Acknowledgement

Four experiments examined the effects of noise on semantic memory. The first was a replication of a study by Eysenck, in which subjects had to retrieve words beginning with particular letters which were also instances of specified categories (e.g. Fruit-A). Whereas Eysenck had found that both noise and activation level of the individual interacted with the dominance of the category instance possible, the present study failed to repeat the findings.The remaining experiments used a paper-and-pencil modification of Eysenck's technique; the second and third were successful in showing interactions of dominance and noise, but in opposite directions. The two experiments differed only in the previous experience of the subjects. In a fourth experiment, the same materials were presented in a different sequence, mixing dominant and non-dominant instances. The interaction then disappeared again.These experiments therefore suggest that the effect of noise on memory is not a uniform and mechanical exaggeration of dominance, but depends on the retrieval strategies being employed by the particular subject.     

Fourier components of moving gratings

In designing experiments in which the proximal stimulus is a moving grating (including cases in which the distal stimulus is stationary but eye movements play a significant role), one must consider the effects of the motion of the stimulus on its Fourier components in the spatiotemporal frequency domain. Some of these effects are unexpected and counterintuitive. For example, the Fourier components of a moving grating do not include its stationary (or “instantaneous”) spatial frequency. Thus there is no linear filter that can extract a stationary grating from a moving one. Several useful relations are given for analyzing such stimuli.     

Compensatory Response to Anticipated Densities1

The coping processes associated with crowding stress were conceptualized as dynamic sequences of personal or situational adjustments and readjustments directed toward maintaining desired frequencies of social contact. By studying ongoing coping processes as subjects prepared for anticipated crowding, evidence of social withdrawal as a response to crowding was obtained. In addition, findings suggested that these processes were sensitive to change in the situation, seeking or avoiding interaction as anticipated group size changed. Subjects who were subsequently told that they would be interacting in small groups rather than in larger groups reported less crowding and discomfort than subjects whose anticipation of large group interaction was maintained. Furthermore, subjects whose expectations of large group interaction were disconfirmed increased facial regard for others following disconfirmation, indicating a greater willingness to interact. These findings were discussed as evidence of optimization processes governing desired levels of social contact, intimacy, and personal space.     

Perception of numerical stimuli felt by fingers of the left and right hands

Three experiments are reported in which blindfolded right-handed adults felt numerical stimuli with the middle fingers of their left or right hands. These stimuli consisted of collections of raised dots in random arrangement to be enumerated (Experiment I), collections of evenly spaced raised dots in a straight line to be enumerated (Experiment II), and raised digits to be identified (Experiment III). Differences between hands were only found in Experiment I. The left hand was faster, apparently reflecting specialisation of the right cerebral hemisphere for the analysis of complex spatial stimuli. A fourth experiment, in which collections of raised dots in random arrangement to be enumerated were felt through a piece of cloth by subjects who were not blindfolded, confirmed the left hand superiority and demonstrated that it had not arisen from loss of sight of the movements of the dominant hand.     

Vocational maturity and anxiety among vocationally undecided and indecisive students : The effectiveness of Holland's Self-Directed Search

This study was designed with two purposes in mind: (1) to measure the effectiveness of Holland's Self-Directed Search for Educational and Vocational Planning (SDS); and (2) to test the validity of Goodstein's (Theories of Counseling. B. Stefflure, Ed., 1965) hypothesis that career indecision and indecisiveness are differentially related to anxiety and vocational maturity. A total of 66 high school males and 60 high school females were randomly assigned to experimental and control groups and tested for anxiety and vocational maturity levels; the experimental subjects were given the SDS. Statistical analysis indicated that the SDS was an effective instrument in reducing career indecision; Goodstein's hypothesis was not supported by the results of the study.     

A simple technique for correlating film and EMG in locomotion studies

Two recurring problems hampering investigations of muscular activity patterns during locomotion are electrical “noise” and movement artifact in the electromyographic (EMG) signal and proper synchronization of behavioral events to the EMG. A relatively simple technique for achieving these ends is presented. Vigorous locomotor movements of unrestrained animals are recorded on 16-mm film and synchronized with one or more EMGs from selected muscles with little electrical noise or movement artifact interference. The system employs telemetry which is compared to hardwire techniques.