On the Relation Between Time Perception and the Timing of Motor Action: Evidence for a Temporal Oscillator Controlling the Timing of Movement

Studies of time estimation have provided evidence that human time perception is determined by an internal clock containing a temporal oscillator and have also provided estimates of the frequency of this oscillator (Treisman, Faulkner, Naish, & Brogan, 1992; Treisman & Brogan, 1992). These estimates were based on the observation that when the intervals to be estimated are accompanied by auditory clicks that recur at certain critical rates, perturbations in time estimation occur. To test the hypothesis that the mechanisms that underlie the perception of time and those that control the timing of motor performance are similar, analogous experiments were performed on motor timing, with the object of seeing whether evidence for a clock would be obtained and if so whether its properties resemble those of the time perception clock. The prediction was made that perturbations in motor timing would be seen at the same or similar critical auditory click rates. The experiments examined choice reaction time and typing. The results support the hypothesis that a temporal oscillator paces motor performance and that this oscillator is similar to the oscillator underlying time perception. They also provide an estimate of the characteristic frequency of the oscillator.     

Work,leisure, and psychological well-being in a sample of young adults

This study of 20 ‘white-collar’ workers aged 20–30 measured motivation, enjoyment and access to various categories of experience in both work and leisure, and examined their relationship with psychological well-being on a number of dimensions. The method used a short questionnaire, psychological scales and the innovatory ‘experience sampling methodology’ (ESM) where respondents answer questions in a diary on the receipt of a signal from a pre-programmed watch or radio pager eight times a day for 1 week. The results show, in line with other studies, that intrinsic motivation in daily life is correlated with happiness but that, not previously reported, when motivation at work is examined both extrinsic motivation and instances where a person had to do the activity but did not wish to be doing something else, i.e. ‘positive motivational change’, are correlated with positive aspects of psychological well-being, while instances where a person wanted to do the activity but wished to be doing something else, i.e. ‘negative motivational change’, correlated with negative aspects. The results also show that enjoyment in both work and leisure correlates with aspects of psychological wellbeing; and that macro ‘flow’ experiences, where high skills and high challenges are perceived as equal, are enjoyable and interesting and come primarily from work. The study also shows that categories of experience considered important for psychological well-being and deemed to come primarily from work can be obtained in leisure. The results are discussed in the context of person—situation interactions and processes, and it is advocated that these should be studied in a variety of samples.     

A note on russell's paradox in locally cartesian closed categories

Working in the fragment of Martin-Löfs extensional type theory [12] which has products (but not sums) of dependent types, we consider two additional assumptions: firstly, that there are (strong) equality types; and secondly, that there is a type which is universal in the sense that terms of that type name all types, up to isomorphism. For such a type theory, we give a version of Russell's paradox showing that each type possesses a closed term and (hence) that all terms of each type are provably equal. We consider the kind of category theoretic structure which corresponds to this kind of type theory and obtain a categorical version of the paradox. A special case of this result is the degeneracy of a locally cartesian closed category with a morphism which is generic in the sense that every other morphism in the category can be obtained from it via pullback.The financial support of the Royal Society in London is gratefully acknowledged.     

Apparent motion: evidence of the influence of shape, slant, and size on the correspondence process

Four stimulus elements configured as a notional diamond were flashed in pairs to elicit apparent motion. When the elements were identical (4 Zs), the direction of apparent motion was ambiguous. When the elements were pairs of different letters (Cs and Os, Es and Zs), letters of different sizes (Zs and zs), or oppositely oblique lines, the direction of apparent motion tended to be between identical elements. This was true, however, only for an initial, brief observation period. Subsequently, the direction of apparent motion tended to be determined by the direction of motion perceived at first, regardless of the character of the elements. This quickly established directional set (within 10 sec) largely swamped any tendency to resolve correspondence in terms of a feature of the stimulus. It appears to be based on spatial rather than retinal or egocentric coordinates.     

