An examination of the relationship between visual capture and prism adaptation

The phenomena of prismatically induced “visual capture” and adaptation of the hand were compared. In Experiment 1, it was demonstrated that when the subject’s hand was transported for him by the experimenter (passive movement) immediately preceding the measure of visual capture, the magnitude of the immediate shift in felt limb position (visual capture) was enhanced relative to when the subject moved the hand himself (active movement). In Experiment 2, where the dependent measure was adaptation of the prism-exposed hand, the opposite effect was produced by the active/passive manipulation. It appears, then, that different processes operate to produce visual capture and adaptation. It was speculated that visual capture represents an immediate weighting of visual over proprioceptive input as a result of the greater precision of vision and/or the subject’s tendency to direct his attention more heavily to this modality. In contrast, prism adaptation is probably a recalibration of felt limb position in the direction of vision, induced by the presence of a registered discordance between visual and proprioceptive inputs.     

The internal clock: Electroencephalographic evidence for oscillatory processes underlying time perception

It has been proposed that temporal perception and performance depend on a biological source of temporal information. A model for a temporal oscillator put forward by Treisman, Faulkner, Naish, and Brogan (1990) predicted that if intense sensory pulses (such as auditory clicks) were presented to subjects at suitable rates they would perturb the frequency at which the temporal oscillator runs and so cause over- or underestimation of time. The resulting pattern of interference between sensory pulse rates and time judgments would depend on the frequency of the temporal oscillator and so might allow that frequency to be estimated. Such interference patterns were found using auditory clicks and visual flicker (Treisman & Brogan, 1992; Treisman et al., 1990). The present study examines time estimation together with the simultaneously recorded electroencephalogram to examine whether evidence of such an interference pattern can be found in the EEG.

Alternative models for the organization of a temporal system consisting of an oscillator or multiple oscillators are considered and predictions derived from them relating to the EEG. An experiment was run in which time intervals were presented for estimation, auditory clicks being given during those intervals, and the EEG was recorded concurrently. Analyses of the EEG revealed interactions between auditory click rates and certain EEG components which parallel the interference patterns previously found. The overall pattern of EEG results is interpreted as favouring a model for the organization of the temporal system in which sets of click-sensitive oscillators spaced at intervals of about 12.8 Hz contribute to the EEG spectrum. These are taken to represent a series of harmonically spaced distributions of oscillators involved in time-keeping.     

Inferring sexual interest from behavioral cues: Effects of gender and sexually relevant attitudes

Research has found that men impute more sexual meaning to others' behavior than do women. However, little research has examined the possibility that men and women share perceptions of the sexual connotativeness of certain behaviors but diverge in their perceptions of other behaviors. In Study 1, 162 male and 186 female undergraduates, predominantly Caucasian, rated the degree to which each of 27 behaviors of male and female targets connoted a desire for sexual intercourse. Multivariate analyses of variance revealed that, whereas men perceived all but two of the female target behaviors more sexually than women, men and women differed in their perceptions of the sexual connotativeness of only about half of the male target behaviors. A factor analysis revealed three factors for both male and female target behaviors, reflecting mundane dating behaviors, romantic behaviors, and sexual behaviors. Relative to women, men perceived only the mundane dating behaviors more sexually, although regression analyses showed these effects to be moderated by subjects' attitudes toward women. Study 2 examined the extent to which sexually relevant attitudes (e.g., sex role stereotyping, adversarial sexual beliefs, and rape myth acceptance) moderate subjects' perceptions of the sexual connotativeness of the behaviors. Men, particularly those who endorsed traditional, sexually relevant attitudes, were more likely than women to impute sexual meaning to the behaviors. The implications of this for dating situations are discussed.The author wishes to thank Mark Leary and two anonymous reviewers for their comments and suggestions on earlier versions of this article.     

Contextual interference effect: elaborative processing or forgetting-reconstruction? A post hoc analysis of transcranial magnetic stimulation-induced effects on motor learning

The elaborative-processing and forgetting-reconstruction hypotheses are the 2 principal explanations for the contextual interference (CI) effect. The present authors' purpose was to identify which of these 2 hypotheses better accounts for the CI effect. They synchronized single transcranial magnetic stimulation (TMS) pulses to each intertrial interval to modulate information processing during Blocked and Random Practice conditions. Participants practiced 3 arm tasks with either a Blocked or Random Practice order. The 3 stimulation conditions (No TMS, TMS, Sham TMS) by 2-practice order (Blocked, Random) between-participant design resulted in 6 experimental groups. Without TMS, motor learning increased under Random Practice. With TMS, this learning benefit diminished. These results support the elaborative-processing hypothesis by showing that perturbing information processing, evoked by Random Practice, deteriorates the learning benefit. Unlike the prediction of the forgetting-reconstruction hypothesis, adding perturbation during Blocked Practice did not significantly enhance motor learning.