Term
| Do electrical signals that represent objects at different places in a scene go to different places in the brain? (pg 78) |
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Definition
| Yes, different locations on the retina correspond with different areas on the cortex. This is called a retinotopic map. This means that two points that are close together on an object and on the retina will activate neurons that are close together on the brain. Cortical magnification apportions the fovea's info into a larger cortical representation than images seen in the visual periphery. |
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Term
| How can brain damage affect a person's perception? (pg 85) |
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Definition
Patient DF damaged ventral stream means that she cant perform in static orientation tasks but can perform when action is involved
People with ventral stream orientation can judge visual orientation but cant combine vision and action. |
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Term
| Are there separate brain areas that deteremine our perception of different qualities? (pg 84, 87) |
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Definition
Yes. The ventral stream codes objects in terms of what they are. The dorsal stream codes objects in terms of where they are.
inferotemporal cortex(IT)/ fusiform face area (FFA) = faces
parahippocampal place area (PPA) = spatial layouts (scene perception)
extrastriate body area (EBA) = pictures of bodies |
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Term
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Definition
the way stimuli at specific location in the environment are reprsetned by activity at specific location in the nervous system
ie retinatopic maps, electronic maps |
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Term
| retinal images are represented ____ on the striate cortex |
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Definition
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Term
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Definition
| more cortical space is devoted to areas of the retina near the fovea |
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Term
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Definition
| electronic map of the retina on the cortex |
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Term
| Even though the fovea accounts for only 0.01% of the retina's area, signals from the fovea account for __ to __% of the retinotopic map on the cortex. Also called ___ ___ |
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Definition
8 to 10%
cortical magnification |
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Term
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Definition
| Positron emission tomography |
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Term
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Definition
-person's blood is injected with radioactive tracer
-brain areas with higher activity require greater volume of blood
-monitoring the radioactivity of the injected tracer provides a measure of brain activity |
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Term
| How PET and fMRI are similar |
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Definition
| both brain imaging techniques that are based on the measurement of blood flow |
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Term
| presenting a magnetic field to the brain causes the ____ molecules to line up like tiny magnets. (relevant to fMRI) |
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Definition
| presenting a magnetic field to the brain causes the **hemoglobin** molecules to line up like tiny magnets. |
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Term
| Magnification factor: when you look at a scene, information about the part of the scene you are looking at takes up a ___ space on your cortex than an area of equal size that is off to the side |
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Definition
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Term
| More space on the cortex translates into better ___ ___ rather than larger size |
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Definition
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Term
| the striate cortex is organized into ___ ___ that are perpendicular to the surface of the cortex |
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Definition
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Term
| All of the neurons within a location column have their ___ ___ at the same location on the retina |
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Definition
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Term
| the cortex is organized into these, with each column containing cells that respond best to a particular orientation |
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Definition
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Term
| T/F one location column is large enough to contain orientation columns that cover all possible orientations |
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Definition
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Term
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Definition
a location column with all its orientation columns
recieves info about all possible orientations that fall within a small area of the retina. Well suited for processing info from a small area in the visual field. |
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Term
| The cortical representation of a stimulus does not have to ___ the stimulus; it just has to contain information that ___ the stimulus |
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Definition
The cortical representation of a stimulus does not have to RESEMBLE the stimulus; it just has to contain information that REPRESENTS the stimulus.
ie A single scene representation is contained in the firings of neurons in separate cortical columns and at some point in the cortex they information is combined to create our perception. |
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Term
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Definition
| the visual field is served by adjacent (and often overlapping) location columns |
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Term
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Definition
| the destruction or removal of tissue in the nervous system aka lesioning |
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Term
| The two types of discrimination tasks used by Ungerleider and Miskin |
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Definition
A) Object discrimination: pick the correct shaped object. Lesioning the temporal lobe makes this task difficult.
B) Landmark discrimination: Pick the food well closer to te cylinder. Lesioning the parietal lobe makes this task difficult. |
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Term
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Definition
the pathway leading from the striate cortex to the temporal lobe
ventral pathway
Note: the fusiform face area is in the temporal lobe -> helps us identify faces (WHAT they are) |
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Term
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Definition
pathway leading from the striate cortex to the parietal lobe
dorsal pathway
Note: the parietal lobe contains the motor cortex -> helps us get WHERE we want to go! |
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Term
| What does dorsal refer to? In regards to the human brain? In regards to the human body? |
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Definition
dorsal brain = top of head
dorsal body = the back |
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Term
| It has been suggested that the dorsal stream not only codes WHERE an object is but also .... |
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Definition
| information about how to direct action with regard to a stimulus |
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Term
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Definition
| the study of the behavioural effects of brain damage in humans |
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Term
| double dissociations (pg 85) |
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Definition
Involves two people: in one person, damage to one area of the brain causes function A to be absent while function B is present; in the other person, damage to another area of the brain causes function B to be absent while function A is present.
