Table 1.

Studies examining the P50 and sensory gating

Study	Subjects	Paradigm	Results
[51]	46 prisoners of war 36 healthy controls	Checkerboard reversal (visual)	Significantly greater P50 amplitude and latency
[52]	10 inpatient combat PTSD 5 inpatient alcohol-dependents 5 combat-exposed and 5 combat-non-exposed healthy subjects	Paired click	Diminished P50 habituation in PTSD
[25]	13 female with sexual assault PTSD 16 healthy controls	Auditory oddball	No difference in P50 peak amplitude and latency
[53]	15 combat veterans 12 healthy control	Paired click	P50 amplitude in response to the conditioning stimulus did not differ. P50 T/C ratio was increased in PTSD subjects.
[54]	10 male veteran PTSD + 9 female rape victims matched control groups	Paired click	Decreased P50 gating
[32]	29 PTSD nurse veterans 38 non-PTSD	Paired click	Reduced P50 suppression associated with increased severity of general psychopathology, but not with PTSD.
[27]	12 urban violence PTSD/24 healthy subjects/12 schizophrenics	Paired click	Higher P50 ratios in subjects with PTSD
[55]	27 civilian with mixed types of trauma and 24 control subjects	Paired click	Impaired P50 suppression in PTSD subjects
[26]	Seven combat veterans with PTSD and 11 matched controls	Paired click	Impaired M50 gating in the right hemisphere in PTSD subjects. Thinner right STG (Superior Temporal Gyrus) cortical thickness was associated with worse right sensory gating in the PTSD group. The right S1 P50 source strength and gating ratio were correlated with PTSD symptomatology.