Premature visual stimulation accelerates intersensory functioning in bobwhite quail neonates

Recent evidence from both altricial and precocial neonates suggests that premature stimulation of a later developing sensory system may alter the functioning of earlier developing sensory systems. The present study examined the influence of prenatal visual stimulation on postnatal auditory functioning in precocial bobwhite quail chicks. Hatchlings that experienced patterned light during the 24-36 hr prior to hatching did not exhibit a naive auditory preference for their species-specific maternal call at 24 hr or 48 hr following hatching, a reliable phenomenon in chicks not receiving embryonic visual stimulation. To examine whether this lack of responsiveness resulted from enhanced intersensory functioning, hatchlings were tested for preference for both auditory and visual features of the bobwhite hen. Results indicate that prematurely stimulated chicks require species-typical auditory and visual stimulation earlier in postnatal development than do normally reared chicks to direct their filial behavior. These findings point to the importance of normally occurring developmental limitation of sensory input to early species-typical sensory/perceptual organization.     

Prenatal visual experience influences the development of turning bias in bobwhite quail chicks (Colinus virginianus)

This study examined the effects of prenatal sensory experience on the development of turning bias in a precocial avian species (bobwhite quail). Control tests with naive bobwhite quail chicks revealed a left-side turning bias in 85% of subjects. Such large population biases are considered unusual in nonhuman species. Experiments 1, 2, and 3 demonstrated that prenatal visual experience is a significant contributor to this population level left-side turning bias in bobwhite quail chicks. In contrast, prenatal auditory experience did not appear to significantly influence the development of postnatal turning bias. The findings of this study are discussed in terms of an epigenetic theory for the development of hemispheric specialization and behavioral asymmetry. © 1998 John Wiley & Sons, Inc. Dev Psychobiol 32: 327–338, 1998     

Intersensory functioning in bobwhite quail chicks: early sensory dominance

Two sensory systems known to be important for the control of early filial behavior in precocial avian neonates are the auditory and visual modalities. This study examined the interaction between naturally occurring auditory and visual stimulation in the control of filial behavior in bobwhite quail (Colinus virginianus) during the first four days of postnatal development. Results revealed a hierarchy in the functional priority of the auditory and visual systems in the days immediately following hatchling. At one and two days of age, species identification in quail hatchlings was found to depend on the auditory component of maternal stimulation. Later in development (at three and four days of age), combined auditory-visual stimulation was necessary to control species-specific filial behavior. Even at these later stages of development, however, the auditory modality remained dominant over the visual in eliciting responsiveness to the maternal hen. These findings conform well to what is known about the neuroembryological development of the sensory systems, in that the auditory system of birds (and mammals) develops in advance of the visual system. This prenatal sequence of sensory system development appears to influence the nature of early postnatal perceptual preferences and serves to question several traditional assumptions regarding the imprinting process.     

Augmented prenatal visual stimulation alters postnatal auditory and visual responsiveness in bobwhite quail chicks

This study examined whether previously reported effects of altered prenatal sensory experience on subsequent acceleration of intersensory development in precocial birds are mediated by mechanisms sensitive to the overall amount of stimulation provided. Results revealed that bobwhite quail chicks exposed to substantially augmented amounts of prenatal visual stimulation show altered patterns of species-typical perceptual development. Specifically, chicks continued to respond to maternal auditory cues into later stages of postnatal development and failed to demonstrate responsiveness to maternal visual cues. Embryos also failed to demonstrate prenatal auditory learning of an individual maternal call, a behavior reliably seen in unmanipulated embryos. These findings suggest that substantially increased amounts of prenatal sensory stimulation can interfere with the emergence of species-typical patterns of postnatal intersensory functioning and lend support to the notion that sensory stimulation that falls within some optimal range maintains or facilitates normal patterns of perceptual development, whereas stimulation beyond the range of the species norm can result in intersensory interference. © 1995 John Wiley & Sons, Inc.     

