Contrast processing is a fundamental function of the visual system, and contrast sensitivity as a function of spatial frequency (CSF) provides critical information about the integrity of the system. Here, we used a novel iPad-based instrument to collect CSFs and fitted the data with a difference of Gaussians model to investigate the neurophysiological bases of the spatial CSF. The reliability of repeat testing within and across sessions was evaluated in a sample of 22 adults for five spatial frequencies (0.
View Article and Find Full Text PDFBoth emotion and visual processing deficits are documented in schizophrenia, and preferential magnocellular visual pathway dysfunction has been reported in several studies. This study examined the contribution to emotion-processing deficits of magnocellular and parvocellular visual pathway function, based on stimulus properties and shape of contrast response functions. Experiment 1 examined the relationship between contrast sensitivity to magnocellular- and parvocellular-biased stimuli and emotion recognition using the Penn Emotion Recognition (ER-40) and Emotion Differentiation (EMODIFF) tests.
View Article and Find Full Text PDFObjective: The purpose of the study was to assess the prevalence of DSM-IV dissociative disorders in an inner-city outpatient psychiatric population.
Method: Subjects were 231 consecutive admissions (84 men and 147 women, mean age=37 years) to an inner-city, hospital-based outpatient psychiatric clinic. The subjects completed self-report measures of dissociation (Dissociative Experiences Scale) and trauma history (Traumatic Experiences Questionnaire).