A system for the assessment of human performance in concurrent verbal and manual control tasks

A multipurpose laboratory system incorporating a voice interactive terminal and graphic display system is described. The facility is designed to investigate some aspects of human performance on concurrent verbal and tracking tasks. The results of a pilot study showing decrements in dual-task performance are reported.     

Treatment of obsessive-compulsive patients: The contribution of self-instructional training to the effectiveness of exposure

Fifteen obsessive-compulsive patients were given treatment consisting of ten sessions of gradual exposure in vivo. For half of the patients gradual exposure in vivo was preceded by self-instructional training.Treatment resulted in significant improvement on anxiety and avoidance scales, Leyton Obsessional Inventory, Self-rating Depression Scale and on ratings for anxious mood and depression. Neither the post-test nor the follow-ups 1 month and 6 months later indicated a difference between the effects of the two conditions. Self-instructional training did not enhance the effectiveness of gradual exposure in vivo.     

Alcohol consumption by college women following exposure to unsolvable problems: Learned helplessness or stress induced drinking?

Three experiments were intended to examine the relationship between alcohol, depression and learned helplessness. In Study I, more female undergraduate heavy drinkers than light drinkers were found to have critically elevated scores on a depression index. A sex difference in the relationship between drinking and depression is suggested since male depressives were equally distributed among drinking categories. In Studies II and III, female undergraduates were given unsolvable problems in a learned helplessness paradigm. Relative to controls these subjects reported increased depressive and hostile affect and drank more beer in a taste rating task. However, we failed to find deficits in anagram solution with those subjects given the learned helplessness manipulation. Specific questions are raised regarding the boundary conditions of learned helplessness while implications bearing on stress-related alcohol consumption are discussed.     

Self-report and physiologic responding during in vivo flooding

Self-report and physiologic measures of arousal were obtained during in vivo flooding sessions. Minimal correspondence was found between these two assessment modalities. The significance of these findings for treatment is discussed.     

Effects of stress and retesting on role play tests of social skill

The purpose of this study was to examine the role of stress in performance on role play tests of social skill. Chronic psychiatric patients were tested in a formal videotape studio or in an informal consulting room setting. Motoric and physiological measures were secured. In addition, one-half of the subjects were retested one week later. In contrast to previous studies, results indicated that the assessment was not stressful. The two groups were not different on any measure, and the mean heart rates ranged from only 80 to 84 b.p.m. The effects of retesting were difficult to interpret. There were reductions in motoric indices of anxiety (speech disruptions) but not on physiological indices. Overall, testretest reliability was quite high. The results raise several questions which affect interpretation of many social skills studies in the literature.     

Suprathreshold binocular interactions for grating patterns

Binocular interactions of suprathreshold grating patterns have been investigated using a reaction time measure of contrast detection. Simple reaction times were determined for monocular and binocular viewing conditions over a contrast range from .63 to near threshold. The results from all subjects showed binocular summation for contrast levels near threshold, but there was considerable variation across subjects for contrast levels above threshold. Some subjects showed summation over the entire contrast range, but other subjects showed either binocular inhibition or binocular facilitation for some range of contrast levels. The pattern of binocular interaction for a given subject was consistent for several spatial frequencies. The differences in types of interaction between subjects, the variation in magnitude of binocular interaction with contrast level for each subject, and the data from experiments involving stimulation of noncorresponding retinal areas show that the binocular interactions found for suprathreshold stimuli cannot be accounted for on the basis of probability, and must, therefore, result from physiological interactions between the two eyes. These interactions have been investigated further under conditions of (1) induced fixation disparity, (2) horizontal gratings, and (3) orthogonally oriented gratings.     

Saltation through the blind spot

At least three localization illusions can be produced by varying the time relations between two stimuli. Two of these, phi motion and Békésy’s illusion, have been induced in areas lacking receptors. To learn if this also occurred with the third illusion, sensory saltation, people reported their observations when Geldard’s visual rabbit was induced by stimulating points around the optic disk. The rabbit crossed the blind spot as well as other portions of the eyes, and the illusory point was often localized within the region of the blind spot. All three illusions can be localized in an area devoid of receptors.     

Intracranial cannulation of small animals

Special difficulties are encountered when attempting to provide intracranial cannulation of small animals that have floating or fragile skull bones. The technique described was developed for mice but seems applicable to other species. The cannula system is inexpensive and easy to use. A wound clip anchor seems superior to either skull screws or bonded acrylic, producing less damage to the brain and no necrosis of bone or tissue on the wound margin. Patency data up to 25 days is presented, and the system is as efficacious as other techniques.