Cognitive function in post-traumatic stress disorder
Complaints of poor memory by individuals with posttraumatic stress disorder (PTSD) have engendered research into attention and memory functioning in this disorder. Due to numerous methodological difficulties encountered in research with this group, results have been inconclusive. In Chapter 1 of this thesis the existing literature is reviewed to ascertain whether there is any evidence of a specific pattern of memory disorder associated with PTSD. Studies are reviewed for evidence of cognitive deficits relating to the structures of the limbic system. dysfunction in which has been implicated in PTSD. It is concluded that there is relatively good evidence of deficits related to probable frontal lobe functions. However, there is very little evidence of hippocampal related disorders and no studies have investigated memory functions relating to hypothesised roles of the amygdala in this group. In chapters 2 and 3 experiments are described that aim to investigate cognitive abilities related to amygdala functioning in PTSD. Chapter 2 investigates an hypothesised role of the amygdala in the consolidation of memory for emotional material. The results confirm the possibility of amygdala dysfunction in PTSD by showing that on a test of free recall participants with PTSD forgot emotional word stimuli at a faster rate than control participants, whereas non-emotional stimuli were forgotten at a more normal rate. Chapter 3 investigated a second hypothesised role for the amygdala in the recognition of facial expressions of fear and anger. Results showed that PTSD participants were somewhat impaired in their recognition of these expressions, which contrasted with an enhanced ability, associated with symptoms of hyperarousal, in identifying other negative facial expressions. In Chapter 4, the relevance of neuropsychological research to Clinical Psychology is discussed. It is argued that such research is vital if we are to fully understand the difficulties clients could face on a day-to-day basis.