Download Basic Cognitive Processes

Basic Cognitive Processes - 2
Psych. 414
Prof. Jessica Sommerville
Infant perception
• Visual perception
• Auditory perception
• Intermodal perception
Face perception
• By 3 months look longer at face than non-face, and show a
preference for familiar faces
• After 6 months face perception becomes more adult-like
– Orientation, gender, emotional expression, attractiveness
• Faces as preferred stimuli from birth?
– Preferential tracking of faces from birth
– Innate template for detecting faces based on configurational
elements
Auditory perception
• Head-turn paradigm
• HAS paradigm
Head-turn paradigm
•Hear noise
•Reinforced for turning head in particular direction
High-amplitude sucking (HAS) paradigm
• Baseline sucking
• Reinforced for increases in sucking rate
• Sucking wanes with repeated presentation
(habituation)
• Different sound: increased sucking?
Speech perception
• Preferences:
– Speech over non-speech; infant-directed speech
– Preference for mother’s voice: due to
familiarity
• From birth: Cat in the Hat study (DeCasper &
Spence, 1986; txt p. 49-50)
Speech perception
• Discriminations:
– Categorical speech perception: differences between
speech sounds are continuous -- we perceive them as
categorical
• Present in adults and infants
• Initially discriminate speech sounds across all languages
• Decline in non-native contrasts between 6 and 12 months of
age
• Matter of degree not overall loss
• Categorical perception not unique to humans or speech
Intermodal perception
• Recognition of common source of sensation;
ability to match information across senses
• Sights and sounds
– By 3 months match voice to face based on sex, age, and
mouth movements
• Sights and feels
– Match visual impression to touch by 1 month
– Imitation (at birth)
Memory development:
The traditional view
Recognition
Recall
Applying schemas to objects
Habituation/dishabituation
Requires mental representation
Deferred imitation
Operant conditioning
TIME
18 months
Recognition
• Familiarity with a reencountered stimulus
• Habituation paradigms
– Infants habituate to a repeated stimulus and dishabituate
to a novel stimulus from birth
– 5 month-olds show a novelty preference for new faces
and new objects after two weeks (Fagen, 1973; Fantz et al., 1975)
– 6 month olds remember dynamic stimulus from 3
months ago (Bahrick & Pickens, 1995)
Recognition
• Operant conditioning paradigms (Rovee-Collier and
colleagues)
– Mobile task: 3 minute baseline (no
reinforcement); 9-minute reinforcement period;
expose babies to mobile later
– 3 month-old infants remember for 2 weeks
– Initially, memories are highly specific
Recall
• The ability to retrieve a representation from
memory in the absence of cues
• Measured via deferred imitation
- Infant watches action (no immediate imitation is
allowed)
- Given opportunity to reproduce action at a later
point in time
• Piaget
– Not until 18 months of age
– Relies on mental representation
Recall
• But emerging evidence suggests that it
develops earlier
– First evident in 6-month-olds
– By 9 months infants can reproduce an action
they say 24 hours earlier (a subset up to 1
month)
– 23 month-olds imitate actions they saw
modeled 1 full year ago
Memory development and the brain
• Age-related changes between 6 months and 2
years in deferred imitation linked to brain
development
• Hippocampus
– Develops early
– Underlies deferred imitation of simple actions at 6
months
• Long-term recall of more complex actions requires
additional brain areas
– Prefrontal lobe, temporal lobe