Specific postnatal auditory stimulation interferes with species-typical visual responsiveness in bobwhite quail chicks

The effects that a manipulation of sensory experience may have on perceptual development are likely to depend on a number of factors, including the amount and the type of stimulation provided. To examine the relative influence of these stimulation factors on early perceptual organization, this study exposed bobwhite quail hatchlings to augmented amounts of bobwhite chick distress calls, bobwhite chick contentment calls, domestic chicken distress calls, or no additional auditory stimulation during the first 72 hr following hatching. Results showed that bobwhite hatchlings exposed to bobwhite chick distress calls do not exhibit species-typical visual responsiveness to maternal cues. In contrast, bobwhite hatchlings exposed to bobwhite chick contentment calls, domestic chicken hatchling distress calls, or no agumented auditory stimulation exhibited species-typical auditory and visual responsiveness to maternal cues. These results demonstrate intermodal effects of postnatal sensory stimulation and suggest that specific types of postnatal auditory stimulation, rather than simply increased amount of stimulation, are necessary to interfere with species-typical intersensory functioning.© 1994 John Wiley & Sons, Inc.     

Augmented prenatal tactile and vestibular stimulation alters postnatal auditory and visual responsiveness in bobwhite quail chicks.

The fact that the sensory systems do not become functional at the same time during early development raises the question of how sensory systems and their respective stimulative histories might influence one another. Previous studies have shown that unusually early visual experience can alter subsequent responsiveness of both the visual system and the earlier developing olfactory and auditory systems. The question remains as to the extent which modified stimulation to an earlier developing system can also result in changes in responsiveness in later developing sensory systems. This study examined the effects of augmented prenatal tactile and vestibular stimulation on bobwhite quail chicks' postnatal visual and auditory responsiveness to maternal cues. Results indicate that augmented prenatal tactile and vestibular stimulation can alter postnatal perceptual responsivensss in the later developing auditory and visual sensory systems. Chicks exposed to augmented prenatal proximal stimulation continued to respond to maternal auditory cues into later stages of postnatal development and failed to demonstrate responsiveness to maternal visual cues in the days following hatching. However, augmented tactile and vestibular stimulation did not appear to affect prenatal auditory learning of an individual maternal call. These findings indicate a strong but selective pattern of influence between the sensory modalities during the prenatal period and support the view that substantially increased amounts of prenatal sensory stimulation can interfere with the emergence of species-typical perceptual functioning.     

Duration of early visual experience and visual cliff behavior of chicks.

Visual cliff behavior was studied in 120 chicks as a function of 22, 46, 70, 94, or 118 hr of rearing in a deep or shallow environment. Preference for the deep side of the visual cliff increased directly with duration of depth-rearing but was uninfluenced at any duration of shallow-rearing. Although qualitative differences existed in the behaviors of those shallow- and deep-reared chicks which crossed the cliff, the loss of depth avoidance by the latter group appeared to be specific to the rearing and testing apparatus.     

Effects of prenatal visual stimulation on growth and heart rate in bobwhite quail (Colinus virginianus)

This study examined the effects of prenatal visual stimulation on bobwhite quail embryos' growth and heart rate. No differences in growth rate were found between embryos exposed to visual stimulation during the late prenatal period and control embryos. Embryos exposed to visual stimulation throughout incubation maintained lower heart rates in response to visual stimulation than did naïve embryos. In a subsequent experiment, naïve embryos that underwent an egg‐opening procedure exhibited heart rates that were lower than embryos measured in intact eggshells. Embryos in opened eggs maintained lower heart rates than comparison embryos across time; however, a less invasive egg‐opening procedure led to a quicker heart rate recovery than did a more invasive egg‐opening procedure. These findings indicate that prenatal heart rate responses may be mediated by multiple features of the organism's developmental context, including intensity and duration of sensory stimulation. © 2006 Wiley Periodicals, Inc. Dev Psyshobiol 48: 315–324, 2006.     

