Prediction as a means of inducing tolerance

Female subjects were exposed individually to the attitude item responses of a similar or dissimilar stranger. They were asked either to copy down the stranger's attitudes or to predict (with accurate feedback) how the stranger answered each item. Predict subjects were found to be more tolerant of the dissimilar stranger than were Copy subjects, while both groups were equally attracted to the similar stranger. It was suggested that training people to anticipate disagreements may be a useful way of fostering tolerance.     

A relay driver and contact closure sensing interface for an LSI-11 DRV11 parallel I/O board

A simple input and output circuit is described that allows users to sense contact closures and to drive relays from a Digital Equipment Corporation LSI-11 DRV 11 parallel interface board or a signal-compatible equivalent.     

Interfacing the microcomputer: A component-level approach

A method is described for interfacing relatively inexpensive component- and chip-level devices to a standard Intel microcomputer board for providing an on-line physological monitoring system. The system demonstrates basic interfacing techniques and a highly simplified approach for integrating various state-of-the-art peripheral circuit components to a standard microcomputer configuration.     

Measurement of trace strength in memory for pictures

Four experiments using a yes-no recognition task with snapshots examined (1) the effect of presenting not one but two items simultaneously, either both targets or both distractors, for a single judgment at a retention test trial; (2) the rate of forgetting; (3) the interaction between retention interval and the exposure duration at acquisition; (4) acquisition as a function of the number of times a picture was presented. In each case performance was assessed by calculating the discriminability index d'. The results supported the hypotheses that trace strength is lognormally distributed, that forgetting is exponential, and that in acquisition trace strength is a linear function of the number of presentations.     

The overshadowing of background stimuli: Some effects of varying amounts of training and ucs intensity

Two experiments investigated the capacity of a nominal CS to overshadow background stimuli. Rats received CS-shock pairings in one compartment of a double compartment apparatus. After training the shock compartment was represented, but in the absence of both the CS and shock. Overshadowing was then assessed by measuring rats' latency to enter this compartment. If rats readily entered the shock compartment this indicated that the background cues in that compartment had acquired little or no associative strength during training, and overshadowing was therefore inferred. If however rats avoided the shock compartment, then this indicated that the background stimuli must have become aversive during training, and overshadowing could not then be inferred. In both experiments it was found that the capacity of a CS to overshadow background stimuli was directly related to the amount of training given. The experiments also showed that this capacity is inversely related to shock intensity. The results are discussed in terms of Rescorla and Wagner's (1972) model of conditioning.     

Learning capacities during sleep: A preliminary study in a group of schizophrenic inpatients

The relationship between sleep and learning processes is analysed in a sample of schizophrenic patients, starting from more recent hypotheses about the function of REM sleep in learning and memory processes. This is done by means of two experiments: in the first AA. evaluate the possibility to elicit a simple motor conditional reflex acquired during daytime in different sleep stages. With the second experiment daytime learning performances are evaluated with and without a reinforcement administered during REM sleep. Results for the first experiment underline a qualitative difference between REM and nREM sleep in a reflexological perspective. In nREM sleep the conditional response is better maintained than in REM sleep. The second experiment confirms the possibility to improve daytime learning performances after an additional presentation of learning material in REM. The joint study of sleep abnormalities and learning and cognitive impairment in schizophrenic patients is finally suggested.     

Acquisition and discrimination of appetitively and aversively conditioned heart rate responses in rhesus monkeys

This report describes the acquisition of a conditional heart rate response to both classical aversive and appetitive conditioning in eight rhesus monkeys(Macaca mulatta). The behavioral paradigm consisted of two discrete one minute tones followed by the corresponding unconditional stimuli,i.e., electric shock or Purina monkey chow. A third tone followed by neither food nor shock served as a discriminative stimulus (DS). The conditional heart rate responses developed in two phases. The first phase was characterized by similar responses to both conditional stimuli and the DS. Control heart rate rose during this period. During the second phase, control heart rate decreased (five animals), the DS response disappeared, and different conditional heart rate patterns to food and shock emerged. The existence of distinct conditional response patterns indicates probable differences in the autonomic nervous regulation of the heart during aversive and appetitive conditioning.