An investigation of the arousal model of interpersonal intimacy

In a study designed to test Patterson's arousal model of nonverbal intimacy, the heartrate, gaze, smiles, body orientation, and body lean of each of 40 female subjects who interacted with an accomplice were measured. Within a factorial design, subjects were induced to view more or less favorably the accomplice, who subsequently increased or maintained the same level of nonverbal immediacy as she did in an earlier session. It was hypothesized that (1) an increase in the accomplice's immediacy would effect an increase in subjects' arousal (heartrate) which, in turn, (2) would lead to either reciprocal or compensatory nonverbal adjustments by subjects, depending on whether they viewed the accomplice more or less favorably, respectively. The results supported the first but not the second hypothesis. However, interpretation of the results suggests, nevertheless, that they may be consistent with the arousal model.     

The secretary problem as a model of choice

The finite “secretory problem” in dynamic programming generates a set of mathematically optimal criteria for search strategies in sequential decisions. One of the limitations on its applicability has been its failure to allow for the uncertainty of whether or not a choice alternative which has been inspected sometime previous to the present, will be “available.” In this paper, extensions of the model are presented which incorporate not only a parameter for the uncertain availability of previous alternatives, but for the uncertain availability of an alternative currently being observed. The paper emphasizes socalled heuristic strategies which may be used to approximate optimal solutions, and which entail very reasonable demands on the processing capacity of the decision-maker. Laboratory realizations and potential applications are discussed.     

Sign-tracking in aversive conditioning

Two experiments were conducted to determine if rats tend to avoid contact with a stimulus that signals the occurrence of shock and contact a stimulus that signals the nonoccurrence of shock. The conditioned stimulus was a 60-sec platform presentation, and the unconditioned stimulus was a 2-sec inescapable shock. In each experiment, the emphasis was on two types of Pavlovian pairings: forward pairing in which each platform presentation was followed by shock, and backward pairing in which each platform presentation was preceded by shock and followed by a lengthy shock-free interval. Experiment 1 showed that in comparison with Random and CS-only procedures, the backward procedure produced a significant increase in approach and contact with the platform, but the forward procedure failed to produce a significant decrease in contact with the platform. Experiment 2, in which all groups were roughly equated for baseline levels of platform preference, demonstrated strong effects of both forward and backward conditioning. The experiments provide evidence for an aversive sign-tracking system in which animals' tendencies to withdraw from or approach and contact a platform CS are determined by the Pavlovian contingencies which render it a reliable signal for the occurrence or nonoccurrence of shock.     

Resolution time and the coding of arithmetic relations on supraliminally different visual extents

Comparison time for pairs of vertical-line stimuli, sufficiently different that they can be errorlessly discriminated with respect to visual extent, was examined as a function of arithmetic relations (physical ratio and difference) on members of the pair. Arithmetic relations are coded very precisely by judgment time: Responses slow as stimulus ratios approach one with difference fixed, and as stimulus differences approach zero with ratio fixed. Most models which assume a simple (Difference or Ratio) resolution rule operating on independent sensations require judgment time to depend on either ratios or on differences but not on both. Further tests showed both an index based on median judgment times and a confusion index based on pairs of observed judgment times, satisfied the requirements for a Positive Difference Structure. One representation of these data, which remains acceptable through all analyses, is a Difference resolution rule operating on sensations determined by a power psychophysical function with β < 1. Specifically, L(x, y) = F{ψ(x) ? ψ(y)} + R, where L(x, y) is the judgment time with the stimulus pair x and y, ψ(x) = Ax^β + C, R is a positive constant, and F is a continuous monotone decreasing function.     

Extraversion and the orienting reaction habituation rate to visual stimuli

Eysenck's (1967) proposal that introversion is characterized by increased levels of activity in the cortico-reticular loop was treated in a series of experiments which compared high, middle, and low extraversion groups on the basis of OR habituation rate to visual stimulation. Generally, introverts were observed to have longer OR habituation rates to chromatic and word stimulation than extraverts as evidenced by cardiac, electrodermal, and vasomotor indices of habituation rate, a result which endorses Eysenck's hypothesis. Results are also discussed from the standpoint of individual differences in autonomic response.     

