Development of species identification in ducklings: II. Experiential prevention of perceptual deficit caused by embryonic auditory deprivation.

Devocalized-isolated ducklings are relatively insensitive to the higher frequencies in their species' maternal call 24 hr after hatching. To assess the efficacy of various sounds in preventing this high-frequency perceptual deficit, devocalized-isolated embryos were exposed to 1 of 3 calls and tested with normal vs high-frequency attenuated maternal calls 24 hr after hatching. A total of 506 Peking ducklings were used in 2 experiments. The embryonic vocalization (contact-contentment call) that most closely matched the region of the devocalized Ss' greatest insensitivity (1,500-2,500 Hz) proved most efficacious in remedying (preventing) the high-frequency perceptual deficit. Exposure to the embryonic alarm-distress call was somewhat effective, whereas exposure to low-frequency white noise was not effective at all. This finding suggests that the normal development of innate behavior is partially dependent upon prior experience as well as upon intrinsic processes of neural maturation. Although normally occurring embryonic auditory experience does not induce the preference for the maternal call in this species, such experience does contribute to the sharpness of the discriminative basis of the preference 24 hr after hatching. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of species identification in ducklings: I. Nature of perceptual deficit caused by embryonic auditory deprivation.

Reports results of 2 experiments with over 150 Peking ducklings. In simultaneous choice tests with normal and filtered maternal calls, devocal-isolated Ss were much more likely than vocal-communal Ss to select the mallard maternal call in which the higher frequencies were severely attenuated, thus indicating their relative insensitivity to the higher frequency components of the maternal call. However, the devocal Ss were as adept as vocal Ss in selecting the normal mallard maternal call when it was pitted against a low-frequency attenuated mallard call. Thus, the perceptual deficiency resulting from embryonic and postnatal auditory deprivation is selective in the sense of being relegated to the higher frequency components of the maternal call. Devocalization prevents the embryo and hatchling from hearing their own vocalizations, all of which happen to be in the high-frequency range (greater than 1,500 Hz). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Development of Species Identification in Ducklings: I. Nature of Perceptual Deficit Caused by Embryonic Auditory Deprivation": Erratum.

Reports an error in the original article by Gilbert Gottlieb (Journal of Comparative & Physiological Psychology, 1975[Jul], Vol 89[5], 387-399). The eighth line in the right-hand column on page 392 should read "hatched about 9 hr earlier ...." (The following abstract of this article originally appeared in record 1975-31344-001.) Reports results of 2 experiments with over 150 Peking ducklings. In simultaneous choice tests with normal and filtered maternal calls, devocal-isolated Ss were much more likely than vocal-communal Ss to select the mallard maternal call in which the higher frequencies were severely attenuated, thus indicating their relative insensitivity to the higher frequency components of the maternal call. However, the devocal Ss were as adept as vocal Ss in selecting the normal mallard maternal call when it was pitted against a low-frequency attenuated mallard call. Thus, the perceptual deficiency resulting from embryonic and postnatal auditory deprivation is selective in the sense of being relegated to the higher frequency components of the maternal call. Devocalization prevents the embryo and hatchling from hearing their own vocalizations, all of which happen to be in the high-frequency range (greater than 1,500 Hz). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of species identification in ducklings: VIII. Embryonic versus postnatal critical period for the maintenance of species-typical perception.

It was previously documented that the domestic mallard duck embryo must be exposed to its embryonic contact-contentment call at a repetition rate of 4 notes/sec for the neonate to manifest the species-typical preference for the species maternal call at its normal rate (3.7 notes/sec) after hatching. The present study examined whether the exposure to the contact call must occur in the late embryonic period to be effective. It was found that exposure for as little as 5 min/hr for 24 hrs was sufficient for normal perceptual development and that such stimulation could occur either before or after hatching, provided that a 48-hr "consolidation" period intervened between the end of stimulation and testing. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

Development of species identification in ducklings: XII. Ineffectiveness of auditory self-stimulation in wood ducklings (Aix sponsa).

Examined the actual vocalizations of 24 auditory self-stimulated and 21 unstimulated wood ducklings to explore the possibility that there is a difference in the kind and/or amount of auditory self-stimulation in the 2 groups. Previous research shows that wood ducklings vocalized copiously when in auditory isolation; however, such self-stimulation was ineffective in maintaining their preference for descending frequency-modulated (FM) notes of the maternal call. Only isolated ducklings that had been exposed to recorded descending sib calls exhibited the normal preference for descending maternal notes in a choice test with ascending and descending maternal calls. Results of the present study with a similar choice test show that although stimulated Ss produced more ascending notes than unstimulted Ss, no differences were found in the overall vocal behavior, vocal reactivity, or specific kinds of frequency modulation produced by Ss that preferred the descending maternal call and other Ss that responded in the choice test. This absence of a difference in vocal production supports the previous conclusion that self-stimulation plays no role in the development or maintenance of the species-typical perceptual preference for descending FM notes. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Species-specific auditory preference of bobwhite quail chicks (Colinus virginianus) is altered by social interaction with siblings.

