David A. Sisemore

Social interactions among rodent conspecifics: A review of experimental paradigms

The authors suggest that kin selection theory offers a different perspective from which to examine social interactions among rodent conspecifics. Paradigms designed to investigate various interactions among rodent conspecifics are presented, and include simple affiliative behaviors, social facilitation, and cooperation. It is established that many species of rodents are appropriately social to use as subjects under investigation in research which focuses on topics such as kin selection. Studies reporting positive results as well as some reporting negative or inconclusive results have been presented for the purpose of informing the reader under which conditions we might expect specific social behaviors to occur. It is concluded that a combined method of a sociobiological perspective using established experimental procedures will offer unique opportunities for the investigation of specific predictions suggested by kin selection theory.

Discrimination by olfactory cues in albino rats reflecting familiarity and relatedness among conspecifics.

The present investigation sought to determine whether albino rat pups could discriminate among familiar siblings, nonfamiliar siblings, familiar nonsiblings (foster littermates), and nonfamiliar nonsiblings (unrelated agemates) using only olfactory cues. Pairing all possible combinations of familiarity and kinship variables (six), the odors were presented in paired combinations to each of twelve experimental subjects. Results from dependent t tests indicated that the albino rat pups could discriminate between the following pairs of odors using only the olfactory sensory modality: (a) familial siblings and nonfamiliar siblings, (t = 3.41, p = .006); (b) familiar siblings and nonfamiliar nonsiblings, (t = 9.62, p = .001); (c) nonfamiliar siblings and nonfamiliar nonsiblings, (t = 3.15, p = .009); and (d) familiar nonsiblings and nonfamiliar nonsiblings (t = 2.58, p = .026).

Hungry, drunk, and not real mad: The effects of alcohol injections on aggressive responding

Two studies were conducted to assess the effects of acute, low-dose ethanol injections on single-subject shock-elicited aggression. Ethanol mixtures of 30% and 60% were used in the first study, and 0% and 30% ethanol mixtures were used in conjunction with 48-h periods of fasting or nonfasting in the second study. The results of the first study, while nonsignificant, indicated that a possible depression of aggressive responding was produced by the low-dose injections. A significant decrease in aggressive responses following low-dose injections was shown in the second study.

A Comparison of Three Response-Elimination Procedures Following Vr Training with Institutionalized, Moderately Retarded Individuals

The present experiment attempted to assess the relative response-eliminating efficacy of extinction training, omission training, and graduated omission training following VR training with 30 institutionalized, moderately retarded males. The results indicated that graduated omission training led to significantly greater and more rapid response deceleration than either extinction training or omission training. In addition, extinction training was significantly more efficient in eliminating responding than omission training. The latter finding was not in accord with a majority of previous investigations. It was suggested that the presentation of reinforcement during omission training served as a discriminative stimulus for response resumption.

The failure of methamphetamine hydrochloride to produce dissociation of an escape response

Twenty-seven albino rats were trained to make an escape response at one of two dosage levels of methamphetamine or in a placebo state. Subsequently, they were tested in both drug states, as well as in the nondrugged state, to determine if the conditioned response was associated with the specific drug condition of the organism during training. Virtually no dissociation was observed across different states. Animals trained at one dosage level responded in like fashion when tested at another dosage level and/or after an injection of physiological saline. Possible reasons for the lack of dissociation appeared to be the nature of the task and the minimal potential of methamphetamine to produce state-dependent conditioning.

Huddling preferences among albino rats

The effects of kinship and familiarity upon huddling preferences were examined in 30 albino rat pups. Examined were preferences among familiar siblings, nonfamiliar siblings, familiar nonsiblings, and nonfamiliar agemates. Analysis indicated initial preferences among both related and familiar subjects, but preferences were less obvious on the second day of testing. Familiarity may be a primary influence affecting interactions among rat pup siblings.

An experimental demonstration of learning without awareness

In an attempt to demonstrate the existence of learning without awareness, 18 college students, instructed that ESP was to be studied, were given four trials of guessing card suits in standard decks. Motivation and knowledge of results were afforded. Unknown to the students, decks were arranged with suit sequences. A general learning curve resulted, with no indication of awareness, and group performance significantly exceeded probability expectancy. Existence of learning without awareness was supported.

Responses of albino rats to distress of littermates and nonfamiliar agemates.

It was hypothesized that the pain or distress of littermates would yield higher levels of stress-indicators (urinations and defecations) in rats than the pain or distress of nonfamiliar agemates. Albino rats were exposed to the shock of biological littermates, cross-fostered littermates, biological siblings reared in another litter, and unfamiliar agemates. Statistical analysis indicated that, when the subjects were exposed to the shock of biological littermates, urinations and defecations were more frequent than when the subjects were exposed to the shock of the other animals.

Reacquisition of a conditioned emotional response to visual and auditory stimuli following simple or compound extinction procedures: an investigation of theoretical and therapeutic implications of the Rescorla-Wagner learning theory.

The rate of reacquisition of a conditioned emotional response (conditioned suppression) to visual and auditory stimuli after extinction to the stimuli individually or in compound was investigated to assess the relative efficacy of “simple”- and “compound”-extinction procedures in the elimination of conditioned fear in rats. Results indicated that compound-extinction procedures significantly retarded reacquisition of fear to stimuli of low associative strength and tended to facilitate the re-establishment of fear to stimuli of high associative strength. Also, it was noted that following compound extinction the degree of “retardation” or “acceleration” of fear reacquisition tended to increase with the difference between the associative strengths of the two stimuli extinguished in compound. Over-all, current findings were consistent with theoretical deductions derived from the Rescorla-Wagner learning theory and the implications for developing a more efficacious fear-elimination technique based on a specific learning theory were discussed.

Effect of Response Prevention on Active and Passive Components of Avoidance Behavior

A response prevention procedure with 30 rats eliminated oneway active avoidance. However, residual fear, as indexed by passive avoidance, was maintained following response prevention.