Behavioral assessment of lines of Drosophila melanogaster selected for central excitation.

Selected lines of Drosophila melanogaster, bred for high and low levels of central excitatory state (CES), were used in 3 experiments to assess the effects of artificial selection of CES expression and to identify other correlated traits that may have become manifest during selection. Results indicate that the selected lines displayed (a) different levels of CES, (b) differences in water responsiveness (possibly due to differences in dehydration rates), (c) no water-induced CES, and (d) no significant amounts of sensitization or conditioning. Also, CES in the high line was not dissipated by subsequent posttest stimulations. Comparing the characteristics of CES in Drosophila and in Phormia regina reveals significant species differences. The relevance to earlier P. regina work with respect to CES and conditioning is discussed. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Induced variation of serotonin in Drosophila melanogaster and its relation to learning performance.

In insects the level of serotonin can be modified through the alimentary tract. Drosophila fed on chemically defined media to which has been added a synthesis inhibitor or an immediate precursor of this neurotransmitter have their serotonin level decreased or increased, respectively. (A 4- to 5-day treatment is optimal.) Such treated flies, if tested in a procedure of Pavlovian conditioning, have different learning performances. With the same duration of starvation, nearly the same threshold for sucrose solutions, but different amounts of serotonin, the flies (blindly trained) showed conditioned inhibition of the tarsal (or proboscis-extension) reflex according to the amount of serotonin. The highest level of this biogenic amine gave the best performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A replication demonstrating reduced courtship of Drosophila melanogaster by associative learning.

The study of experience-mediated reductions in the courtship of Drosophila melanogaster has stimulated wide interest because of its apparent importance for reproduction, interaction with chemical communication, and the ability to study individual subjects. This report replicates control procedures developed to account for nonassociative effects. The data indicate that male D. melanogaster associate the responses to inhibitory and excitatory cues provided by a mated female and that subsequent presentation of a virgin female results in lower than expected levels of courtship. This reduction is not a result of habituation or fatigue. I hypothesized that this associative effect results from counterconditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reproductive behavior of Drosophila melanogaster and D. nigrospiracula in the field and in the laboratory.

The reproductive behaviors of two species of fruit fly, Drosophila melanogaster and D. nigrospiracula, were compared in field and laboratory populations. A number of differences were observed in the behavior of the two species in their natural habitats. D. melanogaster, which was observed on citrus, mates at its feeding site, whereas D. nigrospiracula, which is cactiphilic, mates on a non-resource-based male territory adjacent to its feeding site. In both species large male size is important for reproductive success. However, in D. melanogaster smaller males tended to be excluded from the breeding site and were therefore not among the pool of potential mates to which females were exposed. Sex ratios were biased toward females in both species, but the high frequency of female remating in D. nigrospiracula may have provided more mating opportunities for the males of this species. Field observations differed from laboratory observations, and I discuss the importance of these differences for understanding the evolution of Drosophila mating systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experience mediated reduction in courtship of Drosophila melanogaster in large and small chambers.

Drosophila melanogaster males show reduced courtship of virgin females and immature males after experience with either mated females or immature males. However, males experienced with mated females do not show a mating disadvantage, despite the expected reduction in courtship (Zawistowski & Richmond, 1985). This report presents experiments and data concerning D. melanogaster courtships and experience mediated courtship reductions in vials and small chambers. Males observed in small chambers displayed significantly higher levels of courtship toward virgin females, mated females, and immature males when compared with subjects observed in vials, with or without food. Males trained in vials with mated females do not subsequently show reduced levels of courtship in either small chambers or vials. It is suggested that the high level of courtship observed in the small chambers is not required to stimulate a female to mate because males mate more successfully in the vials, even though they court less. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioned suppression of the proboscis-extension response in young, middle-aged, and old Drosophila melanogaster flies: Acquisition and extinction.

