Music Perception Among Infants Notes

Changes to a repeating tonal pattern can introduce novelty through pitch alteration, creating two potential sources of change for infants:
- The new pitch itself.
- A new melodic interval defined by the relationship between the new pitch and the preceding one.
Challenge: Determining which change (pitch or interval) infants notice when they turn their heads in response.
Solution: Carefully planned studies, such as repeating the pitch interval C4-G4 (perfect fifth) five times, then changing it to C4-F4 (perfect fourth).
- Head-turning could indicate detection of change in interval size or pitch.
- To isolate sensitivity to relative pitch, present repeated tone sequences in transposition.

Used to determine which melodic intervals are easy or difficult to process and remember.
Easy intervals: Infants show head-turning responses when changes are introduced, indicating sensitivity.
Difficult intervals: Infants unable to form a stable representation; changes go unnoticed, no head-turning.

Method: Letting infants "select" music by looking toward loudspeakers.
- Looking left: Hears one type of music.
- Looking right: Hears another type.
- Infant controls what they hear by gaze direction.
Counterbalancing: Important due to rightward gaze bias.
- Half hear Piece A on left, Piece B on right; other half reverses.
Results: Infants have natural preferences for certain musical sounds.
- Predispositions are overlaid with learning and enculturation.
- Early preferences significantly affect music experiences into adulthood.
- Example: Jazz musicians may prefer dissonant chords over simple major chords.

Children learn to understand spoken language and appreciate music of their culture.
Sensitive periods: Developmental stages when certain language elements are most readily acquired.
Once a sensitive period passes, the brain is less suited to process relevant information.
Skills taught after a sensitive period require conscious effort and are rarely as good as those acquired within the period.
Question: Are there sensitive periods for music elements?
Musical structure dimensions:
- Pitch structure: Pitch, contour, scales, harmony, tonality.
- Temporal structure: Rhythm, metrical structure, grouping structure.
Universal musical structures are acquired earlier.
- Reflect basic auditory system capabilities (e.g., pitch perception).
Less universal structures vary by culture, are harder to learn, and acquired later.

Infants perceive and remember melodies before age one but are not sensitive to precise pitch changes.
Primarily notice whether melody goes up or down in pitch (melodic contour).
Contour changes are highly noticeable; changes in absolute pitch or interval size often go unnoticed.
Sensitivity to contour is present at birth or congenital.
With experience, children develop the capacity to perceive precise intervals.
Why are infants more sensitive to contour?
- Contour is a simple description, easy to perceive and remember.
- Perceptual analysis begins with coarse descriptions, detailed descriptions require more experience.
- Adults with little musical experience also remember novel melodies primarily by contour.
Infants may have heightened sensitivity to pitch contour due to its adaptive significance in speech.
- Mothers use exaggerated intonation patterns (infant-directed speech or motherese).
- Infants prefer infant-directed speech, implying sensitivity to tone of voice or speech prosody.

Differs from adult-directed speech.
Functions as a primitive communication system.
Each pitch contour is associated with a unique communicative aim (approval, comfort, attention, emotion, warning).
Structure is similar across cultures.
Implications of early sensitivity to contour patterns in speech:
- Enhances bonding between infants and caregivers.
- Facilitates language acquisition by providing emotional context, drawing attention to word boundaries, and signaling semantic novelty.
Our perceptions and experiences of music may be shaped by a predisposition specialized for speech.

Distinguishing consonance and dissonance is basic to music experience.
Consonant events: Warm, peaceful, harmonious, sense of resolution and relaxation.
Dissonant events: Tension, edginess, discord.
Composers use consonance and dissonance to create tension and relaxation.
This creates an emotional story or narrative and is a basic dimension of aesthetic response to music.
Infants and adults are highly sensitive to the difference between consonant and dissonant sounds.

Infants have a natural ability to discriminate tone combinations based on consonance or dissonance.
Consonant intervals are easier to process.
Analogy: Discriminating words in one's own language vs. an unfamiliar language.
Processing advantage for consonant intervals seen from six months of age to adulthood.
Schellenberg and Trainor (1996) study:
- Seven-month-olds and adults presented with background of simultaneous fifths.
- Discriminated from tritone or fourth.
- Fifths and fourths are consonant; tritones are dissonant.
- Fifth and tritone were better discriminated than fifth and fourth.
- Dissonance of tritone made it stand out; consonance of fourth made it sound similar to fifth.
Capacity to differentiate consonance and dissonance is not unique to humans.
Nonhuman animals can differentiate consonant and dissonant tone combinations.
Sensitivity arises as a natural consequence of peripheral auditory mechanisms in mammals.
Distinction between consonance and dissonance has a psychoacoustic basis (as outlined in Chapter 3).
Consonant intervals consist of notes that have simple ratios of frequencies.

Williams Syndrome (WMS) is a developmental disorder occurring in about one out of 20,000 births.
Characterized by deficits in spatial, quantitative, and reasoning abilities, and an "elfin" physical appearance.
Cognitive traits spared/heightened in WMS:
- Rich, colorful, and creative use of vocabulary.
- Abilities in music perception and production.
WMS individuals often exhibit attraction to broadband noise (e.g., appliance motors, helicopters).
- Some can identify makes and models of cars and vacuum cleaners by motor sound.
WMS individuals may display a musical precocity that is fundamentally creative.
Echo clapping task study (Levitin & Bellugi, 1998):
- WMS participants as accurate as controls.
- "Errors" in reproduction in WMS group tended to be creative elaborations preserving pulse and meter.