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Biomedical subjects

D A Dewsbury

Publications and source records attributed to D A Dewsbury.

At least 19 recordsLinked to original sources

The Chicago Five: a family group of integrative psychobiologists.

The "Chicago Five" was a group of integrative psychobiologists, including Frank A. Beach, Donald O. Hebb, David Krech, Norman R. F. Maier, and Theodore C. Schneirla, all of whom worked with Karl S. Lashley at the University of Chicago during 1929 -1935. Although they went on to careers in diverse fields of psychology, their approaches reflect a set of underlying themes that can be traced to their experiences in Chicago. Nine primary beliefs that, with occasional exceptions, underlie their work are delineated. The term family is proposed to refer to a group of psychologists who share a common professional development in one place within a limited time period and whose later work although it may be diverse, reflects commonalities that may be traced to that experience.

History, 20th Century↗

Issues in comparative psychology at the dawn of the 20th century.

Comparative psychology emerged as part of the "new psychology" that took hold in the United States around 1900. Many of the issues that have occupied comparative psychologists throughout the 20th century were developed as research problems during this period. In some respects, comparative psychology was then an integral and widely respected part of psychology at large; in others, it was already marginalized. Issues emerging during this critical period set the program for the upcoming century and included those of methodology in the conduct of experiments and conceptual issues related to evolution, development, intelligence, and higher processes.

Animals↗

Comparative cognition in the 1930s.

According to the received view of the history of psychology, behaviorism so dominated psychology prior to the 1960s that there was little research in animal cognition. A review of the research on animal cognition during the 1930s reveals a rich literature dealing with such topics as insight, reasoning, tool use, delay problems, oddity learning, abstraction, spatial cognition, and problem solving, among others. Material on "higher processes" or a related topic was prominent in the textbooks of the period. Tracing academic lineages reveals such teachers as Harvey Carr, Robert M. Yerkes, and Edward C. Tolman as sources of this interest. The alleged hegemony of strict behavioristic psychology, interpreted as excluding research on animal cognition, requires revision. Some possible reasons for this neglect are suggested.

Animals↗

Role of male proximity in pregnancy maintenance in prairie voles, Microtus ochrogaster.

Three experiments were conducted to determine whether the presence of a male partner during the gestation period facilitates pregnancy maintenance in female prairie voles. In each of the three experiments more females delivered litters when the male was present and separated from them by a wire-mesh barrier than when the male was absent. The effect was present in both nulliparous and parous females. At the ultimate level this suggests a constraint on male mating strategies. At the proximate level these results show that the facilitation of pregnancy maintenance by males (a) occurs in this species and (b) is not dependent on prolonged vaginal stimulation of the female or any other mechanism requiring full contact between partners.

Animals↗

Three experiments on mate choice in meadow voles (Microtus pennsylvanicus).

Species differences in selectivity with respect to mate choice have been hypothesized to be related to mating systems. Procedures used in 3 previous experiments on monogamous prairie voles (Microtus ochrogaster) and polygamous montane voles (M. montanus) were used with polygamous meadow voles (M. pennsylvanicus). The expectation was that meadow voles would show few preferences. Female meadow voles preferred mating with familiar versus unfamiliar males but displayed no preference for unmated versus mated males. Male meadow voles displayed no preference for unmated versus mated females. The results are partially consistent with the hypothesis that relates mate choice to social and mating system, as this polygamous species resembles polygamous montane voles species in 2 situations but is similar to monogamous prairie voles in the 3rd.

Animals↗

Comparisons of nipple attachment and incisor growth among four species of voles (Microtus).

Patterns of nipple attachment and incisor growth were compared between four species of voles (Microtus). Offspring of two highly social species, prairie voles (M. ochrogaster) and pine voles (M. pinetorum), were shown to cling tightly to the nipples of their dams on Days 2, 6, and 10. This pattern contrasted to weak nipple attachment displayed by two less-social species, meadow voles (M. pennsylvanicus) and montane voles (M. montanus). Lengths of the upper (maxillary) and lower (mandibular) incisors of the four species were recorded throughout the first 10 days of age and in adults. Incisors of the pine and prairie voles typically erupted earlier and grew longer than those of the meadow or montane voles during the first few days of development. Incisors grew at a substantial rate in the latter two species, such that they equalled or surpassed the incisor lengths of the former two species as Day 10 and weaning approached. Patterns of incisor growth, in part, reflected those for nipple attachment, but do not appear to account substantially for differences in nipple attachment.