Young (7 days old), middle-aged (30 days old), and old (50 days old) Drosophila melanogaster males were used in an inhibitory conditioning of the proboscis-extension response. Two reinforcement schedules were applied, constant vs. partial. Partial reinforcement increased the number of trials needed to reach the learning criterion to the same extent in all age groups. Young flies needed fewer trials to reach the criterion than both middle-aged and old flies, which did not differ from each other. Extinction was delayed in the partial reinforcement groups by the same amount in all age groups. The slowest rate of extinction was observed in the old group and the fastest for the middle-aged flies. The results are discussed in connection with hypotheses that consider extinction an index either of behavioral rigidity or of strength of the initial learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioned suppression of proboscis extension in Drosophila melanogaster..

Conducted a modified replication of J. Médioni and G. Vaysse's (1975) observations on conditioned inhibition of proboscis extension in the fruit fly. Médioni and Vaysse reported that the inhibition of the proboscis-extension response can be conditioned over trials if such proboscis extensions are punished by applying an aversive stimulus to the foreleg tarsi. In the present study, quinine was used as the aversive stimulus, and Ss were adult virgin female D. melanogaster of the Berlin wild-type strain. Ss in the experimental group showed a consistent decrement (62%) in the number of proboscis extensions over trials relative to the random control group, thus replicating Médioni and Vaysse's basic observations of conditioning, using a different strain of flies and a modified conditioning apparatus. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic architecture of olfactory discriminative avoidance conditioning in Drosophila melanogaster..

Recent claims to have demonstrated associative learning ability in fruitflies raise questions about the adaptive significance of behavioral modifiability of this species. In a strain survey and a 9?×?9 half diallel cross study of olfactory discriminative avoidance conditioning, a low narrow heritability and strong directional dominance or heterosis controlling nonrandom phenotypic variation were found. Furthermore, the predicted inbreeding depression and asymmetrical response to bidirectional genetic selection were both observed. The genetic architecture revealed in these 3 experiments is consistent with a close association between this conditioning phenotype and evolutionary fitness. Predictions from this interpretation to the nature of new mutations have been confirmed, and a possible role for conditioning in courtship behavior has been identified. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reversal of genetic homeostasis in laboratory populations of Drosophila melanogaster under long-term selection for geotaxis and estimates of gene correlates: Evolution of behavior-genetic systems.

Among Drosophila melanogaster, divergently selected for geotaxis intermittently over 600 generations (28 years), about 80,000 animals have been analyzed behavior-genetically. Each major chromosome pair from two lines was isogenized on an unselected isogenic background. Measurement of their behavioral effects revealed the relative magnitudes II?>?III?>?X for the negatively geotactic (high) line and X?>?III?>?II for the positively geotactic (low) line. When reversing selection for the now phenotypically stable high and low lines and then repeatedly relaxing the reversals, a new genetic homeostasis in the low line was indicated by the return of the reversed-line average scores towards the low extreme; that is, the low line has attained a stable equilibrium for positive geotaxis, an uncharacteristic behavior and an effect not seen before 1979. This change suggests the recent evolution of a new coadaptation among genes. Although not as conclusive, a similar genetic interpretation is suggested for the high line. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A gene correlate of geotaxis near Adh (2-50.1) in Drosophila melangoster.

As part of a long-term study (38+ years) to identify genetic correlates of geotaxis in Drosophila melanogaster, the investigators report the results of allozyme-level analyses of 2 lines derived from hybridizing high- and low-selected lines that have evolved stable, extreme expressions of geotaxis. Allele variation at Adh was associated with geotactic performance in 1 hybrid-derived line, but not in another, after 66 free-mating generations beyond the F? generation. A second-chromosome gene correlate of geotaxis may lie within 1 map unit of Adh. Population genetic analyses suggest that there were different selection pressures on the hybrid-derived lines and that the fixation of PGD-A in the high-geotaxis line was probably due to a founder-effect event. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evolution of an instinct under long-term divergent selection for geotaxis in domesticated populations of Drosophila melanogaster..

