Characteristics associated with improved knee extension after strength training for individuals with cerebral palsy and crouch gait.

Muscle weakness may contribute to crouch gait in individuals with cerebral palsy, and some individuals participate in strength training programs to improve crouch gait. Unfortunately, improvements in muscle strength and gait are inconsistent after completing strength training programs. The purpose of this study was to examine changes in knee extensor strength and knee extension angle during walking after strength training in individuals with cerebral palsy who walk in crouch gait and to determine subject characteristics associated with these changes. A literature review was performed of studies published since January 2000 that included strength training, three-dimensional motion analysis, and knee extensor strength measurements for individuals with cerebral palsy. Three studies met these criteria and individual subject data was obtained from the authors for thirty crouch gait subjects. Univariate regression analyses were performed to determine which of ten physical examination and motor performance variables were associated with changes in strength and knee extension during gait. Change in knee extensor strength ranged from a 25% decrease to a 215% increase, and change in minimum knee flexion angle during gait ranged from an improvement of 9° more knee extension to 15° more knee flexion. Individuals without hamstring spasticity had greater improvement in knee extension after strength training. Hamstring spasticity was associated with an undesired increase in knee flexion during walking. Subject-specific factors such as hamstring spasticity may be useful for predicting which subjects will benefit from strength training to improve crouch gait.

Arousal and mood factors in the "Mozart effect".

Some investigators of the "Mozart effect" have not controlled for the influence of differences in arousal or mood induced by treatment conditions. Studies by Rideout and colleagues reported differences in spatial reasoning after listening to a Mozart sonata compared against a relaxation instruction tape. The conditions may have affected subjects' arousal differentially, with the sonata increasing arousal and the relaxation instructions decreasing arousal, which could have affected spatial reasoning performance. Evidence is cited in support of this suggestion and indicates the importance of analyzing the influence of arousal differences in Mozart effect research.

Failure to confirm the Rauscher and Shaw description of recovery of the Mozart effect.

The Mozart effect is an increase in spatial reasoning scores detected immediately after listening to the first movement of a Mozart piano sonata. Rauscher and Shaw (1998) suggested that failure to produce a Mozart effect could arise from carryover effects of a spatial reasoning pretest which may interfere with the effect of listening to Mozart. They cited an unpublished study in which a verbal distractor was inserted between the pretest and listening condition, and the manipulation produced the recovery of a Mozart effect. This experiment attempted to confirm the unpublished study. 206 college students were exposed to one of three sequences, pretest-Verbal distractor material-Mozart, pretest-Mozart-Verbal distractor material, and pretest-Verbal distractor material. An immediate posttest indicated no significant difference on solution of paper folding and cutting items among the three groups. The results do not support Rauscher and Shaw (1998). Our negative results are consistent with prior failures in other laboratories to produce a Mozart effect.

Changes in perceived color with intermittent illumination.

Using 24 observers with normal color vision, perceived shifts in hue were determined for a yellow-red, green, and blue-green at intermittencies of 5, 10, and 20 cps. The hue shift for yellow-red was consistent with the hue shift exhibited by a deuteranomalous observer while the hue shift for green and blue-green was consistent with that exhibited by a protanomalous observer.

Listening to Mozart does not enhance backwards digit span performance.

Rauscher, Shaw, and Ky recently reported that exposure to brief periods of music by Mozart produced a temporary increase in performance on tasks taken from the Stanford-Binet Intelligence Scale-IV. The present study examined whether this effect occurred in performance on a backwards digit span task. In a within-subjects design 36 undergraduates were exposed to 10-min. periods of Mozart music, a recording of rain, or silence. After each stimulus period, undergraduates had three attempts to hear and recall different 9-digit strings in reverse order. No significant differences among treatment conditions were found. There was a significant effect of practice. Results are discussed in terms of the need to isolate the conditions responsible for production of the Mozart effect.

A looming-recession threshold.

When the origin of magnification-minification of an outline rectangle had a horizontal locus which exceeded one-fourth of the rectangle's horizontal dimension, 16 observers of 21 reported apparent depth characteristic of looming and recession.

Perceived depth from simultaneous changes in length and direction of a single line.

Using a configuration of three lines joined like hands on a clockface, Brigner, Deni, and Hildreth in 1994 reported empirical support for Wallach, Adams, and Weisz's 1956 hypothesis regarding the elicitation of perceived depth by simultaneous changes in length and orientation of a configuration's elements. The current investigation extended these findings by showing that perceived depth can be elicited by simultaneous changes in size and orientation of either two lines or a single line.

Microdialysis sampling coupled to on-line microbore liquid chromatography for pharmacokinetic studies.

Microdialysis sampling has been coupled on-line to microbore liquid chromatography for pharmacokinetic investigations in awake, freely-moving animals. Valve systems are described which provide continuous collection of the microdialysis sample for injection into the chromatographic system. One valve system consisted of two six-port valves used in tandem. The other valve system consisted of an eight-port valve with two sample loops. The eight-port valve system provided better precision than the dual six-port valve system yet worse than an autosampler. However, when used for dialysis samples, the precision of the various injection methods was equivalent. The on-line system was capable of rapidly following changes in the dialysate concentration and provided near real-time analysis of the plasma concentration of analytes. The system was evaluated by monitoring the pharmacokinetics of acetaminophen in awake, freely-moving rats.