Visual preferences of imprinted ducklings are altered by the maternal call.

Domestic mallard (Peking) ducklings were visually imprinted to a stuffed model of a mallard duck during a 30-min following trial at 24 hrs after hatching. Simultaneous choice tests between the familiar model and an unfamiliar red-and-white-striped box at 48 and 72 hrs confirmed the efficacy of the imprinting procedure: When both models were silent, Ss preferred to follow the familiar model. However, when a recording of the mallard maternal assembly call was played from a speaker inside the red box, Ss imprinted to the mallard preferred to follow the unfamiliar box rather than the familiar method (Exp I). That preference was not due merely to the audiovisual stimulation provided by the box, since when a recording of intermittent tones was played from the mallard model, Ss imprinted to the mallard still preferred to follow the red box emitting the mallard call (Exp II). Playing only the tones from the red box disrupted the stability of the Ss' imprinted preferences between the 1st and 2nd tests but did not produce a preference for the box (Exp III). Results show that the mallard maternal call is more important than visual experience with an inanimate model in determining the maternal preferences of visually imprinted Peking ducklings. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Irreversibility of imprinting after active versus passive exposure to the object.

64 isolated Peking ducklings were reared for 4 days with a hanging colored object (passive training). Half of the Ss also received 3 1-hr following sessions with the object (active training). Findings indicate that both groups chose the imprinting object in a simultaneous choice test administered on Day 5, but the preference of active-trained Ss was more robust than of passive-trained Ss. Each S was then reared with an object of a different color and shape. The preference for the 1st object was maintained in active-trained Ss, but not in passive-trained Ss. These results were also found when the objects were removed from the cages for 4 days. Findings suggest that preferences established during the sensitive period for imprinting can be eliminated (but not necessarily reversed) in Ss that are prevented from following the original object, but they are resistant to change in Ss given the following experience. A hypothesis is presented that emphasizes the importance of reafference and activation of brain stem pathways involved in following the formation of specific affiliative bonds. (44 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Postnatal development of absolute auditory thresholds in kittens.

Measured postnatal development of absolute auditory thresholds in kittens from birth up to 1 mo of age. UCRs to pure tones were observed for Ss up to Day 12, and CRs were used from Day 10 onward. At 1 day after birth, the first noticeable responses were obtained in 4 of 11 Ss at frequencies of .5–2 kHz. At 2 days of age, 12 of 16 responded. Thresholds remained high (above 100 db) up to the 6th day, but the range of behaviorally effective frequencies extended from .2 to 6 kHz. All CR thresholds at Day 10 and most at Day 12 were significantly lower than those measured by UCRs. From 10 days onward, all threshold curves showed a characteristic sensitivity optimum at 4 kHz. For frequencies below 1 kHz, maximum sensitivity was reached at Day 15; for frequencies up to 20 kHz, at Day 20; and for even higher frequencies, at Day 30. At 1 mo of age, the frequency range was adultlike. Results closely follow structural maturation of the acoustic pathway and demonstrate limitations of the ability for acoustical communication during the 1st wk of life. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distinction between places and paths in rats' spatial representations.

Rats were trained on a 3-dimensional, 4-arm radial maze. In Exp 1, Ss trained to climb to the single goal platform chose fewer novel routes to the goal than Ss trained to climb to the 4 spatially distinct platforms. In Exp 2, a reinforcement contingency was imposed, requiring a novel route choice on each trial to receive reinforcement. Learning to associate route choice with reinforcement outcome was much more difficult for Ss tested with the single goal than for Ss tested with the 4 distinct goals. In Exp 3, a partitioned central platform group learned the reinforcement contingency as quickly as the Ss given 4 spatially distinct platforms. In Exp 4, distinctive floor inserts did not affect performance relative to no inserts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Affiliation in highly aggressive domesticated rats.

