acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

It has been postulated that two sets of information-processing channels exist in the visual system: a high spatial frequency set responding optimally to slow-moving or stationary patterns, and a low spatial frequency set of motion-analyzers which respond optimally to stimuli of rapid rates of temporal presentation (Tolhurst et al., 1973). In the present study, spatial and temporal channels of processing were investigated with three visual tests: visual masking, evoked potentials, and contrast sensitivity Both normal observers and 13 patients with optic neuritis secondary to multiple sclerosis (MS) performed these tests. It was proposed that the difficulties encountered in seeing by MS patients might derive from processing problems associated with primarily the low spatial frequency or motion-detector channels, based on previous reports that some MS patients exhibited losses of contrast sensitivity to low and medium (but not high) spatial frequency gratings, and also experienced discrimination problems when faced with different rates of flicker Results of the present study indicated that both spatial and temporal channels were compromised for the MS patients. Performance of the MS patients was significantly below performance of the norm for all three tests. However, these losses of visual functioning for the MS patients were idiosyncratic, indicating that although spatio-temporal processing had been affected by the disease, no one of the three tests served as the best indicator of visual disorder In summary, it appears that visual tests which incorporate both spatial and temporal manipulations improve the detection of visual abnormalities due to optic neuritis or multiple sclerosis / acase@tulane.edu

Recent research indicates that although most treatment approaches for obesity can produce some temporary weight loss, few sustain long-term maintenance (Abramson, 1983: Stunkard & Penick, 1979). Brownell (1982) has recommended aggressive new approaches to weight loss which can produce medically, psychologically, and cosmetically significant weight losses. In combination with behavior therapy, he suggested the use of very low calorie diets (VLCD's) which are now proven safe and effective if patients are monitored medically (Wadden et al., 1983). Traditionally, very low calorie diets produce large weight losses, but the losses are usually poorly maintained (Van Itallie, 1980). The hope, then, would be that in conjunction with the very low calorie diet, behavior therapy might sustain the large diet-produced losses (Brownell, 1982) It may be important to conceptualize interventions to produce weight loss and weight maintenance as necessarily different learning experiences. Through this differentiation, an additional treatment strategy (i.e., a post weight loss, pre-maintenance treatment) would be required before successful maintenance can ensue This investigation evaluates the effectiveness of a premaintenance treatment in maintaining prior weight loss. All subjects in this study completed a medical weight loss regimen and achieved 'ideal weight' prior to entering treatment. One third of the subjects (N = 10) received individualized calorie training and behavior rehearsal under personalized maintenance level. One third (N = 10) were exposed to standard maintenance (booster) sessions. The remaining one third (N = 10) were monitored through weekly and then biweekly clinic weigh-ins, but no other intervention was provided. All subjects were required to keep daily logs (self-monitored records of daily weight, caloric intake, water intake) which were turned in at the time of each clinic weighing. Additionally, subjects were administered calorie proficiency tests during weeks one, four and twelve. Dependent measures were clinic measures of weight and the scores on the calorie proficiency tests The first prediction was that maintenance of weight losses for the three groups would be differentially affected by the experimental training. However, this was not substantiated. Interestingly, based on clinic standards which define weight gain as an upward deviation from the criterion of ideal weight by more than three pounds, all subjects on the whole were very successful in weight maintenance. (Abstract shortened with permission of author.) / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu