Cognitive change processes in a group cognitive behavior therapy of depression

The present study attempted to examine the causal relationships among changes in automatic thoughts, dysfunctional attitudes, and depressive symptoms in a 12-week group cognitive behavior therapy (GCBT) program for depression. In all, 35 depressed patients attending the GCBT program were monitored with the Automatic Thoughts Questionnaire, Dysfunctional Attitudes Scale, and Beck Depression Inventory at the pre-treatment, 4th and 8th sessions, and post-treatment. The results were as follows: (1) GCBT reduces negative cognitions; (2) changes in automatic thoughts and dysfunctional attitudes lead to change in depressive symptoms; and (3) automatic thoughts play a mediating role between dysfunctional attitudes and depression. The findings taken as a whole support the Causal Cognition Model of depression. (C) 2003 Elsevier Science Ltd. All rights reserved.

Temporal precision of interceptive action: differential effects of target size and speed

The duration of movements made to intercept moving targets decreases and movement speed increases when interception requires greater temporal precision. Changes in target size and target speed can have the same effect on required temporal precision, but the response to these changes differs: changes in target speed elicit larger changes in response speed. A possible explanation is that people attempt to strike the target in a central zone that does not vary much with variation in physical target size: the effective size of the target is relatively constant over changes in physical size. Three experiments are reported that test this idea. Participants performed two tasks: (1) strike a moving target with a bat moved perpendicular to the path of the target; (2) press on a force transducer when the target was in a location where it could be struck by the bat. Target speed was varied and target size held constant in experiment 1. Target speed and size were co-varied in experiment 2, keeping the required temporal precision constant. Target size was varied and target speed held constant in experiment 3 to give the same temporal precision as experiment 1. Duration of hitting movements decreased and maximum movement speed increased with increases in target speed and/or temporal precision requirements in all experiments. The effects were largest in experiment 1 and smallest in experiment 3. Analysis of a measure of effective target size (standard deviation of strike locations on the target) failed to support the hypothesis that performance differences could be explained in terms of effective size rather than actual physical size. In the pressing task, participants produced greater peak forces and shorter force pulses when the temporal precision required was greater, showing that the response to increasing temporal precision generalizes to different responses. It is concluded that target size and target speed have independent effects on performance.

The accuracy of interceptive action in time and space

Hitting a moving target demands that movement is both spatially and temporally accurate. Recent experiments have begun to reveal how performance of such actions depends on the spatial and temporal accuracy requirements of the task. The results suggest a simple strategy for achieving spatiotemporal accuracy using brief, high-speed movements.

Women, violence and nonviolent resistance in east Timor

A growing literature in peace and conflict studies assesses the relationship between women and nonviolence. Numerous national liberation fronts and academic critiques assess how women participate in nonviolent resistance from Tibet and West Papua to Palestine and Eritrea. However, many liberation struggles that include female nonviolent resistance remain undocumented, and this article aims to delve into one case study in particular. The article examines the nonviolent roles adopted by women in the East Timorese liberation struggle, a national liberation movement in which the participation of female combatants was low but nonviolent participation by women in the resistance movement overall was high. However, the consequences for such women was, and remains, shaped by the overarching patriarchal structures of both the Indonesian occupiers and East Timorese society itself Female nonviolent resistance was met with highly violent responses from Indonesian troops, especially in the form of rape and sexual exploitation. Yet, this study also found that women acting under religious auspices faced less violent responses overall. Interviews with East Timorese women are used to reveal some of the sexual dynamics of nonviolent action and reprisal. This material is placed in the context of theoretical work on gender, violence and nonviolence.

Influence of Observer Presence on Pacific Damsel Bug Behavior: Who is Watching Whom?

