Study sets, textbooks, questions
Upgrade to remove ads
Terms in this set (51)
Which of the following best describes the Platonic view of vision and the world?
Vision as Reflection - A 'real world' but our mortal senses are only capable of sampling a small subsection of that world.
Which of the following is the alternative view which is illustrated in the writing of Friedrich Nietzsche?
Vision as Construction - There was no 'real world', only the world inside your head.
The world that we visually sense is entirely dependent upon...
Individual experience and perception. Our own retina perceives light properties from the objects around us.
Excitation refers to...
The detection of different wavelengths from our immediate environment. AP stimulated along axon of neuron in photoreceptors which continue message from one to next.
Sensation refers to...
An experience of events unique to each individual.
At what stage in the visual pathway is an action potential first generated?
When the image from the outside world is imprinted on the retina of the eye (photon becomes receptor output). This sends signals to the primary visual cortex via action potentials.
What do L, M and S denote when applied to cones?
L = Long (red),
M = Medium (green),
S = Short (blue).
Cones that respond to different wavelengths of light.
What reason may you have for expecting the photoreceptors to be physically anchored on the retina despite the observation that this means that there is neural matter between the light source and the photoreceptor?
The retina consists of photoreceptors, bipolar cells, horizontal cells and ganglion cells - they are not separate entities. This is our only contact with the world. Since photoreceptors receive the initial input/stimulus from the environment, they must be 'anchored' down to retina to ensure it to be this first point of contact. Each neuron can really only influence what it is connected to. Having them anchored ensures the message is passed on rather than having them floating around aimlessly.
The presence of the blind spot.
A colour space is...
A method by which a particular light and colour may be represented such that its definition is unique and replicable.
Orthogonality in the vector representation of signal coding confers which of the following properties upon that stage of the system?
Orthogonality - a property that allows overlapping stimulus coding (e.g. location and quality).
Which statement best describes a receptive field?
The sensitivity range (L) and area over which a cone will respond. Size and shape dependent on what and how it will respond to a stimulus. (Cone = photoreceptor).
What is the most likely format of the first spatially structured (or differentiated) receptive fields in the visual system?
Center-surround organization receptive field with excitatory receptors in the middle and inhibitory receptors in the periphery. Increasing events in the centre of the receptive field increases the output and vice versa.
The receptive field arrangement referred to in Question 12 confers what properties to the system?
Receptive fields provide the tool which we can cross boundaries of disciplines in vision to achieve some kind of resonance in the data from different approaches - how you utilize components and construct them into an apparent whole.
Ability to understand edges - ignores areas that are the same, acknowledges areas where there is difference.
The term "opponency" refers to...
Colour opponency refers to the fact that there are three pairs of colours which have been described as those that "cannot live with each other, and yet cannot live without each other."
Red-green, blue-yellow, white-black.
Refers to relationship between surround and centre of receptive field. Increasing in the surround decreases the output, and increasing events in the centre increase the output, therefore the centre and surround are opponent to one another.
Why, when considering the processing of the neural signal, is the actual physical location of any visual neurone other than the photoreceptors, arbitrary?
Spatiotemporal volume - the properties of the receptive field are independent of the location of the neuron since all receptive fields in the visual system have some relationship to the x,y,t space that constitutes the axes of the visual input, but located at varying positions within the visual pathway. Photoreceptors are our only like to the visual world. Once the photoreceptors have encoded the relevant information, it doesn't make any difference where that information is processed.
Why, however, is the relative location of any sensory neurone potentially important?
Due to the other imagery being perceived first and detected by photoreceptors/neurons. Without this initial point of contact, everything beyond this initial contact is lost since the image is lost; the relative location of the sensory neuron is important because lines/contours next to each other in the "real" world have to be represented next to each other in the mind, otherwise they would be random lines and we wouldn't be able to work out shape, outline or further detail.
What is meant by the term "retinotopic mapping"?
Different regions of the retina are represented and processed by different areas within the primary visual cortex, forming a retinotopic map.
The term "phase-coherence" refers to the hypothesis that...
An edge or border is signaled consistently across all scales of analysis.
The idea of modularity in visual processing refers to...
The binding problem, modularity in that things are given certain segments or different bits of experience that are all present within the brain at the one time.
Within visual processing, modularity is an organizational concept of how vision works. Different properties (motion, colour, form) require different functionally distinct regions to be processed within.
What reason may you have for questioning the assumption that the LGN is just a relay station for signals traveling from the retina to the cortex?
There are more connections carrying signals from the cortex back to the LGN than from the LGN to the cortex.
The LGN have their own receptive fields with centre-surround organization, however only the firing rate of neuron can be altered, meaning that the LGN is only a relay that holds information until it is ready to be passed on.
Taken as a population, primary visual cortical (v1) neurones have what critical property?
V1 is the first cortical region to receive axons from visual cells in the LGN. Area V1 in each hemisphere contains retinotopic map of the contralateral half of the visual field. V1 represents everything that one is able to see.
An example of context-dependency in vision is...
Straight matchsticks arrange into a curve gives the whole impressions of a curve even though individual matchsticks are straight.
What is red?
A colour that is subjective and unique to any individual as its perception varies depending on experience. Any one individual's world is a construct of their own experiences, environment and perceptions, therefore the colour red to one person may appear different to another (whether that be the shade its seen in or associations formed)
An attentionally controlled motion system may....
Allow isolation of a particular aspect of motion. A good example would be how turning our heads, under normal circumstances, doesn't make us dizzy but we are still able to distinguish objects in our field of vision.
The visual system appears to dissociate motion-signals elicited by eye-movements or from retinal motion by...
Basic-1-dimensional motion vectors. Attentionally modulated motion.
