Variations of tool and task characteristics reveal that tool-use postures are anticipated

The authors examined anticipation in tool use, focusing on tool length and tool-use posture. Adults (9 women and 9 men in each experiment) held a rod (length 0.4-0.8 m), with the tip upward; walked toward a cube; chose a place to stop; and displaced the cube with the rod's tip. In 2 experiments, rod length, mass, and mass distribution, and the size of the cube were manipulated. Chosen distance depended on rod length and cube size. Because effects of cube size on distance resulted only from postural changes related to required control, distance anticipated displacement posture. A postural synergy comprising legs and trunk provided a stable platform for the displacement. An arm synergy was less extended for small cubes, longer rods, and handle-weighted rods. Selected distance anticipated those postures.     

On being lonely: fear of one's own aggression as an impediment to intimacy

This paper considers loneliness from the point of view of compromise formation and the development of fantasy as a means of defending against painful affect. Our idea is that at least one strand of loneliness derives from longing for an ideal object with whom one would never have to feel aggression and from whom no aggressive actions would have to be tolerated. The development of such a fantasy in a middle-aged man is traced to early loss of a parent with missed mourning, and is shown to be ameliorated by psychoanalytic treatment that allowed the mourning to take place.     

The information for catching fly balls: judging and intercepting virtual balls in a CAVE

Visually guided action implies the existence of information as well as a control law relating that information to movement. For ball catching, the Chapman Strategy--keeping constant the rate of change of the tangent of the elevation angle (d(tan(alpha))/dt)--leads a catcher to the right location at the right time to intercept a fly ball. Previous studies showed the ability to detect the information and the consistency of running patterns with the use of the strategy. However, only direct manipulation of information can show its use. Participants were asked to intercept virtual balls in a Cave Automated Virtual Environment (CAVE) or to judge whether balls would pass behind or in front of them. Catchers in the CAVE successfully intercepted virtual balls with their forehead. Furthermore, the timing of judgments was related to the patterns of changing d(tan(alpha))/dt. The advantages and disadvantages of a CAVE as a tool for studying interceptive action are discussed.     

Trial spacing is a determinant of cue interaction

Four conditioned lick suppression experiments with rats examined the effect of trial spacing on cue interaction. Experiments 1 and 2 found overshadowing to be eliminated with massed compound stimulus-outcome pairings and the usual trial spacing effect to be reversed with compound acquisition trials. Experiment 3 found that whether acquisition compound-outcome pairings were massed or spaced determined the effect of posttraining extinction treatment. Extinction of the overshadowing cue reduced responding following massed training and increased responding following spaced training. Extinction of the context decreased responding following massed training. Experiment 4 found the conditioning and devaluation results to be associative and stimulus specific. These results are in accord with the extended comparator hypothesis (J. C. Denniston, H. I. Savastano, & R. R. Miller, 2001).     

Geometrics and dynamics of a rod determine how it is used for reaching

Displacing an object with a hand-held rod provided a simple paradigm for studying tool use. The authors asked how reaching was affected by manipulations of rod properties. Adults held a rod (length =.10 to 1.5 m), with its tip in the air; walked toward an object on a table; chose a place to stop; and displaced the object with the rod's tip. In 3 experiments (Ns = 9, 22, and 17 participants), the authors manipulated rod length, mass, and mass distribution to determine whether and how geometric and dynamic properties affected the chosen distance and the posture. Both the chosen stopping distance and the postures were well accommodated to rod characteristics. Postural adaptations took place only in the arm, which was organized as a synergy. Predictably, rod length explained most of the variance, but small and reliable differences in both distance and posture depended on mass and mass distribution. The chosen distance anticipated not only rod length but also the upcoming posture needed to control the rod.     

Cognitive Testing Battery: differences among groups with dementia, Huntington's disease, and controls

This study evaluated a new test for dementia, the Cognitive Testing Battery, used for over six years in outpatient clinics for aging-related disorders. This battery was developed to be brief, easy to administer, and to provide useful feedback as a cognitive profile for clinicians, patients, and caregivers. 489 participants were tested during a 5-yr. period. Multidisicplinary teams diagnosed these patients with dementia, depression, or Huntington's Disease. A control group was also included. Groups were then compared on the 10 key subscales that subserve dementia populations. Analysis showed there were significant differences among the groups on all measures and that selected scales differentiated the groups. The total score maximally differentiated the groups, and the dementia group was most different from the other groups.     

The persuasiveness of racial arguments as a subtle measure of racism

These studies provide evidence of the reliability and validity of a new indirect measure of racism, the Racial Argument Scale (RAS). On the RAS, participants rate how well arguments support conclusions that are positive or negative toward Blacks rather than their agreement with the arguments and conclusions. These studies show that the RAS has good internal consistency, high levels of test-retest reliability, good convergent validity with other self-report measures of racism, and does not correlate with social desirability or right-wing authoritarianism. Furthermore, these studies show that the RAS predicts behavioral measures of racism and that the RAS is able to predict positivity and negativity toward Blacks that is not measured by other self-report measures of racism. These studies suggest that the RAS is a reliable and valid measure of racial attitudes.     

The clinician-investigator: unavoidable but manageable tension

The "difference position" holds that clinical research and therapeutic medical practice are sufficiently distinct activities to require different ethical rules and principles. The "similarity position" holds instead that clinical investigators ought to be bound by the same fundamental principles that govern therapeutic medicine--specifically, a duty to provide the optimal therapeutic benefit to each patient or subject. Some defenders of the similarity position defend it because of the overlap between the role of attending physician and the role of investigator in a research trial. This overlap is maximal when the same physician occupies both roles with respect to a particular patient-subject. We address the ethical tensions inherent in that role conflict and argue that the tensions are real but manageable. The difference position provides a sound ethical framework within which to manage those tensions, while the similarity position is unsatisfactory because it seeks to deny the existence of the tensions.     

Representing tools: how two non-human primate species distinguish between the functionally relevant and irrelevant features of a tool

Few studies have examined whether non-human tool-users understand the properties that are relevant for a tool's function. We tested cotton-top tamarins (Saguinus oedipus) and rhesus macaques (Macaca mulatta) on an expectancy violation procedure designed to assess whether these species make distinctions between the functionally relevant and irrelevant features of a tool. Subjects watched an experimenter use a tool to push a grape down a ramp, and then were presented with different displays in which the features of the original tool (shape, color, orientation) were selectively varied. Results indicated that both species looked longer when a newly shaped stick acted on the grape than when a newly colored stick performed the same action, suggesting that both species perceive shape as a more salient transformation than color. In contrast, tamarins, but not rhesus, attended to changes in the tool's orientation. We propose that some non-human primates begin with a predisposition to attend to a tool's shape and, with sufficient experience, develop a more sophisticated understanding of the features that are functionally relevant to tools.     

Instructions for Authors

Instructions for Authors

Instructions for Authors