Intersensory experience and early perceptual development: The role of spatial contiguity in bobwhite quail chicks' responsiveness to multimodal maternal cues

In contrast to the large body of work on young infants' capacity to perceive temporarilly based intersensory relations, little research has been done on the role of spatial contiguity in the development of audio-visual integration. This study examined the effects of early postnatal sensory experience on an avian neonate's responsiveness to the spatial contiguity between maternal auditory and visual cues. Specifically, we assessed whether a bobwhite quail chick's ability to respond to the correspondence between the location of auditory and visual events is affected by its sensory-stimulation history. Results revealed that chicks denied species-typical auditory or visual experience in the period immediately following hatching showed altered patterns of responsiveness to maternal auditory and visual cues. In particular, chicks that received modified postnatal sensory experience demonstrated a higher tolerance for audio-visual spatial discrepancy than did control chicks. These results provide evidence of the important role of sensory experience in the emergence of intersensory integration during the perinatal period and highlight the role of spatial information in early perceptual responsiveness to maternal cues. © 1996 John Wiley & Sons, Inc.     

Augmented prenatal auditory stimulation alters postnatal perception,arousal, and survival in bobwhite quail chicks

This study examined whether previously reported effects of altered prenatal sensory experience on subsequent acceleration of intersensory development in precocial birds are mediated by mechanisms sensitive to the overall amount of stimulation provided. Results revealed that bobwhite quail chicks exposed to substantially augmented amounts of prenatal auditory stimulation show altered patterns of species-typical perceptual development. Specifically, chicks continued to respond to maternal auditory cues into later stages of postnatal development and failed to demonstrate responsiveness to maternal visual cues. In addition, embryos exposed to substantially augmented amounts of prenatal auditory stimulation exhibited a higher level of behavioral arousal and higher mortality rates than embryos provided either moderately augmented amounts or no additional amount of prenatal auditory stimulation. These findings suggest that substantially increased amounts of prenatal sensory stimulation can interfere with the emergence of species-typical patterns of postnatal perceptual functioning and lend support to the notion that sensory stimulation that falls within some optimal range maintains or facilitates normal patterns of perceptual development, whereas stimulation beyond the range of the species norm can result in intrasensory and intersensory interference. © 1997 John Wiley & Sons, Inc. Dev Psychobiol 30: 201–212, 1997     

Role of motor and visual experience during development of bipedal locomotion in chicks

The purpose of this research was to investigate the role of motor and visual experience during the development of locomotion in chicks. We have previously demonstrated that when locomotor activity is restricted immediately posthatching, chicks walk with shorter stride lengths and attenuated head bobbing movements. Head bobbing is an optokinetic response in birds, driven by the movement of the visual world across the retina (i.e., optic flow). During locomotion, optic flow is generated by forward translation, and we have shown that the magnitude of head bobbing movements and stride lengths are moderately correlated in walking chicks. In the present study, we investigated this relationship more closely by examining whether imposed changes in stride length could affect head excursions during head bobbing. We manipulated stride length by hobbling chicks immediately after hatching and subsequently quantified kinematic parameters, including step timing and head excursions, during walking. Imposition of shorter stride lengths induced chicks to take more frequent steps, spend less time in contact with the ground, and shortened head excursions during head bobbing. Nevertheless, the developmental changes in head excursions were not fully accounted for by altered stride lengths, so in a separate experiment, we investigated whether the development of head bobbing relies on the normal experience of optic flow. We raised chicks under stroboscopic illumination to eliminate chicks' experience of optic flow but found that this did not significantly alter head bobbing. These results are discussed along with related findings in other species and the possible neural and biomechanical constraints underlying development of walking and head bobbing in birds.     