Obstacle perception by congenitally blind children

The ability to perceive objects from a distance and navigate without vision depends principally on auditory information. Two experiments were conducted in order to assess this ability in congenitally blind children aged 4 to 12 years who had negligible amounts of visual experience or formal mobility training. In Experiment 1, children walked along a sidewalk toward a target location to get some candy. A box was placed along the path on some trials, and the children were instructed to avoid the box if it was present. The children spent more time in the region just in front of the box than in the region just behind it, indicating that they perceived the box and acted so as to navigate around it. In Experiment 2, children attempted to discriminate whether a nearby disk was on their left or on their right. The children performed at above-chance levels, again indicating distal perception of objects. The results of both experiments suggest that blind children with little or no visual experience or formal training utilize nonvisual information, presumably auditory, to perceive objects. The specific nature of this auditory information requires further investigation, but these findings imply that the underlying perceptual ability does not require experience in spatial vision or deliberate training and intervention.     

Chest pain without coronary artery disease: An exploratory comparison with panic disorder

Recent reports have indicated similarities between patients with persistent chest pain of nonorganic origin and patients with panic disorder. In order to explore this association further, we administered a structured interview and three self-report measures (State-Trait Inventory, Beck Depression Inventory, and SCL90-R) to three subject groups: (1) a sample with persistent chest pain (CP; n=14) who had been screened and found to have normal coronary arteries, (2) a sample of patients with panic disorder (PD; n=14), and (3) a sample of matched normals (n=14). CP patients were considered to be free of coronary artery disease (CAD) following normal cardiac catheterization and/or normal thallium stress tests and were not diagnosed initially with panic disorder. PD patients were diagnosed with a standardized psychiatric interview and were free of organic causes of panic. Using an exploratory data analytic approach, the results indicated that both CP and PD samples reported increased levels of state and trait anxiety (p <.0001), depression (p <.01), and somatization (p <.0001) compared with normals. CP patients differed from PD patients in their less frequent use of anxiolytic medication (p <.01) and lower levels of reported panic anxiety and phobic avoidance (p <.0001). These data suggest that persistent chest pain in the absence of CAD shares some features with panic disorder, yet differs from panic in key ways as well. The results are discussed in light of the role of anxiety in contributing to symptom labeling.This research was supported by Grant 86G-491 from the American Heart Association, Texas Affiliate, to J.G.B. H.T. is the recipient of USPHS Research Career Development Award K04-HL-0122246.     

Frequency analysis of electromyographically measured covert speech behavior

Eleven subjects were asked to silently read slides of the letters “P” and “T,” and to view meaningless control slides similarly as they were presented visually. One-eighth-second electromyographic excerpts were sampled from the baseline and response periods. The data were then transformed into the frequency domain for inferential analyses. The mean power spectral frequencies for the response period were significantly lower than those for the base-line in the overall analysis. There were, however, no significant changes from baseline as a function of kind of stimulus (T, P, or Control) or muscle activated (lips or tongue). It was concluded that there was a generalized responding, not unique to the processing of the specific stimuli studied. Frequency analysis of EMG measures of covert behavior holds some promise of yielding unique information not available through traditional analysis procedures, but more sensitive methods than those used here would be required to demonstrate this.     

ACQUISITION,GENERALIZATION, AND MAINTENANCE OF QUESTION-ANSWERING SKILLS IN AUTISTIC CHILDREN

We conducted an investigation to evaluate the effects of a training strategy for teaching autistic students generalized responses to three forms of wh— questions (what, how, and why). Students were taught, using modeling and reinforcement procedures, to answer questions with magazine pictures as the referents. Each question form was divided into two or more subcomponents reflective of common social usage and was taught within the context of a modified multiple probe design across subcomponents. Following acquisition of each subcomponent, generalization to natural context and storybook questions was assessed; additional probes were conducted to assess responding over time and whether acquisition of responses to questions promoted question-asking skills. Results showed that the picture training procedure was effective in teaching a generalized response to questions for which the relevant cue was visible, whereas specific generalization programming was required for situations in which the relevant cue was not visible. All acquired responses were durable over time.