L07: Sensation & Perception Flashcards
(54 cards)
Sensation
The ability to detect a stimulus. Features of the environment that are used to create understanding of the world.
Perception
The act of giving meaning to a detected stimulus. Combining of sensations arriving from the sensory system with prior knowledge.
Transduction
Process where stimuli are converted to neural electrochemical energy.
Top-down processing
Applying memory, knowledge, etc. to understand and create perception
Bottom-up processing
Processing the elementary messages from the environment
Psychophysics
The science of defining quantitive relationships between physical & psychological events. Relates physical stimuli to the contents of consciousness.
Gestalt psychology
describes how people tend to organize visual elements into whole entities - “the whole is greater than the sum of its parts”
Figure-ground principle
a form is naturally perceived as a figure while its surrounding area is perceived as ground
Principle of Proximity
elements placed close together are perceived as a group
Principle of Similarity
similar objects are perceived as a group
Principle of Closure
people perceive the whole by filling in missing info
Principle of Good continuation
the eye is compelled to move through one object and continue to another object
Principle of Common fate
objects moving together are grouped together
Blindsight
damage to a visual cortex leads to conscious blindness, typically only on one side. when patients are asked to identify visual stimuli in their blind field, they can do so with accuracy, suggesting conscious and unconscious vision
Visual agnosia
inability to recognize visual objects. associated with issues in the ventral pathway
Prosopagnosia
inability to recognize faces. associated with issues in the ventral pathway. shows emotional responses to very close relatives, suggesting unconscious vision
Cornea
Transparent tissue which allows light rays to enter the eye and focus on objects
iris
Coloured part of the eye consisting of muscular diaphragm which regulates light entering the eye
retina
Contains photoreceptors
fovea
Smallest pit that contains the highest concentration of photoreceptors (rods and cones)
blind spot
Where the optic nerve leaves the eye. no photoreceptors in this area, so the visual system usually fills in the area with info about the surroundings
function of rods
responsible for night vision, dim light, low resolution
function of cones
responsible for daylight vision, bright light, sensitive to blue, red, and green, high resolution
bipolar cells
interneurons that provide the main pathways from photoreceptors to ganglion cells