Describes long-term divergent selection for geotaxis in lines of the fruit fly. After 26 yrs (600+ generations) of intermittent selection, the initial experimental procedure showed that the mean geotactic scores remained stable on relaxed selection, a result suggesting that evolutionary changes had occurred in these lines. Because the stability was not due to genetic fixation (homozygosity) of the lines, it is concluded that it was due to either (a) close linkage of genes associated with geotaxis (which would not result in enduring change) or (b) the development of new coadapted gene complexes utilizing genes associated with extreme geotaxis expression (which should result in enduring change). Better evidence for the latter hypothesis was obtained, during the 2nd experimental procedure, from the low- than the high-geotaxis line. The notions of coadaptation and genetic homeostasis are considered, as well as the prospective use of the geotaxis lines to study such concepts experimentally. The geotactic behavior expressed in each line is defined as instinctive: It increases reproductive success and is characteristic of a population. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ontogeny of aggressive-sexual behavior between males in lines of Japanese quail (Coturnix coturnix japonica) selected for male mating frequency.

100 male Japanese quail, from lines bidirectionally selected for high and low mating frequency and from a random-bred base population, were observed in an ontogenetic study of aggressive/sexual behavior. Ss were reared in sex-intermingled flocks until 28 days of age, at which time half of the Ss from each line were housed as all-male flocks and half were transferred to individual cages. At 41 days of age, individually caged Ss exhibited mounting behavior to win encounters with other Ss. By 45 days, Ss from the high and control lines exhibited significantly more aggressive sexual behavior than those from the low lines. Line?×?Rearing Experience interactions for mounting behavior at 45 and 56 days of age were due to the individually caged high- and control-line Ss' winning encounters by mounts; those maintained in flocks rarely mounted. Although some low-line Ss won encounters by mounts, the occurrence of this behavior was infrequent. Ss maintained in flocks were placed in individual cages at 57 days of age. When these Ss and those housed in individual cages from 28 days of age were compared at 84 days of age and older, the Line?×?Rearing Experience interaction observed previously disappeared, and only differences among genetic lines were evident. Genetic and rearing experience effects are discussed as influencing agonistic and sexual behaviors. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Type I error rate of the chi-square test in independence in R?×?C tables that have small expected frequencies.

Sampling experiments are reported that show that the uncorrected chi-square test of independence is exceptionally robust with respect to small expected frequencies in R?×?C contingency tables. In general, error rates that exceed .06 occurred only when both marginal probability distributions were extremely skewed and sample size was small. Nevertheless, the quality of the approximation of chi-square probabilities for exact multinomial probabilities was sometimes poor, although excessive errors in approximation by W. G. Cochran's (1952) criteria usually resulted from actual error rates being smaller, not larger, than the nominal level. A distinction is made between accuracy of approximation and control of the Type I error rate as considerations dictating the advisability of using an approximate test. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Presence of conspecifics facilitates learning that food is inedible in Aplysia fasciata..

Absence of a conspecific, but not of food, interfered with learning and memory of a feeding task in Aplysia fasciata. Interference was shown by a shortened training session and by lack of savings on retraining. The shortened training was not responsible for the lack of savings because brief training in the presence of a conspecific led to savings on retraining. Animals trained in the absence of a conspecific and then tested in its presence did not show signs of having learned, which indicates that the absence of a conspecific interfered with the ability to learn, rather than with the expression of memory. Absence of a conspecific also inhibited other aspects of feeding behavior, such as the latency to respond to food and the length of time that animals respond to food, which indicate that interference with learning was apparently caused by inhibition of feeding behavior, rather than by block of the mechanisms underlying learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of The impact of television: A natural experiment in three communities.

Reviews the book, The impact of television: A natural experiment in three communities edited by Tannis MacBeth Williams (1986). In their natural experiment, Williams and her colleagues proceeded to research several of the most important questions about the impact of television. This book presents the studies and their findings. Most of studies occurred at two points in time, approximately 6 months prior to the introduction of television in (Phase 1) and again 2 years later (Phase 2). The topics of the studies are: reading competence; children's cognitive abilities; involvement of community activities; impact of television-viewing patterns on the use of other media by both children and adults; the effect of television on children's aggressive behaviour; and television's effects on adults' divergent thinking, cognitive style, perceptions of self and community, and orientation to the environment. The book is written with two kinds of readers in mind--the intelligent general reader and the researcher--and is organized so that both may obtain the information they require efficiently. The quality of the research is excellent. The overall design and each part of the study show careful attention to issues, well-considered methodologies, and relevant data analyses. This book is certain to stand as a classic. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Differential kinship effect on reconciliation in three species of macaques (Macaca fascicularis, M. fuscata, and M. sylvanus).

