THE EFFECT OF PRENATAL SENSORY STIMULATION ON PERCEPTUAL NARROWING IN BOBWHITE QUAIL NEONATES Briana O’Dowd

INTRODUCTION The seemingly effortless and reliable emergence of species-typical perceptual preferences and behaviors has long been attributed to “hard-wired” genetic predispositions ▫Lorenz’s filial imprinting ▫Chomsky’s language acquisition device Beginning with the work of Gottlieb, we see that these processes are the result of probabilistic epigenesis ▫An organism within a particular ontogenetic niche develops in a particular predicable way

INTRODUCTION Alterations to the perinatal environment have demonstrated remarkable changes in species-typical auditory preferences ▫Sensory deprivation (Gottlieb, 1971, 1978, 1984; Gottlieb & Vandenbergh, 1968)  Self  Conspecifics ▫Passive auditory exposure (Lickliter, Bahrick, & Honeycutt, 2002, 2004; Vaillant, 2012)  Unimodal  Multimodal ▫Contingent training (Harshaw & Lickliter, 2010)  Vocalization for auditory response

INTRODUCTION Previous paradigms have largely focused on how environmental stimulation promotes progressive sensory development Perceptual narrowing, a regressive process, describes how environmental stimulation affords sensory specialization, at the expense of complete sensitivity ▫Based on probabilistic experiences

PERCEPTUAL NARROWING & THE DEVELOPMENT OF SPECIES TYPICAL PREFERENCES TIME Early Range of PerceptionExperienceNarrowed Range Species Typical Preference (Bobwhite) Species Typical Experience (Bobwhite) Broad Sensitivity *with a bobwhite quail chick

PERCEPTUAL NARROWING & THE DEVELOPMENT OF SPECIES TYPICAL PREFERENCES TIME Early Range of PerceptionExperienceNarrowed Range Species Atypical Preference (Japanese Quail) Species Atypical Experience (Japanese Quail) Broad Sensitivity *with a bobwhite quail chick

PERCEPTUAL NARROWING & THE DEVELOPMENT OF SPECIES TYPICAL PREFERENCES TIME Early Range of PerceptionExperienceNarrowed Range Decreased Specialization (No preference) Diverse Experience Broad Sensitivity *with a bobwhite quail chick

INTRODUCTION Perceptual narrowing ▫Domain general (Lewkowicz & Ghazanfar, 2009; Scott, Pascalis, & Nelson 2007)  Across sense modalities  Across individual properties of sensation  Multisensory processing ▫Bidirectional (Conboy, Brooks, Meltzoff, & Kuhl, 2008; Rivera-Gaxiola, Silva-Pereyra, & Kuhl, 2005; Scott, Shannon, & Nelson, 2006)  Experience changes neurophysiology  Neural pruning effects sensory discrimination ▫Malleable (Kuhl, Tsao, & Liu, 2003)  Can be delayed

INTRODUCTION Humans ▫The human fetus can exhibit physiological responses in response to changes in maternal speech (DeCasper, Lecanuet, Busnel, Granier- Deferre, & Maugeais, 1994) ▫6-month old infants can make non-native phoneme discriminations; an ability that is lost by 12 months (Werker & Tees, 1984) ▫Infants born prematurely display altered patterns of auditory perceptual narrowing – making non-native phoneme distinctions much later (Jansson-Verkasalo, Ruusuvirta, Huotilainen, Alku, Kushnerenko, Suominen et al, 2010; Krueger, Holditch-Davis, Quint, & DeCasper, 2004)  This predicts future difficulty in language acquisition

INTRODUCTION Avian species ▫Avian species share certain neurophysiological and developmental parallels to humans when comparing birdsong & human language development (Doupe & Kuhl, 1999) ▫Precocial avian species provide additional benefits in the study of prenatal sensory development

INTRODUCTION Avian Species ▫Domestic chicken embryos given auditory enrichment displayed altered levels of proteins associated with neural survival, dendritic arborization, and the regulation of synaptic strength (Chaudhury & Wadhwa, 2009) ▫Bobwhite quail embryos exposed to passive auditory stimulation are able to make nuanced distinctions in the modality specific properties of maternal call variants (Vaillant, 2012) ▫Bobwhite quail embryos exposed to redundant auditory/visual stimulation demonstrate enhanced perceptual learning and memory of a maternal call (Lickliter, Bahrick, & Honeycutt, 2002, 2004)

