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.     

Successive acquisition and extinction in a runway with the domestic Muscovy duck (Cairina moschata)

Twenty domestic Muscovy ducks were trained to traverse a runway for food reward. Subjects were then randomly assigned to treatments. In one treatment, subjects received six nonrewarded trials followed by six rewarded trials every day for 12 days; and, in the other treatment, subjects received six rewarded trials followed by six nonrewarded trials every day for 12 days. These successive acquisition and extinction (SAE) treatments were selected because different extinction rates on the nonrewarded trials are expected on the bases of previous research performed with rats. Analyses of variance revealed the former treatment yielded significantly greater resistance to extinction than did the latter treatment. It was concluded that ducklings performed similarly to rats in the above SAE situation.     

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.     

Do infants see emotional expressions in static faces?

To determine whether young infants discriminate photographs of different emotions on an affect-relevant basis or on the basis of isolated features unrelated to emotion, groups of 17-, 23-, and 29-week-olds were habituated to slides of 8 women posing either Toothy Angry, Nontoothy Angry, or Nontoothy Smiling facial expressions and were then shown 2 new women in the familiarized expression and in a novel Toothy Smiling expression. At all 3 ages, recovery to the novel Toothy Smiling faces occurred only after habituation to Nontoothy faces (whether smiling or angry), not after habituation to Toothy Angry faces, indicating that infants had been responsive to nonspecific features of the photographs (presence or absence of bared teeth) rather than to affectively relevant configurations of features. In a second experiment, 2 older age groups (35 and 41 weeks) also proved to be insensitive to affect-related aspects of still faces, though more so for angry than for happy expressions. It is suggested that the young infant's difficulty in extracting emotional information from static stimuli may be attributable to the absence of the critical invariants (dynamic, multimodally specified) that characterize naturalistic expressions of emotion.     

Long-range course planning by college students

A group of 633 college students at a large midwestern public university was asked fifteen questions pertaining to personal long-term course planning. The results indicated that only 48% of the students sketched out a tentative listing of at least two courses per term for one or more subsequent semesters when first planning courses for the current semester. Long-range planning was positively correlated with the number of years students had already spent in college and with students' perception of the following factors: course planning utility, degree of certainty about pursuing one's current first choice of career, and degree of commitment in using college coursework as a means of achieving a career goal (all p < 0.001). Long-range planning was negatively correlated with the anticipation of a possible change in academic interests. Such planning was not significantly correlated with students' entrance examination aptitude scores or grade point averages. Thus, students' long-range planning of courses was associated more strongly with career commitment than with recent academic performance or aptitude.