chapter 4: perception Flashcards
what is the difference between sensation and perception
sensation: conversion of physical properties of the world or body into a neural code by the PNS
perception: processing and interpretation of sensory information into a form that is useful for a behavioral decision
perception takes place in the … in the nervous system
a. spinal cord
b. sensory receptors
c. motor neurons
d. brain
d. brain
define exteroception
the sensing and processing of information from the external environment through the five basic senses
define interoception
sensing and processing of stimuli inside the body
differentiate proprioception, nociception and equilibrioception
proprioception: sense of where in space our limbs are
nociception: sense of pain due to bodily damage
equilibrioception: sense of balance
when entering the eye, name the components light goes through
focused by the cornea
enters through small opening in the iris, called pupil
focused more by the lens
travels to retina
name the two types of photoreceptors in the retina
rods and cones
which photoreceptors are better for seeing under lower lighting and have reduced resolution
rods
how come rod vision is color blind
all rods respond equally to different wavelengths of light
what is called the center of the retina
fovea
why is it necessary to compress the amount of information that the retina needs to send to the brain
can restrict the movement of the eye if optic nerve is too fat. since it passes through retina, it can restrict the number of photoreceptors that the retina can contain
what is the role of the thalamus
way-station between sensory inputs and cortex
which of the following categories would neurons at the lowest level of the visual stream likely be selective for?
a. specific shapes
b. oriented edges
c. spots of light
d. specific objects and faces
c. spots of light
define prosopagnosia
marked difficulty in recognizing individual faces. no general visual or memory difficulties but can’t identify whose face it it
what is semantic agnosia
can recognize faces, but not everyday objects.
when is the lateral occipital cortex (LOC) more active
when people engage in object recognition tasks
describe the greebles study and the conclusion that was pulled from it
participants had difficulty discriminating between visually similar Greebles. After a while, they became proficient. The Greebles activated the FFA, just as faces do
Conclusion: FFA is specialized for visual “expertise” not for faces
what are the two different visual streams and which aspects do they process
ventral stream processes the “what” aspects
dorsal stream processes the “where” aspects
what are the five basic taste receptors types
sweetness, sourness, saltiness, bitterness, savoriness
True or false? In gustation, the sensory neurons send their signal through the spinal cord
false, they send it through the brainstem
what is the olfactory epithelium
strip of tissue in nasal cavity that contains tens of millions of chemical sensory receptors
in the olfactory system, to which part of the brain do sensory neurons send transduced chemical information to
the olfactory bulb
in order, what are the structures sound goes through when it enters the ear
pinna captures
ear canal amplifies
ear drum amplifies
ossicles relay
cochlea contains fluid
basilar membrane containing hair cells vibrate
hair cells at the … starting point respond to … frequency sound, hair cells at the … starting point respond to … frequency sound
a. outer; high; inner; lower
b. outer; low; inner; high
a. outer; high; inner; lower
in which lobe is the primary auditory cortex situated
temporal lobe
what are sound waves
oscillating movement in the air caused by vibrations of objects in the environment
what are the two properties of sound waves
frequency: distance between crests of waves
amplitude: height from trough to crest of wave
which cortex of the brain receives sensory information from all across the body and in which lobe is it located
somatosensory cortex in the temporal lobe
what is the cortical homunculus
spatially organized map of the human body that processes touch information
what is the constructivist theory of perception
use of sensory information to generate a mental model of the environment that would have caused the sensory stimulus
what is the direct model of perception
approach to perception that holds that the sensory stimuli guides behavior/action in a continuous perception/action loop
when a material absorbs a lot of light, how does it affect how the material is perceived?
a. it will appear light
b. it will appear dark
c. it will appear colorful
d. it will lack color
b. it will appear dark
what do illusions reveal about the assumptions that the brain makes during perception
a. perception is not as useful as sensation
b. these assumptions are usually incorrect
c. perception often depends on guesses
d. our brains cannot be tricked
c. perception often depends on guesses
define the bi-stable property
property of a stimulus that has alternating stable perceptual interpretations
define bottom up processing
processing that does not require any specific knowledge of the stimulus
define top-down processing
processing where we leverage knowledge or expectations that are not in the sensory stimulus itself
define phonemic restoration effect
brain “filling in” missing sounds from a speech signal, based on expectations about which sounds belong in that portion of speech
define image segmentation
brain’s ability to divide up the image into different objects and regions
what is figure-ground assignment
determinating which side of the boundary contains the shape and the background
what are the three figure-ground clues and why
convexity: figures tend to have convex shape
symmetry: figures usually display bilateral symmetry
smaller region: figures are usually smaller than background
define visual grouping
combining spatially separate regions into unified wholes
according to the Gestaltists, what are the three grouping cues and explain them
law of similarity: tendency to group features that have similar properties
law of proximity: tendency to group features that are close together
law of good continuation: tendency to group features to form a smooth, continuous path rather than one with a sharp discontinuity
what is the function of depth perception
figuring out how far an object is away from you to interact with it and determines its shape
name the cues to depth perception
- object that occlude other objects are assumed to be in front
- motion parallax: objects farther away will change their position more slowly on your retina as you move
- binocular disparity: the image on each two eye is different
what is stereopsis
the use of binocular disparity to perceive depth. the higher in depth, the higher disparity. the lower in depth, the lower disparity
what aspects of having two eyes may be used to perceive depth
a. image features will have different sizes in the two retinas
b. image features will fall on the same locations in the two retinas
c. image features will have the same sizes in the two retinas
d. image features will fall on different locations in the two retinas
d. image features will fall on different locations in the two retinas
what is the template model of recognition
matching an object to an image stored in memory
why are template models abject failures when trying to recognize objects in the real world
because every time you view an object, the image it produces on your retina is different due to external factors (depth, lighting, viewpoint)
differentiate these two types of recognition: identification and classification
identification: ability to identify the same object or person across variations
classification: determining whether a given image corresponds to a class or category
define scene schema
learned representation of which objects tend to appear in specific kinds of scenes
true or false? recognition does not require top-down processing
false, the use of past experience to make inferences about current sensory information provides a context which affects recognition
define synaesthesia
neurological condition in which one sense automatically triggers the experiences of another sense
describe the early visual process
- light waves enter the eye and are projected onto the retina
- photoreceptors in retina convert light to electrical activity
- electrical signal is sent to bipolar cells then ganglion cells
- signal exits through optic nerve to brain
why do we not ‘see’ our blindspot
- perceptual filling-in
- left and right visual field compensate for each other’s blindspot
what is the function of the visual association area
interprets visual information and assigns meaning
define akinetopsia
visual motion blindness: cannot see motion. perceives motion as a series of stationary objects
define optic ataxia
inability to reach for objects with the ability to name objects
what is the difference between apperceptive agnosia and associative agnosia
apperceptive: problems perceiving objects
associative: problems assigning meaning or labelling objects
what is the prototype theory
- recognition determined by a ‘good enough’ match (resemblance)
- allows for ‘flexible’ object identification
what are the two pathways that process different auditory information
dorsal: sound localisation
ventral: sound properties
