This study examined the relationship between image vividness and psychophys
iological responses to trauma-related stimuli in participants with Posttrau
matic Stress Disorder (PTSD). An auditory stimulus related to a shared trau
ma was presented to participants with and without PTSD and physiological pa
rameters (heart rate and blood pressure) were measured concurrently. A nega
tive correlation was noted in the PTSD group between image vividness and th
e level of physiological response. When the PTSD group was divided into hig
h and low vividness, the physiological response was higher than that of the
non-PTSD controls only when image vividness was low. The results are discu
ssed in the context of Lang's theoretical model, emphasizing the role of im
age vividness in the mediation and regulation of psychophysiology.