Implicit associational responses produced by words in pairs of unrelated words

The purpose of this study was to determine if implicit associational responses (IARs) occur to individual words presented as pairs for associative learning. The occurrence of IARs was determined by a YES-NO recognition test, and IARs for words presented singly for study provided a base line. For all conditions, false recognitions to assumed IARs occurred; the magnitude was equivalent for words presented for study as pairs as for the same words presented singly. No evidence was found that IARs occurred during the testing phase.     

Coding strategies,perceptual grouping,and the “variability effect” in free recall

Three experiments examined the effects of constant vs. varied input of letter strings on recall, and then examined the effects of such training in the learning of new lists of letter strings. Letter strings were constructed from pairs of trigrams spatially grouped, and were presented either consistently or with different spatial groupings on successive presentations. In Experiments I and II, varied input produced substantially greater recall than constant input. When transferred to a new list of letter strings, containing either the same general structure or a new scrambled structure, recall of the second list was determined primarily by conditions of first-list input, and unaffected by second-list structure. Although the "variability effect" did not appear in the training phase of Experiment III, Varied input led subjects to regroup or integrate the letter sequences more frequently and produced similar transfer effects as in Experiments I and II.     

Reaction time measurement of temporal integration and organization of form

Temporal integration of patterned stimuli was investigated by introducing an interstimulus interval (ISI) between brief exposures of two matrices of illuminated squares. These matrices were identical except for their spatial displacement, arranged such that they could be superimposed to yield either horizontal or vertical stripes. Choice reaction times to the composite stripe orientation were a progressively increasing function of ISI, suggesting some integration over an ISI range in excess of 224 msec. Similar functions were obtained with both regular and irregular order of ISI presentation. The results from an additional experiment employing an extraneous warning signal discounted the possibility that preparatory factors developing over the ISI were responsible for the obtained reaction time functions.     

Uncertainty and social comparison

Two experimetnal tests were conducted of a model which predicts social comparison choices of extreme scores on a personality inventory. In groups of nine, subjects completed a bogus personality inventory that ostensibly measured a desirable or undesirable trait, and were told that either the highest or the lowest obtained score was a positive instance of the trait. The highest score was located for the subjects either with certainty or uncertainty, and the two experiments employed different manipulations of this factor. In both experiments the pattern of subjects' social comparison choices of other subjects' scores was fit best by a model comprising main effects of each factor and interactions between desirability and positive instance and between desirability and certainty.     

The CS-US interval function in rabbit nictitating membrane response conditioning: Single vs multiple trials per conditioning session

The effect of varying trials per day conditions on the CS-US interval or interstimulus interval (ISI) function in rabbit nictitating membrane response conditioning was studied in two experiments. Experiment 1 showed that a 1250-msec ISI was more effective than a 250-msec ISI when there was 1 trial/day. Experiment 2 showed that as the number of trials per day decreased from 20 to 1, the superiority of the 250-msec ISI group over the 1250-msec ISI group declined, with a reversal at 1 trial/day. Results are interpreted in terms of the role of a hypothesized CS-elicited short-duration orienting response in CR performance.     

Fixed-interval schedules of intravenous cocaine presentation in rats

Fixed-interval schedules of intravenous cocaine presentation were examined as a function of injection dose (0.32 to 0.64 mg/kg) and interval duration (200 to 400 sec) in two rats. Cocaine was found to exert a dose-related temporal control over the initiation of responding that was unaffected by the fixed-interval contingency. Fixed-interval pause duration was linearly related to injection dose and was the same duration as the interresponse time found on continuous reinforcement schedules of cocaine presentation. The fixed-interval pause remained constant with changes in interval duration. Characteristic fixed-interval patterns of responding were observed. However, overall response rates were inversely related to injection dose and directly related to interval duration. Running response rates varied unsystematically with both variables. These findings are at variance with results typically found in studies of fixed-interval food and electric shock presentation.     

A digital system for recording startle,responses in small animals

An easily constructed, isometric startle-recording system is described. The animal enclosure is attached to a plywood board-which, in ten, is mounted in a “springboard” arrangement. Movement is detected by a phonocartridge mounted beneath the chamber, and a digital record of this movement is obtained through the use of a voltage-to-frequency converter. A brief experiment in which the system was used to assess the rat’s reaction to electric footshock is also presented.     

Appropriateness of anxiety and drive for affiliation

Anxiety was induced in first/only born and later born subjects by the threatened injection of a harmless drug. Perceived appropriateness of the induced anxiety was manipulated by the experimenter's suggestion that anxiety over an injection was either perfectly natural (appropriate condition) or to be found only in rather nervous and effeminate men (inappropriate condition). The results indicated that the anxiety induction was successful, but that the perceived appropriateness of the anxiety determined the tendency to affiliate. Subjects in the appropriate condition showed a significantly greater tendency to affiliate than did subjects in the inappropriate condition. Birth order was related to anxiety on one of two measures, but was not implicated in the determination of the affiliative tendency.     

Children's binary prediction of partially learnable sequences followed by an all-correct procedure

Six groups of 20 subjects each were run individually in a binary prediction situation with each alternative occurring equally often. Two age groups were employed; subjects were either in second or sixth grades. For one-third of the subjects at each age level, the events occurred in runs of either two or six; another third observed events which occurred in runs of either five or six; the other subjects received a random sequence of events. All subjects then received an additional 50 trials in which every prediction was correct. The results indicated some sensitivity to run length characteristics. Fewer errors of all types were made in the prediction of 5–6 sequences. The verbal reports and all-correct trial protocols revealed that at least the sixth graders employed some simple run length structure rules, although many instances of runs other than those presented in training occurred, showing much processing error. The results were discussed in terms of a general limited-capacity model of information-processing.