Behavioral discrimination of click intensity in cat

Avoidance conditioning procedures were used to train cats to discriminate intensity differences between successive clicks. The discriminative behavior was applied in a modified method of adjustment to determine a difference limen (DL) for click intensity. The obtained DLs were consistent within and between subjects, and averaged 4.4 db. This value is greater than previously reported intensity DLs for pure tones in cats.     

CHARACTERISTICS OF SUCCESSFUL AND DROPOUT MDTA TRAINEES1

A study was designed to compare several variables of Manpower Development Training Act (MDTA) clients who dropped out of the program with those of clients who completed the program. A random sample of application cards was drawn for individuals enrolled in MDTA adult classes in Milwaukee, Wisconsin. Trainees who completed the program were more likely to be married, older, characterized by a more stable employment history prior to entering the program, and slightly more educated than were program dropouts. Clients who completed the program versus those who did not were not significantly different on the following variables: (1) sex; (2) counseling versus no counseling; (3) race; and (4) client reported physical disability.     

Testing significance of differences between two chi-squares

This paper presents a way to test the difference between twoX ²'s. The test requires evaluating the difference with respect to theT _m (x) Bessel function. Included is a table of the 5 percent and 1 percent points for the Bessel function with degrees of freedom up to 100.This investigation was supported by National Science Foundation Grant Number GE 9846.     

Two types of short-term visual storage

Seven-letter words were flashed repetitively at various durations above and below the recognition threshold for single flashes. One form of a short-term storage effect was studied by measuring the interstimulus interval between flashes at which S reported that the stimulus became phenomenally discontinuous in time. Storage times reached a maximum of about 300 msec in this task. A second form of storage effect was measured by decreasing the interstimulus interval until S could correctly recognize a repeated stimulus whose duration was below the single-flash recognition threshold; this effect extended to 900 msec in some cases. Each of these effects was reliably obtained for both rare and frequent words. Both forms of storage were increased by providing a dark rather than a lighted adapting field between presentations of the test stimulus. Implications for Information processing of brief displays are discussed.     

Satiation effects in the perception of single letters’

When single letters were presented for five flashes, with S making a clarity judgment after each exposure, initial potentiation and subsequent satiation effects were found. A processing task and complete prior knowledge led to an increased probability of a “clear” response on the first exposure and to an earlier onset of the satiation effect. The results are discussed in terms of the neural network model underlying this research.     

Calvinism and psychoanalysis: A comparative study

Summary Although the title of this essay suggests a comparison of psychoanalysis and Calvinism, I have chosen to compare primarily the two leaders of these movements. On many points they shared similar beliefs. Certain of these areas have been highlighted and discussed briefly: ascetic tendencies, work, religion, concepts of God and of man, actions as symptoms, and predestination and determinism.     

Variable-interval escape from stimuli accompanied by shocks

Individual performances of three rats were examined under a procedure in which steady rates of bar pressing were maintained by conditioned aversive stimulation. Originally neutral visual and auditory stimuli were accompanied by widely and irregularly spaced pulses of shock; they were terminated on a variable-interval schedule by pressing a bar. The contingencies between behavior and shock were also duplicated in a control procedure in which no visual or auditory stimuli were provided. Pressing observed under the control procedure was attributed to differences in the aversiveness of pressing and nonpressing behavior engendered by differences in the incidence of shock following the two classes of behavior. Increased rates with visual and auditory stimuli were attributed to termination of conditioned aversive stimulation. Control rates declined more rapidly than did experimental rates as the mean interval between successive shocks was lengthened; both rates tended to decline when less than 60 sec was allowed as time out from shocks following the successful response. In the control procedure, discrimination between the continuation and discontinuation of the shock series, as measured by relative rates, depended on the relative length of the interval between shocks and the time-out period. Regular warm-up accelerations in rate were noted following an initial delay in responding at the beginning of each session. The length of time required for the warm-up depended on the length of the mean interval between shocks, indicating that exposure to a certain amount of shock was required to establish a supporting state for the observed performance.