Braking reaching movements: a test of the constant tau-dot strategy under different viewing conditions

Following F. Zaal and R. J. Bootsma (1995), the authors studied whether the decelerative phase of a reaching movement could be modeled as a constant tau-dot strategy resulting in a soft collision with the object. Specifically, they investigated whether that strategy is sustained over different viewing conditions. Participants (N = 11) were required to reach for 15- and 50-mm objects at 2 different distances under 3 conditions in which visual availability of the immediate environment and of the reaching hand were varied. Tau-dot estimates and goodness-of-fit were highly similar across the 3 conditions. Only within-participant variability of tau-dot estimates was increased when environmental cues were removed. That finding suggests that the motor system uses a tau-dot strategy involving the intermodal (i.e., visual, proprioceptive, or both) specification of information to regulate the decelerative phase of reaching under restricted viewing conditions. The authors provide recommendations for improving the derivation of tau;(x) estimates and stress the need for further research on how time-to-contact information is used in the regulation of the dynamics of actions such as reaching.     

Guilt about being born and debt concerning the gift of life

A very powerful form of preoedipal guilt stems from a sense of having damaged the life-giving parent with one's most basic needs. A related phenomenon is the child's sense that another subjectivity has deliberately chosen to give and sustain the child's life. This experience gives rise to a compelling mixture of awe, reverence, and obligation, a sense of guilt about being born, of debt concerning the gift of life. This sense of guilt and debt are part of every child's development. Depending on how conflicts surrounding them are negotiated, the child can come to feel either an appetite for living or a crushing sense of selfishness and unworthiness. Such forms of guilt and debt may lead not only to masochism generally, but to a particularly pernicious form of negative therapeutic reaction that can sabotage psychoanalytic work. A patient may feel, for instance, that a successful psychoanalysis is a selfish indulgence and an immoral betrayal of a sacred duty to rescue his or her parents from their misery. Guilt about being born and the sense of debt concerning the gift of life are linked to various developmental, psychodynamic, interpersonal, and cultural phenomena.     

Investigating the influence of organizational role on perceptions of risk in deep coal mines

The authors replicated O. Ostberg's (1980) study of forestry workers using a range of personnel groups in coal mines. Findings demonstrate a high level of consensus between a range of personnel groups for a set of pictorially depicted behavioral risks, at the level of rank order, but significant differences in terms of relative magnitudes. Magnitudes of perceived risk were found to be greater for those closest to the point of hazard than for members of more geographically and experientially distal groups. Findings are interpreted with reference to experiential influences associated with organizational role. Revealed differences between personnel groups are explained in terms of cognitive availability, specifically effects associated with habituation and familiarity with risk, these sources of perceptual bias appearing to interact with organizational role.     

Sexually selective cognition: beauty captures the mind of the beholder

Across 5 experimental studies, the authors explore selective processing biases for physically attractive others. The findings suggest that (a). both male and female observers selectively attend to physically attractive female targets, (b). limiting the attentional capacity of either gender results in biased frequency estimates of attractive females, (c). although females selectively attend to attractive males, limiting females' attentional capacity does not lead to biased estimates of attractive males, (d). observers of both genders exhibit enhanced recognition memory for attractive females but attenuated recognition for attractive males. Results suggest that different mating-related motives may guide the selective processing of attractive men and women.     

Bias in exponential and power function fits due to noise: Comment on Myung,Kim, and Pitt

Myung, Kim, and Pitt (2000) demonstrated that simple power functions almost always provide a better fit to purely random data than do simple exponential functions. This result has important implications, because it suggests that high noise levels, which are common in psychological experiments, may cause a bias favoring power functions. We replicate their result and extend it by showing strong bias for more realistic sample sizes. We also show that biases occur for data that contain both random and systematic components, as may be expected in real data. We then demonstrate that these biases disappear for two- or three-parameter functions that include linear parameters (in at least one parameterization). Our results suggest that one should exercise caution when proposing simple power and exponential functions as models of learning. More generally, our results suggest that linear parameters should be estimated rather than fixed when one is comparing the fit of nonlinear models to noisy data.     

Cooperation, psychological game theory, and limitations of rationality in social interaction

Rational choice theory enjoys unprecedented popularity and influence in the behavioral and social sciences, but it generates intractable problems when applied to socially interactive decisions. In individual decisions, instrumental rationality is defined in terms of expected utility maximization. This becomes problematic in interactive decisions, when individuals have only partial control over the outcomes, because expected utility maximization is undefined in the absence of assumptions about how the other participants will behave. Game theory therefore incorporates not only rationality but also common knowledge assumptions, enabling players to anticipate their co-players' strategies. Under these assumptions, disparate anomalies emerge. Instrumental rationality, conventionally interpreted, fails to explain intuitively obvious features of human interaction, yields predictions starkly at variance with experimental findings, and breaks down completely in certain cases. In particular, focal point selection in pure coordination games is inexplicable, though it is easily achieved in practice; the intuitively compelling payoff-dominance principle lacks rational justification; rationality in social dilemmas is self-defeating; a key solution concept for cooperative coalition games is frequently inapplicable; and rational choice in certain sequential games generates contradictions. In experiments, human players behave more cooperatively and receive higher payoffs than strict rationality would permit. Orthodox conceptions of rationality are evidently internally deficient and inadequate for explaining human interaction. Psychological game theory, based on nonstandard assumptions, is required to solve these problems, and some suggestions along these lines have already been put forward.     

Failures of retrieval and comparison constrain change detection in natural scenes

In a change detection paradigm, a target object in a natural scene either rotated in depth, was replaced by another object token, or remained the same. Change detection performance was reliably higher when a target postcue allowed participants to restrict retrieval and comparison processes to the target object (Experiment 1). Change detection performance remained excellent when the target object was not attended at change (Experiment 2) and when a concurrent verbal working memory load minimized the possibility of verbal encoding (Experiment 3). Together, these data demonstrate that visual representations accumulate in memory from attended objects as the eyes and attention are oriented within a scene and that change blindness derives, at least in part, from retrieval and comparison failure.     

Transfer of value from fit

People experience regulatory fit when they pursue a goal in a manner that sustains their regulatory orientation (E. T. Higgins, 2000). Five studies tested whether the value experienced from regulatory fit can transfer to a subsequent evaluation of an object. In Studies 1 and 2, participants gave the same coffee mug a higher price if they had chosen it with a strategy that fit their orientation (eager strategy/promotion; vigilant strategy/prevention) than a strategy that did not fit. Studies 3-5 investigated possible mechanisms underlying this effect. Value transfer was independent of positive mood, perceived effectiveness (instrumentality), and perceived efficiency (ease), and occurred for an object that w as independent of the fit process itself. The findings supported a value confusion account of transfer.