INFORMATION-PROCESSING IN POSTTRAUMATIC-STRESS-DISORDER

Previous research has established that patients suffering from anxiety disorders, including post-traumatic stress disorder (PTSD), exhibit a cognitive bias that selectively favours the processing of threat mate rial. This information processing bias has frequently been demonstrate d by subjects' performance on the Stroop colour-naming task. The curre nt experiment investigated the selective processing of threat informat ion in people with PTSD using a modified Stroop procedure. Subjects we re 13 ferry disaster survivors with high PTSD symptomatology, 20 survi vors of the same disaster with low PTSD symptomatology, and 12 non-tra umatized control subjects. All were asked to colour-name five types of words: ferry disaster words, general threat words, neutral semantical ly-unrelated words, neutral semantically-related words, and positive w ords. The disaster survivors with high levels of PTSD symptomatology e videnced a significantly longer response latency for colour-naming dis aster-related words than for other word types. The results of the low- PTSD survivors and non-traumatized controls showed no significant diff erence between response latencies for general threat words and disaste r word, although all 3 groups showed increased latencies for threat wo rds compared with neutral words. The mechanisms proposed to underlie t his response pattern are discussed, and clinical implications are cons idered.