Terminal decline and cognitive performance in very old age: does cause of death matter?

Cross-sectional differences and longitudinal changes in cognitive functioning in relation to mortality across a 7-year follow-up period, with 3 times of measurement, were examined in a population-based sample of very old adults. The authors also sought to determine whether cause of death (cerebro/cardiovascular disease [CVD]; non-CVD) modified the magnitude of mortality-related cognitive deficits. Cognitive performance was indexed by tests of general cognitive ability, episodic memory, primary memory, verbal fluency, and visuospatial ability. Results indicated cross-sectional differences on all domains of functioning, with persons who would die within 3 years after baseline testing performing more poorly. Longitudinally, greater decrements were observed on all domains for persons who would die after the first follow-up period, as compared with survivors. Cause of death failed to modify the magnitude of the cross-sectional and longitudinal deficits. The pattern of results point to the general nature of this phenomenon.     

Sit-and-wait strategies in dynamic visual search

The role of memory in visual search has lately become a controversial issue. Horowitz and Wolfe (1998) observed that performance in a visual search task was little affected by whether the stimuli were static or randomly relocated every 111 ms. Because a memory-based mechanism, such as inhibition of return, would be of no use in the dynamic condition, Horowitz and Wolfe concluded that memory is likewise not involved in the static condition. However, Horowitz and Wolfe could not effectively rule out the possibility that observers adopted a different strategy in the dynamic condition than in the static condition. That is, in the dynamic condition observers may have attended to a subregion of the display and waited for the target to appear there (sit-and-wait strategy). This hypothesis is supported by experimental data showing that performance in their dynamic condition does not differ from performance in another dynamic condition in which observers are forced to adopt a sit-and-wait strategy by being presented with a limited region of the display only.     

Body image and self-esteem in adolescent ballet dancers.

Body-image disturbances and low self-esteem have been implicated in the pathogenesis of eating disorders. This study investigated self-perception of body and personality among adolescent ballet dancers in a cross-sectional survey. Two questionnaires assessing "my body right now" and "my personality right now," using semantic differentials were completed by 90 ballet school students and 156 controls. Adolescent female dancers (ages 13 to 17 years) scored higher than age-matched controls and 11- to 12-yr. old peers on Undesirability and Sensitivity for personality and Unattractiveness for body. For both subscales of personality, differences were also found between male and female dancers; female ballet students scored higher. Within the control group a difference could be found only for Sensitivity on which girls scored higher than boys. Male dancers did not differ from controls except for a lower score on the Body mass measure. Adolescent female dancers showed a distinct answering profile for 7 of 16 semantic differentials in each questionnaire implicating less favorable body image and self-esteem. Interventions focused particularly on enhancing self-esteem may be useful in the prevention of psychopathology in adolescent ballet dancers.     

The effects of abrupt onset of 2-D and 3-D distractors on prehension movements

This article includes two experiments aimed at investigating how two-dimensional (2-D) and three-dimensional (3-D) distractors affect the kinematics of prehension and aiming movements in order to understand the attentional processes involved in visuomotor control. In Experiment 1, subjects grasped large targets in the presence of both large and small 3-D distractors and their corresponding 2-D photographs. The distractors appeared for either 10 sec or appeared simultaneously with the target presentation. It was found that reach and grasp kinematics were influenced primarily by the small, suddenly appearing 3-D distractors. In Experiment 2, the purpose was to examine the conclusion that competition between objects (target and distractor) is related to the behavioral goal of the task. Experiment 2 is a replication of Experiment 1, with the exception that pointing movements were made instead of grasping movements. Results show that both 3-D and 2-D distractors interfered with pointing kinematics, supporting the hypothesis that attentional mechanisms are related to the goal of the task.     

Renatus renatus: the Cartesian tradition in British neuroscience and the neurophilosophy of John Carew Eccles

J. C. Eccles (1903-1997) had a highly distinguished career in neurophysiology, being awarded the Nobel Prize for Medicine or Physiology in 1963. This paper sets him within the Cartesian tradition of British neurophysiology initiated by Thomas Henry Huxley in the mid-19th century. It shows how the mind-brain problematique of the Cartesian tradition troubled him throughout his career, leading him finally to a solution in terms of quantum microphysics and microphysiology. This position, which has subsequently become fashionable, is discussed and shown (at least in the form Eccles espoused) to provide no solution to the problem posed by Descartes in the early 17th century.     

