Varying temporal placement during CS of an added stimulus correlated with non-delivery of UCS

This experiment extends Pavlov’s method of contrasts for training a stimulus discrimination to the case of the cardiac conditional response in the rhesus monkey. It explores the parameter of temporal placement of an additional stimulus (“CS₂”) within a 10-sec CS (or “CS₁”), with the appearance of the former stimulus on any trial signalling the absence of UCS (electric shock) on that trial. This experimental paradigm is a parallel to that of the “intruded stimulus” studies in operant conditioning. In both cases, several ways of describing the function of the added stimulus are possible, but all seem reducible to the same operational terms. Data were taken in the present study with respect to the form and latency of the cardiac rate changes produced by intrusion of CS₂ (light), across a range of placements varying from simultaneity with CS₁ (a different light) onset to two sec before UCS would have been delivered. The control of CS₂ over the cardiac rate CR was occasionally exhibited with a latency as short as three beats after stimulus onset. The order of CS₂ temporal placements to which a subject was exposed was a factor in determining the form of the conditioned cardiac rate response to CS₁.     

Familiarity affects visual processing of words.

While previous research has demonstrated that words can be processed more rapidly and/or more accurately than random strings of letters, it has not been convincingly demonstrated that the superior processing of words is a visual effect. In the present experiment, the cases of letters were manipulated in letter strings that were to be compared on the basis of physical identity. Mean response time was shorter for words than for nonwords even for pairs of letter strings that differed only in case (e.g., site-site). This finding implies that the advantage of words over nonwords (the familiarity effect) typically observed in the simultaneous matching task is not due solely to comparison of either the word names or the letter names and, thus, that at least part of the familiarity effect must be due to more rapid formation and/or comparison of visual representations of the two letter strings when they are words. Further analysis failed to reveal a significant involvement of phonemic or lexical codes in the comparison judgments.     

The effects of censorship and attractiveness of the censor on attitude change

The effects of censoring a communication, overriding the censor, and the attractiveness of the censor on the potential audience's attitude and desire to hear the communication were studied. Subjects were told that a speech which they were to have heard had been censored by a positively, negatively, or neutrally evaluated group. Some subjects were told that the experimenter had decided to override the censor and that they would hear the communication. Other subjects were told they would not hear the censored communication. The results indicated that censorship, regardless of the attractiveness of the censor, caused the potential audience to change their attitudes toward the position to be advocated by the communication and to increase their desire to hear that communication. These effects were interpreted as resulting from the arousal of psychological reactance. When the censor was overriden and the audience felt that they would hear the communication, their desire to hear it decreased. Further, subjects who had been told that a positively evaluated group had censored the speech changed their attitudes away from the position to be advocated by the communication while subjects who believed that a negative group had censored the speech changed their attitudes toward the position of the communication. These results were interpreted as evidence of cognitive balancing.     

Social perception and signal detectability theory: Group influence on discrimination and usage of scale

Summary The influence of social motivation on perception was operationalized as group pressure on the usage of a 4-point scale by which subjects discriminated two stimulus situations in a procedure analogous to signal detection experiments. After a pretest, only those subjects were taken who preferred the left end of the scale. During each main session three confederates influenced one selected subject by the opposite scale preference after each of his judgments had been given. The preformance level of the confederates was equalized to that of the naive subject in the pretest. Both the possibility of an ex post check and the resulting conflict generated motives leading to an increased performance in the experimental group but to a decrease in the control group (without influence). No subject resisted to influence. The theoretical relevance for social perception is discussed.

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Zusammenfassung Der Einfluß sozialer Motivation auf die Wahrnehmung wurde als Gruppendruck auf den Gebrauch einer 4-Punkte-Skala operationalisiert, auf der Versuchspersonen (Vpn) zwei Reizsituationen wie in Signal-Detection-Experimenten unterschieden. Nach einem Vorversuch wurden nur solche Personen genommen, die das linke Ende der Skala bevorzugten. In allen Hauptversuchen beeinflußten 3 Mitwisser des Versuchsleiters eine ausgewählte Vp durch eine gegensätzliche Bevorzugung der Skala nach jeder Antwort der Vp. Das Leistungsniveau der Mitwisser entsprach dem Niveau der naiven Vp im Vorversuch. Die Möglichkeit der nachträglichen Überprüfung und der resultierende Konflikt erzeugten Motive, die zu einer erhöhten Leistung in der experimentellen Gruppe, in der Kontrollgruppe (ohne Einfluß) jedoch zu einer Abnahme führten. Keine Vp widerstand dem Einfluß. Die theoretische Bedeutung für die soziale Wahrnehmung wird diskutiert.

     

Suppression of behavior by timeout punishment when suppression results in loss of positive reinforcement

This investigation, using rats as subjects and punishment by timeout for responses maintained on a ratio schedule, sought to determine whether behavior would be suppressed by timeout punishment when such suppression also reduced reinforcement density or frequency. A series of experiments indicated that timeout punishment suppressed responding, with the degree of suppression increasing as a function of the duration of the timeout period. Suppressive effects were found to decrease as a function of increases in deprivation (body weight) and were eliminated when the punished response also was reinforced. It was concluded that timeout can produce aversive effects even when loss of reinforcement results. An alternative interpretation of the findings, based on the effects of extinction periods and delay of reinforcement on chained behavior, was discussed.     

Facilitation and suppression of human loss-avoidance by signaled, unavoidable loss

A 15-sec stimulus followed by unavoidable monetary loss was presented to human subjects who were avoiding loss on a free-operant schedule. As has been observed in studies where shock is the aversive event, initial reactions to the pre-loss stimulus were transient increases in overall and stimulus rates. Unlike shock studies, continued training produced decreased rates, in the presence of the 15-sec stimulus, which were maintained in two of three subjects. Subsequent observations indicated that lowered rates were a function of the subject's rate of avoidance responding, the duration of the stimulus, and the scheduling of avoidable losses. Increasing the duration of the stimulus eliminated lowered rates in the presence of the stimulus and subsequent exposures to conditions which previously produced lowered rates did not result in recovery of the phenomenon. Introduction of the pre-loss stimulus on an extinction baseline (avoidable losses were omitted), however, reinstituted lowered rates. It is proposed that the pre-loss stimulus assumed discriminative control over low rates because responding in the presence of the stimulus was ineffective in avoiding the unavoidable loss. Recovery from lowered rates is attributed to the occurrence of avoidable losses during the stimulus period, and maintenance of lowered rates on the extinction schedule to the omission of such avoidable losses.     

Association and affect as determinants of displaced aggression

Subjects were angered by an instigator and then given a choice of two targets of aggression: one was a friend of the anger instigator and the other not. In addition, subjects were given a choice of more versus less intense aggression against these two targets. Angered subjects chose to give more intense aggression—regardless of whether the target was associated with the anger instigator. Thus, release of affect (opportunity to aggress intensely) predominated over association as a determinant of displacement.