The fact that function A and function B can be disrupted separately and in opposite ways means that these two functions operate independently of one another.
ie Ungerleider and Miskin's monkeys |
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Term
| D.F. performed poorly in the ____ ___ ___ but did well as soon as ____ was involved. |
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Definition
| D.F. performed poorly in the static-orientation-matching task but did well as soon as action was involved. |
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Term
| Milner and Goodale's name for the dorsal pathway |
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Definition
| how pathway or the action pathway |
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Term
| Ganel's et al (2008)'s results of the length estimation task (the length estimation vs grasping task) |
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Definition
| subjects judged line 1 (the longer line) as looking shorter htan line 2, but in the graspig task, they separated their fingers farther apart for line 1. Thus, the illusion works for perception (the length estimation task) but not for action (the grasping task) |
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Term
| neurons that respond to similar stimuli are often ___ ___ in __#__ area(s) of the brain |
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Definition
| neurons that respond to similar stimuli are often grouped together in one area of the brain |
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Term
| A structure that is specialized to process infomation about a particular type of stimuli |
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Definition
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Term
| Neurons in monkeys infertemporal (IT) cortex respond best to ___ |
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Definition
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Term
| location of the fuisform face area (FFA) |
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Definition
| fuisform gyrus on the underside of the brain directly below the IT cortex |
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Term
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Definition
| difficulty recognizing the faces of familiar people |
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Term
| what is the parahippocampal place (PPA) activated by? |
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Definition
| pictures depicting indoor and outdoor scenes (info about spatial layouts) |
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Term
| what is the extrastriate body area (EBA) activated by? |
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Definition
| pictures of bodies and parts of bodies ( but not faces) |
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Term
| the visual system is organized both ___ and ___ |
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Definition
| spatially and functionally |
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Term
| what does "the spatial map is retiontopic" mean? |
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Definition
| points on the LGN or cortex correspond to specific points on the retina or in a scene |
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Term
| What does "the visual system is organized functionally" mean? |
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Definition
different streams for what and where/how
specific cortical areas that have neurons that repond to specific types of stimuli (faces, places, bodies)
help find way through environment (place neurons) |
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Term
| What did HM get removed? Why? |
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Definition
| bi-lateral lesion of hippocampus due to epileptic seizures |
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Term
| Hippocampus is mainly related to what cognitive function but there are also neurons that respond to these specific things |
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Definition
formation of long-term memory
specific faces (Jennifer Aniston neuron) and specific places |
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Term
| T/F the hippocampus is responsible for recognizing objects |
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Definition
F!
HM could recognize objects but just couldn't remember them later |
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Term
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Definition
people percieve horizontal and vertical orientations more easily than other orientations
occurs b/c there are more cortical neurons that respond to horizontal and verticals
horizontals and verticals occur more frequently in the environment than slanted orientations |
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Term
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Definition
experience with the environment can shape the nervous system
proficiency in perceiving certain things can be explained by changes in the brain caused by long exposure, practice or training |
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Term
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Definition
| computer generated beings, participants were trained to identify aspects of the Greebles and thusly their FFA responded more strongly after training than before hand |
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Term
| T/F the FFA activates for visual items we are experts in, not just faces |
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Definition
T
we are all "experts" with faces, but chess experts show similar activation for chess boards, bird experts show similar activation for birds etc. |
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Term
| How has ablation been used to demonstrate the existence of the ventral and dorsal processing streams? What is the function of these streams? |
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Definition
Ungerleider and Mishkin's monkeys difficulty performing object discrimination with temporal lobe lesions and difficulty with landmark discrimination with parietal lobe lesions
ventral - what
dorsal - where/how |
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Term
| How has neuropsychology been used to show that one of the functions of the dorsal stream is to process information about coordinating vision and action? How do the results of a behavioural experiment support the idea of two primary streams in people without brain damage? |
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Definition
DF - performed poorly in static orientation-matching task but did well as soon action was involved (ventral stream damaged)
other patients with damage to dorsal stream can judge visual orientation but cant accomplish task that combines vision and action
double dissociation |
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Term
| What is the evidence that there are modules for faces, places and bodies? What is the evidence that stimuli like faces and places also activate a wide area of cortex? |
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Definition
module - specialized structure that processes info about a particular type of stimulus
fMRI reveal localized neurons that fire for specific stimuli
FFA-Faces
PPA- Spatial layout, scene perception
EBA - Bodies
fMRI reveal that they cause maximum activation in three separate areas in the IT cortex but also each stimulus also causes substantial activity within the other areas too |
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Term
| Describe the connection b/t vision and memory, as illustrated by experiments that recorded from neurons in the MTL and hippocampus. Describe both the experiments using still pictures and those using film clips. |
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Definition
Quiroga found that some neurons responded to a number of different views of just one person/building or to a number of ways of representing that person/building. Ie the Jennifer Aniston neuron
MTL/hippocampus isnt responsbile for recognizing objects, it is for remembering objects/concepts of the object
The firing to specific video clips is similar to still pictures ie specific neurons for specific clips. The same neuron fires when thinking back and remembering watching the clip.
Neurons in the MTL that respond to perceiving specific objects/events may also be involved in remembering these objects/events. |
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Term
| Describe the possible role of experience-dependent plasticity in determining how neurons and brain areas respond to a) horizontal, vertical and slanted lines b) Greebles |
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Definition
expertise hypothesis: our proficiency in perceiving certain things can be explained by changes in the brain caused by long exposure, practise or training.
a) Oblique effect: people percieve horizontal and vertical orientation more easily than other orientations. Occurs bc there are more neurons that respond to these orientations, and more of these orientations in the environment.
b) Greebles - families of computer generated beings that all have the same basic configuration but differ in the shaes of their parts
Before being trained in Greeble recognition training, low FFA activation by Greebles. After extensive Greeble recongition training, similar responding in FFA as to faces. |
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Term
| Ocular dominance columns (pg 81) |
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Definition
neurons respond better to one eye than the other, and neurons iwth the same ocular dominance are organized into columns in the cortex
there are two ocular dominance columns within each hypercolumn (one for left, one for right) |
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