Face Perception DVML

What is sensation?

Information about the environment picked up by sensory receptors and transmitted to the brain

What is perception?

Interpretation by the brain of the sensation input. How we understand the events, objects and people in our environment

What is visual acuity?

Seeing details at a specific distance.

Poor at birth, rapid increase in first 6 months

Near adult levels by 1

What is visual scanning?

Younger than 2 months, can’t track moving objects smoothly.

1 month: focus on limited features of shape, particularly outside edges

2 month: start to focus on internal features

Colour vision?

Newborns can distinguish between white and red, but not other colours

1 month: look longer at brighter, bold colours

4 months: close to adult ability

Preference tests?

Testing perceptual abilities.

Present two stimuli at the same time. Measuring how long infant looks at each

Habituation tests?

Testing perceptual abilities

Shown interesting stimulus repeatedly, infant loses interest eventually. (Habituation)

Change to a different stimulus, infant shows renewed interest and looks again (dishabituation)

Conditioning?

Testing perceptual abilities.

Repeatedly reward target behaviour.

Infant becomes habituated to stimulus

Why is face perception useful?

Can tell from a face: species, sex, race, identity, mood, intent

Impact on social interactions

Innate face preference?

Fantz - 1-15 week olds prefer complex patterns

Maurer and Barrera - 1 month (no difference in looking times). 2 month (looked longer at natural faces). So previous preference in newborns was for complexity

Goren - used moving stimuli instead of static and found newborns tracked normal face more than blank and schematic

Early face preference?

Johnson: replicated effect with newborns. By 3 months, no longer track face.

Johnson and Morton’s 2 process model: CONSPEC - early system (subcortical structures) biases infants to orient towards faces. CONLEARN - later taken over by more mature system (visual cortex) and more precise recognition

What else can newborns do?

Recognise eye gaze

Recognise expressions

Prefer attractive faces

Discriminate mothers face

What did Pascalis say about mother discrimination?

Preference for mother’s face disappeared when outside of face and hairline masked. Newborns use outer features to identify.

Turati said they use both inner and outer features

What did sugita say?

Monkeys not exposed to faces for first months of life still preferred them

Pascalis (2002) environment?

If exposed to monkey faces, 9m could discriminate

“other-race” effect?

Adults are poorer at discriminating faces of other races compared to own

3m, not newborns, prefer own races

Early social experience?

Better at discriminating and recognising female faces

Preference for primary care giver gender

Institutionalised children showed deficits in identifying emotions in faces

Children raised in abusive environment show bias for angry faces

Adults and face perception?

Adults can recognise faces within 0.5s. Retain info of large number of faces.

Research suggests not until 30+ years for face learning

Face specific perceptual development theory?

Ongoing development of face-specific perception mechanisms; continue to develop into late child and adolescence

Face perception gets better because of increased exposure with faces

General cognitive development theory?

Face perception matures early (4-5y)

Performance increases later as general cognitive mechanisms improve

When does face perception mature?

Early research suggested qualitative change later in childhood/adolescence

More recent suggests to be much earlier like 4-5y

Disproportionate inversion effect?

More accurate when faces are upright.

Larger effect for face vs non-face objects

Holistic/configural processing?

Integration of info from all regions of face.

Code spacing between face and features

Autism and social cognition?

Recognising familiar people

Remembering faces

Interpreting eye-gaze and emotions

Williams syndrome and face perception?

Process unfamiliar faces atypically.

Prolonged face gaze

Prosopagnosia (face blindness)?

Damage or abnormalities in right fusion gyrus (stroke, brain injury)

Congenital prosopagnosia - from birth, appears to run in families