Macaque societies are typically characterized by despotic dominance styles and strong bonds between related individuals. Interspecies variation in dominance style, however, has been recently documented. This study investigated whether kinship effects on social interactions vary depending on the species dominance style. Reconciliation was chosen as a measure of relationship quality between group members. Groups of Japanese (Macaca fuscata) and long-tailed (M. fascicularis) macaques were selected for their highly despotic style, and Barbary (M. sylvanus) macaques were chosen for their lower level of despotism. The findings confirmed the hypothesis that kinship effects on reconciliation are stronger the more despotic the species is. Barbary macaque nonkin reconciled more often than nonkin of the other 2 species. In addition, the differences in reconciliation frequency between kin and nonkin were less pronounced among the less despotic Barbary macaques. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociating the long-term effects of fetal/neonatal iron deficiency on three types of learning in the rat.

Iron deficiency (ID) is a common nutrient deficiency worldwide. This condition is linked to changes in myelin formation, dopaminergic function, and energy metabolism. Early ID results in persistent long-term cognitive and behavioral disturbances in children, despite a return to normal iron status. The present study assesses formerly ID adult rats on maze learning tasks that depend on specific brain regions related to learning, specifically the hippocampus, striatum, and amygdala. Rat dams were fed ID chow starting on gestational Day 2 through postnatal Day 7, and behavioral testing began at postnatal Day 65--following a return to normal iron status. Formerly ID rats exhibited delayed acquisition of the hippocampus-dependant task and no differences from controls on the striatum- and amygdala-dependent tasks. These findings likely reflect long-term reduction in but not abolition of hippocampus-dependent learning and preserved function in other brain structures (e.g., striatum and amygdala). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The performance of bonobos (Pan paniscus), chimpanzees (Pan troglodytes), and orangutans (Pongo pygmaeus) in two versions of an object-choice task.

The object-choice task tests animals’ ability to use human-given cues to find a hidden reward located in 1 of 2 (or more) containers. Great apes are generally unskillful in this task whereas other species including dogs (Canis familiaris) and goats (Capra hircus) can use human-given cues to locate the reward. However, great apes are typically positioned proximal to the containers when receiving the experimenter’s cue whereas other species are invariably positioned distally. The authors investigated how the position of the subject, the human giving the cue and the containers (and the distance among them) affected the performance of 19 captive great apes. Compared to the proximal condition, the distal condition involved larger distances and, critically, it reduced the potential ambiguity of the cues as well as the strong influence that the sight of the containers may have had when subjects received the cue. Subjects were far more successful in the distal compared to the proximal condition. The authors suggest several possibilities to account for this difference and discuss our findings in relation to previous and future object-choice research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Autonomy in the extreme situation: Bruno Bettelheim, the Nazi concentration camps and the mass society.

Review of book: Paul Marcus (Au.) Autonomy in the extreme situation: Bruno Bettelheim, the Nazi concentration camps and the mass society. Westport, CT: Praeger, 1999, 232 pp.. Reviewed by D. Patrick Zimmerman. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Note types, harmonic structure, and note order in the songs of zebra finches (Taeniopygia guttata)..

Zebra finch (Taeniopygia guttata) song notes are acoustically complex, rich in harmonic structure, and variable among birds. This article provides simple, reliable methods for classifying zebra finch song notes into types, for describing the harmonic structure of song notes, and for determining the order of notes in song motifs in samples from 4 captive North American laboratory colonies. Using the note-type classification scheme, 2 observers sorted 90% of readable song notes into 5 types with 94% interobserver agreement. Examination of song-note power spectra revealed that reduced harmonics were a common feature of zebra finch song notes. Finally, an analysis of zebra finches' songs suggests that males produce the notes in their motifs in a consistent but not stereotyped (invariant) order. (PsycINFO Database Record (c) 2010 APA, all rights reserved)