Self-control behavior in hyperactive and nonhyperactive children

This study was aimed at evaluating the self-control behaviors of hyperactive (HA) and nonhyperactive (NHA) first-grade pupils under conditions of repeated failure on a previously learned concept formation task. Subjects were divided into HA and NHA groups on the basis of their scores on the Conners (1969) Teacher Rating Scale. During the training stage of the experiment the children learned a concept formation task under a schedule of contingent positive reinforcement. In the test stage they performed the same task but under a negative noncontingent reinforcement schedule. The results revealed no differences in initial rate of learning the task between the groups. After the introduction of the negative noncontingent reinforcement schedule, however, the HA group showed a marked decrease in the use of effective problem-solving strategies. The HA children's performance on the concept formation task was accompanied by the emission of negative self-evaluations and solution-irrelevant statements. The NHA group used significantly more statements showing useful goal directed cognitive mediations than the HA children. The results suggested that HA children may have deficits in self-control skills.Grateful acknowledgment is made to the two anonymous reviewers whose insightful comments were very helpful in producing the final form of this paper.     

Spontaneous versus instructed use of multiple standards for evaluating comprehension: Effects of age,reading proficiency,and type of standard

Nine- and eleven-year-old children differing in reading proficiency read and commented on brief expository passages containing three different types of embedded problems (nonsense words, prior knowledge violations, and internal inconsistencies). Half of the children were specifically instructed as to the types of standards they should apply in order to detect the problems (lexical, external consistency, and internal consistency); the remaining children were simply instructed to look for problems. Both quantitative and qualitative differences in standard use were revealed by the children's comments about all parts of the passages. Older and better readers used more different standards and they used them more frequently than younger and poorer readers. The lexical standard was more likely to be adopted spontaneously than the other two standards and it was the only standard used by a substantial proportion of both younger and poorer readers. Finally, the consistent effects of instruction type indicate that children's evaluation activities were strongly influenced by the amount of guidance received.     

Behavioral consequences of song learning: Discrimination of song types by male white-crowned sparrows

The functional significance of learned population differences in male song in the white-crowned sparrow was explored in natural populations using playback tests. Laboratory results have shown that learning of the population-specific song seems to take place in early life and is strongly dependent upon the nature of the auditory experience at that time. However, the varied results of recent studies make it difficult to reach a confident conclusion about the ecological functions of song learning. The present research took advantage of naturally occurring variation in the differences between songs of adjacent populations to determine a function relating degree of difference in song to intensity of territorial singing elicited. Applying a typological evaluation of syllable structure to the four segments of the song allowed a crude quantitative ranking of the differences between local songs and playback stimuli. These results, together with those of other studies, suggest a unimodal aggressive response function of males to songs of other males. A maximum response to songs slightly different from the local song environment suggests that male exclusion based upon acquired song components may contribute to the maintenance of discrete and stable song dialects.     

Zebra finches (Taeniopygia guttata) demonstrate cognitive flexibility in using phonology and sequence of syllables in auditory discrimination

Animal Cognition - Zebra finches rely mainly on syllable phonology rather than on syllable sequence when they discriminate between two songs. However, they can also learn to discriminate two...     

Perceptions of candidate strength in job recruitment: Does candidate race moderate the attractiveness bias in White women?

The attractiveness bias suggests that people who are more attractive will be positively favored across life outcomes. This study sought to test whether candidate attractiveness, sex, and race, affect perceptions of candidate strength in a job recruitment task. In total, 338 White women (M_age = 20.94 ± 5.65) were asked to make judgements of a potential candidate for an administrative job (resume with candidate photograph). The vignettes differed in terms of candidate ability (strong/weak), sex (male/female), race (Black/White), and attractiveness (attractive/less attractive). Participants rated perceived candidate strength and likelihood to invite for interview. Results showed no significant main effects for attractiveness. However, there was a significant interaction for target attractiveness and race, such that attractive/White candidates were more likely to be invited for interview than less attractive/White candidates. There was also a significant main effect for race such that Black candidates were rated as stronger and more likely to be interviewed. Sensitivity analyses (with nonheterosexual women removed from the sample) also showed a main effect for target sex such that female candidates were favored over male candidates. Overall, these findings provide evidence that attractiveness, sex, and race have important, albeit complex, effects on hiring decisions in the workplace.     

A signal detection analysis of the effects of hearing on the visual recognition of two-digit numbers

A signal detection measure of visual recognition was used to assess the visual recognition of two-digit numbers in three different conditions: (1) voicing of the number as it was presented visually; (2) voicing of a different number than the one presented; and (3) no voicing. The three treatment means were significantly different, with matched voicing resulting in the best performance and no voicing, in the worst. There was no evidence that the treatments differentially affected response criteria.     

On the rate of stimulus occlusion during intermittent retinal stimulation

The CFF was determined with three sectored disks, each of which corresponded to one of the three rings in a Helmholtz disk. The fusion frequency is identical for all three rings of a Helmholtz disk but with the three sectored disks it was found that the rate of stimulus occlusion is a major factor in determining the CFF. It was tentatively concluded that the effect was not a consequence of different stimulus wave-forms. The phenomenon appears to have been reported late in the last century.     

An alternating least squares method for the weighted approximation of a symmetric matrix

Bailey and Gower examined the least squares approximationC to a symmetric matrixB, when the squared discrepancies for diagonal elements receive specific nonunit weights. They focussed on mathematical properties of the optimalC, in constrained and unconstrained cases, rather than on how to obtainC for any givenB. In the present paper a computational solution is given for the case whereC is constrained to be positive semidefinite and of a fixed rankr or less. The solution is based on weakly constrained linear regression analysis.The authors are obliged to John C. Gower for stimulating this research.