Chapter 5- Perceptual Development
-people are biologically prepared to perceive the world in certain ways
-perception and action are closely connected from the beginning of life, for example: when
infants see a ball rolling they reach not where the ball is when they begin reach, but rather
toward where the ball will be by the time their hands arrive.
-the visual system includes two main subsystems:
1) Ventral: carries information in large part to the temporal cortex of the brain. It recognizes and
represents the visual world.
2) Dorsal: carries information to the perceptual cortex. It uses perceptual information to guide
-aspects of both systems are functional in the first half year of life
-we perceive the world through sensory systems: vision, audition (hearing), gestation (taste),
olfaction (smell) and a few others.
-the task of perception needs to accomplish 3 functions:
1) Attending: determining what in a situation is worthy of detailed processing.
2) Identifying: involves recognizing what we perceive
3) Locating: involves specifying how far away the perceived object or event is and in what
direction relative to the observer. Example: In a jungle and you see a tiger, you turn your
attention towards it, identify it and locate how far away it is from you and where it is heading.
-the lens bends the light rays to protect a focused image on the light-sensitive retina
-the retina has 2 receivers of light:
1) Cones: enable color vision and are used in the day. (Concentrated in the fovea, center of the
2) Rods: enable dim light and are used at night. (In the retina, not the fovea)
Two methods for studying visual perception:
1) Preferential-looking: when an infant looks more at one object than the other object
because of a preferred difference. Example: the child looks more at the red ball, then the
blue ball, they like the color red more, that is the difference.
2) Habituation: infants grow bored with objects that are presented repeatedly. First, the
familiarization phase is when an object is presented repeatedly. When infants get bored of
looking at it, a new object is introduced. If infants show more interest in the new object,
they must perceive a difference between the two. Attending to Visual Patterns
-Attention-getting (grabs initial attention) vs. attention-holding (attention persists)
-the same attention-getting properties continue to influence perception throughout life
and attention-holding properties change with age and experience
-the orienting reflex: when you hear a loud noise you turn your attention to it without
even identifying what it is yet (is present at birth)
-when your attention is attracted to an object, your attention is reflected in overt behavior
-when your attention is looking at something, however your mind is somewhere else,
your attention is reflected in covert behavior
-it is not until 2 months that infants examine other internal features
-infants love moderate stimulation (something that is not too bright and not too dark,
something in the middle) Example: if a loud noise was paired with the middle bright
object, they would switch to liking the dimmer object because together they would
provide a moderate level of stimulation
-Moderate-discrepancy hypothesis: infants are interested in looking at objects that are
moderately discrepant that they already recognize or know about.
- 3 month olds can detect regular alternating patterns as well as more complex patterns of
events (e.g. pictures switching places, a pattern in a list of letters), any infants younger
than this could not form expectancies
Identifying objects and events
- Visual acuity: (vision for fine detail) enables people to see clearly the similarities and
differences among stimuli. Example: the chart at the optometrist’s