Perception of a throwing action from point-light demonstrations

80 adults (40 men and 40 women) aged 18 to 25 yr. and 80 boys aged 14 to 15 yr. observed a throwing action presented in point-light form at a frontoparallel viewpoint either as a video film or computer simulation of the actor. The display consisted of the relative motion of the wrist, elbow, and shoulder joints of the throwing arm. Subjects were asked to report what they observed. The action was recognised immediately by 68% of all subjects, and this value increased to 90% with one more viewing of the demonstration. Response was virtually the same for both types of display, and there were no differences between adults and children. The results were similar to those from other studies from which researchers have concluded that kinematic information alone is sufficient to permit perception of fundamental patterns of movement.     

Effect of mouth opening on bite-force discrimination

The purpose of this study was to determine whether different extents of mouth opening affect normal subjects' (N = 24; 12 women, 12 men) ability to discriminate differences in their interincisor bite force. Three mouth openings were selected including 50, 70, and 90 percent of maximum opening for each subject. Bite force was measured using a specially designed strain gauge scale which permitted subjects to monitor visually when their biting force equalled a preset resistance. Resistance forces of 500 and 1000 gm. were selected as standards. The procedure involved the use of a modified method of constant stimuli in which each subject was presented with a series of paired resistance settings, one at a time--the first resistance setting being the standard and the second resistance was the comparator. This paired-comparisons procedure was continued until the subjects' difference limen (DL) value (the threshold of discrimination between two forces) could be established. An analysis of variance yielded no significant differences in subjects' ability to discriminate bite force as a function of mouth opening.     

Some types of conditioned inhibitors carry collateral excitatory associations

Two experiments using summation tests in conditioned suppression with rats examined whether conditioned inhibitors generated by five different conditioning procedures have an associative structure which includes collateral excitatory associations. The existence of collateral conditioned excitation was inferred from an increase in the amount of manifest conditioned inhibition after a conditioned inhibitory stimulus (CS-) extinction treatment. The five CS-s evaluated were differential, explicitly unpaired, conditional, backward, and trace. With abbreviated conditioning (Experiment 1), the differential and explicitly unpaired CS-s exhibited conditioned inhibitory properties; the conditional, backward, and trace CS-s did not. Repeated extinction presentations of the CS- in the absence of the unconditioned stimulus unmasked conditioned inhibition to the conditional, backward, and trace CS-s revealing moderate degrees of conditioned inhibition for all five CS-s. After more extensive conditioning (Experiment 2), the explicitly unpaired and conditional CS-s were strongly inhibitory and the differential and trace CS-s were moderately inhibitory. The backward CS- was not inhibitory. Repeated presentations of the CS- in extinction unmasked conditioned inhibition to trace and backward CS-s. All five CS-s were now nearly equally inhibitory. That the measured inhibitory power of backward, trace, and conditional (after few trials) CS-s can be modulated by a CS- extinction treatment suggests that they have similar associative structures and carry, in addition to inhibitory associations, collateral excitatory associations that mask the expression of conditioned inhibition.     

Tendency to display spontaneous incubation does not affect maternal responsiveness in the domestic hen

Induction of maternal behavior was performed in 63-week-old hens of the JV15 (or "Vedette") strain which had previously exhibited brief incubating phases during the preceding egg-laying period to discover if their maternal behavior differed from that induced in hens who had no previous record of incubating. The degree of maternal behavior exhibited showed large variation among individuals. However, hens with a history of one or more spontaneous, brief incubation bouts and hens without such histories showed similar responsiveness toward chicks and similar levels of general activity. In most of the subjects, the establishment of maternal behavior was accompanied by a significant long-term fall in the plasma levels of luteinizing hormone whereas the plasma levels of prolactin appeared to be unaffected.     

The Hopelessness Scale for Children: Psychometric properties with normal and emotionally disturbed adolescents

The psychometric properties of the Hopelessness Scale for Children (HSC) were evaluated with a sample of 834 normal adolescents and 93 adolescent suicide attempters. Factor analyses studies revealed two factors with both groups. Internal consistency with item-total score correlations were acceptable, while moderate test-retest reliability was found over a 10-week period with the normal sample. Support for the validity of the HSC was provided via studies with the suicide attempter group in which positive correlations with depression and depressive attributional style were found. Predicted differences between the suicide attempters, an outpatient psychiatric sample, and normal controls were also found. However, some items did not appear to discriminate suicide attempters from controls. Results are discussed in terms of the utility of the HSC with adolescents and adolescent suicide attempters and with regard to differences between child and adult samples in hopelessness.     

Predicting outcome of insanity acquittees released to the community

This research developed a model for forensic release decisions that incorporated actuarial and psychiatric predictors. The model was based on research that compared 127 insanity acquittees in the State of Maryland with a matched control group of 127 convicted felons and a comparison group of 135 mentally disordered prison transfers. The three cohorts were followed for an average of 10 years after release from hospital or prison. Findings on two outcome indicators are reported in this article: rearrests within 5 years after release and overall functioning in the community during 2½ years after release. Discriminant analysis was performed on the outcome variable of rearrest; it was found to accurately predict the outcome of 75% of the subjects with the following six variables: adjustment in hospital, clinical assessment of hospital staff, Global Assessment Scale score at release, functioning prior to instant offense, heroin addiction, and birth order. A second discriminant analysis identified seven variables that accurately predicted the overall functioning of 80.4% of the insanity acquittees.     

Influence of sex and gender roles on high school status systems

Past research has indicated significant sex differences in determinants of male and female high school students' status as measured by how subjects would like to have been remembered from their high school years. In order to determine if remembrance preference is sex or gender role related, 671 subjects were administered the Bem Sex-Role Inventory (BSRI) and a questionnaire asking if they most wanted to be remembered from high school as a brilliant student, leader in activities, athletic star or most popular. Using both the median split and t-ratio procedures in scoring the BSRI, 206 subjects were selected because they were sex-typed (masculine males, feminine females), cross sex-typed (masculine females, feminine males), or androgynous (scoring high on both masculine and feminine traits). To find a model of best fit, the data were subjected to a log-linear analysis. The variables included were sex, gender role, and remembrance preference. Rather than sex being the influential factor, the model of best fit was a gender role by remembrance preference interaction. If subjects were masculine, they were more likely to choose athletic star than were feminine or androgynous subjects. Most popular and leader in activities were both more likely to be chosen by feminine and androgynous subjects. All groups chose brilliant student more often than any other category. It was concluded that some previously designated sex differences may instead be differences in gender role. Further research should address the distinction between the two.     

Cautiousness and visual selective attention performance among older adults

Cautiousness has been implicated in the literature as a possible factor responsible for observed performance decrements among older adults in a number of research paradigms. This study sought to assess whether the speed and accuracy of performance on a perceptual-cognitive task (the Stroop Color-Word Interference Test) differed significantly for more and less cautious older adults. The participants (N = 41), ranging from 55 to 81 years of age, were classified as either more cautious (n = 20) or less cautious (n = 21) on the basis of their responses on a personality test. Results indicated that cautiousness among older adults was manifested more in terms of the accuracy of response (fewer errors of commission) than in terms of the speed of response, and that level of cautiousness increased with increasing age.