When direct observations are used to study animal behavior the presence of the observer may alter the animal and hence influence the data being collected, yet few studies have quantified this effect. We conducted direct observation studies in the glasshouse to assess the relative influence of observer presence on the behavior of Pacific damsel bugs, Nabis kinbergii, a potentially important predator of crop pests. Comparisons of predator activity, predator distribution, prey (Helicoverpa armigera) mortality and prey distribution between frequently observed and minimally observed treatments, during diurnal and nocturnal observation sessions showed that the frequency of observer presence had no apparent impact on Pacific damsel bug behavior. This is the first documented test of the impact of observer presence in an insect system. To place our results in context, we reviewed 15 papers on the influence of observer presence in a range of animals. We established that just over half of these papers found evidence for an effect. Nevertheless, direct observations should be useful in further studies of Pacific damsel bug behavior, and researchers using direct observations to study the behavior of other animals should be cognizant of observer effects during design and interpretation of their study.

The impact of residential respite care on the behavior of older people

Background: The aim of this study was to examine the impact of residential respite care on disruptive behavior displayed by older people, particularly those with dementia. Methods: A quasi-experimental, repeated-measures, single-group design was used. The participants were a consecutive series of 100 older people with a mean age of 81.8 years (range 66-96 years) who had been booked for a respite admission to one of several residential aged care facilities in a provincial Australian city. A diagnosis of dementia was reported for 29% of the sample. Disruptive behaviors were rated before and after the period of respite by home caregivers (N = 100) and during the period of respite by nurses (N= 25) using the Dementia Behavior Disturbance Scale (DBDS). Results: Age, male gender and the presence of dementia were all significantly related to the frequency of reported disruptive behaviors. Residential respite care was associated with a significant reduction in the frequency of reported disruptive behaviors in older people (Wald chi(2) = 28.28, P < 0.0001). However, this improvement in behavior did not persist into the post-respite period. The deteriorating behavioral trajectory that was evident prior to respite care continued following the period of respite care. Conclusions: Residential respite care was associated with a temporary diminution in the frequency of reported disruptive behaviors in older people. This finding should be reassuring both for family carets considering placing a relative in residential respite care and for health workers considering whether to recommend such a course of action.

Muscle fiber and motor unit behavior in the longest human skeletal muscle

The sartorius muscle is the longest muscle in the human body. It is strap-like, up to 600 mm in length, and contains five to seven neurovascular compartments, each with a neuromuscular endplate zone. Some of its fibers terminate intrafascicularly, whereas others may run the full length of the muscle. To assess the location and timing of activation within motor units of this long muscle, we recorded electromyographic potentials from multiple intramuscular electrodes along sartorius muscle during steady voluntary contraction and analyzed their activity with spike-triggered averaging from a needle electrode inserted near the proximal end of the muscle. Approximately 30% of sartorius motor units included muscle fibers that ran the full length of the muscle, conducting action potentials at 3.9 +/- 0.1 m/s. Most motor units were innervated within a single muscle endplate zone that was not necessarily near the midpoint of the fiber. As a consequence, action potentials reached the distal end of a unit as late as 100 ms after initiation at an endplate zone. Thus, contractile activity is not synchronized along the length of single sartorius fibers. We postulate that lateral transmission of force from fiber to endomysium and a wide distribution of motor unit endplates along the muscle are critical for the efficient transmission of force from sarcomere to tendon and for the prevention of muscle injury caused by overextension of inactive regions of muscle fibers.

Does anticipation training affect drivers' risk taking?

Skill and risk taking are argued to be independent and to require different remedial programs. However, it is possible to contend that skill-based training could be associated with an increase, a decrease, or no change in fisk-taking behavior. In 3 experiments, the authors examined the influence of a skill-based training program (hazard perception) on the fisk-taking behavior of car drivers (using video-based driving simulations). Experiment 1 demonstrated a decrease in risk taking for novice drivers. In Experiment 2, the authors examined the possibilities that the skills training might operate through either a nonspecific reduction in risk taking or a specific improvement in hazard perception. Evidence supported the latter. These findings were replicated in a more ecological context in Experiment 3, which compared advanced and nonadvanced police drivers.