Child performance on discrimination tasks: Effects of amount of stimulus variation

Two independently conducted studies investigated stimulus variation effects on children's discrimination learning. The stimuli in the first study were generated by a conjunctive rule and were presented in pairs. Mean trials to criterion was significantly lower for the single-feature change treatment (17.4) than for the multiple-feature change treatment (29.9). Single-feature change-treatment transfer scores were significantly higher only for stimuli that differed in terms of one of the features. The second study not only replicated the initial finding concerning the single-feature change treatment but also found that students made more errors in reaching criterion when stimuli were generated by an exclusive disjunctive rule and were presented singly. For all tasks, the single-feature change treatment with stimuli presented in pairs was accompanied by fewer errors to criterion than the other treatments.     

Male and Female Preferences in Selected Career Factors

This study investigated seven factors relating to personal preferences in choosing a career. Differences between male and female preferences were also studied. While males and females express similarities relating to the seven factors, they also reveal differences that should be considered by counselors helping individuals explore career choices.     

Introtacts as predictors of discrimination performance in kindergarten children

Kindergarten children were given simultaneous discrimination tasks with two irrelevant dimensions varying within settings. Prior to each block of eight feed-back trials, the children were asked to attempt to provide a statement of the solution. The introtacts thus provided were found to have several of the desirable characteristics that have been reported for older children with either introtact or blank-trial probes, but which have not been found previously for kindergarten children with the blank-trial probe. Classification of the children according to the trial block on which they first verbalized the correct relevant dimension was found to account for more than 60% of the total variability in discrimination performance. The introtacts were also used to assign parameters to theoretical prediction equations, with nearly two-thirds of the total variability in discrimination performance accounted for by the theory. Extension of the method to other models is discussed.     

Probabilities of homomorphic mappings from multiple graphs

Each partition of a population defines a homomorphic mapping of sociometric graphs onto a corresponding set of image graphs. For sets of images selected by substantive importance, the expected number of mappings is calculated when the array of sociometric graphs is drawn at random with equal probabilities. Upper and lower bounds are computed for the probability of finding at least one mapping from an array to the given images, and for the expected number of mappings given that there is at least one. Results of small Monte Carlo trials are reported.     

Developmental analysis of human figure drawings in adolescence, young adulthood, and middle age.

Analyzed 195 human figure drawings (HFDs) of adolescents, young adults, and middle-aged adults in terms of developmental differences in anxiety signs, grouped into aggressive-hostile and insecure-labile categories, and according to sex-role stereotype, as measured by the Broverman Sex-role Stereotype Scale. Adolescent males and females were significantly more likely to obtain more anxiety signs than the two adult groups, although young adults and middle-aged adults did not differ from one another in HFD performance. The most reliable sex difference was that males reveal significantly more aggressive-hostile indices in the HFDs relative to females; no significant sex differences were obtained for number of insecure-labile indices. The degree to which one has adopted a conventional sex-role stereotype was not predictive of anxiety sign differences in HFD performance for either sex or for any age group.     

An illusion of auditory saltation similar to the cutaneous "rabbit"

Trains of brief clicks produced successively at 3 points in a horizontal array were not localized accurately. Observers reported clicks occurring in succession across the spaces between sources as well as at the sources themselves. The illusion is functionally related to interstimulus interval, number of clicks per speaker, and regularity of pulsing. It appears similar to Geldard and Sherrick's cutaneous "rabbit" illusion.     

Long-term effects of prior experience in attenuating amnesia

In Experiment I, prior experience with passive-avoidance training followed by latent extinction was given 1, 3, 5, or 15 days before criterion (re) training and an amnesic treatment. It produced nearly complete protection from retrograde amnesia at the three shorter intervals; at the longest interval, amnesia was present but less severe than in a control group without the familiarization. In Experiment II, prior experience was given 1, 5, or 15 days before a noncontingent shock and an amnesic treatment. Evidence of a reactivation of memory was obtained only at the longest interval. Thus, familiarization and reactivation seem to represent different processes. The results are interpreted as consistent with explanations stressing the disruption of retrieval in retrograde amnesia.