GPS analysis of human locomotion: further evidence for long-range correlations in stride-to-stride fluctuations of gait parameters

During free walking, gait is automatically adjusted to provide optimal mechanical output and minimal energy expenditure; gait parameters, such as cadence, fluctuate from one stride to the next around average values. It was described that this fluctuation exhibited long-range correlations and fractal-like patterns. In addition, it was suggested that these long-range correlations disappeared if the participant followed the beep of metronome to regulate his or her pace. Until now, these fractal fluctuations were only observed for stride interval, because no technique existed to adequately analyze an extended time of free walking. The aim of the present study was to measure walking speed (WS), step frequency (SF) and step length (SL) with high accuracy (<1 cm) satellite positioning method (global positioning system or GPS) in order to detect long-range correlations in the stride-to-stride fluctuations. Eight participants walked 30 min under free and constrained (metronome) conditions. Under free walking conditions, DFA (detrended fluctuation analysis) and surrogate data tests showed that the fluctuation of WS, SL and SF exhibited a fractal pattern (i.e., scaling exponent alpha: 0.5 < alpha < 1) in a large majority of participants (7/8). Under constrained conditions (metronome), SF fluctuations became significantly anti-correlated (alpha < 0.5) in all participants. However, the scaling exponent of SL and WS was not modified. We conclude that, when the walking pace is controlled by an auditory signal, the feedback loop between the planned movement (at supraspinal level) and the sensory inputs induces a continual shifting of SF around the mean (persistent anti-correlation), but with no effect on the fluctuation dynamics of the other parameters (SL, WS).     

Differences in heaviness in relation to density and weight

Eight Ss (Group L) judged differences in heaviness between all pairs of stimuli in three series of five weights each, in the range of 100–300 g, presented randomly. Series L varied in weight and density, Series LVW varied only in weight, and Series LVD varied only in density. Another eight Ss (Group H) judged heaviness differences between all pairs of stimuli in three similar series (H, HVW, and HVD) in the range 700–900 g. Differences in density alone yielded relatively greater impressions of difference in heaviness in Group H than in Group L. Predictions from Ross and Di Lollo’s vector theory were confirmed.     

A consistent failure of the power law for lifted weight

The apparent size of squares was determined as a function of physical area and of surface complexity using the method of magnitude estimation. Apparent area increases as a power function of physical area with a slope of about 0.90. The judged areas also increased as a function of complexity of patterns upon the surface, the most complex surfaces being judged approximately 30% larger than the most simple surfaces.     

The Effect of a Discrete Signal on Context Conditioning: Assessment by Preference and Freezing Tests

Four experiments with rats assessed conditioning to contextual cues after the delivery of footshocks that were either signaled by a discrete stimulus or unsignaled. Two different tests were used. The first was a context preference test in which subjects were allowed to move freely in a brightly lit, unconditionally aversive context and the former shock context. The second test consisted of scoring freezing behavior while the animals were confined to the former conditioning context. During context preference tests, signaled-shock animals spent more time in the conditioning context and/or entered that context more frequently than did unsignaled-shock subjects. However, freezing tests largely failed to detect a difference between groups. These results were discussed in terms of possible interactions between the formation of context-shock, signal-shock, and context-signal associations and their effect on performance in each of the two types of tests.     

Personality Adjustment in College Students With a Parent Perceived as Alcoholic or Nonalcoholic

Adjustment of 547 college students was examined by the variables of alcoholic parentage and participant gender. Results from a multivariate analysis of variance, using the Diagnostic Inventory of Personality and Symptoms, indicated significant main effects for gender but not for alcoholic parentage. Significant gender differences occurred for alcohol abuse, drug abuse, paranoid psychosis, affective depression, anxiety disorders, psychological factors affecting physical condition, immature character, and neurotic character. Findings suggest that college students from alcoholic homes should not be distinguished from the general population in terms of their adjustment.     

Uses of rational emotive behavior therapy with juvenile sex offenders

Juvenile sexual offenses appear to be on the rise. This contributes to harm and trauma to the victims and the community at large. For many years the major interest in sex offender treatment has been directed toward assessment and treatment of the adult offender in spite of the reported large proportion of all sex crimes committed by juveniles (Uniform Crime Reports, FBI, 1985). Our article addresses three uses of Rational-Emotive Behavior Therapy (REBT): 1) in group and individual therapy, 2) in work with the offender's family, and 3) in staff training. The issues of the client's faulty learning and cognitive distortions is critical in the habilitation and rehabilitation process and may include such messages as: 1) I am powerless to control my sexual arousal, 2) I won't get caught if I am careful, 3) Masturbating about little kids is OK, 4) I need to feel better and when I am sexual with someone I feel better. This article will describe how the theory and practice of REBT (Ellis' 1984) is applied with juvenile sex offenders. A key feature is its use with the offending juvenile in the teaching of a rational belief system as well as ways to reduce emotional disturbances.     

EFFECTIVENESS OF A THREE-WEEK INSTITUTE FOR EMPLOYMENT SERVICE COUNSELORS

Forty-three employment service counselors participated in a three-week institute designed to improve their understanding of the conditions of poverty and of counseling theory and techniques. At the end of the institute, participants evaluated their experence favorably with substantial minority group criticisms, however, that (1) institute faculty were not sufficiently informed about Employment Service techniques and experiences and, that (2) not enough counseling practicum experiences were provided. Significant shifts in attitudes toward the poor were found at the end of the institute for 14 of 35 items of an attitude scale. For 6 of these 14 items, shifts in attitude were in the same direction and intensified after four and one-half months of field experience.