The effect of prolonged practice of pursuit eye movement

Prolonged exposure to a reciprocating motion that is tracked by the eyes results in diminished extent of perceived motion. Investigation of this effect showed that it becomes manifest only in perceived motion that is caused by ocular pursuit, but that it is not an eye muscle effect. It may consist in a changed evaluation of eye movements. The results throw some light on the relations between the processes that are caused by different stimuli for motion.     

Is recognition accuracy really impaired when the target is repeated in the display?

Bjork and Murray (1977) have presented a feature-specific interactive channels model that predicts perceptual interference between letters presented simultaneously in visual displays. Maximum interference is predicted when a target letter is presented with an identical letter. In their experiment, Bjork and Murray found support for their model, but their results could have occurred artifactually from response biases of their subjects. Santee and Egeth (1980) used a different paradigm that eliminated the possibility of this particular response bias and reported that their data supported the feature-specific model. However, the present paper shows that analysis of their data by Santee and Egeth was incomplete and the comparisons inappropriate. In two experiments that used the Santee and Egeth paradigm, we failed to find support for the feature-specific model when more detailed analyses of the data were undertaken. In a third experiment, one that used the Bjork and Murray paradigm, but with control of response bias, no significant or suggestive evidence was found that feature similarity between noise and target letters affected recognition of the latter.     

Slope of regard as a distance cue

It is proposed that some distance cues are learned when a perceptual parameter that varies with observation distance is regularly associated with objects whose distances are perceived because another distance cue operates. If that is the way distance cues can come into existence, it may be possible to identify a parameter that varies with distance but is not a known distance cue and to show that it functions as one. The slope of regard with which an object on the ground is viewed is such a potential distance cue. Its angle varies approximately with the reciprocal of distance. An experiment was done that showed that this slope angle functions as a distance cue. Subjects who looked through a device that altered slope angles gave estimates of the dimensions of an object on the ground. Perceived sizes, which vary inversely with distance, were found to be altered in accordance with the altered slope angle.     

Improved real-time control on the apple by mimicking an on-board 60-Hz clock

By delivering the vertical synch pulse to the maskable interrupt, it is possible to supply the Apple with a functional on-board 60-Hz clock that operates virtually independently of the CPU. This modification makes it easier to program more complex experiments involving independent control over stimulus exposure duration and the timing of response latency.     

A software system for real-time control of psychological experiments

This paper describes an all-purpose experimental system, “APES,” for use in a microprocessor-controlled behavioral pharmacology laboratory. APES is an assembly language program that can run on any of the DEC PDP-11 family processors under an RT-11 single-job operating system. Its main purpose is the real-time control of psychological experimentation. The capabilities of the system are: (1) system generation of all operant or Pavlovian conditioning paradigms, (2) collection and storage of both behavioral and physiological data in a machine-readable format for later statistical analysis, and (3) operation that can be accomplished by individuals who have no computer programming experience.     

Self-directed career exploration: A comparison of CHOICES and the Self-Directed Search

This study compared student satisfaction ratings for CHOICES, an interactive computer-based career guidance program, and the Self-Directed Search,a pencil-and-paper career planning guide. During the first testing session, subjects (N = 75) completed a biographical data sheet and were alternately assigned to either the CHOICES or the SDS treatment. Later, each subject completed the other treatment and two research instruments designed to assess their reactions to both treatments. Results indicated a user preference for CHOICES over the SDS, although both programs received positive ratings. The findings were discussed in terms of user reactions to career guidance programs and the selection of the most cost-effective treatment.     

The expression of feelings as assertive behavior: A factor analytic extension of PRI

The aims of the study were to construct two assertiveness measures, expression of positive feeling and expression of hostile feeling, and to establish their factor analytic independence. One hundred and ninety-seven adults were administered the PRI along with the two new scales. The correlations of the 40 items of the two scales were first analyzed separately to identify the two hypothesized constructs. The five scale scores of the PRI (Defense of Rights, Social Assertiveness. Directiveness, Independence and Approval Seeking) were divided into half-scale scores on the basis of keying (the sums of true-keyed and false-keyed items), and then intercorrelated with the half-scale scores of the new scales. A principal components analysis demonstrated the presence of the six dimensions hypothesized and a measure of validity.