Conducted 2 experiments with 131 male Long-Evans rats to examine the relationship between agonistic behavior and the subsequent probability of approaching a conspecific. Highly agressive Ss were given a choice in a –T maze to interact with another male or enter an empty compartment (Exp I) or to interact with 1 of 2 conspecifics (Exp II). In the 1st experiment, the experimental Ss consistently chose the social alternative over the empty goal area. The preference for affiliation was notably strong, not only when the waiting S was a submissive male but also when it was a highly aggressive stimulus male. The aggressive Ss of Exp II were allowed to choose between an equally aggressive male or a submissive male. Ss preferred to interact with the less aggressive male. It was suprising, however, that the Ss often chose to interact with the highly aggressive target S. Data suggest that even after an aversive agonistic attack, the affiliation-response in highly social rodents is remarkably persistent. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexual differentiation of play behavior in the ferret.

Three experiments examined the endocrine mechanisms responsible for sex differences in prepubertal play behavior of ferrets. In Exp I, 6 gonadally intact adolescent males exhibited higher levels of "stand-over" behavior than 6 females did in tests between 63 and 123 days of age with gonadally intact female partners of the same age. In Exp II, with 69 Ss, those Ss exposed to androgen or to ovarian steroids over Days 5–20 of postnatal life subsequently exhibited significantly higher levels of stand-over behavior in tests with females than did control females gonadectomized on Day 5 and not given steroids. None of the Ss in Exp II exhibited levels of stand-over behavior comparable to those of the gonadally intact males in Exp I. In Exp III, with 36 Ss, males gonadectomized and implanted subcutaneously with testosterone capsules on Day 70 and tested with females at 84–96 days of age exhibited levels of stand-over behavior comparable to those observed in Exp I in gonadally intact males of the same age (Weeks 12–24). Males gonadectomized on Day 70 and given no hormone at testing exhibited significantly lower levels of this behavior. Significantly lower levels were also exhibited by males gonadectomized on Day 35 and females gonadectomized on Day 70, regardless of whether they were tested with testosterone present after Day 70. Sex differences in the expression of prepubertal play behavior of ferrets apparently result from differential exposure of males and females to androgen over an extended postnatal period. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of cross-modal recognition in infant pigtail monkeys (Macaca nemestrina).

Examined the development of cross-modal recognition in 48 infant pigtail monkeys in 2 studies by using an adaptation of the visual preference technique. Ss were first familiarized orally with pacifiers of 1 of 2 shapes and were then tested on corresponding visual stimuli. In a cross-sectional experiment (Exp I), Ss under 200 days postconception at test (approximately 4 postnatal weeks) showed a visual preference for the orally familiar stimuli, which provided evidence for cross-modal recognition. Ss over 200 days postconception at test showed a visual preference for 1 of the test stimuli, which made their data uninterpretable with respect to cross-modal abilities. In a longitudinal experiment (Exp II), Ss were tested once when they were younger than 200 days postconception and once when they were older. When young, they showed a visual preference for the orally familiar stimuli. When older, they showed a visual preference for the same test stimuli found for the cross-sectional Ss. Results are discussed relative to human infant cross-modal data obtained by similar procedures. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Directional responses to sounds in young gerbils (Meriones unguiculatus).

Conducted 3 experiments to determine the ability of infant gerbils to approach an auditory stimulus. In Exp I, 48 16–23 day old Ss were tested in a circular apparatus with a central start area and a movable sound source located at 1 of 8 positions around the perimeter. Stimuli included high- and low-intensity presentations of a tape-recorded gerbil social call, a broad-band white noise stimulus, and a no-stimulus control condition. Ss showed a strong tendency to approach the low-intensity social call and a less pronounced tendency to approach the white noise. In Exp II, 24 16–23 day old Ss were tested in the same apparatus with or without ear blocks to determine the role of binaural cues in directional approach responding. The tendency to approach a low-intensity vocalization was disrupted by obstruction of one ear but not by blocking both ears. Thus, binaural balance was shown to be important for early sound localization. In Exp III, using 6 12–27 day old Ss, the tendency to approach a social call was compared at 12–25, 16–29, 20–23, and 24–27 days after birth. Approach responses were first seen at 16–29 days of age. The responses continued at 20–23 days of age but began to wane at 24–27 days of age. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of overtraining and high activation on bar pressing of rats tested under water deprivation.