The study examined whether reinstating specific aspects of the normally occurring postnatal setting (ongoing social interaction with siblings during rearing and/or testing) would influence bobwhite quail chicks' attraction to their species-typical maternal call. Results revealed that incubator-reared chicks exhibit a strong preference for the species-typical bobwhite maternal call over a group of the same-aged siblings in simultaneous choice tests at 24 hr and 48 hr after hatching, but only if the birds are kept in relative social isolation. No preference for the maternal call was found at 24 hr or at 48 hr if chicks were reared in a group of same-aged chicks from hatching and tested to the maternal call vs. siblings or the maternal call paired with a live adult bobwhite hen vs. siblings. These results raise doubts about the appropriateness of the usual methods of isolation rearing in the study of species-typical perceptual preferences and underscore the importance of considering features of the natural social context in the analysis of early perceptual and social behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of species identification in ducklings: VII. Highly specific early experience fosters species-specific perception in wood ducklings.

Wood ducklings find the maternal assembly call of their species attractive in advance of exposure to it. A critical acoustic feature of the maternal call is the descending frequency modulation (FM) of its notes. The ducklings' vocalizations themselves have a pronounced descending FM, albeit in a much higher frequency range than the maternal call. Four experiments tested the possibility that the maternally naive duckling's sensitivity to the descending FM of the maternal call notes might derive from prior exposure to its own vocalizations. 184 wood duck embryos were placed in individual auditory isolation several days before hatching and tested for their preference for the descending FM in choice tests with ascending and descending synthetic maternal calls after hatching. Results indicate the wood ducklings' usual preference for the descending frequency modulation in the maternal call of its species is a function of prior exposure to specific properties of their own vocalizations in the normal course of events. Since the fit between the relevant acoustic feature of the ducklings' vocalizations and the critical perceptual feature of the maternal call is an abstract one, the present finding is an example of a nonobvious experiential precursor to behavior that otherwise would seem to be "innate" or "instinctive." (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Type of prenatal sensory experience affects auditory learning in bobwhite quail (Colinus virginianus).

This study examined the effects of specific types of prenatal auditory stimulation on the auditory learning capacity of bobwhite embryos (Colinus virginianus) incubated in either communal or isolation conditions. Results revealed that socially incubated embryos could learn an individual bobwhite maternal call, whereas embryos denied physical and tactile stimulation as a result of isolation incubation failed to demonstrate prenatal auditory learning of the maternal call. In contrast, embryos exposed to bobwhite chick contentment calls in the period prior to hatching demonstrated prenatal auditory learning, whether they were incubated socially or in isolation. Socially incubated and isolation-incubated embryos exposed to bobwhite chick distress calls failed to learn the individual maternal call, indicating that the type of sensory stimulation the developing organism encounters prenatally is important in fostering normal perceptual learning ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of species identification in ducklings: V. Perceptual differentiation in the embryo.

Studied the precise manner in which normally occurring exposure to embryonic vocalization contributes to the Peking duckling's ability to detect distinctive features of the maternal call. Polygraphic recordings of heartbeat, bill-clapping, and vocalization were made from embryos that were exposed to maternal calls or were incubated in silence. The key acoustic features of the maternal call for the embryo were high- and low-frequency components and repetition rate. Embryonic auditory experience facilitated the development of high-frequency sensitivity, whereas it maintained repetition-rate specificity. The single most important finding was that the embryo's initial perceptual response to the maternal call was not fully differentiated in advance of exposure to its own or sib vocalizations. The youngest (Day 22) aurally inexperienced embryo's behavioral response to the maternal call was based on only the low-frequency components, whereas the aurally experienced Day 22 embryo's response was based on both high- and low-frequency components. Although the initial repetition-rate specificity of the Day 22 embryos was as sharp without auditory experience as it was with it, subsequent development on this perceptual dimension, if it is to be species-typical, requires auditory experience. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intersensory experience and early perceptual development: Postnatal experience with multimodal maternal cues affects intersensory responsiveness in Bobwhite Quail Chicks.

