Stabilization and destabilization of perception--action patterns influence the self-organized recruitment of degrees of freedom

The recruitment of an additional biomechanical degree of freedom in a unimanual rhythmic task was explored. Subjects were asked to synchronize adduction or abduction of their right index finger with a metronome, the frequency of which was increased systematically. In addition, haptic contact on or off the metronome beat was provided. Results showed that the pattern exhibiting the highest intrinsic stability recruited the vertical plane more than did the less stable one. Moreover, presence and location of haptic contact modulated coordination stability and therefore induced changes in the recruitment of the vertical plane. Thus, a trade-off was shown between coordination stability on the horizontal plane and recruitment of the vertical one. These findings suggest that recruitment of degrees of freedom is governed by general principles of coordination dynamics.     

Distant melodies: statistical learning of nonadjacent dependencies in tone sequences

Human listeners can keep track of statistical regularities among temporally adjacent elements in both speech and musical streams. However, for speech streams, when statistical regularities occur among nonadjacent elements, only certain types of patterns are acquired. Here, using musical tone sequences, the authors investigate nonadjacent learning. When the elements were all similar in pitch range and timbre, learners acquired moderate regularities among adjacent tones but did not acquire highly consistent regularities among nonadjacent tones. However, when elements differed in pitch range or timbre, learners acquired statistical regularities among the similar, but temporally nonadjacent, elements. Finally, with a moderate grouping cue, both adjacent and nonadjacent statistics were learned, indicating that statistical learning is governed not only by temporal adjacency but also by Gestalt principles of similarity.     

Six-year-olds' difficulties handling intensional contexts

Previous research shows that children have difficulties handling intensional contexts even when they can pass a test of false belief (e.g. Cognition 67 (1998) 287; Cognition 25 (1987) 289). Some authors (Perner, J. (1991). Understanding the representational mind. Cambridge, MA: MIT Press; Cognition 25 (1987) 289) place these difficulties in the linguistic and not the mental representational domain. The experiments reported here examined whether 6-year-old children could answer questions in an intensional context that did not require the explicit verbal characterization of a belief. We replicated previous findings and found that children answered according to their own knowledge in an intensional context. This occurred even though they responded by choosing a picture to insert into a protagonist's thought bubble rather than report the belief verbally. Children could correctly answer questions about the knowledge state of the protagonist and pass a test of false belief. Further experiments ruled out methodological explanations. Experiment 2 showed that the difference in answering according to own knowledge between the false belief and intensional stories is not accounted for by procedural factors in the two types of test. Experiment 3 revealed that children did not answer according to their own knowledge by default. Experiment 4 suggested that answering according to own knowledge was not a result of pictorial salience. Results are discussed in relation to the simulation-theory debate.     

Tooth color: effects on judgments of attractiveness and age

Tooth whitening has become a very popular procedure. Advertisements for whitening products imply that whiter teeth are more attractive than yellower teeth. We tested this idea empirically by manipulating the tooth color of pictures of male and female targets. Participants' ratings of attractiveness were not influenced by tooth color. Exp. 2 yielded a negative correlation between attractiveness and age ratings: targets judged to be older were rated as less attractive. Unless whiter teeth help in some other way, e.g., improved self-esteem or confidence, it seems that tooth whitening procedures or products are not associated with increased attractiveness to others.     

In the privacy of their own homes: using the internet to assess racial bias

Recent studies suggest that research participants show reduced distortion of their taboo attitudes and behaviors when they take part in Internet-based procedures from outside the laboratory. We explored whether such procedures would reduce distortion in the assessment of racial bias. In Study 1, White participants who completed the study in the laboratory evaluated Black targets more favorably than White targets. This unexpected "outgroup-favoring" pattern occurred in both pencil-and-paper and Internet versions of the study, showing that modality did not produce it; but when participants worked outside the laboratory via the Internet, this pattern disappeared. Study 2 replicated the above findings and further indicated that the reduced distortion in Internet-based studies was due to the removal of the experimenter rather than removing the participants from the laboratory environment. The implications of these findings for the study of controlled processes of prejudice and the nature of Internet-based social communication are discussed.     

A review of the biological bases of ADHD: what have we learned from imaging studies?

Attention Deficit Hyperactivity Disorder (ADHD) is a common and impairing neuropsychiatric disorder with onset at preschool age. Although a significant amount of progress has been made investigating the neurobiology of this disorder, its precise etiology still remains unclear. Converging evidence from studies of the neuropharmacology, genetics, neuropsychology, and neuroimaging of ADHD imply the involvement of fronto-striatal circuitry in ADHD. However, while it does appear that poor inhibitory control and the deficits in fronto-striatal circuitry associated with it are central, there is evidence to suggest that more posterior cerebral areas are also implicated in this disorder. Anatomical studies suggest widespread reductions in volume throughout the cerebrum and cerebellum, while functional imaging studies suggest that affected individuals activate more diffuse areas than controls during the performance of cognitive tasks. The future impact of new MR imaging methodologies on the field is discussed.     

Alcohol consumption, drinking patterns, and alcohol problems among managerial versus non-managerial women and men

In the present study, we examined alcohol consumption and alcohol problems between managerial and nonmanagerial men and women. We also examined alcohol problems as a function of drinking context (i.e., when they drink and with whom they drink) for each of these four groups. Survey data and data from company records were collected from a large sample of blue and white collar employees (n = 2279). Participants completed a detailed questionnaire aimed at assessing many work-related attitudes, general mental and physical health-related perceptions, motivations for alcohol use, alcohol consumption indices, and alcohol problems. We found that several of the demographic variables differentially predicted alcohol consumption and problems for the four groups. In addition, drinking alone and immediately after work were associated with alcohol problems for women managers at a significantly higher rate than for the other groups of employees. These results support the assertion that more complex models are needed to understand the linkages between work and alcohol use. The research reported in this paper was supported by Grant AA 10690-02, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health.     

HYPERFEMININITY AND INFLUENCE

Murnen and Byrne (1991) have defined hyperfemininity as an exaggerated adherence to a feminine gender role as it relates to heterosexual relationships. Hyperfeminine women believe their success is determined by maintaining a romantic relationship with a man, and that their sexuality can be used to maintain this relationship. Extrapolating from theory concerning gender and status, including expectation states theory, it was hypothesized that a woman's expression of hyperfeminine attitudes would lead male college student participants to agree with her in response to a persuasive speech because it would indicate her compliance with women's subordinate status. It was found that men (but not women) who listened to a very hyperfeminine (high) speaker agreed with her more than did men who heard a mildly hyperfeminine (low) speaker, despite the fact that the high hyperfeminine speaker was judged less competent and knowledgeable. Implications of the results, including the idea that the sexual objectification of women perpetuates women's subordinate status, were discussed.     

A Lay Perspective on the Accuracy of Eyewitness Testimony1

To understand more about what laypeople think they “know” about eyewitness testimony, 276 jury-eligible university students were asked to indicate what factors they believe affect the accuracy of eyewitness testimony. In contrast to the large proportion of eyewitness-memory research that concerns system variables, the lay respondents overwhelmingly generated factors related to estimator variables, while system-variable factors such as police questioning and identification procedures were rarely mentioned. Respondents also reported that their own common sense and everyday life experiences were their most important sources of information about the accuracy of eyewitness testimony. Not only do these results clarify the need for further research on the lay perspective of eyewitness testimony, but they also provide some insight into the way in which many jurors might approach cases involving eyewitness evidence.