Week 2 Flashcards
sensation
information about environment picked up by sensory receptors and sent to the brain
Perception
brain’s interpretation of sensory input
Preference technique
Baby looks at new shapes in a room
Habituation: should dishabituate and look longer. Shows can distinguish between pictures
Conditioning
Reward when turn head to side (e.g. peekaboo)
Link with noise until habituated
Change noise
Event related potentials ERPs
Most commonly used brain imaging technique with infants
Measuring evoked potentials
Auditory perception
22-24 weeks foetus respond to sound (Hepper & Shahidullah, 1994)
Measured by heart rate & movements
Low frequency range (250-500 Hz)
Expands as foetus matures (Hepper, 2005)
Sound reaching foetus is distorted
Skin, muscle, amniotic fluid
Noisy environment
Non-nutritive sucking technique
Rubber teat placed in infant’s mouth
Filled with fluid and connected to a pressure-sensitive device.
Sound is played
Babied learn quickly that each time they suck they hear a sound
After a while the infant habituates to the sound and sucks less often
When new sound is place the baby sucks more again
Prenatal Learning Revisited DeCasper & Spence (1986)
33 pregnant women read a target story to their unborn babies twice a day during the last 6 weeks of pregnancy
Non-nutritive sucking technique used with newborn infants
Infants preferred the story they had heard in utero to a control story
Sucked faster to hear target story
Control group (infants matched for sex, age, ethnicity) showed no difference in responses to stories
Auditory perception: after birth
Auditory acuity at birth better than visual
Newborns turn head towards sound
Preference for mums voice (DeCasper & Fifer, 1980)
3 day olds suck more to hear mum than stranger
Learnt mums voice prenatally or v. rapidly since birth?
No preference between dad and stranger…. Mum’s voice learnt prenatally.
Prefer mum’s voice as heard in womb rather than after birth (Moon & Fifer, 1990)
Speech pereception
(Mehler et al., 1988)
40 4-day-old French babies from monolingual families
Speech stimuli (French-Russian speaker talking about events from her life)
4 conditions: F-F R-R F-R R-F
Non-nutritive sucking technique
Infants could discriminate between familiar & unfamiliar language… and preferred the familiar language.
No effect observed when experiment was repeated with infants where French was not the home language.
Accents (Kitamura et al., 2013)
Explore the abilities of 6- and 9-month-olds to discriminate between accented speech in their own native language (AusE, AmE and SAE).
Infant fixation-controlled serial preference procedure (apart from study 3 and 6).
Study 1: 6-month-olds looked longer at AusE than SAE.
Study 2: 9-month-olds no significant difference in fixation time for AusE and SAE.
Study 3: 9-month-olds played accented speech (AusE v SAE) until there was a 50% reduction in fixation (becoming bored) then half played same accented speech and half played the other accented speech. No significant difference.
Study 4: 6-month-olds no significant difference between AusE and AmE fixation times.
Study 5: 3-month-olds fixated significantly longer on AusE than AmE
Study 6: 6-month-olds discriminate between AusE and SAE but not AusE and AmE
Accent findings
6-month-olds show accent preference; but only when unfamiliar accent utilised.
9-month-olds able to ignore differences in accents regardless of exposure.
Antecedent to ability to recognise words despite highly variant pronunciations.
Occurs outside of language exposure (e.g. SAE)
When exposed to different accents earlier on this developmental pattern shifts e.g. 6-month-olds ignore differences between AusE and AmE, high exposure due to tv, films, music in the home.
Later on in development accents become important for social reasons; by 5 years preference for native accent versus foreign accent (Kinzler, Dupoux, & Spelke, 2007)
Visual perception
Newborns have poor visual acuity
Limited ability to detect colour in newborn
Can’t track a a moving object smoothly at 2 months
Visual scanning
To perceive objects it is necessary to scan the object
1 month olds start by focusing on single feature then tend to scan the outer the outer edges of an object
2 months olds move in to scan the internal features. A shift from where things are to what things are
Pattern Perception (Fantz & Fagan, 1975)
As the visual system develops, a preference for complex stimuli increases
1 month prefer less complex. 2 month prefer complex
Face perception
3 stimuli based on faces
1 to 15 week old infants
Slight preference for natural face over others
Strong preference for face like over non-faces