Effects of attack and uncontrollable noise on aggression

After being either attacked or treated in a more neutral manner by an experimental confederate, male subjects shocked the confederate while being stimulated by loud noise. Among previously attacked subjects, possession of control over offset of the noise led to the delivery of shocks significantly shorter in duration than those given by subjects who did not have control. Mere predictability of noise offset did not have the same effect. Subjects who could control the noise did not differ from those who heard no noise with respect to the duration of shocks given. Noise had no effect on shock duration among nonattacked subjects. In a follow-up study subjects who were given bogus information that they were aroused by noise were less punitive toward an attacking confederate than subjects given no such information. The overall conclusion is that noise facilitates aggression in subjects who have been instigated to aggress to the degree that noise-produced arousal is misattributed to the instigating stimulus.     

Memory for movement: Interaction of location and distance cues and imagery ability

The present experiments examined the role of imagery ability in recall of either the terminal location or the distance of a preselected horizontal linear movement following changes in the recall starting position. Subjects were selected on the basis of their scores on a shortened version of the Betts Questionnaire upon Mental Imagery (Betts Q.M.I., Sheehan 1967). Both high and low imagers were assigned to one of four groups, HIL, LIL, HID, LID, the last letter indicating the movement cue (terminal location or distance moved) to be recalled. Recall of the appropriate movement cue from one of four new recall starting positions occurred after either a 5-sec or 30-sec unfilled retention interval. Analysis of constant error indicated all groups were unable to recall the specified movement cue independent of the other source of information, even when subjects were given explicit instructions to utilise an imagery strategy. The data corroborate our earlier findings that memory for self paced movements is based on an interaction of location and distance cues derived from the criterion movement.     

Observing behavior in monkeys (Macaca arctoides): Support for the information hypothesis

A single lever, discrete-trials observing procedure was used with stumptailed monkeys (Macaca arctoides). Lever-presses during a trial produced colored key lights (IS⁺ and IS^?) which signaled whether the trial would end with response-independent food or without food. During the baseline period, both IS⁺ and IS^? were produced on a variable-interval (VI) 15-sec schedule which began operating at the onset of the trial. The two experimental conditions involved a combination of this VI schedule and a DRL schedule. In one of these conditions, only a response that both met the VI requirement and was preceded by at least 6 sec of nonresponding could produce IS^? on nonfood trials, while the schedule for IS⁺ on food trials remained VI 15 sec. In the other experimental condition, the schedules for producing the two stimuli were the reverse. All subjects eventually learned to produce either IS⁺ or IS^? on the combined VI-DRL schedule. These data support an information hypothesis of observing in monkeys and contrast with data from pigeons which support a conditioned reinforcement hypothesis.     

Fluid and crystallized intelligence: effects of diffuse brain damage on the WAIS

In the 1940's two forms of intelligence, fluid and crystallized, were postulated. Active mental processing (WAIS performance subtests) were fluid while well learned abilities (WAIS verbal subtests) were crystallized. Brain damage was considered to affect fluid abilities more than crystallized. WAIS scores comparing normal and diffusely organically damaged subjects indicated that, as hypothesized, the verbal subtests were more affected than the performance subtests.     

Assessment of the relative importance of S+ and S− in rats using differential training on intercurrent discriminations

The present studies assessed the degree of stimulus control exerted by S+ and S? without confoundings of stimulus novelty and stimulus ambiguity. In Experiment 1, rats were trained on two intercurrent simultaneous discrimination problems with nine times more training given on one than the other. Then the animals were given transfer tests with re-paired stimuli. The results showed that S? exerts greater stimulus control than S+ in a two-choice simultaneous discrimination. Experiment 2 provided a test of the possibility that the relative degree of control by S? varies with different amounts of training. Three groups were trained on two intercurrent simultaneous discrimination problems; each group was given 7, 11, or 15 times more training on one problem than the other. Then transfer tests were given with re-paired stimuli. Again the results showed that S? exerts greater stimulus control than S+ in a two-choice simultaneous discrimination.     

THE DEVELOPMENT OF KNOWLEDGE CONCERNING WRITTEN ARITHMETIC: A CROSS-CULTURAL STUDY

This study is concerned with the manner in which Western mathematics is assimilated by children raised in traditional African cultures. It was predicted that after an initial period of difficulty in learning school arithmetic, African children (Baoulé and Dioula from the Ivory Coast) acquire basic concepts, develop invented strategies, and make errors similar to those of American children. Further, it was predicted that Dioula children, since they are members of a commercial culture, perform at a somewhat higher level than the Baoulé, members of a farming culture which does not seem to stress computational activity. To investigate these hypotheses, American, Baoulé, and Dioula children at two age levels were given a variety of arithmetic problems involving basic skills (e.g., reading numbers), number knowledge (e.g., place value), and calculational abilities (e.g., written computation). The results showed that, in general, older African and American children (fifth- and sixth-graders) were quite similar in all respects. The only large and significant differences occurred in the case of younger children (second- and third-graders). At this level American children generally performed at a higher level than Africans, as predicted, and Dioula occasionally at a higher level than Baoulé, also as predicted. At the same time, qualitative aspects of African and American children's performance were similar: for example, both groups made the same types and proportions of errors in written calculations. The results generally support the hypotheses and can be explained in terms of both educational and cognitive factors.     

External memory: High speed,low speed,and no speed

This paper describes potential constraints on the selection of external memory devices (stimulus sources) and suggests options available to the would-be user of such systems for estimating research requirements and the functional parameters of the available external memory devices.     

Drug effects on repeated acquisition: comparison of cumulative and non-cumulative dosing

Pigeons acquired a different four-response chain each session by responding sequentially on three keys in the presence of a sequence of four colors. The response chain was maintained by food presentation under a fixed-ratio schedule. Errors produced a brief timeout but did not reset the chain. Each day there were four 15-minute sessions, with a 10-minute inter-session interval. Cumulative dose-effect curves for phencyclidine, pentobarbital, and d-amphetamine were obtained by giving an injection before each of the four sessions; successive injections increased the cumulative dose in equally spaced logarithmic steps. For comparison, non-cumulative doses of each drug (i.e., doses not preceded by other doses on the same day) were also tested. As the cumulative dose of each drug increased, the overall response rate decreased, the percent errors increased, and there was less within-session error reduction (acquisition). With phencyclidine and pentobarbital, the rate-decreasing and error-increasing effects tended to be greater with a non-cumulative dose than with the corresponding cumulative dose. In contrast, with d-amphetamine, the effects were considerably greater with the cumulative doses. The results indicate that although the cumulative-dosing procedure saved a substantial amount of time in determining dose-effect curves, there were quantitative differences in effects between cumulative and non-cumulative doses.