Perceptual development

For adults, the main purpose of motion perception is to guide movement. 

For infants who can’t move, the main purpose is to learn about the environment. 

Motion provides information about the stable properties of the environment. 

Motion informs us about changes and events. 

We need motion perception to meet our basic needs: move toward food, avoid danger, approach comfort.

Your ability to resolve the onset and offset of stimulus changes in order to detect change and motion

The highest frequency at which a flicker can be detected

60Hz (60 cycles of on/off per second)

a electrophysiological indicator of retinal activity

For a stationary observer, a target translating perpendicular to the line of sight produces a continuously changing projective location

Can be measured using a displacement threshold – the smallest amplitude of oscillation of a target, which gives rise to the perception of movement

it is important for us to detect motion in space

Infants are sensitive to motion but are not really good with direction when they are really young (until 6-8 weeks)

the slowest movement that is detectable

velocity sensitivity for infants are poorer than in adults