Ch 4 Flashcards
This is _: taking in information through our senses and processing it in order to determine what is out there in the world
perception
T or F: there is not a gap between the information coming into our senses and the kind of information that the brain actually wants to figure out about the world
false - quite the opposite. There can be a huge disconnect, for which it requires an accelerated brain to understand
_, the conversion of physical properties of the world or body into a neural code by the peripheral nervous system
sensation
The conversion of physical properties of the world or body into a neural code by the PNS takes place in the _ _s
sensory neurons
Sensory neurons are spread throughout the _ nervous system
peripheral
Sensory neurons respond by specific kinds of physical properties such as:
_
heat
light
pressure
Does physical stimulation always lead to excitation of a sensory neuron?
no, but often it does
Excitation of the neuron means there are more frequent _ _
action potentials
_ is the process of converting physical stimulation into a neural code
transduction
Transduction may be thought of as a kind of _ of local conditions in the environment and the body
measurement; as though a barometer
Order of perception:
1. …
2. the neural code is passed along to the central nervous system to be processed
3. processing in the cortex generates behaviour
- the senses have converted their measurements into a neural code, i.e., transduction
T or F: we see with our eyes or hear with our ears
False - we do so with our brain which converts sensory signals from those parts into our senses
Sensory stimulus consists of _ of local measurements of pressure/temperature made by specialized neurons embedded in your skin
millions
To perceive the identify of an object when touching something, the brain must combine millions of sensory measurements and .compare the input to…
stored representations of that which has been encountered before
Does perception require some or a majority of the cortex?
the majority - it’s a difficult problem
Senses involve measuring and interpreting properties of the external environment, which is called _eption
exteroception
Gustation/taste is based on substance-bound _ _ in the mouth
chemical compounds
The five _n senses include: touch, gustation/taste, olfaction/smell, vision/seeing
exteroception
We have multiple senses that measure properties of our own body, which is called _ception
interoception
_eption is the sense of where in space our limbs are
proprioception
Nociception is the sense of…
pain due to bodily damage
_ception is our sense of balance
equilibrioception
Two additional senses that measure properties of our own body include…
the feeling of something in your throat
the sense of f…
fullness from eating
There are _ broad classes of sensory receptors found throughout different parts of the body
four
_ceptors have specialized nerve endings that respond to concentrations of chemicals in their local environment
chemoreceptors
Chemoreceptors are found in your _ and _, and they are also present in less obvious places, like the skin or internal organs, where they can measure buildup of chemicals related to tissue damage
nose and mouth
By measuring buildup or chemicals related to tissue DAMAGE, chemoreceptors can support a kind of _ception
nociception
_ceptors are stimulated by physical force and are present throughout multiple parts of the body
mechanoreceptors
Mechanoreceptors are present in multiple parts including the skin, where they detect _ due to touch; the inner ear where they detect air _; and the arteries, where they detect blood _
pressure due to touch
air vibrations
blood pressure
_ceptors are stimulated by heat or cold and may be found in the skin as well as throughout several internal organs
thermoreceptors
_ceptors have responses that are modified by light, and are found only in the eye
photoreceptors
Increased light energy sensed by photoreceptors results in a _ level of neurotransmitters being released
lower level of neurotransmitters being released
- perhaps it assumes that we are in a light-filled space, and is more interested in when it’s dark to thwart predators?
T or F: typically, sensory receptors respond more vigorously with greater amounts of stimulation, apart from photoreceptors
true - photoreceptors seem more interested in when it’s dark than when it’s light out
One-third to one-half of the cortex is involved in _ processing
visual
_ is the most widely studied and best understood of the modalities and therefore provides a lot of insight into the methods and findings of cognitive research into perception
vision
T or F: lessons drawn from the visual system have application to the other sensory modalities as well
true - they all depend on the same process of transduction of physical energy into a neural code by the senses, transmission to the brain through subcortical and then cortical structures, and then processing in the cortex to generate behaviour
_ is the fastest thing in the universe, making it ideal for trying to infer detailed spatial properties of objects even when they are far away
light
In order for light to enter the eye, it must first pass through the _, which is a transparent, rubbery layer of tissue at the front of the eye
cornea
The cornea _s light in order to help it land on the correct part of the eye
bends
After the cornea, the light passes through a small opening in the _, the circular ring of coloured muscle at the front of the eyeball
iris
The small opening in the iris is called the _
pupil
The _ can contract and relax in order to change the size of the _ to allow in more or less light
the iris moves to change the amount the pupil takes in
The cornea is the clear portion of the anterior area of the eye, then there is a space, the pupil for light to bypass, and then it is…
focused more by the lens
The order that light enters the eyes is…
- cornea
- pupil
- lens (contracts and focuses)
Functional _zation, the concept that specific brain areas are concerned with specific types of capabilities
functional localization
Visual _s, cases in which a person has difficulty recognizing or perceiving one kind of visual stimulus while maintaining the ability to process other kinds of stimuli
visual agnosias
Prosopagnosia is a marked difficulting in recognizing…
individual faces, not faces in general
T OR F: individuals diagnosed with prosopagnosia suffer from general visual or memory difficulties
false - they are able to recognize objects and remember their function and can also recall names and facts about people as well
Can those with prosopagnosia not recognize their own reflection?