Animals↗

Conspecific odor preferences in Montane voles (Microtus montanus): effects of sexual experience.

Sexually naive male and female montane voles (Microtus montanus) were tested in a two-choice odor preference situation. Females, but not males, spent more time investigating bedding soiled by a conspecific of the other sex than clean, unsoiled bedding. Both naive females and males spent more time near male-soiled rather than female-soiled bedding. Males with extensive monogamous sexual experience exhibited a preference for female-soiled bedding when the comparison stimulus was clean bedding but no preference when the comparison was with male-soiled bedding.

Animals↗

On publishing controversy. Norman R. F. Maier and the genesis of seizures.

The award of the AAAS Thousand Dollar Prize to Norman R. F. Maier in 1938 for research on conflict-induced seizures in rats was a major event that received appreciable media coverage. However, substantial criticism of Maier's research, spearheaded by Clifford T. Morgan, eventually led to the generally accepted conclusion that the seizures were artifactual and "audiogenic." Unpublished documents have revealed, contrary to the public conclusion of this controversy, that in private Morgan conceded error. Nevertheless, whereas Morgan went on to an important career in experimental psychology. Maier left animal research. The case suggests that it is important to publish controversy and illustrates the power of those working at the core of a discipline over maverick scientists.

Acoustic Stimulation↗

Affiliative behavior in different species of voles (Microtus).

Data were collected on the huddling behavior of pine voles, Microtus pinetorum, and meadow voles, M. pennsylvanicus, to supplement earlier data on prairie voles and montane voles. Species that are social/monogamous in the field tended to huddle more in the laboratory. Contact proneness may be one factor driving different mating systems in the field.

Animals↗

Estrus induction in four species of voles (Microtus).

Male-induced estrus was examined in montane (Microtus montanus), meadow (M. pennsylvanicus), prairie (M. ochrogaster), and pine (M. pinetorum) voles. Duration of male contact needed for receptivity, effects of parity, and vaginal cytology were assessed. Among nulliparous females, montane voles attained receptivity with less male contact than prairie voles. Meadow and pine voles showed very low receptivity rates. Among parous females, montane and meadow voles did not differ in duration of male contact needed for receptivity and required less than prairie voles. Overall, parous females had higher receptivity rates than nulliparous females. When isolated from males, prairie and pine voles had more leukocytes and fewer cornified cells in vaginal smears than montane or meadow voles. Species differences in estrus induction are discussed in relation to species differences in social organization.

Animals↗

Ejaculate disruption in two species of voles (Microtus): on the PEI matching law.

We permitted male prairie and montane voles (Microtus ochrogaster and M. montanus) five thrusts, without ejaculation, with a female at variable times after a 1st male ejaculated. In both prairie and montane voles, there were fewer sperm, in relation to control conditions, in the female's tract 1 hr after ejaculation if the female received thrusts immediately or 15 min after the ejaculate. There was no such effect after a 50-min delay. There was no significant decrease in litter production in prairie voles caused by thrusts delivered either immediately or after a 15-min delay. Sperm transport in these species is susceptible to disruption for a longer period than in deer mice or rats. The proposal that the postejaculatory interval protects a male from disrupting its own sperm transport (the PEI matching law) appears not to hold for these species.

Animals↗

Comparative neuroanatomy of the sexually dimorphic hypothalamus in monogamous and polygamous voles.

