perceptual development

Nativism

Perceptual abilities are inborn and lead to innate cognitive skills. 'Present at birth.'

Constructivism

Knowledge built through sensorimotor experience; infant as 'scientist.'

Neo-Constructivism

Combination: innate abilities refined through experience and interaction.

Sensorimotor Stage

Learning through action and senses; object permanence develops (0-2 yrs).

Preoperational Stage

Language and symbolic thinking (2-7 yrs).

Concrete Operational Stage

Logical reasoning about tangible objects (7-11 yrs).

Formal Operational Stage

Abstract and hypothetical thinking (12+ yrs).

Non-nutritive nipple sucking

Changes in sucking rate indicate preference or recognition.

Heart rate monitoring

Changes reflect attention/arousal.

Preferential Looking

Infants look longer at what interests them (Fantz, 1961).

Orienting & Head Turning

Used to measure hearing and discrimination.

Eye-tracking

Measures where and how long infants look.

Reaching & Grasping

Measures visual-motor coordination.

EEG & ERP

Measure brain activity in response to stimuli.

Fetal senses

Touch, hearing, taste, and smell functional by 3rd trimester.

Vision at birth

Rudimentary at birth (~8-12 inches focus range).

Reflexes

Sucking, rooting, grasping, stepping (primitive/involuntary).

Familiarity preferences

Newborns show familiarity preferences for stimuli experienced in utero (sounds, flavors).

Visual Acuity at birth

20/400-20/600 (very blurry).

Visual Acuity at 6 months

Near-adult levels (20/40).

Visual Acuity at 1 year

Full adult acuity.

Reasons for poor acuity

Immature cones and visual cortex.

Experience-dependent synaptic growth

Improves vision.

Color Vision

Develops around 2 months.

Habituation-Dishabituation method

4-month-olds could discriminate colors (e.g., 480 nm vs. 510 nm). Infants categorize hues like adults.

Fetal Hearing

Fetuses hear muffled sounds through amniotic fluid.

Familiar stories

Babies recognize familiar stories read by their mothers before birth.

Non-nutritive sucking task

Faster sucking indicates preference for familiar story, suggesting memory and learning in the womb.

Mother's voice preference

Infants prefer mother's voice over other voices.

Native language preference

Infants prefer native language over foreign.

Sucking control

Infants can control sucking to influence what they hear or see.

Mother's scent recognition

Newborns recognize mother's scent through fabric studies.

Sweet taste preference

Newborns prefer sweet tastes, linked to survival (high calories, breast milk).

Flavor preferences

Flavor preferences are shaped in utero and through breast milk.

Carrot juice study

Mothers who drank carrot juice during pregnancy had infants who later preferred carrot-flavored milk/formula.

Early flavor learning

Suggests early flavor learning and sensory memory before birth.

Touch receptors

Touch receptors form in the 2nd trimester.

Newborn touch response

Newborns show reflexive responses to touch and are sensitive to pain.

Pain relief methods

Pain relief via breast milk, anesthetics, or gentle contact.

Touch and bonding

Touch promotes bonding and releases endorphins.

Intermodal perception

Integration of multiple senses (e.g., sight and sound).

Audio-visual synchrony

Matching sounds to corresponding visuals (e.g., hammer hitting).

Kuhl & Meltzoff study

4-month-olds preferred faces that matched vocal sounds ("EEE" vs. "AHH").

Face-like configurations

Newborns prefer face-like configurations.

Top-heavy stimuli preference

Newborns prefer top-heavy stimuli (eyes/upper features).

Mother's face preference

Newborns prefer mother's face and female faces over males.

Same-race faces preference

Newborns prefer same-race faces by 3 months (familiarity).

Object permanence

Understanding that objects continue to exist even when out of sight.

Object permanence timeline

Emerges gradually between 4-12 months.

Baillargeon study

4-month-olds understand physical rules (objects can't pass through each other).

A-not-B task

Measures memory and inhibitory control; success improves with brain maturation and experience.

Peek-a-boo game

Games like Peek-a-boo reinforce permanence.

Depth perception timeline

Sensitivity to kinetic cues (motion) from birth to 1 month.

Binocular cues emergence

Binocular (stereoscopic) cues emerge at 2-3 months.

pictorial cues

Sensitivity to pictorial cues (interposition, shading, linear perspective).

Fear of heights

Fear of heights develops (Visual Cliff).

depth perception

Experienced crawlers avoid 'deep' side = depth perception.

social referencing

Fear of heights not innate—develops through social referencing (caregiver's facial expressions).

Y-junctions

3-month-olds detect Y-junctions (3D corners).

impossible cubes

4-month-olds prefer 'impossible' cubes—detect T-junction/interposition violations.

possible cubes

Newborn chicks prefer possible cubes, suggesting innate bias toward real-world shapes.

monocular cues

5-7-month-olds reach for objects appearing closer under monocular cues.

Habituation/Dishabituation

Decreased attention to repeated stimulus; renewed interest when new stimulus appears.

Visual Acuity

Sharpness of vision; poor at birth, adult-like by ~1 year.

Nativism vs. Constructivism

Debate over innate vs. learned perceptual abilities.

Fantz (1961)

Face preference.

Bornstein (1976)

Infant color discrimination.

DeCasper & Spence (1986)

Prenatal auditory memory ('Cat in the Hat').

Kuhl & Meltzoff (1982)

Audio-visual matching.

Baillargeon (1987)

Object permanence.

Gibson & Walk (1960)

Visual cliff/depth perception.

Bhatt & Bertin (2001)

3D shape perception.

Shuwairi et al. (2007)

3D shape perception.

Mennella (1990s)

Early taste learning.