Unlike the other sensory modalities of precocial infants, the visual modality does not normally become functional until after birth or hatching. Despite this unique developmental status, the role of emerging visual experience on postnatal perceptual organization remains unclear. In this study, bobwhite quail hatchlings were reared in conditions that manipulated postnatal experience with maternal visual cues, either alone or in conjunction with maternal auditory cues. Results revealed that bobwhite chicks require postnatal exposure to both maternal auditory and visual cues following hatching to demonstrate species-specific perceptual preferences. Chicks that received temporally disparate maternal auditory and visual cues or experience with only maternal visual or maternal auditory cues failed to show species-typical perceptual responsiveness. These results suggest that developmental mechanisms involving both visual and auditory sensory experience underlie the emergence of early intersensory integration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modified sensory features of social stimulation alter the perceptual responsiveness of bobwhite quail chicks (Colinus virginianus).

This study examined the sensory features of postnatal social experience that bobwhite quail chicks (Colinus virginianus) require to maintain species-typical responding to maternal auditory–visual cues. Chicks were reared in 1 of 3 conditions after hatching: altered tactile, auditory, or visual experience with siblings. Findings revealed that altered tactile, auditory, or visual experience during the first 36 or the first 72 hr following hatching modified chicks' preferential responding to species-specific maternal cues. During the second 36 hr, altered tactile or auditory experience disrupted chicks' perceptual development, whereas altered visual experience did not affect species-typical responsiveness. Results indicate that (a) timing of early postnatal visual experience can affect early filial responsiveness to maternal cues and (b) normal sensory experience derived from early social interaction affects species-typical perceptual development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of amygdala, hippocampus, and periaqueductal gray lesions on short- and long-term contextual fear.

Examines the effects of amygdala, hippocampus, and periaqueductal gray (PAG) lesions on contextual fear conditioning in 48 female rats. Freezing behavior served as the measure of conditioning. Unlesioned control Ss showed reliable conditional freezing in the testing chamber when observed both immediately and 24 hrs after footshocks. In contrast, Ss with amygdala or ventral PAG lesions exhibited a significant attenuation in freezing both immediately and 24 hrs after the shocks. Dorsal PAG lesions had no effect on freezing at either time. Ss with hippocampal lesions displayed robust freezing behavior immediately following the shock, even though they showed a marked deficit in freezing 24 hrs after the shock. These results indicate that there are anatomically dissociable short- and long-term conditional fear states. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of domestication on production and perception of mallard maternal alarm calls: Developmental lag in behavioral arousal.

Conducted field and laboratory studies to assess the effects of intense genetic selection on the production and perception of the maternal alarm calls of 150 domestic (Peking) and 120 wild mallard ducks (Anas platyrhynchos). With respect to production, the calls of wild and domestic Ss were comparable on 4 acoustic features and differed only slightly on 2 features. With respect to perception, the calls of wild and domestic hens were equally effective in promoting behavioral inhibition in wild and domestic ducklings. Although data reveal little or no effect of domestication on maternal alarm call, an unexpected effect was found regarding the domestic ducklings' behavior. Peking Ss showed a greater level of behavioral inhibition than mallards at 24 hrs of age. Further experiments indicated that the differential level of inhibition in the wild and domestic birds reflects a developmental lag in arousal consequent to domestication: 72-hr-old Peking ducklings were behaviorally more aroused than 24-hr-old Peking ducklings and were similar to 24-hr-old mallard ducklings in that respect. This appears to be the first demonstration of behavioral heterochrony, which is believed to be an important mechanism of behavioral evolution. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early undernutrition impairs hippocampal long-term potentiation in adult rats.

Investigated the effects of early malnutrition on the ability to establish and maintain hippocampal long-term potentiation (LTP), a relatively permanent enhancement of synaptic and cellular responses induced by high-frequency stimulation. Six control male rats and 8 previously undernourished Ss were used in the acute preparation, and 4 controls and 6 previously undernourished Ss in the chronic preparation. Following high-frequency stimulation of hippocampal dentate granule cells, potentiation was difficult to achieve in undernourished Ss. LTP showed a significant decline within 3–6 hrs and was completely absent at 24 hrs. Further trains of stimulation resulted in only small benefits in undernourished Ss. Coupled with previously reported morphological and behavioral deficits, these findings indicate a marked hippocampal dysfunction resulting from early undernutrition and provide a potentially valuable approach for relating nutritionally induced behavioral impairments to brain function. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intersensory experience and early perceptual development: Attenuated prenatal sensory stimulation affects postnatal auditory and visual responsiveness in bobwhite quail chicks (Colinus virginianus).

