Speed of aiming movements

Fitts' Law describes human movement time in the horizontal and frontal planes, but its application to movement in the sagittal plane has been questioned by Beggs and Howarth. To evaluate the Law in this plane, eight subjects performed a forearm action, similar to dart-throwing without release, moving a stylus through the sagittal plane from a back contact plate forward to a target. Four movement distances, 8, 12, 16 and 20 in, were combined with four target widths, 1/4, 1/2, 1 and 2 in, in 16 experimental conditions. Following practice all subjects were tested in each condition, with visual knowledge of results. The plot of movement time against log 2A/W was essentially linear, accounting for 92.6% of the variance.     

The effects of reordering the response categories on the area under the ROC

The area under the rating ROC can be a useful index of stimulus discriminability. It has the advantage that few assumptions must be made about the underlying distributions of signal and noise. One of the assumptions that must be made is the order of the subject’s response scale. A procedure is outlined for determining the order of the response scale actually used by the subject, and some of the implications of reordering the scale used in analysis are discussed. Results of computer simulation of the effects of varying some important experimental parameters are presented.     

Cancer Recovery and the Spirit

The present study addresses the definition and exploration of the existential and spiritual experience of persons who had spontaneously remitted or made a remarkable recovery from cancer. Spontaneous remitters had experienced a remission without having allopathic treatment which could account for the cancer regression. Those with remarkable recoveries may have had treatment, but had been given a prognosis of less than a 20% chance of survival in a specific number of months or years, and had survived at least five years past this time. The narratives of the ten participants indicated that cancer proved to be a wake-up call propelling them into unprecedented existential and spiritual growth. Nine of the participants reported that they had healed not only at physical, but also at emotional and spiritual levels. Most described a new and intensely numinous relationship with the divine and with the unity of all beings which was not religiously oriented. Nine out of ten participants felt that cancer had been a gift.     

Cue interaction in human contingency judgment

Most studies of human contingency judgment have been based on the assumption that frequency information about one predictor is assessed in isolation of information about other predictors. Recent evidence, however, suggests that the judged predictive strength of one cue is influenced by the predictive strengths of other copresent cues. Two experiments demonstrate that stimuli with the same outcome contingencies may nonetheless have different predictive strengths as the result of cue interaction. The first experiment, in which a within-subject design was used, provides a demonstration of blocking. A stimulus presented in compound with a strong predictor was rated as less predictive than another stimulus that was presented in compound with a nonpredictive cue. In the second experiment, cue interactions in conditioned inhibition were examined. A stimulus gained negative predictive strength as the result of compound presentations with a positive predictor when the outcome was not presented. This negative predictor was compared with an otherwise analogous stimulus that was not presented in compound with a positive predictor. These results support the use of animal-conditioning models as accounts of human contingency learning.     

Cognition and mood in relation to the performance of squash tasks

The purpose of this investigation was to determine the role of cognition and mood in the performance of squash tasks, with particular reference to attention and self-reported arousal and stress. Volunteer male subjects (n = 40), divided into three ability groups, 'skilled', 'average' and 'novice', were required to perform two squash tasks with different degrees of difficulty. Order of presentation of the tasks was controlled. Results indicated that subjects completing the easier squash task first performed better on the subsequent difficult task than those subjects who completed the more difficult task first. No differences in scores across tasks were found for subjects completing the tasks in reverse order. Performance was related to level of skill. Furthermore, significant differences in attentional style were revealed when average subjects were compared with skilled and novice players. Skilled players were also found to exhibit significantly different personality characteristics from novice players. Specifically, skilled players exhibited higher levels of extraversion and appeared less neurotic. For the average and novice groups, reports of high levels of stress accompanied those of high levels of arousal and these remained constant throughout the experiment. By contrast, for the skilled group low levels of stress accompanied high levels of arousal. The results are discussed in terms of the effects of these cognitive and mood factors on performance and a suggested direction for future research is offered.     

Achievement Motivation,Expected Coworker Performance,and Collective Task Motivation: Working Hard or Hardly Working?1

Social loafing is the tendency of individuals to work less hard collectively than individually. The present study examined the joint influence of achievement motivation and expected coworker effort on collective task performance. Participants (N= 107) who qualified and were available after pretesting on an achievement motivation scale were randomly assigned to a work condition and coworker effort condition. Dyads were asked to generate as many uses for a knife as possible within a 12‐min time period. Participants low in achievement motivation engaged in social loafing, but only when expected coworker effort was high, whereas participants high in achievement motivation did not engage in social loafing, regardless of expected coworker effort. The implication of achievement motivation for collective task performance settings is discussed.