Detection of stimulus change: The hypothetical roles of visual transient responses

Two random-dot patterns (D1 and D2) were displayed briefly in close temporal succession, separated by an interstimulus interval (ISI). The two patterns were identical except that D2 could contain one more element (addition) or one less element (subtraction) than D1. Observers were required to detect the addition or subtraction using a two-alternative forced-choice method. Three experiments were designed to examine Phillips and Singer’s (1974) suggestion that detection of additions and subtractions can be explained in terms of neural ON and OFF responses. Experiment 1 replicated Phillips and Singer’s finding that performance is progressively impaired as the ISI is increased. In Experiment 2, sudden shifts in luminance between D1 and D2 were combined with several durations of ISI to produce transient responses in a novel manner. Experiment 3 explored the roles of transient neural responses and of configurational changes as determinants of performance. Most predictions based on Phillips and Singer’s model were confirmed by the experimental outcomes. Some discrepancies between theory and data are noted, and directions for further research are suggested.     

Relations between visceral and behavioral function in men at bedrest

Multiple physiological measurements as well as a self-assessment of arousal was made in eight men on the first, third, and fifth days of bedrest. On the third day, additional measurements of performance on memory and dexterity tasks were made. Univariate analysis did not reveal any physiological variable to either predict subsequent performance well or to co-vary acutely with it; however, self-rating scores did prove to be useful predictors of subsequent performance. Principal components analysis suggested an“alertness” factor comprised of physiological measures as well as selfratings which helped in predicting better performance. Although the individual patterns of correlations between variables on each of the three test days was variable, even more variability between subjects was found on the performance testing day. We believe this effect of behavioral activation may be due to the injection of common, slow temporal trends into many of the different data sets.     

Preschool children's preferences and recall for stereotyped versus nonstereotyped stories

This study assessed children's preferences and recall for stereotyped versus non-stereotyped stories. The sample consisted of 32 preschool children, ranging in age from 60 months to 75 months. Four stories with boys or girls as the main character, each portraying typically masculine or feminine activities, were read to each child. Both preference and recall measures were obtained immediately and one day later. The hypothesis was confirmed that the stories were differentially preferred by boys and girls as a function of stereotyping of story. Girls preferred the story with a female character and a feminine activity and least preferred the story with a male character and a masculine activity. For boys, the reverse was true. The second choice for both boys and girls involved preference for activity, not sex of main character. A cross-lagged panel revealed that preference at Time 1 was causally related to recall at Time 2. The children remembered the most at Time 2 about the stories they liked the least at Time 1.This article is based on the first author's master's thesis, submitted in partial fulfillment of the requirements for a M.S. degree at the University of Georgia. A summary of this research was presented at the Fourth Annual Southeastern Conference on the Family and the Child, Athens, Ga., 1979.     

The management of children''s distress in response to painful medical treatment for burn injuries

The purpose of the current study was to develop an initial assessment of the efficacy of astress-management program designed to reduce the behavioral distress of children undergoing highlypainful medical treatments for their burn injuries. The stress-management program was delivered to 4 male patients, ages 5–12 yr and its effects assessed in a combined multiple-baseline and reversal design. Results indicated that the program was moderately effective at reducing behavioral distress during the burntreatment procedures for 3 of the 4 patients and less effective with the fourth. However, the design also revealed that the presence of a therapist to coach the patient in the use of these techniques was essential and that distress levels rose substantially on days when there was no therapist present. Finally, speculations concerning the factors responsible for the effectiveness of the stress-management program as well as its reduced efficacy with 1 S were discussed.     

Nearest neighbor analysis of point processes: Applications to multidimensional scaling

A new approach for evaluating spatial statistical models based on the (random) number 0 ≤ N(i, n) ≤ n of points whose nearest neighbor is i in an ensemble of n + 1 points is discussed. The second moment of N(i, n) offers a measure of the centrality of the ensemble. The asymptotic distribution of N(i, n) and the expected degree of centrality for several spatial and nonspatial point processes is described. The use of centrality as a diagnostic statistic for multidimensional scaling is explored.     

Distractibility and hypersensitivity

The present paper reports on the development of a modified problem checklist for use in normal samples of elementary school children. The two factors, Hypersensitivity and Distractibility, replicated over male and female samples. Hypersensitivity showed a significant grade effect, with a decrease between the first and second grade for both boys and girls. In contrast, boys scored higher than girls on Distractibility and there were no grade differences. Convergent validitiy data from peer judgments, in-class activity level, physical fitness measures, standardized achievement scores, and a comparison with another teacher judgment are presented. In addition, three Behavioral Problem Checklist (Quay & Peterson, 1967) dimensions, Conduct Problem, Personality Problem, and Inadequacy--Immaturity, were developed and their relationships to the independent measures, as well as to the new dimensions, are presented. The pattern of correlations of Distractibility was quite similar for boys and girls, with both being rated as Mean-Noisy by their peers. The findings for Hypersensitivity were somewhat weaker. Distractibility and Conduct Problem scores reflected a similar pattern of correlations with other variables; in a like manner, Hypersensitivity and Personality Problem scores reflected a similar pattern of correlations with other variables. Distractibility was related to an increased activity level and Hypersensitivity was related to a decreased activity level in young boys. The total number of behavior problems was related to a decrease in activity level for young girls. Older Distractible and Hypersensitive girls showed different patterns of activity level. It is proposed that problem behavior is more complex for older children and that Distractibility may be less influenced by the usual socialization process of school than is Hypersensitivity and may have some congenital antecedents.     

Minority influence: The effect of majority reactionaries and defectors,and minority and majority compromisers,upon majority opinion and attraction

The effects of shifting opinions within a group upon majority opinion, communication between members and perceived attractiveness of other members were studied. Each subject perceived himself to be a member of the majority in a group whose opinion was divided 6–2 on an important issue. But later one to three group members changed their vote. Six conditions of change were established: Control, majority reactionary, majority compromise, majority defection (5-3), minority compromise, minority compromise plus majority reactionary. Only majority compromise or defection affected majority opinion (private and public). Majority members were disliked when they deviated from majority opinion, but particularly so when they shifted toward minority opinion. Minority members were liked most when they induced a majority member to compromise (but not defect). Majority communication to minority occurred most when the minority was compromising, but most disagreement with minority opinion was expressed when a majority member had either compromised or defected.     

Marginal distributions for the estimation of proportions inm groups

A Bayesian Model II approach to the estimation of proportions inm groups (discussed by Novick, Lewis, and Jackson) is extended to obtain posterior marginal distributions for the proportions. It is anticipated that these will be useful in applications (such as Individually Prescribed Instruction) where decisions are to be made separately for each proportion, rather than jointly for the set of proportions. In addition, the approach is extended to allow greater use of prior information than previously and the specification of this prior information is discussed.We are grateful to a reviewer for suggestions that made possible a more concise and complete presentation of our work.     

Stimulus probability and prediction outcome as determinants of choice reaction time: Some procedural considerations

Effects of stimulus probability and prediction outcome on two-choice reaction speed (CRS) were determined when a frequency imbalance was reversed half-way through 300 samples of a 70/30 stimulus distribution and when the same 70/30 distribution was sampled for 1200 trials. Prior to each presentation Ss made a prediction; following each presentation Ss identified the stimulus by pressing a right-hand or left-hand trigger. CRS was faster to correctly predicted stimuli, and faster to the more probable stimulus. Ss who were informed of the frequency imbalance reacted significantly faster than Ss who were not. Both practice and boredom effects were demonstrated by using the extended number of trials. CRS was faster during the second session of 300 trials than during the first; after two sessions, CRS was slower during the second half of two additional sessions.