Temporal integration differences between crossed and uncrossed stereoscopic mechanisms

In this study, we investigated temporal integration of disparity information for crossed and uncrossed stereopsis. Across three experiments, exposure duration thresholds were measured for stereoscopic stimuli created from dynamic random-dot stereograms. In Experiment 1, an investigation of disparity detection showed that detection thresholds were equal for the crossed and uncrossed directions. In Experiment 2, an examination of duration limits for depth perception showed that critical durations were lower, and depth more veridical, for crossed depth than for uncrossed depth. In Experiment 3, an investigation of depth discrimination revealed that discrimination thresholds were lower for crossed depth than for uncrossed depth. These results suggest that crossed and uncrossed mechanisms differ in terms of their temporal integration properties at processing levels involving the computation and discrimination of depth.     

The Internet and sexuality education: Tapping into the wild side

To see whether observing information exchanges in “cyberspace” had a positive effect on computer usage and attitudes, students in an advanced undergraduate sexuality class were given an Internet project. Their pre- and postproject computer attitude and utilization reports were compared with those of a traditional computer usage research methods course taught by the same instructor. Overall, the e-mail/Internet project did not have a positive effect on computer usage and attitudes, whereas the more traditional computer as research tool usage taught in the methods class did have a positive effect.     

Increase in mastery levels using a computer-based tutorial/simulation in experimental psychology

A computer program was written in PCPilot to teach a unit in basic concepts in experimental design. The graphics-based program includes both tutorials and simulations. The students who used the program had significantly higher test scores than those in another class who did not; they reported that they enjoyed learning to use the program.     

Natural Disasters and Post-traumatic Stress Disorder Short-Term versus Long-Term Recovery in Two Disaster-Affected Communities1

Post-traumatic stress disorder (PTSD) in adults following disaster-precipitated family relocation was investigated in a longitudinal study of family and individual response to natural disasters. Adult participants included 78 women and 77 men in two communities. Psychosocial adjustment was measured at two points in time: at 4 months and 16 months after the disaster. Instruments used for assessing stress-related symptomatology included the Horowitz Impact of Event Scale (HIES) and the Diagnostic Interview Schedule (DIS). Major findings included: (a) levels of short-term stress symptomatology and diagnosable PTSD were substantial in both communities; (b) significant decrements in these levels occurred by 16-months postdisaster;(c) substantial gender differences (greater levels for women) were apparent in both short- and long-term PTSD response rates; and (d) patterns and levels of PTSD symptoms were different in the two communities. Findings have implications for the interpretation of PTSD within the context of family- and community-level variables.     

The Biological Findings in Post-Traumatic Stress Disorder: A Review1

In this paper the authors review the literature on biological and treatment studies of post-traumatic stress disorder (PTSD) and present current unifying hypotheses regarding the pathophysiology. The psychophysiological studies stress overarousal, while endocrine studies suggest a decreased Cortisol production in denial and low symptom states with increases in highly symptomatic states. Suggestive evidence is provided that PTSD is associated with permanent changes in brain mechanisms involving the locus coeruleus, amygdala, and the hypothalamo-pituitary-adrenal axis. Drug treatments are promising but not fully satisfactory as yet. Directions for further research are provided.     

Severity of psychosocial stress and outcome of alcoholism treatment

We examined the relation between stressful life events and drinking outcome among 129 male alcoholics who had completed an alcohol treatment program. Life events were assessed for the year prior to treatment and for the 3 months after treatment and were rated on the Psychiatric Epidemiology Research Interview and the Contextual Rating System. Approximately 40% of the pretreatment stressors were found to be directly or indirectly related to alcohol use. When stressors related to drinking were excluded from consideration, we found that men who returned to drinking after treatment experienced more severe or highly threatening stress before their relapse than men who remained abstinent during the follow-up period. These data suggest that although less severe stress may not increase risk for relapse, acute severe stressors and highly threatening chronic difficulties may be associated with elevated relapse risk.     

The effects of muscle tension on cerebral circulation in blood-phobic and non-phobic subjects

This study aimed to assess whether (1) a muscle tensing procedure which has been found to be useful in the treatment of blood-phobic patients produces an increase in heart rate and cerebral blood flow and (2) whether this increase is greater than that produced by mental effort alone. Subjects were 17 volunteers with a history of fainting in response to blood-injury stimuli, (12 were phobic) and 8 volunteers with no fainting history. They were required to (a) rest, (b) do mental arithmetic, and (c) repeatedly tense and release their arm and leg muscles. It was found that Ss, heart rate and cerebral blood flow velocity were significantly greater during the muscle tensing procedure than during mental arithmetic or resting conditions. The increased cerebral blood flow produced by muscle tensing may enable blood phobic patients to prevent fainting during exposure treatment.     

MMPI configural interpretation as applied to posttraumatic stress disorder in Vietnam veterans

This study investigated the systems of Minnesota Multiphasic Personality Inventory (MMPI) configural interpretation of Skinner and Jackson (1978) and Kunce (1979) with Vietnam veterans with posttraumatic stress disorder (PTSD). MMPI profiles of four groups differing in combat exposure were compared on four MMPI configural variables from Kunce (1979) and Skinner and Jackson (1978). The four groups were (a) PTSD sufferers, (b) Vietnam combat veterans without PTSD, (c) Vietnam noncombat veterans, and (d) Vietnam era veterans. All groups were further divided into hospitalized versus nonhospitalized subgroups. Dependent variables were Skinner and Jackson's (a) sociopathic modal profile, (b) neurotic profile, (c) psychotic profile, and (d) Kunce's emotional expression (enthusiastic-reserved) dimension. Results indicated that hospitalized PTSD subjects had significantly higher scores on Skinner and Jackson's neurotic profile; both hospitalized and nonhospitalized PTSD subjects had higher scores on the psychotic profile and were more "reserved" on Kunce's emotional expression dimension. Results were interpreted in terms of configural MMPI interpretation systems and the adjustment of Vietnam veterans with PTSD. PTSD was viewed as exhibiting cognitive, somatic, and affective features.