Individuals with schizophrenia have problems with visual contrast processing. The current study investigated contrast sensitivity (CS) in schizophrenia/schizoaffective disorder to elucidate the underlying neural mechanisms affected by this disorder and to identify critical testing conditions that distinguish individuals with the disorder from healthy individuals. Principal component analysis was applied to the data (N = 143) to separate responses from distinct visual pathways. Participants were 68 patients and 75 age-similar controls. CS was obtained using a forced-choice psychophysical paradigm with grating patterns of low to high spatial frequency presented at short and long durations. Linear mixed-effects models were used to examine differences in log CS with respect to group, duration, and stimulus condition. Lower CSs were found in patients compared to controls over all stimulus conditions with the magnitude of deficits dependent on both spatial frequency and stimulus duration. Log CSs to low and high spatial frequencies loaded onto separate principal components, supporting the existence of two psychophysical mechanisms, transient and sustained. Critical conditions were identified to tap each mechanism. Visual acuity was correlated moderately with log CS to high, but not low, spatial frequencies, and deficits found for acuity and CS to moderate/high spatial frequencies (4-21 cycles/ degree) appear to reflect dysfunction in the sustained mechanism. CS deficits found at the lowest spatial frequency tested (0.5 cycles/degree) appear to reflect dysfunction in the transient mechanism. Both types of CS deficits may have diagnostic value and implications for social and neurocognitive deficits in this disorder.
During their return from combat, warriors from Greek mythology and Native American traditions received the support of “helpers” to guide the reintegration back into their communities or tribes. While the military provides our modern warriors (MWs), similar helpers, during their departure from their hometown and during their initiation into the military, there is a dearth of comparable help when MWs reintegrate back into their hometowns. We strive to assist mental health providers to serve as such helpers for MWs to shape their reintegration environment, enable MWs to meet their unique needs after exiting the military, ameliorate the MW suicide epidemic, and facilitate MWs to continue their next “mission” to serve and improve society with a newly forged MW identity, wisdom, and sense of purpose.
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