A right-ear advantage in monotic shadowing

Lists of 30 monosyllabic words drawn at random with replacement from a set of 69 were presented monotically to the right or left ear of 28 subjects for immediate repetition (shadowing) at a rate of 120 words per minute. Each subject shadowed 40 lists. A right-ear advantage was found over the first 1.5 blocks (15 lists) but not for the remaining 2.5 blocks (25 lists). The results are related to previous investigations of monotic and dichotic listening, and are explained by a set (bias) in attention or response which favours the right ear and declines with practice.     

A comparison of signaled and unsignaled delay of reinforcement

Pigeons were trained on either a variable-interval 60-second schedule, or on a schedule that differentially reinforced responses that were spaced at least 20 seconds apart. The birds were then exposed to several durations of reinforcement delay, with comparisons between signaled and unsignaled delays. Although unsignaled delays of 5 and 10 seconds produced large decreases in response rate, signaled delays of up to 10 seconds produced only moderate decreases in response rates. In addition, some subjects responded more rapidly with a .5 or 1.0 second duration of unsignaled delay than with immediate reinforcement. These response rate changes occurred regardless of whether the rate of reinforcement concomitantly decreased or increased.     

The ambiguous-cue problem: The effects of reduced similarity between trials and the schedule of reinforcement

In a series of seven experiments pigeons were trained on the two-choice ambiguous-cue problem that contains PA and NA trials. On PA trials choice of P (the positive stimulus) was reinforced and choice of A (the so-called ambiguous stimulus) was not reinforced; on NA trials choice of A was reinforced and choice of N (the negative stimulus) was not reinforced. When the two types of trials were distinguished by only the presence of P or N and each trial was terminated by one response, subjects quickly attained high levels of performance on NA trials but showed only chance levels of performance on PA trials. PA performance was markedly improved when a variety of additional stimuli distinguished the two types of trials and when a variety of schedules of intermittent reinforcement were employed; these manipulations had little effect on NA performance.     

DRL interresponse-time distributions: quantification by peak deviation analysis.

Peak deviation analysis is a quantitative technique for characterizing interresponse-time distributions that result from training on differential-reinforcement-of-low-rate schedules of reinforcement. It compares each rat's obtained interresponse-time distribution to the corresponding negative exponential distribution that would have occurred if the rat had emitted the same number of responses randomly in time, at the same rate. The comparison of the obtained distributions with corresponding negative exponential distributions provides the basis for computing three standardized metrics (burst ratio, peak location, and peak area) that quantitatively characterize the profile of the obtained interresponse-time distributions. In Experiment 1 peak deviation analysis quantitatively described the difference between the interresponse-time distributions of rats trained on variable-interval 300-s and differential-reinforcement-of-low-rate 72-s schedules of reinforcement. In Experiment 2 peak deviation analysis differentiated between the effects of the psychomotor stimulant d-amphetamine, the anxiolytic compound chlordiazepoxide, and the antidepressant desipramine. The results suggest that peak deviation analysis of interresponse-time distributions may provide a useful behavioral assay system for characterizing the effects of drugs.     

The influence of parenting stress and child behavior problems on parental estimates of expressive and receptive language development

This study examined the relative contributions of parental reports of child-related and parent-related stress to their estimates of expressive and receptive language skills on the Minnesota Child Development Inventory in 152 children referred to a communicative disorders clinic. Correlational analysis showed moderately high agreement between parental estimates and objective measures of expressive and receptive language ability. Multiple-regression analyses revealed that independent measures of language acquisition accounted for the greatest amount of variance in parental estimates of expressive and receptive language skills. Stressful child behavior accounted for a small but statistically significant proportion of the variance in estimates of expressive and receptive language skills. Parental stress, in contrast, did not contribute significantly to language estimates. These findings suggest that parents are able to formulate estimates of language development which are relatively independent of personal or child-related stressors.     

The Role of Mothers and Fathers

The development of personality characteristics appears to differ by sex of child and role of parent, with interpersonal concerns tending to characterize mothers and instrumental concerns describing fathers. Using a semi-structured interview protocol and paper-and-pencil questionnaires, we examined the effects of parenting, as reported by middle-class high school senior boys and girls, on the development of two aspects of personality. Ego development and self-esteem both have demonstrated sex differences, with girls displaying more advanced ego development and boys displaying higher self-esteem. We expected that mothers, because of their greater interpersonal orientation, would influence the development of ego development more than would fathers, and that, based on past findings, the opposite-sex parent would exert the primary influence on self-esteem. While ego development was found to relate to more encouraging, warmer mothering in boys, it related weakly to mothering in girls. Boys and girls who perceived their cross-sex parent to be warm and supportive were found to have higher self-esteem.     

Program report: “time-in”: A two-year project for the reduction of severe maladaptive behaviors in a center for persons with developmental disabilities

The results of a two-year project designed to organize a unit for 18 developmentally disabled clients with severe behavior disorders (primarily aggression) were presented. Providing tightly organized structure and focusing on appropriate resident behavior resulted in substantial gains. Noted changes included significant decreases in aggression, total number of target behaviors, required uses of restrictive procedures, and residents' injuries. Decreases were also noted in staff injuries and turnover. Subjectively, the unit became a better place to work and live. Difficulties encountered with developing, maintaining, and generalizing the project were discussed.     

The distribution of infant attention during object examination

The distribution of attention during toy play was studied in 6‐, 9‐ and 12‐month‐old infants. Heart rate and behavior measures of attention were collected as the infants interacted with objects. There was a large deceleration of heart rate at the beginning of behaviorally defined focused attention, but little heart rate change for looks that only had behaviorally defined casual attention. Heart‐rate‐defined sustained attention occurred more frequently at the transition from the first instance of casual attention within a look to focused attention and during the cycling between subsequent epochs of casual and focused attention. These results show that heart rate and behavioral measures of attention are closely related in young infants at the beginning and end of object interaction but are inconsistently related within a single look at an object.     

A planar and a volumetric test for stereoanomaly

Stereoanomaly is the failure to see differences in depth when the viewer is presented with stimuli having different magnitudes of stereoscopic disparity. In the absence of eye movements, everyone suffers from stereoanomaly for extremely large disparities. Typically, such disparities are seen at the same depth as monocular stimuli. However, about 30%, of the population exhibit some form of stereoanomaly even for very small disparities, provided eye movements are avoided. In some cases, the sign of the disparity will be confused, and the perceived depth will be incorrectly seen as 'behind' rather than 'in front of' the fixation point, for example. Because anomalies provide useful information about perceptual mechanisms, tests that measure and quantify the extent of a blindness are important investigative tools for research. Here we offer two easy-to-administer tests for stereoanomaly. The first test is based on depth judgments of two bars relative to a fixation point. The second test involves judgments of volumetric stimuli, seen stereoscopically. In each case, subjects indicate depth by setting a rectangle (with fixed base) to match the perceived depth. Although both tests are correlated, some differences in stereo processing are seen, depending upon whether or not the stimuli are presented near the point of fixation.