Habituation and dishabituation of rats’ exploration of a novel environment

The habituation of locomotor activity across repeated exposures to a novel maze was studied in a series of experiments using rats as subjects. Habituation, defined as a decrease in ambulation, was greater on a second trial occurring 5 min after a first trial than on one occurring 60 min after. This short-term decrement occurred only when the same maze was used on both trials, and could be dishabituated by intertriai detention in another novel environment. On a delayed test trial, habituation was, in one case, somewhat greater following initial spaced trials, and in another condition, comparable following both massed and spaced trials. The longer term habituation was maze specific, but was not affected by the presence of a dishabituator following either or both of the first two trials. The results were discussed in terms of theories of “priming” and encoding variability.     

Attachment behavior: a validation study in two age groups.

To assess the validity of attachment scores derived from the Ainsworth "strange situation," 56 1-year-olds and 79 2-year-olds accompanied by either the mother, the father, or a brief acquaintance were studied. Proximity to the adult, duration of play, crying, activity, and the incidence of looks and distance bids were measured. 1-year-olds were more secure with their parents: they were more active, played more, cried less, and stood closer to their parents than to an acquaintance. 2-year-olds accompanied by their parents were less settled in the presence of a stranger than children accompanied by the acquaintance. The adequacy of current conceptions and measures of attachment was discussed in light of these results.     

Perceptual training of height and brightness seriation in kindergarten children.

A study of seriation was conducted from the perspective of Gibson's theory of perceptual development. Kindergarten children who evidenced little seriation of height or brightness were assigned to either 1 of 3 perceptual training conditions or to a fourth, control condition. Training consisted of nonreinforced same-different judgments to wooden dowels varying in height, or in brightness, or simultaneously in height and brightness. The theoretical rationale for this training was that it would facilitate perception of the stimulus dimension(s) on which the dowels differed. It was found that perceptual training did facilitate seriation, particularly if both the height and brightness dimensions varied simultaneously in training.     

Self-punitive responding in rats with goal shock and color change

After acquisition avoidance training, rats were assigned on the basis of matched run speed to the following groups: (1) maintenance of avoidance training, (2) extinction procedures with the addition of a brief shock in the goalbox, and (3) regular extinction procedures. Each group was further divided into two minor groups which experienced either change or no change in goalbox color. The results indicated : (1) that self-punitive responding was increased by goal shock, (2) that self-punitive responding was reduced by goalbox color change, and (3) that generalization of goal shock to the startbox and runway areas is a factor in self-punitive responding.     

Instrumental escape learning in the rat at 24-hour intertriai interval: Effects of magnitude and schedule of reinforcement

Three experiments investigated the effects of magnitude and schedule of reinforcement and level of training in instrumental escape learning at a 24-h intertriai interval. In Experiment I, two magnitudes of reinforcement were factorially combined with two schedules of reinforcement (CRF and PRF). Under PRF, large reward produced greater resistance to extinction than did small reward, while the reverse was true under CRF. In Experiment II, two levels of acquisition training were factorially combined with three schedules of reinforcement (CRF, single-alternation, and nonalternated PRF). Patterned running was observed late in acquisition in the single-alternation extended-training condition. Resistance to extinction was greater for the nonalternated PRF condition than for the single-alternation condition following extended acquisition, and the reverse was true following limited acquisition. Experiment III confirmed the extinction findings of Experiment II. The results of all three experiments supported an analysis of escape learning at spaced trials in terms of Capaldi’s (1967) sequential theory.     

Three types of conduct‐problem boys in an educational setting

Third grade boys identified as being disruptive to on‐going classroom activities were grouped according to their teacher's ratings of their behaviour characteristics as unco‐operative (Type I), easily flustered (Type II), and unco‐operative and easily flustered (Type III). No significant differences in performance existed between types on individually administered tests of perception and psycholinguistic abilities. On group administered tests of academic achievement and intelligence, the uncooperative boys did significantly better than the other two types. It was also determined that the easily flustered boys did substantially better on individually administered measures of IQ. than they did on group administered measures. These findings suggest that teachers should avoid using group tests to evaluate disruptive boys they perceive as being easily flustered.     

The evaluation from the program director's viewpoint

In considering the evaluation of the preceptorship and residency programs, our faculty were asked to react to specific dimensions and aspects of the studies. Viewpoints about these data were submitted in formal critiques which will be summarized only briefly here. A number of the comments were in response to specific questions which had been posed; other were spontaneous from the faculty.