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.     

The effects of thematic context and presentation mode on memory for sentence voice

A sentence in discourse may appear in the passive voice to emphasize the logical object rather than the logical subject when it is thematically more important. Two experiments are reported that explore the impact of this textual function of voice on sentence memory. The first experiment required subjects to listen to prose passages and then recall them. Sentences were recalled predominantly in the active voice regardless of voice or thematic focus in the prose passage, showing that the English-language bias for the active voice was a more important determinant of sentence reconstruction than was the experimental manipulation of thematic context. The second experiment required subjects to listen to or read either prose passages or lists of unrelated sentences and then to try to recognize key sentences that were either unchanged or changed lexically, semantically, or in voice. Recognition, both overall and specifically for voice, was better for sentences that were read than for those that were heard, and recognition for semantic change was consistently higher than for any other. Only when passages were read was there evidence in support of a thematic textual influence on memory for sentence voice.This research was supported in part by NIMH Grant 32063.     

Independence of Multiple Verdicts by Jurors and Juries1

An assumption underlying the common practice of permitting a juror to serve on more than one jury is that jurors can and will reach multiple verdicts independently. Two studies were carried out to examine this assumption. The first experiment had mock jurors consider several cases in succession. Subjects exhibited a clear contrast effect on the strength of evidence; those subjects who initially saw strong prosecution cases were less likely to convict in a moderate test case than those who had initially seen wcak prosecution cases. In the second study, the contrast hypothesis was tested for actual juries' verdicts through archival analyses. The results of this field study paralleled those obtained in the experimental study. The discussion focused upon alternative theoretical explanations for these results, implications for trial practice, and the strengths and weak-nesses of the methodologies applied in these studies.     

Specific and diversive curiosity and depression in junior high school students of divorced and nondivorced parents.

124 junior high school students (Grades 5 to 8) from a small school district in north central Kansas completed the Beck Depression Scale, the Maze test, and the Which-to-Discuss test. Background information, such as age, sex, grade, and marital status of parents, were also collected. There were no significant differences between boys and girls of divorced and nondivorced parents or across grades for scores on the Which-to-Discuss (specific curiosity) and depression, but boys scored significantly higher on the Maze test (diversive curiosity). No differences were noted between the students of divorced and nondivorced parents or across grades. Scores on Which-to-Discuss test and Maze test were not significantly correlated, but scores on one Maze test and depression correlated positively and significantly. When these students scored as more depressed, although in the normal range, they tended to score higher on diversive curiosity.     

Diving, adaptation, and Fitts law

To assess Welford's dual controlling factor interpretation of Fitts' law, 20 scuba divers performed a reciprocal tapping task. In an attempt to separate the two factors, the subjects were tested on land and underwater. This does not change the basic parameters of the task but does put the subjects under informational stress, in that underwater the movement is less ballistic in nature and should require the processing of more information (feedback) in each tap. On land, the contributions of movement amplitude and precision were approximately equal. However, the relative changes in contribution of these factors to movement time underwater suggests that these parameters do in fact represent separate controlling factors.     

The stigma of mental illness: Explanatory models and methods for change

For people with mental illness, diminished quality of life and loss of personal goals does not result solely from the symptoms, distress, and disabilities caused by their psychiatric disorder. Quality of life and personal goals are also hindered by people who embrace the stigma that accompanies mental illness and mental health care. This paper reviews evidence of the impact of mental illness stigma and strategies for seeking to ease its impact. To achieve these goals, we (a) describe the ways in which stigma harm people with mental illness, (b) summarize models that explain the development and maintenance of these stigmatizing effects, and (c) review strategies that have been shown to decrease the impact of stigma. Concerns about stigma are on the political agendas of many mental health advocacy groups. It has recently also become the focus of extensive research. Our goal in this paper is to balance the practical concerns raised by mental health advocates against data that support or contradicts specific assertions.