yes, remarkably
Prosopagnosia is also NOT associated with _ agnosia, those who can recognize faces but not everyday objects such as tools, eating implements, and so on
semantic agnosia
Is semantic agnosia only a visual deficit?
yes, people understand what items are used for, they just can’t recognize them unless prompted
The existence of dissociated agnosias suggest that these different visual capabilities may depend on…
different regions of the brain
Imaging studies support the view that dissociated agnosias depend on…
different regions of the brain
The _ face area (FFA) is in the inferior temporal cortex, or on the left side of the brain facing below
fusiform face area
The FFA shows greater activity when people engage in a _ recognition task than when they perform other kinds of recognition (Kanwisher et al., 1992)
facial recognition task
By showing greater activity in a region during a specific recognition task, we can determine that similar individuals with deficit in that area will…
have difficulties with performing said recognition task
The lateral occipital cortex (LOC) is selectively activated when people do…
an object recognition task
The presence of specialized brain activity has suggested to some researchers that these parts of the brain are geared towards processing … of objects
particular classes - depending on the brain region, one may have deficits in tasks specific to only particular objects, as opposed to general issues with all objects
Do all researches suggest that brain regions are specialized for certain classes of objects?
no - some argue certain KINDS OF PROCESSING occur to apply to these objects (Gautherier and Tarr)
Gauthier and Tarr proposed that the FFA is not concerned with faces per see, but rather with the ability to discriminate between… based on experiments in which participants learn to discriminate between sets of visually similar computer-generated stimuli called Greebles
visually similar stimuli
Gauthier and Tarr argue that FFA is associated with faces because…
of the social importance of being able to distinguish people, rather than using the fusiform face area specific to face recognition
After the visual input first reaches the visual cortex, the axons leading away diverge in two different directions, referred to as different _s of _n
streams of information
The _ stream of information projects upward and terminates in the parietal lobe, while the _ stream projects downward and terminates in the temporal lobe
dorsal stream moves up and front, ventral moves down and to the left site
Mishkin and Ungerleider (1982) observed monkeys that had lesions to either their dorsal or ventral stream of information [for vision]. They found that monkeys with _ damage had difficulty doing a visual matching task when it involved determining whether some object was the same or different across trials
ventral damage - moving down and to the left site, in the temporal lobe
Mishkin and Ungerleider (1982) observed monkeys that had lesions to either their dorsal or ventral stream of information [for vision]. They found that monkeys with _ damage could do a visual matching task when it involved determining whether some object was the same or different across trials, but had difficulty when they had to compare the LOCATION of an object across trials
dorsal damage - moving up towards the parietal lobe
Mishkin and Ungerleider (1982)’s study on monkeys with lesions determined that ventral stream is concerned with processing the “” aspects of visual input, whereas the dorsal stream is concerned with the “” aspects
what - ventral
where, how - dorsal
The _ lobe integrates internal and external perceptions (dorsal pathway)
parietal
The _ lobe processes schematic memory (ventral pathway)
temporal
Goodale and Milner (1991) argued that pathway of information damage affects perception if it does not include _
action - a patient with ventral damage but intact dorsal stream was able to turn a letter as if putting it into a mailbox, but otherwise was not able to match a line on its orientation, simply by looking at it. it is by the doing (i.e., visually guided behaviour) that damages were able to be overcome
T or F: Goodale and Milner had seen that patients with dorsal damage but an intact ventral stream were able to do a perceptual matching task perfectly, but were not able to perform a visually guided action
true - they conversely had seen patients with ventral damage but an intact dorsal stream not be able to do a perceptual matching task, but were able to perform a visually guided action
Goodale and Milner’s theory suggests the dorsal/ventral streams process which kind of information, respectively?
