Topic 7: Perception and Action Flashcards
Ecological Approach to Perception
this approach focuses on specifying the information in the environment that is used for perception, emphasizing the study of moving observers to determine how their movements results in perceptual information that both creates perception and guides further movement
Optic Flow
the flow of stimuli in the environment that occurs when an observer moves relative to the environment
forward movement causes an expanding optic flow, whereas backward movement causes a contracting optic flow
some researchers use the term optic flow field to refer to this flow
Gradient of Flow
in an optic flow pattern, a gradient is created by movement of an observer through the environment
the “gradient” refers to the fact that the optic flow is rapid in the foreground and becomes slower as distance from the observer increases
Focus of Expansion (FOE)
the point in the flow pattern caused by observer movement in which there is no expansion
according to J.J. Gibson, the focus of expansion always remains centered on the observer’s destination
Invariant Information
environmental properties that do not change as the observer moves relative to an object or scene
for example, the spacing, or texture, of the elements in a homogenous texture gradient does not change as the observer moves on the gradient
the texture of the gradient therefore supplies information for depth perception
Affordances
the information specified by a stimulus patter that indicates how the stimulus can be used
an example of an affordance would be seeing a chair as something to sit on or a flight of stairs as something to climb
Action Affordances
a response to an object that involves both its affordance (what it is for) and the action associated with it
Visual Direction Strategy
a strategy used by moving observers to reach a destination by keeping their body oriented toward the target
Spatial Updating
process by which people and animals keep track of their position within a surrounding environment when they move
Wayfinding
the process of navigating through the environment
wayfinding involves perceiving objects in the environment, remembering objects and their relation to the overall scene, and knowing when to turn and in what direction
Landmarks
object on a route that serves as a cue to indicate where to turn
a source of information for wayfinding
Cognitive Map
a mental map of the spatial layout of an area of the environment
Place Cells
neurons that fire only when an animal is in a certain place in the environment
Place Field
area of the environment within which a place cell fires
Grid Cells
cells in the entorhinal cortex that fire when an animal is in a particular place in the environment, and which have multiple place field arranged in a grid-like pattern
Parietal Reach Region (PRR)
network of areas in the parietal cortex that contains neurons that are involved in reaching behavior