In the present work we evaluated the degree of sexual dimorphism in two cell groups of the medial preoptic-anterior hypothalamus (MPOA-AH) in monogamous and polygamous voles. Quantitative determinations were made of volume, cell number, and cell density for the anteroventral-periventricular nucleus (AVPV) and the sexually dimorphic nucleus of the preoptic area (SDN-POA). Polygamous montane voles (Microtus montanus) had a greater degree of sexual dimorphism in both cell groups than did monogamous prairie voles (M. ochrogaster). Most notable was the complete absence of the AVPV in male montane voles; male montane voles also had a significantly larger SDN-POA volume than did females. The only sexual dimorphism in prairie voles was a greater cell density in the female AVPV. In addition, prairie voles had larger relative brain size than did montane voles. Comparative behavioral studies have revealed a correlation between the degree of sexual dimorphism in external morphology and mating system, i.e., polygamous species display greater levels of dimorphism than do monogamous species. The present results indicate that the effects of sexual selection can also be seen in those brain regions, like the hypothalamus, that underlie social and reproductive behavior. Moreover, these results support the hypothesis that neuroanatomic dimorphisms in the MPOA-AH may be related to sex differences in behavior.

Animals↗

"Psychobiology".

The term psychobiology is often used to refer to various biological approaches to psychology that have emerged in the 20th century. The term generally has been used to locate an approach with respect to both disciplines, sometimes in an effort to distance the author from psychology as a whole. When viewed in broad historical perspective, however, it is seen that more often the word has been used to designate a number of very different forms of opposition to the excessive reductionism characteristic of many biological approaches to psychology. "Psychobiology' represents a family of attempts to incorporate biological perspectives in the study of dynamic processes in whole, integrated, adapted, and organized organisms, not to reduce complex, dynamic relationships to physiological processes.

Animals↗

Modes of estrus induction as a factor in studies of the reproductive behavior of rodents.

The choice of a mode of estrus for use in studies related to reproductive processes often is made arbitrarily. Females may be in hormone-induced estrus (HIE), cycling estrus (CE), male-induced estrus (MIE), or postpartum estrus (PPE). Although mode of estrus affects various aspects of copulatory behavior in different species in different ways, males mating with PPE females generally require more intromissions to reach ejaculation than with females in HIE or CE; males mating with females in CE generally attain more ejaculations than with PPE females. The duration of receptivity generally is shorter in PPE than in CE. Females in CE and PPE have different stimulus thresholds for pregnancy initiation, with the direction of the difference varying with the species. Among the other phenomena affected by mode of estrus are sperm competition, mate choice, and the Bruce effect. Because mode of estrus can be an important determinant of results, selection of a mode of estrus for any experiment should not be simply a matter of convenience. Further study of effects of mode of estrus is warranted.

Animals↗

Early interactions between animal psychologists and animal activists and the founding of the APA Committee on Precautions in Animal Experimentation.

The current conflict between animal psychologists and animal rights activists often is presented as a recent and unique phenomenon. Although its scope may be unprecedented, the fundamental issues are longstanding. Early criticisms of animal psychologists are viewed in the context of the broader Victorian antivivisectionist movement and are seen as similar to those of the present time. Various attitudes toward animals and research were expressed by individuals such as Charles Darwin, George John Romanes, William James, and John Dewey. Media attacks on animal research were directed at psychologists such as G. Stanley Hall, John B. Watson, Ivan P. Pavlov, and Edward L. Thorndike. The American Psychological Association Committee on Precautions in Animal Experimentation was founded in 1925 at the instigation of Walter B. Cannon, with Robert M. Yerkes as the first chair.

Animal Welfare↗

Tests of preferences of young deer mice (Peromyscus maniculatus bairdi) for siblings versus nonsiblings.

Three experiments were conducted to test the performance of young deer mice (Peromyscus maniculatus bairdi) in associating preferentially with siblings versus nonsiblings. In Experiment 1, neither males nor females preferred caged siblings versus nonsiblings. In Experiment 2, with full contact permitted, nonsibling males were in contact as much as were sibling males. In Experiment 3, with pairs of littermate pairs permitted full contact, there was no significant differential association. Although discrimination and preferences related to kinship have been demonstrated in some species, they cannot be assumed to be universal.

Aging↗