Male versus female Siamese fighting fish as reinforcing stimuli for conspecific males in single- and two-choice operant situations

Two experiments attempted to determine the reinforcing effectiveness of visual exposure to a female versus a male stimulus in male Siamese fighting fish (Betta splendens). This was accomplished by making male or female presentation contingent upon an operant ring swimming response in single- (Experiment 1) and two-choice (Experiment 2) continuous reinforcement operant situations for 1 hr per day. It was found that visual exposure to a female stimulus was behaviorally reinforcing in a way comparable to that typically found in intermale studies. If given a choice, male test subjects were observed to demonstrate a consistent preference for the female as opposed to the male stimulus. The results are discussed in terms of stimulus discrimination and approach-avoidance conflict as differentially elicited by male and female target stimuli.     

Variables affecting subjective organization during posthypnotic amnesia

Subjects learned a list of unrelated words to a criterion of either two successive correct trials (standard criterion), or two successive correct trials plus five additional recall trials (extra criterion). The extra recall trials significantly increased the subjective organization of recall. In the extra criterion group, a posthypnotic amnesia suggestion and a nonhypnotic distraction task produced equivalent decrements both in the amount recalled and in the subjective organization of recall. In the standard criterion group, suggestion and distraction reduced the amount recalled, but not the subjective organization of recall. The implications of these findings for understanding the contradictory results of earlier studies of recall organization during amnesia are discussed. Implications for theories of hypnotic amnesia are also discussed.     

Personality and the effects of stress on recognition memory

The experiment examined the contribution of anxiety, extraversion, neuroticism, and psychoticism to recognition memory for pictures and words using a signal detection method. Independent groups of subjects performed a recognition memory task under one of four conditions (control, noise, threat, and reward) that was intended to capitalize on dispositions which characterize the personality dimensions. In an ego threat condition involving personal evaluation, introverts displayed a performance decrement relative to noise and reward conditions. Psychoticism was inversely related to performance in the noise and threat conditions and directly related in a reward condition. In general, J. A. Gray's (1981) model of anxiety and impulsiveness accommodates much of the data, but the mechanisms which mediate the influence of personality on memory performance are not clear.     

Sign-tracking behavior in aversive conditioning: Its acquisition via a Pavlovian mechanism and its suppression by operant contingencies

When rats are presented with Pavlovian backward pairings in which shock is the unconditioned stimulus (US) and an elevated platform the conditioned stimulus (CS), they show a strong tendency to approach the platform. Attempts were made at evaluating the nature of the associative mechanisms responsible for the acwuisition and maintenance of the approach behavior. In Experiment 1, following a baseline period when platform presentations were given in the absence of shocks, first (training I), approach to the platform was prevented and subjects were exposed to either backward, forward, or random presentations of shock and platform: this procedure attempted to minimize the effects of response learning on the acquisition of approach behavior. Then (training II), all subjects received backward shock-platform pairings and had access to the platform. Approach to the platform was stronger in animals previously exposed to backward pairings than in the animals of the other two groups. Also, animals preexposed to forward platform-shock pairings showed suppression of approach behavior on the first trial of training II relative to their performance on the last trial of baseline. These data suggest that a stimulus-reinforcer learning mechanism alone is sufficent for the acquisition of approach. Experiments 2a and 2b evaluated the effects of “punishing” operant contingencies on Pavlovian-produced approach behavior. The results showed that approach can be eliminated, but only after repeated exposure to an operant contingency which consisted of the immediate closure of the platform upon approach responding. These data suggest that approach behavior produced by Pavlovian contingencies can be modified by operant contingencies. Taken together, these data provide additional support for a sign-tracking notion in aversive conditioning.     

The effects of suggestion structure and hypnotic vs task-motivation instructions on response to hallucination suggestions

Hypnotic and task-motivated subjects were given both auditory and visual hallucination suggestions that were either Brief, Long, or provided an imaginary Context. The Long and Context suggestions were equated for length. Task-motivated subjects scored higher than hypnotic subjects on both auditory and visual hallucination suggestions. Suggestion-type (Brief, Long, Context) affected response to the auditory but not the visual suggestion. Hypnotic and task-motivated hallucinators were equally likely to describe their images as being transparent. Theoretical implications are discussed.