Statistical properties of the rWG(J) index of agreement

L. R. James, R. G. Demaree, and G. Wolf (1984) introduced rWG(J) to estimate interrater agreement for a group. This index is calculated by comparing an observed group variance with an expected random variance. As researchers have gained experience using this index, several questions have arisen. What are the consequences of replacing values beyond the unit interval by 0? What is the dependence of rWG(J) on the group size? The authors' simulations show that a positive bias is caused by the truncation, but for large population values of rWG(J) it is negligible. Also, in this case, the group size has no effect on the expected value of rWG(J). For inference on rWG(J), researchers can exploit the availability of computers to simulate data from the hypothesized distribution and then compare the simulation results for rWG(J) with the actual values. In addition, it is shown how the bootstrap method can be used for comparing the indices of 2 groups.     

Engagement and outcome in the treatment of bulimia nervosa: first phase of a sequential design comparing motivation enhancement therapy and cognitive behavioural therapy

Despite the major advances in the development of treatments for bulimia nervosa, drop-outs and a lack of engagement in treatment, continue to be problems. Recent studies suggest that the transtheoretical model of change may be applicable to bulimia nervosa. The aim of this study was to examine the roles of readiness to change and therapeutic alliance in determining engagement and outcome in the first phase of treatment. One hundred and twenty five consecutive female patients meeting DSM-IV criteria for bulimia nervosa took part in a randomised controlled treatment trial. The first phase of the sequential treatment compared four sessions of either cognitive behavioural therapy (CBT) or motivational enhancement therapy (MET) in engaging patients in treatment and reducing symptoms. Patients in the action stage showed greater improvement in symptoms of binge eating than did patients in the contemplation stage. Higher pretreatment scores on action were also related to the development of a better therapeutic alliance (as perceived by patients) after four weeks. However, pretreatment stage of change did not predict who dropped out of treatment. There were no differences between MET and CBT in terms of reducing bulimic symptoms or in terms of developing a therapeutic alliance or increasing readiness to change. The results suggest that the transtheoretical model of change may have some validity in the treatment of bulimia nervosa although current measures of readiness to change may require modification. Overall, readiness to change is more strongly related to improvement and the development of a therapeutic alliance than the specific type of treatment.     

The myth of upright vision. A psychophysical and functional imaging study of adaptation to inverting spectacles

The adaptation to inverting prisms and mirror spectacles was studied in four subjects over periods of six to ten days. Subjects showed rapid adaptation of visuomotor functions, but did not report return of upright vision. The persistence of the transformed visual image was confirmed by the subjects' perception of shape from shading. No alteration of the retinotopy of early visual cortical areas was seen in the functional magnetic resonance images. These results are discussed in the context of previous claims of upright vision with inverting prisms and mirror spectacles.     

Color filling-in under steady fixation: behavioral demonstration in monkeys and humans

Color filling-in is a phenomenon in which the color of an object appears to be filled-in by the color of the surrounding field. We have studied the question of whether monkeys perceive color filling-in with near-foveal stimuli under steady fixation. Two monkeys were trained to fixate steadily and to attend to a disk, surrounded by an annulus of the complementary color, in parafoveal vision. Using displays in which the color of the disk was gradually changed to that of the annulus, we trained the animals to signal when they perceived a uniform color field. During the experiment, we introduced a small percentage of trials in which the disk color remained constant, and looked for 'filling-in' responses in these trials. Three human subjects were also tested for comparison. All subjects produced 'filling-in' responses with frequencies that were significantly higher for static disks with blurred borders than for moving disks or disks with sharp borders. This indicates that the monkeys' responses reflected perceptual filling-in, rather than random behavior. The time course of filling-in was similar in monkeys and humans. For the blurred static disks, responses occurred first after 3-4 s of fixation, reaching a probability of 0.2-0.8 by the end of 6 s, depending on the subject.