The effects of aversive conditioned stimuli on the timing of unsignalled avoidance responding in rats

Rats received unsignalled avoidance training in a shuttlebox. After acquisition, classical conditioning sessions were administered. The Excitatory Group received signals paired with shock, the Inhibitory Group received signals explicitly unpaired with shock, while the Random Control Group received signals and shocks randomly in time. When subsequently superimposed on the avoidance baseline, the excitatory signal increased response rate, the inhibitory signal decreased rate and the random signal had no effect compared to signal-only control data. Unsignalled avoidance generates temporal gradients of responding; the major purpose of this study was to determine how these rate changes were reflected in the baseline temporal behavior. Very clear and simple summation rules emerged: In the presence of the excitatory signal, rats acted as if they were ahead of their actual location in the response-shock interval regardless of where the signal occurred; the inhibitory signal had the opposite effect while the random signal did not change the temporal behavior relative to signal-only control data. These results were interpreted within a motivational framework.     

Warning signal termination and a feedback signal may not serve the same function

Three experiments were conducted to test the possibility that a feedback signal (FS) and warning signal termination (WST), while equally reinforcing in the avoidance learning situation, reinforce through different underlying mechanisms. The first experiment showed that the reinforcing properties of an FS are reduced more than those of WST when these stimulus changes are made unreliable by the presence of shock following a CR on specified trials throughout acquisition. Experiment 2 confirmed this effect on avoidance performance when only a few punishment trials were administered following asymptotic avoidance acquisition. Experiment 3 demonstrated this effect during avoidance extinction with and without the presentation of punishment trials between acquisition and extinction performance. The results provided no support for the expectancy explanation of avoidance learning and were interpreted as consistent with the assumption that WST reinforces by permitting fear to dissipate and that the FS reinforces through fear inhibition.     

Learned taste aversions in rats as a function of delay,speed, and duration of rotation

Rats fed a saccharin solution and then rotated on a turntable showed an aversion to the saccharin solution on later testing. In the first experiment, the rats learned to avoid saccharin with delays of as much as 9 hr between drinking the saccharin and the start of rotation. The second experiment showed that the critical determinant of aversiveness of rotation was number of rotations. The rats avoided saccharin as much after rotation at high speeds for short durations as after rotation at low speeds for long durations.     

Observation and discrimination learning in the rat: Effects of stimulus substitution

Effects of prior observation of modeling performances upon learning simultaneous visual discriminations were studied in nine groups of rats. Stimulus patterns which had been positive (“Cued”) or negative (“Uncued”) for the model animal and novel stimuli were presented. Observers learned faster if discriminations required approach to, rather than avoidance of, the previously positive stimulus. Approach to the negative stimulus was acquired more rapidly only if the second stimulus was novel. Approaches to a substituted new stimulus combined with either of the previously viewed stimulus patterns required nearly twice the training needed for a similar response attachment when both stimuli were novel. Attentional changes appear to underlie the stimulus control exerted over the observer rat in instrumental learning situations.     

Causal attributions and information seeking to explain success and failure

Previous studies of attributions for success and failure have relied upon a theoretically derived set of causal attributions, either luck versus skill (derived from Rotter, 1966) or ability, effort, luck, and task difficulty (Weiner et al., 1971; Weiner, 1972). The same tendency of relying upon a set of logically derived cues has been evident in investigations of information-processing in making attributional judgments for success and failure (e.g., Fontaine, 1972; Frieze & Weiner, 1971). Two studies were conducted which employed an open-ended format to determine the relevance of the causal categories and information which have been utilized in previous studies. Results of these studies supported the validity of previously employed causal categories and information cues as well as establishing other important but previously ignored causes and sources of information.     

The actor's behavioral history,his current role,and the divergence between actor and observer responsibility attributions

The actor's behavioral (High or Low) and role (High, Medium, or Low) respectability were varied in an actor-observer attribution study. A scenario described the actor's background combination of behavioral and role respectability and an event in which the actor participated. Subjects assigned actor and situational responsibilities to the event from their own viewpoint and from their perceptions of the actor's viewpoint. Subjects' awareness of the attributional divergence between actors and observers (Jones, E. E. & Nisbett, R. E. In Attribution: Perceiving the causes of behavior. New York: General Learning Press, 1971) and the information (public versus private) utilized by each were reflected in the results.     

Handedness and sex differences in hemispheric asymmetry

A study was designed to assess the contributions of the factors of sex and familial history to cerebral dominance, where cerebral dominance was inferred from laterality on a dichotic listening task. The 144 subjects were selected from a larger sample on the basis of handedness, sex, and familial history of sinistrality, and tested on a task involving the dichotic presentation of CV syllables. Analysis of the data indicated that in female subjects, the presence of familial sinistrality increased the likelihood that they present atypical left-ear superiorities, while in males the converse was the case. Moreover, there was a significant sex difference overall, such that males were more clearly lateralized than females. A review of other dichotic listening studies provided support for the reliability of this sex difference for dichotic tasks using verbal material. A review of the clinical literature indicated that the hypothesis of a sex difference is at least tenable and merits further investigation. However, the possibility that there is a sex difference in the cognitive strategy used in dichotic listening cannot be ruled out.     

The effects of sensation seeking and misattribution of arousal on attraction toward similar or dissimilar strangers

While previous research has indicated that certain situational variables can mediate the typical positive relationship between attitudinal similarity and attraction, investigations focusing on the impact of individual difference variables on this relationship have typically yielded unimpressive results. The present experiment was conducted to test the prediction that individual differences in sensation seeking do moderate this relationship. The major results showed that, as predicted, high sensation seekers were more attracted than low sensation seekers to dissimilar others, whereas low sensation seekers were more attracted than high sensation seekers to people with similar attitudes. The data also indicated that a misattribution of arousal manipulation serves to increase attraction under certain conditions. Specifically, misattribution of aversive arousal increased low sensation seekers' attraction to a dissimilar stranger and increased high sensation seekers' attraction to a similar stranger.