INTRODUCTION Intersensory Redundancy ▫Intersensory redundancy & perceptual narrowing both draw on rich, socially-derived stimulation ▫Both human infants and precocial birds have demonstrated altered discrimination and retention when exposed to multimodal stimulation (Bahrick & Lickliter, 2000; Lickliter, Bahrick, & Honeycutt, 2004)  Multimodal redundant stimulation – amodal properties  Unimodal stimulation – modality specific properties ▫It is unclear what stimulus properties early perceptual narrowing may be more sensitive to

STUDY AIMS Can diverse and prolonged prenatal auditory enrichment delay the emergence species-typical auditory preferences? What type of sensory information (amodal or modality specific) may contribute more to auditory perceptual narrowing during prenatal development?

HYPOTHESES Experiment 1 ▫Hypothesis 1: Bobwhite quail embryos exposed to a soundtrack of several different species of quail will not demonstrate a preference for any call at 24 hours following hatching. ▫Hypothesis 2: Quail chicks originally exposed to the “Quail Mix” prenatally will, after accruing experience postnatally, develop a species typical auditory preference by 48 hours following hatching.

HYPOTHESES Experiment 2 Hypothesis 3A: Bimodal synchronous stimulation will facilitate learning of the amodal properties (tempo, intensity, rhythmic pattern) of the “Quail Mix” audio. If perceptual narrowing occurs primarily via amodal properties, quail embryos receiving the bimodal synchronous presentation of the quail mix will not show a preference for a species-typical call at 24 hours postnatal. ▫Hypothesis 3B: Bimodal synchronous stimulation will disrupt learning of the modality-specific properties (pitch, tone, timbre) of the “Quail Mix” audio. ▫ If perceptual narrowing occurs primarily via modality-specific properties, quail embryos receiving the bimodal synchronous presentation of the quail mix should show a preference for a species-typical call at 24 hours postnatal.

HYPOTHESES Hypothesis 4: If perceptual narrowing occurs through discrimination of amodal properties (tempo, rhythm), quail chicks receiving synchronous bimodal stimulation will remain without a preference for the species-typical call at 48 hours postnatal, an additional 24 hours compared to unimodal conditions.

METHOD Subjects: ▫360 bobwhite quail chicks Postnatal Age Condition24 Hours48 Hours Unimodal “Quail Mix” (Audio Only)30 Bimodal Synchronous “Quail Mix”30 Bimodal Asynchronous “Quail Mix”30 Bobwhite Audio30 Japanese Quail Audio30 Control (no manipulated stimuli)30 Total 360

METHOD Prenatal Procedure:  Eggs will be transferred out of the main incubator on day 15 (of 23) of incubation  Eggs will be set in a small Styrofoam incubator in a sound and light attenuated room  Eggs receiving exposure will receive stimulation 10 minutes per hour; 24 hours/day; for the remaining incubation duration  9 total days of passive stimulation

METHOD Procedure: ▫Prenatal Stimulation Bimodal Synchronous (Quail Mix)

METHOD Postnatal testing:  Chicks will be tested individually either at 24 or 48 hours of age  Chicks will be placed in a circular arena with two semicircular approach areas  Each approach area comprises 5% of the arena’s surface ▫Bobwhite Maternal Call ▫Japanese Quail Maternal Call  Calibrated to 65DB  Each trial will be 5 minutes long

METHOD Testing Arena start

DATA ANALYSIS Data will be collected using a computer tracking software Preference will be measured by a Proportion of Total Duration (PTD) score ▫PTD = Time spent in proximity to bobwhite call Total time spent in proximity to both calls

DATA ANALYSIS The PTD score will be used to measure preference ▫The PTD score of each group will be tested using a one-sample t-test against a value of.5 (chance) ▫The PTD scores of each condition will be tested against each other using one-way Analysis of Variance (ANOVA), with separate analysis run at each time point

PRELIMINARY DATA * ** * * †

SIGNIFICANCE Adding to the existing, but small literature on perceptual narrowing ▫Can postponing perceptual narrowing through auditory enrichment delay species-typical auditory preferences from emerging? ▫What are the effects of redundancy on perceptual narrowing? Enhancing the existing model of how prenatal experience contributes to species-typical auditory preferences ▫Including both progressive & regressive mechanisms ▫No excuse make “innate” attributions Knowing what kind of sensory enrichment can alter the perceptual narrowing window could help inform care of preterm human infants ▫What kind of stimulation is most effective

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