Habit reversal vs. negative practice treatment of nailbiting

A previous study of the habit reversal treatment of nailbiting was extended by using more subjects (97) and a comparison with an alternative method (negative practice). Negative practice reduced nailbiting episodes by about 60% whereas habit reversal reduced nailbiting episodes by about 99% throughout the 5-month follow-up.     

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.     

Infant search tasks reveal early concepts of containment and canonical usage of objects

It is difficult to gain unambiguous evidence on the use of concepts by infants. Many results can be accounted for in terms of action-based strategies. The evidence reported here fulfils the minimal criteria for the operation of working concepts in infants. Search tasks are used with a filled interval which forces memory-search, and the object is hidden in containers which fulfil their customary job or violate it. Infants treat an upright cup as a more reliable location marker than an inverted one. A series of experiments probes the phenomenon. The results indicate that the infants have a working concept of containment which can be triggered by the provision of containers in their canonical orientation. Even “object permanence tasks” lead infants to access their knowledge of the relationships into which things typically enter in the world outside the laboratory.     

Statistical significance tests for binormal ROC curves

Statistical significance tests are derived and evaluated for measuring apparent differences between an obtained and an expected binormal ROC curve, between two independent binormal ROC curves, and among groups of independent binormal ROC curves. A binormal ROC curve is described by two parameters which represent the spread of the means and the ratio of the standard deviations of the two underlying Gaussian decision variable distributions. To test the significance of apparent differences between or among ROC curves, approximate χ² statistics for each of the three tests were constructed from maximum likelihood estimates of the two parameters defining the binormal ROC curve. The performance of each test statistic was evaluated by simulating five-category rating scale data with equal numbers of noise and signal-plus-noise trials (set at 50, 250, and 500) for each of three typical ROC curves. For the significance test involving only one ROC curve, rating scale data were generated from the chance diagonal of the ROC space also. Although test performance was found to be somewhat dependent on the number of trials and on the location of the ROC curve in the ROC space, comparisons of the obtained and expected fractions of (falsely) significant results at various α levels showed the proposed statistical significance tests to be reliable under practical experimental conditions.     

The effects of expected future interaction and prior group support on the conformity process

Previous results indicate that people conform more to group judgments when they have received unanimous group support for their opinions than when they have received no support. The present study tested the hypothesis that these differences would be attenuated when future interaction with the group members was anticipated. The 70 male subjects were tested in a Crutchfield-type conformity situation, where prior group support (100 vs 0%) and anticipation of future interaction (alone vs group) were manipulated. Predictions were based on an examination of conformity incentives that considered normative and informational sources of social influence, as well as Hollander's model of idiosyncracy credit. Consistent with predictions, conformity in the 0% prior support condition was greater when subjects anticipated future group interaction than when they did not, whereas the reverse was true in the 100% prior support condition. In addition, conformity was correlated negatively with both confidence in task ability and feelings of group acceptance when future interaction with the group was anticipated. These data suggest that when future group activity is expected, the tendency to reciprocate past treatment from the group is reduced.     

An investigation of the arousal model of interpersonal intimacy

In a study designed to test Patterson's arousal model of nonverbal intimacy, the heartrate, gaze, smiles, body orientation, and body lean of each of 40 female subjects who interacted with an accomplice were measured. Within a factorial design, subjects were induced to view more or less favorably the accomplice, who subsequently increased or maintained the same level of nonverbal immediacy as she did in an earlier session. It was hypothesized that (1) an increase in the accomplice's immediacy would effect an increase in subjects' arousal (heartrate) which, in turn, (2) would lead to either reciprocal or compensatory nonverbal adjustments by subjects, depending on whether they viewed the accomplice more or less favorably, respectively. The results supported the first but not the second hypothesis. However, interpretation of the results suggests, nevertheless, that they may be consistent with the arousal model.     

Semantic differential studies of children's language development: Some methodological problems

A semantic differential study of development of antonym meanings revealed methodological problems (e.g., concept-scale interaction and developmental changes in scale-checking style) not fully considered in previous semantic differential investigations of child language development. Twenty adjectives were rated on 10 scales by subjects from grades K to 5 (approximately 6 through 11 years old) and adults. Analyses by means, polarity ratings, and average sums of squared differences failed to yield consistent developmental trends. Subjects' choices of scale ratings did show clear age-related differences: Grades K and 1 chose extreme ratings almost exclusively; grades 2 through 4 showed an increase in neutral choices and decreases in extreme ratings; grades 4 and 5 and adults chose extreme ratings least often, neutral choices most often, and more intermediate ratings than any younger subjects. Results show that scale choice is a crucial factor in designing semantic differential studies with children, there is a low correlation between mean scores and ratings given by individual children, and shifts in scale-checking style should be considered when interpreting apparent developmental changes in children's semantic differential ratings.     

Incidental learning,attention, and curiosity in squirrel monkeys calorie deprived as infants

The long-term effects of infantile malnutrition on information processing were studied in squirrel monkeys. From 2 through 8 weeks of age, four low-calorie infants were fed reduced amounts of a high protein diet, limiting their mean body weight gain to 23% of that of four well-fed controls, with all of this gain occurring during the first 2 weeks on the low-calorie diet. Thereafter, both groups received the standard diet ad libitum. At 68 weeks of age, incidental learning was tested by introducing shape cues that were redundant to the solution of a previously learned, two-choice, color discrimination. Removal of the color cues showed that the low-calorie monkeys had learned significantly less about the shape cues than had the controls. The basis for this incidental learning failure was then examined with an embedded-figures dicrimination, to measure attentional ability, and a novel stimulus substitution task, to measure curiosity. The groups did not differ in detecting embedded figures, but the low-calorie monkeys were significantly less likely than controls to select or handle novel stimuli that had been substituted for previously learned discriminative cues. It was concluded that undernutrition in infancy may induce a long-term strategy of only learning information which leads to an immediate reward, while suppressing the acquisition of information due to intrinsic curiosity.