An egocentric frame of reference in implicit motor sequence learning

We investigated which frame of reference is evoked during implicit motor sequence learning. Participants completed a typical serial reaction time task. In the first experiment, we isolated egocentric and allocentric frames of reference and found that learning was solely in an egocentric reference frame. In a second experiment, we isolated hand-centered space from other egocentric frames of reference. We found that for a one-handed sequencing task, the sequence was coded in an egocentric reference frame but not a hand-centered reference frame. Our results are restricted to implicit learning of novel sequences in the early stages of learning. These findings are consistent with claims that the neural mechanisms involved in motor skill learning operate in egocentric coordinates.     

Changing circumstances, disrupting habits

The present research investigated the mechanisms guiding habitual behavior, specifically, the stimulus cues that trigger habit performance. When usual contexts for performance change, habits cannot be cued by recurring stimuli, and performance should be disrupted. Thus, the exercising, newspaper reading, and TV watching habits of students transferring to a new university were found to survive the transfer only when aspects of the performance context did not change (e.g., participants continued to read the paper with others). In some cases, the disruption in habits also placed behavior under intentional control so that participants acted on their current intentions. Changes in circumstances also affected the favorability of intentions, but changes in intentions alone could not explain the disruption of habits. Furthermore, regardless of whether contexts changed, nonhabitual behavior was guided by intentions.     

book review

Crime and Human Nature: The Definitive Study of the Causes of Crime by James Q. Wilson and Richard J. Herrnstein. New York: Simon and Schuster, 1985, 639 pp., $12.95 paper.

The Negative Scream by Sally O'Brien. London: Routledge &; Kegan Paul, 1985, 148 pp., $12.95 paper.

Captain Kidd and the War Against the Pirates by Robert C. Ritchie. Cambridge: Harvard University Press, 1986, 306 pp., $20.00 hb.

American Violence &; Public Policy by Lynn A. Curtis (ed.). New Haven: Yale University Press, 1985.

Taking Care of Business: The Economics of Crime by Heroin Abusers by Bruce D. Johnson, Paul J. Goldstein, Edward Preble, James Schmeidler, Douglas S. Lipton, Barry Spunt and Thomas Miller. Lexington, MA: Lexington Books, 1985, 275 pp., $29.00 hb.

Life With Heroin: Voices From the Inner City by Bill Hanson, George Beschner, James M. Walters and Elliott Bovelle (eds.). Lexington, MA: Lexington Books, 1985, 208 pp., hb.

Policy Analysts in the Bureauaraay by Arnold Meltsner. Berkeley: University of California Press, 1976 hb, 1986 paper, 326 pp., $11.95.

>The War on Drugs: Heroin, Cocaine, and Public Policy by James A. Inciardi. Palo Alto, California: Mayfield Publishing Company, 1986, $9.95 paper.

Sartre and Marxist Existentialism by Thomas R. Flynn. Chicago: The University of Chicago Press, 1984, 265 pp., $10.95 paper.     

When walls are no longer barriers: perception of wall height in parkour

Through training, skilled parkour athletes (traceurs) overcome everyday obstacles, such as walls, that are typically insurmountable. Traceurs and untrained novices estimated the height of walls and reported their anticipated ability to climb the wall. The traceurs perceived the walls as shorter than did novices. This result suggests that perception is scaled by the perceiver's anticipated ability to act, and is consistent with the action-specific account of perception.     

The Illness/Injury Sensitivity Index: Validation of a German Version of the ISI-R

Three fundamental fears-anxiety sensitivity, fear of negative evaluation, and illness/injury sensitivity-are considered integral components of anxiety-related psychopathology and also bear connections with chronic pain. Scales measuring the first two fears, the Anxiety Sensitivity Index and the Fear of Negative Evaluation Scale, have been translated into German; however, the nine-item Illness/Injury Sensitivity Index-Revised (ISI-R) that measures fears of injury and illness has not been available in German language yet. The aim of this study therefore was a translation of the ISI-R into German language and an initial validation of the translated scale in two different samples. The German ISI-R was translated by both professionals and laypersons, and a final version was decided on by consensus. In Study 1, participants included 96 undergraduate students (85% women) who completed the German version of the ISI as part of a larger study. An exploratory factor analysis with oblique rotation was conducted and suggested a two-factor-solution with one factor representing fears of illness and the other fears of injury. This factor structure was confirmed via a confirmatory factor analysis (CFA) in Study 2. Participants included 117 community members (79% women). Convergent validity was supported using a visual analogue scale for fear of illness in both samples and the German translation of the Whiteley Index in Study. Overall, the results supported the German translation of the ISI-R. Comprehensive results, limitations, and directions for future research are discussed.