Robert Lickliter

The phylogeny fallacy: Developmental psychology's misapplication of evolutionary theory

The habit of thinking about ontogeny and phylogeny as alternative means by which information is made available to the developing individual has a long history in both biology and psychology. This article examines existing proximate (ontogenetic) and ultimate (preontogenetic) approaches to the study of human development and describes an alternative, developmental systems approach for directing research programs. On this view, phenotypes are not simply transmitted in the genes, nor are they contained in features of the environment. Rather, traits or characters are always constructed by the complex coaction of organic, organismic, and environmental factors operating during individual ontogeny. This expanded, systematic view of heredity and phenotypic development serves to eliminate the need for the dichotomization of developmental explanations into proximate and ultimate causes and directs research attention to the organism-context transaction process, thereby including a large class of variables typically omitted from preontogenetic explanations of development.

Order-dependent timing of unimodal and multimodal stimulation affects prenatal auditory learning in bobwhite quail embryos

This study examined the relationship between unimodal and multimodal sensory stimulation and their effects on prenatal auditory learning in bobwhite quail embryos. Embryos exposed to a maternal call in the 24 hr prior to hatching (unimodal condition) significantly preferred this familiar call over an unfamiliar call in postnatal testing, but failed to demonstrate this preference when the maternal call was presented concurrently with non-synchronized patterned light (multimodal condition). To further explore this interference effect, we provided one group of embryos concurrent exposure to a maternal call and patterned light for 12 hr followed by 12 hr exposure to the call alone (multimodal-->unimodal call). This group failed to prefer the familiar call during postnatal testing. In contrast, reversing the order of presentation during prenatal exposure (unimodal call-->multimodal) led a second group of subjects to significantly prefer the familiar call, suggesting that the order-dependent timing of sensory stimulation can significantly impact prenatal auditory learning. Experiment 3 examined the influence of modality versus timing of sensory stimulation on prenatal auditory learning by providing three groups of embryos with exposure to a maternal call during the 12 hr prior to hatching and by varying the duration of visual stimulation. Results indicate that 12 hr unimodal exposure to patterned light does not support prenatal auditory learning when it is followed by 12 hr exposure to multimodal stimulation (light-->multimodal), but can facilitate prenatal auditory learning when it is followed by unimodal exposure to the call alone (light-->call). Results are discussed in terms of intersensory relationships during perinatal development.

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 intersensory and intersensory interference.

Enhanced prenatal auditory experience facilitates species-specific visual responsiveness in bobwhite quail chicks (Colinus virginianus)

Premature stimulation of a later developing sensory system is known to impact the functioning of earlier developing sensory systems. For example, exposure to premature (prenatal) visual experience results in a decline in species-typical auditory responsiveness in several precocial bird species. The present study examined the influence of experiential enhancement of an earlier developing sensory system on a later developing modality. Specifically, the influence of enhanced prenatal auditory stimulation on subsequent postnatal auditory and visual functioning of bobwhite quail (Colinus virginianus) chicks was assessed. Results indicate that birds receiving exposure to increased amounts of unaltered, species-typical embryonic vocalizations before hatching show species-typical auditory responsiveness at both 12 hr and 24 hr after hatching, but exhibit an accelerated pattern of species-typical visual responsiveness by 24 hr of age. These findings suggest that enhancement of an earlier developing sensory system can facilitate the development of a later developing sensory system and serve to demonstrate the dynamic nature of early perceptual organization.

Premature visual experience facilitates visual responsiveness in bobwhite quail neonates

Abstract Exposing precocial avian neonates to premature (prenatal) visual experience appears to accelerate postnatal intersensory functioning. For example, bobwhite quail chicks who received patterned visual stimulation as embryos require auditory and visual cues to direct their filial behavior earlier in postnatal development than do normally reared chicks. The mechanism(s) for this alteration in perceptual organization has, however, not been investigated. The present study examined whether accelerated postnatal intersensory functioning is the result of reduced species-specific auditory responsiveness and/or enhanced postnatal visual responsiveness. Results revealed that bobwhite quail embryos exposed to unusually early visual stimulation do not show reduced auditory responsiveness in the period immediately following hatching but do exhibit an accelerated pattern of species-typical visual functioning. Specifically, chicks who experienced patterned light during the last 24 to 36 hours prior to hatching were able to use visual cues to direct their species-specific social preferences earlier in postnatal development than were control chicks. This finding suggests that one result of unusually early visual stimulation is that subsequent behavior is organized to include the earlier-than-normal sensory information.

Prenatal visual experience alters postnatal sensory dominance hierarchy in bobwhite quail chicks

Abstract Work with a variety of precocial animal infants has demonstrated a hierarchy in the functional priority of the auditory and visual systems in the period following birth or hatching with infants initially utilizing auditory rather than visual cues to direct their early perceptual and social preferences. This experiment utilized bobwhite quail embryos and hatchlings to examine whether this pattern of early sensory dominance is influenced by the nature of prenatal sensory experience. Results revealed that bobwhite quail chicks that received unusually early (prenatal) visual experience demonstrate an altered pattern of postnatal sensory dominance but only under specific conditions. Whereas these chicks continued to prefer maternal auditory cues over visual cues when the maternal visual cues provided were motionless, chicks that received prenatal visual experience preferred maternal visual cues over auditory cues by 96 hours of postnatal age when the visual cues provided were kinetic. These results emphasize the importance of considering both extra- and intraorganismic variables when characterizing the nature of early perceptual organization.

Type of prenatal sensory experience affects prenatal 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.

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.

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.

Prenatal Experience and Postnatal Perceptual Preferences: Evidence for Attentional-Bias in Bobwhite Quail Embryos (Colinus virginianus)

Previous studies have indicated that concurrent multimodal sensory stimulation can interfere with prenatal perceptual learning. This study further examined this issue by exposing 3 groups of bobwhite quail embryos (Colinus virginianus) to (a) no supplemental stimulation, (b) a bobwhite maternal call, or (c) a maternal call paired with a pulsating light in the period prior to hatching. Experiments differed in terms of the types of stimuli presented during postnatal preference tests. Embryos receiving no supplemental stimulation showed no preference between stimulus events in all testing conditions. Embryos receiving exposure to the unimodal maternal call preferred the familiar call over an unfamiliar call regardless of the presence or absence of pulsating light during testing. Embryos exposed to the call-light compound preferred the familiar call only when it was paired with the light during testing. These results suggest that concurrent multimodal stimulation does not interfere with prenatal perceptual learning by overwhelming the young organisms limited attentional capacities. Rather, multimodal stimulation biases what information is attended to during exposure and subsequent testing.