Prenatal exposure to temporal and spatial stimulus properties affects postnatal responsiveness to spatial contiguity in bobwhite quail chicks

Little is known about how experiential factors guide and organize the development of intersensory perception. This study manipulated the amount of late prenatal and early postnatal experience with the temporal synchrony and spatial contiguity of audio-visual stimulation available to bobwhite quail embryos and hatchlings to explore this question. Results revealed that only embryos exposed to temporally synchronous and spatially contiguous audio-visual stimulation prior to hatching subsequently preferred spatially contiguous audio-visual maternal information following hatching, despite being denied postnatal visual experience. In contrast, embryos that did not receive exposure to both temporal synchrony and spatial contiguity (and were also denied postnatal visual experience) failed to show a preference for the spatial contiguity of maternal auditory and visual information following hatching. These results suggest that prenatal exposure to the amodal properties of temporal synchrony and spatial contiguity facilitate chicks' emerging sensitivity to the spatial contiguity of audio-visual information in the period following hatching.     

Effects of redundant and nonredundant bimodal sensory stimulation on heart rate in bobwhite quail embryos

Research with both animal embryos and human infants has provided evidence that information presented redundantly and in temporal synchrony across sensory modalities (intersensory redundancy) can guide selective attention, perceptual learning, and memory during early development. How this facilitation is achieved remains relatively unexamined. This study examined the effects of redundant versus nonredundant bimodal stimulation on a measure of physiological arousal (heart rate) in bobwhite quail embryos. Results show that quail embryos exposed to concurrent but nonredundant auditory and visual stimulation during the late stages of incubation exhibit significantly elevated heart rates following stimulus exposure and during stimulus reexposure when compared to embryos exposed to redundant and synchronous audiovisual stimulation, unimodal auditory stimulation, or no supplemental prenatal sensory stimulation. These findings indicate a functional distinction between redundant and nonredundant bimodal stimulation during early development and suggest that nonredundant bimodal stimulation during the prenatal period can raise arousal levels, thereby potentially interfering with the attentional capacities and perceptual learning of bobwhite quail. In contrast, intersensory redundancy appears to foster arousal levels that facilitate selective attention and perceptual learning during prenatal development.     

Biased embryos: Prenatal experience alters the postnatal malleability of auditory preferences in bobwhite quail

Many precocial birds show a robust preference for the maternal call of their own species before and after hatching. This differential responsiveness to species-specific auditory stimuli by embryos and neonates has been the subject of study for more than four decades, but much remains unknown about the dynamics of this ability. Gottlieb [Gottlieb [1971]. Development of species identification in birds: An enquiry into the prenatal determinants of perception. Chicago/London: University of Chicago Press.] demonstrated that prenatal exposure to embryonic vocalizations serves to canalize the formation of species-specific preferences in ducklings. Apart from this, little is known about the features of the developmental system that serve to canalize such species-typical preferences, on the one hand, and generate novel behavioral phenotypes, on the other. In the current study, we show that briefly exposing bobwhite quail embryos to a heterospecific Japanese quail (JQ) maternal call significantly enhanced their acquisition of a preference for that call when chicks were provided with subsequent postnatal exposure to the same call. This was true whether postnatal exposure involved playback of the maternal call contingent upon chick contact vocalizations or yoked, non-contingent exposure to the call. Chicks that received both passive prenatal and contingent postnatal exposure to the JQ maternal call redirected their species-typical auditory preference, showing a significant preference for JQ call over the call of their own species. In contrast, chicks receiving only prenatal or only postnatal exposure to the JQ call did not show this redirection of their auditory preference. Our results indicate that prenatal sensory stimulation can significantly bias postnatal responsiveness to social stimuli, thereby altering the course of early learning and memory.     

The development of direction selectivity in ferret visual cortex requires early visual experience

Development of the selective response properties that define columns in sensory cortex is thought to begin early in cortical maturation, without the need for experience. We investigated the development of direction selectivity in ferret visual cortex using optical imaging and electrophysiological techniques and found an exception to this view. Unlike orientation selectivity and ocular dominance, direction selectivity was not detected at eye opening. Direction selectivity emerged several days later and strengthened to adult levels over the following 2 weeks. Visual experience was essential for this process, as shown by the absence of direction selectivity in dark-reared ferrets. The impairment persisted in dark-reared ferrets that were given experience after this period, despite the recovery of response amplitude, preference and bandwidth for stimulus orientation, spatial and temporal frequency, and contrast. Visual experience in early postnatal life plays a necessary and unique role in the development of cortical direction selectivity.     