Related experiments examined the effects of attenuated prenatal sensory stimulation on subsequent postnatal auditory and visual responsiveness in precocial bobwhite quail chicks (Colinus virginianus). Results revealed that denying quail embryos the prenatal vestibular and tactile stimulation provided by broodmates during incubation altered pre- and postnatal perceptual functioning. Chicks incubated in physical isolation during the late stages of prenatal development responded to maternal auditory cues into later stages of the postnatal period and failed to respond to maternal visual cues at ages communally incubated chicks typically display such visual responsiveness. In addition, embryos incubated in physical isolation failed to exhibit early auditory learning of an individual maternal call, a behavior reliably seen in communally incubated embryos. Taken together, these results and those from related studies indicate that a substantial decrease or increase in the range of sensory stimulation normally present in the prenatal period can result in a slowing of the rate of species specific perceptual development and suggest that some optimal range of prenatal sensory stimulation is necessary for species-typical perceptual capacities to emerge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of species identification in ducklings: XIV. Malleability of species-specific perception.

Whereas auditory self-stimulation suffices to promote the mallard duckling's selective response to the maternal call of its species, wood ducklings must hear sibling vocalizations to maintain a selective response to the maternal call of their species. The present experiment was undertaken to determine whether the wood ducklings' dependence on environmental stimulation signified that their species-specific perceptual development might be more malleable than that of the mallard ducklings. In order to examine the malleability of species-specific perceptual development, each species of duckling was exposed to the maternal call of the other species, along with sibling vocalizations from their own species, in order to see whether a preference for the alien species maternal call could be induced. Under these conditions the wood ducklings developed a preference for the mallard call over the wood duck call, but the mallard ducklings' preference for the mallard call was unaffected by exposure to the wood duck call. Therefore, as predicted, the species-specific perceptual development of wood ducklings is more malleable than that of mallard duckling. Environmental or social dependence is thus correlated with a malleable species-specific perceptual development, and effective self-stimulation is correlated with a resistance to species-specific perceptual modification. Other experimental results do suggest that self-stimulation may canalize perceptual development in mallard ducklings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of auditory cortical lesions on pure-tone sound localization by the albino rat.

Used 2-choice and 3-choice tests to evaluate the effects of bilateral auditory cortical lesions on pure-tone sound localization by 10 male albino rats. Both tests required that Ss approach a distant sound source to obtain water reinforcement. Stimuli were single noise and tone bursts, 65 msec in duration including 20-msec rise and fall times. Tone frequencies were 2, 4, 8, 16, and 32 kHz adjusted to 40 dB (sound pressure level) above the S's absolute threshold. Five Ss were tested in the 2-choice situation following bilateral ablation of auditory cortex. Some reduction in performance was observed relative to normals, but impairments were not severe. Similar results were obtained for 2 brain-damaged Ss tested in the 3-choice situation. Thus, the ability to localize sounds in space remained intact after complete destruction of auditory cortex, and there was no indication of a frequency-dependent deficit. Findings are considered in relation to the more severe deficits observed in other mammals after lesions of the auditory cortex. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intersensory redundancy facilitates prenatal perceptual learning in bobwhite quail (Colinus virginianus) embryos.

Information presented redundantly and in temporal synchrony across sensory modalities (intersensory redundancy) selectively recruits attention and facilitates perceptual learning in human infants. This comparative study examined whether intersensory redundancy also facilitates perceptual learning prenatally. The authors assessed quail (Colinus virginianus) embryos' ability to learn a maternal call when it was (a) unimodal, (b) concurrent but asynchronous with patterned light, or (c) redundant and synchronous with patterned light. Chicks' preference for the familiar over a novel maternal call was assessed 24 hr following hatching. Chicks receiving redundant, synchronous stimulation as embryos learned the call 4 times faster than those who received unimodal exposure. Chicks who received asynchronous bimodal stimulation showed no evidence of learning. These results provide the first evidence that embryos are sensitive to redundant, bimodal information and that it can facilitate learning during the prenatal period. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prenatally elevated physiological arousal interferes with perceptual learning in bobwhite quail (Colinus virginianus) embryos.

Neonatal studies suggest elevated arousal can negatively influence perceptual and cognitive processes during early development. The authors explored this issue during the prenatal period by pharmacologically elevating physiological arousal in bobwhite quail (Colinus virginianus) embryos during exposure to a maternal call, then assessing preference for the familiar call following hatching. Embryos receiving norepinephrine showed a prenatal elevation in heart rate and failed to demonstrate a preference for the familiar call following hatching. Embryos not receiving norepinephrine showed no elevation in heart rate and demonstrated a preference for the familiar call. These results indicate elevated arousal can interfere with perceptual learning during the prenatal period and provide additional evidence for an optimal window of arousal necessary to foster species-typical perceptual functioning during early development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)