Retinal movement is initially detected and two potential mechanisms allow us to deal with conflicting signals - inflow hypothesis and outflow hypothesis (we use the same bits of information that say to move your eyes that also say that motion was from an eye movement).
The spatial structure of natural textures is consistent with the properties of the system because...
It has tiny receptive fields sensitive to tiny texture fragments; the same component input but interaction between them is different; some receptive fields indicate texture, some smooth lines.
Signalled within the output of small centre-surround receptive fields (2D) which give some sense of scale of the texture, this is then modified into orientation selective signals or may remain as a colour signal. Similar orientation fragments allow the understanding of a relationship between areas of vision - smooth, grainy, etc. - each tiny fragments responses individually but interact coherently - creating pattern components. Different size receptive fields will response to different amounts of change.
"Adaptation" refers to...
Reduced, or perhaps heightened, sensitivity to stimulation as a result of repeated exposure to stimuli.
What is meant by the term "parallel processing"...
The ability of the brain to do many processes simultaneously.
The terms M and P in the context of the visual system refer to....
Retinal ganglion cells come in 2 sorts: M and P.
P cells exhibit colour-opponent responses: their firing is also dependent on wavelength of life in their receptive field. M cells do not exhibit colour opponency. M cells make transient responses: they fire APs when a stimulus is introduced but quickly fade if the stimulus doesn't change. P cells give sustained responses to stimuli in their receptive fields.
1. Physiologically/functionally distinct
2. Anatomically distinct
3. Complete coverage
The perception that our sensory organs create the outside world (i.e. what we see is translated into information for the brain to process so that we see what we see).
A vector is...
A quantity having direction as well as magnitude, especially as determining the position of one point in space relative to another.
The theoretical hierarchy established by David Marr is...
The theoretical hierarchy established by Marr is that it's more efficient to analyze a complex input parallel in term of its fundamental modules than in serial. Therefore, parallel is top of hierarchy, serial is bottom of hierarchy.
An informational processing system where there are 3 ways to approach a problem. Define the problem clearly then look for solution, then look for implementation. Do not limit yourself when you might not know everything about the problem.
"Retino-cortical expansion" refers to...
There are more cortical neurons dedicated to figure out what's going on in visual field.
The two most likely kinds of motion detector in the human visual system are called....
1. Correspondence detector - came from fly and betel psychophysics; capture a fly, stick it on a device and responses by thinking where motion is
2. Spatiotemporal gradient - either us humans have the same visual system as flies, or we have bother that and spatiotemporal gradient
The three critical dimensions of vision are...
x, y, t.
The third dimension is reconstructed from a variety of cues but is never explicitly coded in the output.
Computational, algorithmic and implementation according to David Marr.
The term "Biological motion" describes...
The unique visual phenomenon of a moving, animate object. Often, the stimuli used in biological motion experiments are just a few moving dots that reflect the motion of some key joints in the moving organism.
Interaction between V1 orientation-selective receptive fields follows what ʻlawsʼ?
Parallel processing, modulation, computational/algorithmic/implementation.
The visual system is sensitive to...
Light, colour, and what we see in the outside world.
One critical similarity between the visual and auditory systems is...
They both have the ability to perceive speed and direction of a moving object. Both systems may also indirect to coordinate and direct attention to one modality or the other and to control subsequent action. Both systems receive information form the outside world and processes them to allow the formation of our sensation and perception. Motion processing is not confined to a single 'dorsal' pathway in both systems.
(both neurons only see input and only influence ouput).
One critical difference between visual and auditory systems is...
While the visual system has a set receptive field within the photoreceptors, the auditory systems receptive field is not confined to a particular region of the somatosensory system.
(vision has multiple dimensions, sound only has one).
Which two structures or processes exploit the properties of orthogonality in their operation?
Semicircular canal - responsible for spatial recognition (i.e. moving one's head)
Motion detection - one structure in the ear, one process in the visual system (mutually independent).
What aspect of the relationship between the stimulus and the cortical representation is different between vision and audition?
Vision stimulus - different regions of stimulus/retina are represented by different cortical regions.
Audition - cochlea translates stimulus to something the brain can understand (single dimension), and cortical representation represents frequency of sound.
What is meant by "tonotopic mapping"?
Sounds of different frequencies are represented and processed by different areas within the primary auditory cortex, forming a tonotopic map.
"Place theory" in hearing refers to...
Inner ear acts as a tuned resonator, which extracts a spectral representation of the incoming sounds, which it passes via the auditory nerve to the brainstem and auditory cortex. The basilar membrane, not under tension, but captures the travelling wave. The position of the wave against the membrane is relative to given frequencies.
"Frequency theory" in hearing refers to...
Assumes that a complete time domain representation of the incoming waveform is directly encoded in the time pattern of firings of the auditory nerve.
A form of parallel processing in the auditory system is implemented in the cochlear nucleus by...
The divergence of auditory signals received.
What particular aspect of the relationship between the stimulus and the cortical representation is different between vision and audition?
What critical neural interaction is affected by, among other things, hallucinogenic drugs?
Hallucinogenic drugs directly affect the serotonin receptors (specifically serotonin receptor subtype, 5-HT2), which is what eventually results in a complex pattern of AP and activity.
Your experience of reality is...
Subjective, unique, and individual.
The involuntary conjoint perception across two modalities or sense (e.g. letters with colours, or sound with colour).
One fish, two fish...
Red fish, blue fish.
Sets found in the same folder
Sensation and Perception
Sensation and Perception
S & P - MBB1
Sets with similar terms
MBB1 Sensation and Perception
S & P - MBB1
Other sets by this creator
17.2 & 17.3
16.3 & 16.4
Other Quizlet sets
Sensation and Perception
Module 2: Sense and Perception Questions