The effects of conditioning and novelty on the rat's analgesic and pyretic responses to morphine

Six experiments with rat subjects investigated the role of conditioning in morphine tolerance. Concurrent assessments of body temperature and pain sensitivity were conducted. Experience with morphine produced tolerance to its analgesic effects but enhancement of its hyperthermic effects. Environmental novelty enhanced analgesia but not body temperature (Experiments 1 and 4). Under conditions in which a discriminated hyperthermic CR provided clear evidence that morphine-environment learning had developed, discriminated analgesic tolerance was not obtained (Experiments 2 and 3). Similarly, whereas placebo administrations extinguished the hyperthermic CR (Experiments 4 and 6), analgesic tolerance remained unaffected (Experiments 4, 5, and 6). These experiments suggest that the pyretic and analgesic systems are differentially sensitive to conditioning and the effects of novelty.     

Response and encoding factors in “ignoring” irrelevant information

Subjects classified either the numerosity or numeric value of elements in successive stimulus displays. In separate experiments, responses were indicated by oral naming, card sorting, manual tapping, and oral “tapping.” Incongruent levels of numeric value slowed naming and sorting, but not tapping, when numerosity was the cue for responding. Incongruent numerosity slowed tapping, but not naming and sorting, when numeric value was the cue. Changes in stimulus response mapping may thus critically alter the ability to ignore an irrelevant stimulus dimension.     

A general scheme for the analytic decomposition of objective test scores: Illustrative demonstrations using the Rod-and-Frame test and the Müller-Lyer illusion

Objective tests of personality typically include a number of items or trials; the total score on the test is the sum of the subject's “correct” responses across all such trials. Normally, the trials are varied systematically across various facets of the test design, so that the total score represents a composite measure of accuracy averaged across these test facets. However, since only one score is computed for each subject, some potentially important kinds of individual differences—namely all those associated with each particular variation in the test design—are treated solely as measurement unreliability. Such a psychometric stance may serve to obscure more differentiated types of individual differences, with the result that composite scores from trials based on one type of experimental design may not be highly related to such scores from trials using a somewhat different design. The present paper presents a general procedure for scoring objective tests more analytically. To illustrate this general rationale, and to demonstrate its potential utility, data have been reanalyzed from two previous studies, one using the Rod-and-Frame test, the other the Müller-Lyer illusion. In both cases, the traditional global accuracy score did not correlate significantly with other theoretically related variables, while a number of component scores were quite highly related.     

A preparation for the experimental analysis of human cigarette smoking behavior

A preparation for the experimental analysis of cigarette smoking is described in detail. The preparation permits the intensive study of cigarette smoking in individual subjects under controlled laboratory conditions. A variety of behavioral and physiological measures used include rate and pattern of puffing, duration of each puff, time spent smoking cigarettes, expired air carbon monoxide levels, cigarette butt weights, and subjective rating scales of various aspects of smoking. The preparation is reliable and permits relatively unobtrusive monitoring of smoking performance. Cigarette smoking occurs in orderly patterns, within subjects; it varies as a function of number of cigarettes provided and hours of smoking deprivation.     

Reactions of college recruiters to interviewee sex and self-presentation style

College recruiters evaluated the qualifications and employability of either a male or a female applicant for a supervisory position. Half the recruiters in the experiment viewed a videotape of the candidate presenting himself or herself in a passive manner. The other half of the recruiters viewed a moderately aggressive interviewee. Contrary to the hypotheses, the moderately aggressive female was rated as favorably as the moderately aggressive male and the passive male was rated as negatively as the passive female. Although recruiters were as willing to hire a moderately aggressive male as they were the moderately aggressive female, they perceived the female's overall qualifications and her experience/training as superior to that of the male's.     

CS duration,amount, and concentration effects in conditioning taste aversions

The relative contributions of the duration, amount, and concentration of a taste CS were assessed in pairings with an ionizing radiation US in two experiments. Increasing the duration of the CS (0.1% saccharin) up to 9 min yielded increasingly better conditioning over a $\text{1}\text{2}\text{-}\text{hr}$ CS-US delay interval. When the concentration of the sacharin was increased, only a few seconds' exposure to the CS was necessary for near asymptotic conditioning. It was observed that the CS duration effect had not been identified earlier because most investigators utilize 10–20 min CS access periods. The role of CS duration in conditioning over a delay was discussed with reference to the probability of the memory of the CS being present at the time of the pairing with the US event.     

Positive contrast following gradual and abrupt increases in reward magnitude using delay of reinforcement

In Experiment 1, rats were given a 1-pellet reward for 48 preshift trials. During a subsequent 20-trial postshift phase, one group was shifted to a 12-pellet reward on Trial 1, a second was shifted on Trial 11, and a third was given 1 more pellet each trial and then 12 pellets for the last 10 trials. The speeds of all three groups increased to a level above that of a control group given a 12-pellet food reward throughout training (positive contrast). In experiment 2, rats were shifted from 1 to 12 pellets either gradually or abruptly following either abbreviated training (9 trials) or extended training (20 trials). One group of control subjects received 12 pellets throughout training. The results revealed a positive contrast effect for gradually shifted subjects following extended training but not following abbreviated training. The abrupt shift procedure produced positive contrast following abbreviated training but only a marginal effect following extended training. These results indicate that, contingent upon the amount of preshift training, either gradual or abrupt reward increases may produce positive contrast.     

Effect of CS-US pairings on shock-elicited aggression as a function of US intensity

In two experiments with paired rats, the effect of superimposing CS-US pairings on a baseline of shock-elicited aggression was studied. Baseline shocks (3.0 mA, 0.125-sec duration) occurred at a rate of 20 shocks per min throughout each session. In Experiment I, each independent group of two pairs of subjects received (in addition to baseline shocks) US shocks of 1.0, 3.0, or 5.0 mA and 5-sec duration, each shock signalled by a 1-min CS. At all three US intensities, aggression increased during the CS. In Experiment II, pairs of subjects received each unconditioned stimulus intensity in a within-subjects design. This procedure revealed a direct relationship between rate of responding and unconditioned shock intensity.     

Monaural right-ear advantage in a target-identification task

Subjects were monaurally presented with consonant—vowel syllables to the right or left ear, with or without simultaneous noise to the other ear. The subject's task on each trial was to indicate whether or not the item presented was the target item /ba/. A right-ear advantage in reaction time was obtained: 14 msec for target items, 6 msec for nontarget items. The size of this effect was comparable in the presence vs. absence of competing noise. No consistent individual differences were found in the size of the right-ear advantage for this task, although such differences were obtained in a dichotic-perception pretest.It is argued that data of this type do not permit inferences about the use of particular ear/hemisphere neural pathways.