Infancy: Perceptual & Cognitive Development

Week 3 | Sept 28

Concepts in Perceptual Development: Sensation

Sensory receptors detect stimulus

Receptor neurons turn it into a signal to the brain

Concepts in Perceptual Development: Perception

The psychological process of organizing and interpreting sensory input

Perception: What are the 2 methods for studying infant Perception?

• Preferential-looking tests

• Habituation-recovery tests

Who invented the looking chamber?

Robert Fantz 1960

Preferential-looking tests

Present 2 stimuli and measure attention to both

• longer looking is not preference, its surprise, pleasure, confusion

Habituation-recovery tests

Present 1 stimulus until infant gets bored

Present new stimulus and see if attention increases

• Overt behaviour & physiological measures

What are the 3 components of Baby’s Basic Perception?

1. Vision

2. Hearing

3. Tasting & Smelling

Least mature sense in newborns, yet the most studied in infant perception. What is it, and what does it include?

Vision

• Looking

• Tracking things

• Recognizing faces

What is Visual Acuity?

The ability to see fine details (clearness and sharpness)

Visual Perception: Perceptual Constancy → What is size constancy?

• Habituate to a cube (large or small)

• Show both at different distances so they look the same size

• Newborns look longer at the different size one than the one they were exposed to earlier

Visual Perception: What is Pattern Perception?

Integrate elements to perceive a pattern

(early preference for human faces and moving objects)

What is Subjective Contour? + when does it happen for infants?

Infants detect static objects defined by illusory contours

• around 7 months

What is Good Continuation?

A Gestalt principle with a natural tendency to view objects or stimuli as continuous or whole

Depth perception: Optical expansion (what and when)

Kinetic cues, looming or approaching

• 1 month

Depth perception: Stereopsis (what and when)

Binocular cues

• 4 month

Depth perception: Pictorial

Monocular cues

• 6/7 month

Who did the visual cliff experiment? What was it?

Gibson & Walk

• 2 month = detect difference

• 6 month = 90% crawled across the shallow side but not the deep side

Which bias does infants visual system have?

Biased to attend to a socially significant stimulus

A random guess about infants face preferences

Infants may look at faces because of their top-heavy features

Perceptual narrowing

A developmental process characterized by a diminished ability to distinguish among less-frequently encountered stimuli

Perceptual narrowing before 6 months old vs after 6 months old

Newborn-6 month: Can distinguish both humans and monkeys

After 6 month: Can no longer distinguish between monkeys

Hearing: quality of loudness and pitch in infants

• Better developed than vision at birth

• not adult-like until 5-8 years old

Hearing: Absolute Threshold

The minimum sound level of a stimulus required to detect a sound

Hearing: Relative Threshold

The minimum difference in loudness or pitch required to distinguish between two sounds

Speech Perception: Listening preferences for socially significant stimuli (newborns and 3 month olds)

Newborns prefer

• speech over non speech (moms voice), humans over animals

Newborns

• human sounds = animal sounds

3 month olds prefer

• species-specific (human over animal)

Taste preferences: newborns (3)

• sweet tooth

• facial expressions to bitter, sour, sweet

• mothers eating habits and early food influences preference

Smell preferences: newborns (3)

• react to unpleasant odours

• prefer milk to amniotic fluid

• recognize scent of mother

Intermodal perception

Perceives and connects information available to multiple senses simultaneously

Temporal synchrony

When different types of perceptual information occur at the same time

• creates unitary perceptual experience

Auditory-visual intermodal perception

Using hearing and sight to understand and relate stimuli

Perceptual categories (what and when?)

Physical appearance

• birds equal airplanes

7 months

Conceptual categories (what and when?)

Use and function, birds do not equal airplanes

• 9 months

What do infants categorize first: visually salient features OR conceptual criteria?

Visually salient features comes before conceptual criteria

What are the 4 stages of cognitive development within Jean Piagets theory of Cognitive Development within the Constructivist framework?

1. Sensorimotor (0-2)

2. Preoperational (2-7)

3. Concrete operational (7-12)

4. Formal operations (12+)

What are schemas like in the Sensorimotor stage?

Schemas are limited to sensory experiences and motor actions

6 Sensorimotor sub-stages

Reflexes and spontaneous movements (0-1m)

• Involuntary actions

Primary circular reactions (1-4m)

• Repeat actions immediate to their bodies

Secondary circular reactions (4-8m)

• Repeat actions to affect the external world

Coordination of secondary schemes (8-12m)

• Combining actions to achieve a goal

Tertiary circular reactions (12-18m)

• Trial and error to explore new solutions

Mental representation (18-24m)

• Hold and manipulate objects/events in mind

Sensorimotor stage: Object Permanence + when do infants gain object permanence?

The knowledge that objects continue to exist even when we cant see them

• starts around 8 months

What is the A-not-B error within object permanence? + when does it happen

The tendency to search where objects have been found rather than where they were last hidden

• 8-12 months

Deferred Imitation + when does it happen

The delayed copying of other peoples behaviour

• 8-24 months

Displaced Reference

Understand and use words to refer to things that are not present

Symbolic Play

Use actions and words in a pretend mode