a) size/distance
b) where/what
c) meaning/form
d) action/perception
d) action/perception
Yes, the dorsal stream, towards the parietal lobe focuses on action and “where” things are relative to your body in space and the ventral stream, towards the temporal lobe determines “what” things are
this makes sense, considering the dorsal stream goes towards motor information in the cortex
Perceptual processing is your brain’s attempt to construct a … based on sensory input
a mental model of the external world
Perceptual processing is your brain’s attempt to construct a a mental model of the external world based on sensory input. This is considered the _e _n model
constructive perception model
According to the constructive perception model, _ _ are based on the inferred model rather than on the sensory stimulation itself
behavioural decisions
German physicist Hermann von Helmholtz determined that sensory stimulus would consist of a pattern of stimuli (air vibrations, etc.) while the precept is the sense (sound of a baby crying). He referred to this perspective as “_ inference”
unconscious inference
we create a mental model of the external world based on sensory input
An image falling on each of one’s two eyes is somewhat different because of the angle of light hitting them. But perceptually, we tend to only see one copy of the world out there. These observations suggest that our brains…and turn it into a stable, unified model of the world
take an unstable, divided sensory input
The idea that our brains take an unstable, divided sensory input and turn it into a stable, unified model of the world is aligned with the “_s _” model
unconscious inference model
_ perception involves a sensory stimulus, a mental model, and then action
constructive perception
_ perception involves sensory stimulus and action in a continuous loop
direct perception
The direct perception model rejects the idea that the brain…which is used to guide behaviour
constructs an intermediate mental model of the world which is then used to guide behaviour
direct perception suggests there is only sensory input and action based on that input
James J. Gibson, American psychologist, did important work on behaviours such as locomotion based on the _ perception viewpoint, often referred to as “Gibsonian”
direct perception viewpoint
T or F: Gibson initially proposed the direct perception model
false - it was proposed by physiologist Muller, teacher of Helmholtz (constructive perception model) who suggested that nerves form pathways that led directly from sensation to behaviour
You are using your vision to walk towards a desk that is a few feet away from you in a room. The properties of light on the eye are used by the brain to infer the location of a desk in 3D. You then execute motor movements that correspond with moving your body in that direction in space for the correct amount of time to reach the desk. This model is indicative of the _ perception perspective
constructive
You are using your vision to walk towards a desk that is a few feet away from you in a room. According to the _ perception model, you would start moving your body in such a way that the image of the desk in the center of your field of view and continues to correct and update your motion if the image of the desk strays to the right or left
direct perception model - interplay from visual stimulus and action behaviour
The entire notion of an external world, filled with objects and other people laid out in 3D space is a _ of the brain, based on available sensory evidence. This is indicative of the _ [similar word] theory of perception
construct; constructive perception
T or F: sensory evidence is unambiguous according to the construct perception model
false - it is ambiguous; any sensory stimulus is consistent with many possible distal stimuli
The ambiguous nature of sensory stimuli is best understood when considering _, the rare examples where our brain consistently makes the wrong guess
illusions
Illusions reveal the underlying …during perception
the underlying assumptions that the brain makes during perception
A surface that is “white” typically reflects _% of the light that hits it, whereas for “black” it’s _%
90%; 10%
Our perceptual brain is more concerned with the properties of an object that remain stable…
across variable conditions
Having properties of an object remain stable across variable conditions is a property of the _ perception model
constructive perception model
A surface’s _ refers to our perception of how dark or light an object’s surface is. This perception tends to map well to the physical reflectance of the surface
a surface’s LIGHTNESS
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
Staring at an imagine of a (Necker) cube compels the brain to change its interpretation of which direction it’s pointing, suggestive of the _ility of perception
bi-stability; bi-stable
The “dress illusion” suggests the _ility of perception
bi-stability
Illusions and effects of bi-stability are rare. T OR F?
true - they don’t happen alot
There are two mechanisms in perception:
- processing
- processing
bottom-up
top-down
- processing does not require any general knowledge of the stimulus
bottom-up; induce - make assumptions based on data
- processing is where we leverage knowledge or expectations that are not in the sensory stimulus itself in order to process it
top-down processing; we deduce, based on what we know already