Effects of food and mates on time budget in Aplysia fasciata: integration of feeding, reproduction, and locomotion

This study examines the time budgeted to different behaviors in Aplysia fasciata under three conditions: (1) animals have constant access to food and mates: (2) there is access to food, but not to mates; (3) neither food nor mates are present. The data suggest a number of rules underlying behavioral integration: (1) Feeding, reproductive behaviors, and activity seem to be natural categories for behavioral choice. Feeding and reproductive behaviors are controlled in tandem by a common arousal mechanism, while time left over after animals feed and reproduce is distributed in a fixed ratio between locomotion (crawling and swimming) and inactivity (immobility and movement in place). (2) Relative distribution between different forms of locomotion and inactivity is modified by changes in motivational state. More time is spent swimming than crawling when feeding and/or mating is prevented, while more time is spent moving in place than immobile when the arousal level is increased. (3) Feedback control of feeding and reproduction is asymmetric. Satiation of feeding inhibits the common arousal. In the absence of food, time spent on reproductive behaviors increases due to disinhibition of the common arousal. By contrast, positive feedback arising from sexual behavior excites the common arousal. When mating is prevented by removing potential mates, time spent feeding decreases. (4) Generally, animals choose between performing the three main categories of behavior. Although Aplysia simultaneously can feed and mate, or locomote and mate, they do so infrequently. By contrast, different types of reproductive behaviors (male mating, female mating, egg-laying) are commonly performed simultaneously.     

Common regulation of feeding and mating in Aplysia fasciata: pheromones released by mating and by egg cordons increase feeding behavior.

We examined whether pheromones released by reproductive behaviors (mating and egg-laying) affect feeding behavior. A preliminary experiment demonstrated that the quantity of food eaten can be used to measure the effects of pheromones on feeding. Using this measure, we then showed that Aplysia that were prevented from mating, but that were in the same aquarium as mating conspecifics, eat more food than do Aplysia in a medium lacking mating animals. Mating and feeding were not temporally correlated, indicating that pheromones released by mating probably do not initiate feeding, but rather modulate feeding after it has begun. Aplysia that were in the same aquarium as freshly deposited egg cordons also ate more than did animals in a medium lacking eggs.     

Aggression and Heat: The Mediating Role of Negative Affect1

Sixty-four undergraduate males received either very postive or very negative personal evaluations from an attitudinally similar or dissimilar stranger, and were then given an opportunity to aggress against this person by means of electric shock. Half were exposed to these stimuli under comfortably cool environmental conditions, while half were so treated under uncomfortably hot conditions. It was predicted that aggression toward the victim would increase as the degree of negative affect induced among subjects by the experimental conditions increased up to moderate levels, but that beyond this point, further increments in negative affect would actually tend to inhibit such behavior. A significant (p < .007) curvilinear relationship between negative affect and aggression supported these predictions, and suggested that such affect mediates the influence of high ambient temperatures on human aggression.     

When unexpected behavior is attributed to the environment

Two experiments were conducted to investigate a modification of the Jones and Davis (1965) analysis of attribution. Subjects were confronted with a situation in which there were two possible causes for an event, and differential information about these causes was provided such that subjects were much more informed about the nature of one potential cause than the other. This information also imparted to the subjects a definite expectancy about the forthcoming event. When the event disconfirmed subjects' expectancies, responsibility was attributed to the cause about which least was known. This result was found in both experiments. In addition, Experiment II offered some suggestive evidence that a disconfirmed expectancy will lead the person to direct his attention toward potential causes about which he is uninformed.     

Aggression and heat: mediating effects of prior provocation and exposure to an aggressive model.

Sixty-four undergraduate males participated in an experiment designed to examine the effects of level of prior anger arousal, exposure to an aggressive model, and ambient temperature on physical aggression. On the basis of Bandura's social learning theory of aggression, it was predicted that uncomfortably hot environmental conditions would be most effective in facilitating later aggression when subjects had both witnessed the actions of the model and been exposed to strong provocation from the victim, but least effective in this regard when they had neither witnessed the actions of the model nor been exposed to prior instigation. In contrast to these predictions, results indicated that high ambient temperatures facilitated aggression by nonangered subjects but actually inhibited such behavior by those who had previously been provoked.     

Switching from competition to sharing or cooperation at large response requirements: competition requires more responding

Two pairs of high-school students matched-to-sample for money. On each trial, a subject could either respond on one lever to take the matching-to-sample problem himself (taking response) or respond on a second lever to give the problem to his coactor (giving response). The first subject to complete the response requirement determined the distribution of the problem. Competition maximizes the amount of responding over trials, i.e., both subjects make taking responses on each trial. Sharing and cooperation minimize responding: only one subject makes a taking response (sharing) or a giving response (cooperation) on each trial, and the subjects alternate responding such that there is an equitable distribution of responses and reinforcers over trials. Large increases in the fixed-ratio response requirement to distribute problems produced: (1) a switch from competition to sharing or cooperation, (2) the expected concomitant change from inequitable to equitable distributions of reinforcers, and (3) a reduction in the amount of responding for three of the four subjects. Previous animal research has shown that large response requirements may have aversive properties. Switching from competition to sharing or cooperation at large response requirements allows a reduction in responding and, at the same time, a moderate number of reinforcers for each subject.     

Two types of information in picture memory.

It is assumed that recognition memory for pictures is based on two types of information. The first is information about specific details in a picture. The process of encoding this type of information is identified with what N. H. Mackworth and others have termed looking at "informative areas" in pictures. The second informational component is designated as "general visual information." Two experiments were carried out investigating (a) the extent to which recognition responses to pictures are based on specific detail vs. general visual information, (b) whether the amount of specific detail information may be manipulated by varying the complexity of a target picture, and (c) the rate at which the two types of information are acquired. The results indicate that the rate of encoding specific details varies with the number of potential informative areas in a pictures and, given that a detail is encoded, memory performance is not substantially affected by target complexity, exposure time, or presence or absence of a mask.     

The effects of psychological androgyny on attributions of causality for success and failure

Sixty female subjects and sixty male subjects, either sex-typed or androgynous, based on scores on the Bem Sex-Role Inventory (BSRI), made causal attributions for their own success or failure. Subjects also predicted future performance on a similar task. Sex differences were revealed which are only partially consistent with a cognitive-based expectancy model. It is suggested that outcome and ego involvement in the task are crucial factors in whether cognitive-based or more self-serving attributions are used in accounting for performance. Androgynous subjects predicted higher future performance. However, contrary to prediction, attributional behavior of androgynous and sex-typed subjects did not differ. Results are discussed in terms of rapidly changing views, in both the conceptualization and the measurement of psychological androgyny, since Bem's original report of behavioral correlates to scores on the BSRI.