Trained 2 groups of 9 male albino Sprague-Dawley rats each in a Skinner box under 24 hrs of water deprivation; Group 1 received 15 daily training sessions, Group 2 30 sessions. In Exp II, 4 groups (9 Ss each) were also trained in a Skinner box but under different conditions of water deprivation (24, 36, 48, and 60 hrs, respectively). In both experiments, the relationship between performance and activation was evaluated by submitting each group to successive and independent conditions of water deprivation (24, 36, 48, 60, and 72 hrs). Heart rate was used as an index of activation during training and during the test phase. Overtraining (Exp I) and high activation during training (Exp II) prevented the drop in performance usually observed under high levels of activation. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rats prefer signaled over unsignaled shock-free periods.

Three experiments with 48 female rats investigated Ss' preference for a schedule of shock containing signaled shock-free periods (SSF schedule) or the same shock schedule without signals (unsignaled schedule). Exp I was a replication of the shuttle-box experiment reported by M. S. Fanselow (see record 1981-00807-001), in which rats preferred unsignaled shock over the SSF schedule. Contrary to Fanselow's results, Ss in Exp I failed to develop a preference. In Exp II, forced-exposure training was added, testing was extended from 2 165-min sessions to 8, and a reversal phase was added. Results show that 3 of 4 Ss preferred the SSF schedule, and 2 of these continued to prefer it after reversal. In Exp III, forced-exposure training was eliminated, but signals were lengthened from 30 to 60 sec, and the test was extended to 12 sessions. Results show that Ss choosing between the unsignaled and SSF schedules chose the SSF schedule, whereas a random control group chose the unsignaled schedule. Findings indicate that choice between active schedules is determined by the relative aversiveness of all stimuli presented and not, as implied by contextual fear analysis, by that of contextual stimuli alone. (25 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Some sources of variation in the bar-pressing versus freeloading phenomenon in rats.

Gave 40 albino rats a choice between barpressing for food or taking it freely from a dish. In Exp I Ss were given 3 days of free-food training and 6 days of barpress training before the choice. In Exp II the number of prechoice bar presses was varied within the choice sessions, and in Exp. III the choice sessions were extended over 10 days. In all 3 experiments the mean number of pellets obtained via bar pressing was over 70%. In Exp IV and V the amount of time spent and the number of pellets obtained in freeloading and barpressing were equalized. In both studies Ss greatly preferred to freeload. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some determinants of a natural food aversion in Norway rats.

Adult male Long-Evans rats were permitted to feed on the carcasses of adult male rodents, freshly sacrificed by CO? asphyxiation. In a 2-choice preference test (Exp I), hungry Ss were offered 1 conspecific and 1 house mouse, the pair of carcasses being either intact or skinned. 18 Ss offered intact carcasses fed on the mouse or on neither carcass, but 18 Ss offered skinned carcasses fed indiscriminately, usually on both carcasses. In Exp II, 10 hungry Ss that earlier had observed a cagemate feeding on intact conspecific carcasses fed more readily on a similar carcass during a single-choice test than did 8 controls. In Exp II, 20 food-deprived Ss (96 hrs) fed more readily and consumed more tissue from an intact conspecific carcass than did 20 nondeprived Ss. It is concluded that the aversion to feeding on the intact carcass of a freshly sacrificed adult conspecific is deprivation dependent and is mediated by chemoreceptive stimuli from the skin and/or fur. The aversion is diminished by social facilitation. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ontogeny of thermal and olfactory determinants of huddling in the rat.

