the group of schizophrenia patients. Most important patients similarly to healthy controls were able to shift their attention to the center according to expectations (overall faster responses to the central targets). These results suggest that endogenous manipulation of attention does not remove abnormally increased facilitation in schizophrenia. Furthermore, the lack of significant IOR in the group of patient cannot be attributed to a re-orienting deficit.