Sensation and Perception Part 2 Flashcards
What does shape perception depend on?
Feature detector cells
What are receptor cells?
Receptor Cells are specialised cells that respond to certain characteristics of the stimulus such as curves and straight edges.
Different receptor cells respond to different ______.
lines
Optimal input for each cell, defines what?
it defines the cell’s receptive field.
Hubel and Wiesel studied _____ _____ on a cat.
receptive fields
Anesthetized cat had one eye propped open so that a series of visual _____ (lines with different ______) could be directed to particular regions of its _______.
stimuli, orientations, retina
A micro-electrode was implanted in the cat’s visual cortex to do what?
To monitor a single cell’s firing rates in response to the lines.
When the cells fired, its neural impulses were amplified, then displayed on an _______.
oscilloscope
What were the conclusions of Hubel and Wiesel’s cat receptive field study?
- Each neuron in the visual cortex has a “target” stimulus that evokes especially rapid firing
- These cells respond to the preferred line/edge the most
In cats and monkeys, features detectors in ____ seem to respond most when a ____ or edge of a specific ________ is in view.
V1, line, orientation
Other cells assemble elements in order to detect more ______ patterns (see the full ____).
complex, full
What does form recognition of form begin with?
The detection of simple features.
When recognition of form gets more complex, what does it depend on?
It depends on how the perceiver has organised the features (eg. colour- red/green and shape- straight?horizontal line, target=red horizontal line with the distractors)
Analysis of features (feature analysis) depends on a preliminary step in which the viewer must ______ the figure.
organise
We need to identify what the object of _____ is and then _______ the object of interest.
interest, segregate
The features of an object also determine how the viewer perceives the figure, give two examples of this.
T Junction = corner disappears from view
Y Junction = corner coming towards us
There are 5 ______ principles of Organisation.
Gestalt
Name the 5 principles of Gestalt Organisation.
Similarity Proximity Good Continuation Closure Simplicity
Explain Similarity.
We tend to group objects according to their similarities eg. we group dots in vertical rows as they are the same colour (red and blue) instead of horizontal rows as the colours alternate this way.
Explain Proximity.
We tend to perceive groups, linking dots that are close together.
When we perceive a continuous green bar behind a cylinder instead of two smaller rectangles this is known as _______ ________.
Good Continuation
When we perceive an intact shape, even when some parts are missing, what is this known as?
Closure
Explain Simplicity.
We tend to interpret a form in the simplest way possible. eg. we see two crossing rectangles instead of a 12-sided irregular polygon :)
To organise input, the perceiver must first _____ the visual scene.
analyse