In Exp I, in standardized tests of huddling behavior, 64 5-, 10-, 15-, and 20-day-old Sprague-Dawley rat pups spent substantial and equivalent amounts of time with an immobile rat or a heated, fur-covered tube, which suggests that the conspecific and inanimate stimuli were equally attractive to the pups. In Exp II, with 32 Ss, 2-choice preference tests showed developmental differences in attraction. Younger Ss preferred to huddle with the warmer, inanimate target, whereas older Ss preferred the conspecific. The emergent conspecific preference appears mediated by attraction to species odors. In Exp III (64 Ss), the 5- and 10-day-olds huddled equally with an immobile rat and an immobile gerbil (stimuli with similar thermal and tactile properties), but older Ss preferred the conspecific. In Exp IV, with 16 15-day-old and 16 20-day-old Ss, intranasal zinc sulfate treatment eliminated preference for the conspecific but did not disrupt huddling per se. Results from all experiments show that thermal cues were sufficient to elicit huddling at all ages, but olfactory cues became a more salient influence before weaning. An ontogenetic transition from "physiological" to "filial" huddling is discussed in terms of changes in sensory control of early behavior. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerical competence in rats (Rattus norvegicus): Davis and Bradford (1986) extended.

The task of rats (Rattus norvegicus) was to enter 1 box of a defined ordinal number among an array of boxes. In Experiments 1 and 2, the rats correctly chose the 4th box from arrays of 6 and 12 boxes, respectively. In Experiments 3 and 4, in which the ordinal number of the correct box was increased in a graduated fashion, they were able to select the correct box even when its position was higher than 10th among 12 and 18 boxes, respectively. In Experiment 5, the possibility that the rats had used cues to the openability of the box doors was ruled out. In Experiments 6 and 7, the rats succeeded in the task even when the total number of boxes was varied from trial to trial. In Experiment 8, both small- and large-sized boxes were used to control for the possibility of using the cumulative length of the boxes as a cue. Overall, the results suggest that performance was based on numerical cues. Intentional acts were occasionally observed but appeared not to be essential for solving the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition of lordosis in rats by the antiestrogen CI-628 in the absence of progesterone.

Assessed whether the ability of the antiestrogen CI-628 to inhibit estrogen-stimulated lordosis behavior (LB) in adult ovariectomized Sprague-Dawley rats depends on its interference with the synergistic effects of estrogen with progesterone. In Exp I the effect of CI-628 was contrasted in Ss brought into estrus by estradiol benzoate (EB; 0 or 3 μg/.1 ml) combined with progesterone (P; 42 or 500 μg/.1 ml) vs 4 daily injections of EB (without P). CI-628 effectively antagonized LB in both conditions. In the absence of CI-628, Ss receiving P had significantly higher LB scores than the 4-day EB controls. In Exp II Ss receiving CI-628 on only the 1st 2 of 4 days of EB injections had decreased LB scores unless P was also given on the day of testing. This suggested that the EB from the latter injections was not acting as a progestin "mimic." In Exp III LB stimulated by EB (without P) was inhibited by CI-628 in Ss that were both ovariectomized and adrenalectomized. This suggested that adrenal progestins were not involved in the ability of CI-628 to inhibit LB. Results suggest that the mechanism of action of CI-628 for the inhibition of LB does not depend on its ability to antagonize an estrogen-induced increase in neural progestin receptors. Implications for estrogen-mediated behaviors, for which CI-628 has little or no antagonistic effects, are discussed. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strychnine increases acoustic startle amplitude but does not alter short-term or long-term habituation.

Used the glycine antagonist strychnine (1.0 mg/kg, ip, 10 min before treatment) to investigate the involvement of glycinergic neurons in the development and/or expression of short-term (within-session) habituation (Exp I) and long-term (between-sessions) habituation (Exps II and III) of the acoustic startle response in 120 male albino Sprague-Dawley rats. Over a range of eliciting-stimulus intensities (95, 105, and 115 db) and interstimulus intervals (3, 7, 13, and 27 sec), strychnine markedly increased startle amplitude, relative to water injection, whereas it failed to attenuate the rate of within-session habituation (Exp I). In Exp II, Ss that were exposed to daily sessions of startle-eliciting stimuli for 4 days and then tested on Day 5 showed lower levels of startle amplitude than Ss with no prior habituation training. Strychnine injected prior to the test session again increased startle amplitude but did not block the expression of between-sessions habituation. In Exp III, Ss injected with either strychnine or water prior to each of 3 daily habituation training sessions and subsequently tested on Day 4 showed similar between-sessions habituation. In general, results show that strychnine increased startle amplitude without affecting either within-session or between-sessions habituation of acoustic startle. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social facilitation of feeding in newly hatched chickens as a function of imprinting.