Effects of prenatal sensory stimulation on heart rate and behavioral measures of arousal in bobwhite quail embryos

Although a number of studies have demonstrated the effects of altered prenatal experience on subsequent behavioral development, how these effects are achieved remains a topic of enduring interest. The present study examined the immediate effects of unimodal and multimodal prenatal sensory stimulation on physiological and behavioral arousal in bobwhite quail embryos. Embryos were videotaped and their heart rate was monitored during a 4-min exposure period to (a) no supplemental sensory stimulation, (b) unimodal auditory stimulation, (c) unimodal visual stimulation, (d) two sources of concurrent auditory stimulation, or (e) concurrent auditory/visual stimulation. Results indicated that quail embryos' overall activity levels and heart rate can be significantly affected by the type of prenatal sensory stimulation provided during the period prior to hatching. In particular, multimodal stimulation increased both behavioral activity levels and heart rate compared to controls. Across the unimodal and intramodal groups, however, behavioral and physiological measures revealed different patterns of activity in response to supplemental sensory stimulation, highlighting the value of using multiple levels of analysis in exploring arousal mechanisms involved in prenatal perceptual responsiveness.     

The influence of prenatal tactile and vestibular stimulation on auditory and visual responsiveness in bobwhite quail: A matter of timing

The fact that the sensory systems do not become functional at the same time during prenatal development raises the question of how experience in a given modality can influence functioning in other sensory modalities. The present study exposed groups of bobwhite quail embryos to augmented tactile and vestibular stimulation at times that either coincided with or followed the period of onset of function in the later-developing auditory and visual modalities. Differences in the timing of augmented prenatal stimulation led to different patterns of subsequent auditory and visual responsiveness following hatching. No effect on normal visual responsiveness to species-typical maternal cues was found when exposure to tactile and vestibular stimulation coincided with the emergence of visual function (Days 14-19), but when exposure took place after the onset of visual functioning (Days 17-22), chicks displayed enhanced responsiveness to the same maternal visual cues. When augmented tactile and vestibular stimulation coincided with the onset of auditory function (Days 9-14), embryos subsequently failed to learn a species-typical maternal call prior to hatching. However, when given exposure to the same type and amount of augmented stimulation following the onset of auditory function (Days 14-19), embryos did learn the maternal call. These findings demonstrate that augmented stimulation to earlier-emerging sensory modalities can either facilitate or interfere with perceptual responsiveness in later-developing modalities, depending on when that stimulation takes place.     

Effects of rearing conditions on early visual development in common marmosets

Early development of visual behavior was examined in hand‐reared (HR) and parentally reared (PR) common marmosets (Callithrix jacchus). On the day of birth, most of the marmosets exhibited sensitivity to light and sound: they closed their eyes in response to light and oriented to the sound sources. The behavior of tracking moving visual stimuli was exhibited at around 10 days postnatally in PR marmosets, but the onset of this behavior was delayed to the age of 16 days in HR marmosets. The delay occurred possibly because of the poor input of optical flow under the HR environment. The onset age of head‐cocking was about 2 weeks in both groups of marmosets, and the HR marmosets began head‐cocking and visual tracking simultaneously. Both groups of marmosets exhibited sensitivity to optical approach at the age of around 30 days: the age to wean and increase independent locomotion. The results suggested that the onset of motion perception preceded detailed shape and depth perception in marmosets, and the developmental sequence in marmosets was similar to those in humans and macaque monkeys. Marmosets appear to be useful animal models to examine environmental effects on early visual development. © 2011 Wiley Periodicals,Inc. Dev Psychobiol 54: 700–705, 2012.