Increment thresholds against pulsed and steady backgrounds

Cornsweet and Pinsker reported that ΔL/L was constant at all values of L for briefly pulsed fields (ΔL was the luminance increment required for discriminating which of two nearby flashed fields was brighter). We obtain the same result when the subject must detect which of two briefly (4-msec) flashed backgrounds contains an increment at its center. However, when the background and increment are flashed at a longer duration (200 msec) ΔL/L decreases with increasing L as is obtained with a steady background. Two previous models which handle earlier work do not readily accommodate this result; we suggest a theoretical approach that does.     

U-shaped masking functions in visual backward masking: Effects of target configuration and retinal position

Printed letters were found to become increasingly susceptible to visual backward masking when presented to one side of the point of fixation: All masking was found to be a u-shaped function of the time interval separating the offset of the target from the onset of the masking figure. The interval at which maximum masking was observed, as well as the amount of masking observed, varied with the target-mask configuration studied. More masking was found when the ISI field was lighted than when it was not.     

Developing the Individual: Life Skills and Family Therapy

Two bodies of literature on life skills and on family therapy have developed from different sources but have interesting similarities. Life skills comes from training and educational thinking, and concentrates upon the skills of and strategies for coping. Family therapy focuses upon the disturbance of an individual as symbolic of the dynamics of the family, but has at its roots a more-or-less explicit model of what constitutes an effective family, where the interactions can be readily understood in life-skill terms. The two approaches are compared and contrasted.     

The force/force-variability relationship under controlled temporal conditions

Previously, an inverted U relationship between force and force variability was demonstrated in both static and dynamic responses. Recent research suggests that the inverted U function may be due to a lack of control of the temporal aspects of the response. To investigate this hypothesis, we examined the relationship between force and force variability in rapid movements under controlled temporal conditions. Subjects (N = 4) made rapid reversal responses with a horizontal lever (using elbow flexion and extension) such that the time to reversal (160 ms) and the distance to reversal (45 degrees ) were held constant in each of six load conditions (either 0,.260,.780, 1.040, or 1.560 kg added to the lever). When time to reversal and time to peak acceleration were held constant, a curvilinear relationship between force and force variability resulted, suggesting that the inverted U function is related to control of the temporal aspects of the response.     

Reexamination of relations between the Myers-Briggs type indicator and field dependence-independence

The Group Embedded Figures Test and the Myers-Briggs Type Indicator were administered to 210 undergraduate and graduate students. Bivariate relations between the embedded figures test and the Indicator scales of Extraversion-Introversion (EI), Thinking-Feeling (TF), and Judgment-Perception (JP) were nonsignificant while the relation between scores on embedded figures and Sensing-Intuition (SN) was statistically significant. ESFP, ISFJ, and ESFJ types were significantly more field-dependent than the INFP and ENTP types.     

Clinical and pathophysiologic aspects of viral infections of the CNS

The available defensive mechanisms are generally sufficient to protect the central nervous system (CNS) against the penetration of infectious particles. The blood-brain-barrier plays a decisive role in this process. The present paper represents the most important circumstances realizing that: 1. The macrophage-lymphocyte-system, 2. the "oligoclonal-CSF-IgG-reaction", and 3. the influence of psychological and physiological burdens on clinical-chemical or immunological parameters. It seems to be important to overcome the instability of the immunosystem and to reestablish the base-line.     

Inhibition by Reinforcement: Effects of Reinforcer Magnitude and Timeout on Fixed-Ratio Pausing

The Psychological Record - Rats were trained on fixed-ratio schedules with different reinforcer magnitudes (concentrations of sweetened milk), using procedures in which responding was allowed to...     

Catecholamine training effects from exercise programs: A bridge to exercise-temperament relationships

Three studies were conducted to test whether a catecholamine training effect results from a long-term aerobic exercise program. Study I showed significant increases in urinary adrenaline and noradrenaline following moderate mental stress/challenge for male aerobics subjects after a semester of training. Control groups of nonexercisers and continuously in-condition marathoners showed no comparable pre- to post semester catecholamine increases. Male and female Aerobics subjects were contrasted with nonexercisers across a semester in Study 2; the hypothesis was confirmed that postsemester increases in catecholamines occurred only following an episode of mental challenges/stress, and not following base-rate-rest conditions. Under conditions of more active challenge than in Studies 1 and 2, women subjects in Study 3 provided directional but nonsignificant support for the Study 2 findings. The results are discussed in the context of literature on the relationship of catecholamine availability during challenge/stress to temperament and on the relationship of aerobic training to temperament. At a theoretical level, the question is discussed of increased catecholamine availability being a likely mediator in the exercise program to temperament relationship.This research was supported by a grant from the Research Council of the University of Nebraska Lincoln. Our thanks to Prof. James Crabbe for assistance in recruiting subjects in Study 2, and to Pamela Brown and Prof. Wes Sime for assistance with Study 3.