Describes 3 experiments with cornish * white ruck or white comet * New Hampshire red newly hatched chicks. In Exp. I, it was demonstrated that 12 Ss fed communally gained more weight during a test period than 12 Ss fed in isolation. This effect seemed more pronounced in Ss reared communally. Exp. II showed that 30 communally reared Ss ate very much more, as measured by weight gain, than 30 isolated Ss, but if communal experience was started after Day 3 of life this effect was not observed. However, communally reared Ss that were placed in isolation after Day 3 continued to gain weight at the same rate as those remaining in community. In Exp. III, with 24 Ss, it was found that brief exposures to an artificial imprinting stimulus in the 1st 3 days of life also had a marked facilitating effect on eating in a communal test situation. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failure to learn to escape in rats previously exposed to inescapable shock depends on nature of escape response.

Results of previous studies show that dogs exposed to inescapable shocks in a Pavlov harness subsequently fail to learn to escape shock in a shuttle box. The present 6 experiments attempted to replicate this finding with male Sprague-Dawley rats (N = 182). In agreement with many previous investigations, Exp I found that Ss exposed to inescapable shock did not fail to learn to escape in a shuttle box. Exp II, III, and IV varied the number, intensity, and temporal interval between inescapable shocks and did not find failure to learn in the shuttle box. An analysis of responding in the shuttle box revealed that Ss shuttled rapidly from the very 1st trial, whereas dogs acquire shuttling more gradually. Exp V and VI revealed that Ss exposed to inescapable shock failed to learn to escape when the escape response was one that was acquired more gradually. Exp V utilized a double crossing of the shuttle box as the escape response and Exp VI utilized a wheel-turn response. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social interaction modifies learned aversions, sodium appetite, and both palatability and handling-time induced dietary preference in rats (Rattus norvegicus).

Four studies examined whether socially transmitted diet preference could counteract the effects of a learned aversion, a palatability-based diet preference, a polyethylene glycol 20,000-induced sodium appetite, and a handling time-induced dietary preference. Results indicate that (a) Ss poisoned after eating a novel diet ate substantial amounts of the averted diet following interaction with conspecifics that had eaten the averted diet. (b) Following interaction with conspecifics that had eaten an unpalatable diet, Ss offered a choice between palatable and unpalatable diets ate more than twice as much unpalatable diet as did controls lacking social experience. (c) Sodium-deficient Ss offered a choice between sodium-enriched and sodium-adequate diets ate less than half as much sodium-enriched diet, following interaction with conspecifics that had eaten sodium-adequate diet as did controls lacking social experience. (d) Ss offered a choice between isocaloric, roughly equipalatable foods with long and short handling times chose the food having the longer handling time after interacting with conspecifics eating that food. It is suggested that social influence is a major factor in guiding diet selection by rats. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequential attributional feedback and children's achievement behaviors.

Determined how the sequence of ability and effort attributional feedback influenced task motivation, attributions for success, self-efficacy, and skillful performance in 80 elementary school Ss (aged 8 yrs 2 mo to 10 yrs 5 mo) in 2 experiments. In Exp I, 40 Ss lacking subtraction skills received training and problem-solved over 4 sessions. During the problem solving, Group 1 (ability-ability) periodically received ability feedback; Group 2 (effort-effort) received little effort feedback; Group 3 (ability-effort) was given ability feedback during the 1st 2 sessions and effort feedback during the last 2; Group 4 (effort-ability) had this sequence reversed. In Exp II, 40 Ss (chosen with the same criteria as in Exp I) followed the same procedures except they were asked about their perceptions of success or failure following training. Results for both experiments show that Ss in Groups 1 and 3 developed higher ability attributions, self-efficacy, and subtraction skills compared with Ss in Groups 2 and 4. The sequence of attributional feedback did not differentially affect motivation, effort attributions, or perceptions of training successes. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)