Motherese

Characteristics Higher pitch Exaggerated pitch excursions Sometimes slower in tempo More repetition Simplified sentence structure Simplified vocabulary

Universal or Culture-Specific? Found in nearly every culture/language –May not be as exaggerated in every culture (Schiefflin & Ochs; Fernald) –May not be specifically directed at infants in Quiche-Mayan (Pye) –May not be delivered by parents (Bryce-Heath) But, something like motherese almost everywhere

Often accompanied by special body movements (Sullivan & Horowitz) And facial expressions

Infant directed facial expressions Chong, Werker, Russel, & Martin, 2003

More on Universality Used not just by mothers, but also by fathers Even used by children as young as age 3 –Some suggest calling it “Parentese” –Others, “Infant directed Talk” (IDT) Diminished in depressed parents

What is the function of IDT? Several Hypothesese: –To attract infant attention –To facilitate establishment of an emotional bond between parent and infant –To modulate infant affect –To facilitate language development

Research to date IDT does attract infant attention –Brief review of research –Wiley’s 4 features that increase signal detection Redundancy, conspicuousness as in exaggerations, small repertoire, alerting components as in “Hiiii sweetie” IDT does modulate arousal effectively Hard to establish if plays a role in establishment of attachment relation, but all research consistent Role in language development more controversial

Possible impact of IDT in language acquisition Acquisition of syntax –Simplified syntax, highlights Acquisition of vocabulary –Simplified vocabulary, more repetition, new words stressed, and at ends of utterances Phonological (or perceptual ) bootstrapping –IDT highlights clause and phrase boundaries –Facilitates word segmentation

Fernald Model Intrinsic perception and effective salience –attentional salience Modulation of attention, arousal, & affect –modulation of affect Communication of intention and emotion –like a proto-language; primitive sound-meaning correspondences –English infants differentiate message in most languages Acoustic highlighting of words –facilitation of language acquisition (word learning)

Where did IDT come from? Learned? Part of our basic biology? –Darwin (1872), “sweet to the ear of the species” The Expression of the Emotions in Man & Animals Evolved as part of language? Evolved separately? –Bowlby, Ainsworth, part of the attachment (proximity) system

Constructs in the Fernald Paper Evolution selected IDT, but not directly IDT likely first a non-signalling behaviour that was then “exapted” for signalling Exaptation: “adoption of a character that had one use in an ancestral form into a new, different use in a descendant form ” Can still be “adaptive” however, as once in place, selective pressure can modify it to make it more optimal for its new function

IDT as a parenting behaviour Argues IDT “exapted” from primate vocalizations as a species-specific parenting behaviour Outlines why it is an effective parenting behavior Argues adaptive because increases survival not only in infancy period, but via state regulation early, increases fitness later in life as well

A second exaptation? Fernald talks about primate vocalizations being exapted for human parenting behaviours But claims IDT plays a rrole in language acquisition Should she discuss a second exaptation here?

Discrete vs. Graded vocalizations Discrete vocalizations: Non-overlapping acoustic characteristics, as in bird calls Graded: considerable acoustic variability within a vocalization category, and may even overlap in features with other categories Human vocalizations tend to be graded, BUT Our perceptual systems impose categories on phonetic information (categorical perception of speech) But allow continuous, graded signal in affect

Further thoughts Function of ID speech Is it necessary for affective development? Is it for language development? Similarity between ID speech and music?