Sensation And Perception

Front 1

Why is the actual physical location of any visual neurone other than photoreceptors arbitrary?

Back 1

As long as then information is coming in at the level of the photoreceptors, it does not matter where that information is being processed

Front 2

Why is the relative location of sensory neurones important

Back 2

The relative location of the neurones need to have some form of organisation in ration to the physical world.

Front 3

Retinotopic mapping

Back 3

Mapping of the visual input from the retina to neurones in the visual system . The neurones are organised in a 2d representation of the visual image formed on the retina in such a way that neighbouring regions are represented by other neighbouring regions of neurones

Front 4

The idea of modularity in visual processing refers to?

Back 4

The theory of different properties of the visual world ( motion, colour, form), require different computational solutions which are implemented in anatomically/ functionally distinct regions which operate independently- that is, in a modular fashion

Front 5

An example of context dependency in vision is?

Back 5

Colour is dependent on context

Front 6

Attentionally controlled motion system may..?

Back 6

Allow isolation of a particular aspect of motion. A good example is how turning our heads doesn't make us dizzy and we are still able to distinguish objects in our visual field

Front 7

Information is?

Back 7

What happens at the level of the photoreceptors once photons - have been absorbed- transduction / conversion from electromagnetic to electrochemical - this means the image becomes a three dimensional (x,y,t) array of independent signals carried within three 'channels' of overlapping wavelength sensitivity

Information is the perception our sensory organs create of the outside world. I.e. why we see us translated into information for the brain to process so that we see what we see

Front 8

Which of the following best describes the platonic view of the world?

Back 8

Our visual system is a small reflection of the outside world- we are only cable of knowing/ seeing a small part if the world

Front 9

Which is the alternative view by friedrich Nietzsche?

Back 9

There is no real world- only the one created inside your head- true world vs apparent world

Front 10

What do L, M, S denote when applied to cones?

Back 10

Long wavelength sensitive cones short, medium. It is called trichromatic theory of vision- the distribution if the cones responses overlap, the brain can then use mean firing to infer the actual wavelength

Front 11

What does opponency refer to?

Back 11

Refers to the three pairs of colours red/green, blue/yellow and white black. These are believed to have a relationship of where one cannot live without the other. This process of two properties set up in balance with on another is a critical aspect I how the brain works

Front 12

The world we visually see is entirely dependent on...

Back 12

Individual experiences
Our internal experiences- the brain creates the world you perceive from its input
The interaction between light and the photoreceptors on the retina

Front 13

Excitation refers to?

Back 13

The cone spectral sensitivities at the retinal level are called cone excitations. Stimulation an result in the firing of action potentials. Absorption of photons

Front 14

Sensation refers to?

Back 14

Stimulated receptors (eyes/ears) create patterns of neural messages that represents the stimulus in the brain, giving rise to our initial experience to the stimulus.

Sensation involves converting stimulation into a form the brain can understand

Front 15

A colour space is...

Back 15

Represents colour in terms of axis and data- unique and replicable. Any visible coloured light can be expressed in any one of the three colour spaces, each wig a level of particular processing within the system

Front 16

The crux of the argument between Hering and Helmholtz was...

Back 16

Hering thought we had four photoreceptors - because of complementary colours when we looked away from another colour ( theory of opponency)

Helmholtz believed there were three- trichromacy

Both were correct- most humans are trichromatic and we also have opponency functioning in the visual system as well as all over the brain

Front 17

The spectral sensitivity of the cones must overlap in order to see the colours that we do because...

Back 17

We only have three cones. Red/green/blue. From these, all colours are created through the overlapping of cones- the brain is also able to compare ratios and make detections which indicate different levels of colour. We couldn't possibly see all the colours we see without the overlapping of the three cones

Front 18

Your perception of a particular colour depends on...

Back 18

A person's unique retinal structure. Colour is an internal representation of the absorption process- it is our interpretation of he wavelength ranges in our retina

Front 19

Your perception of a particular colour depends on...

Back 19

A person's unique retinal structure. Colour is an internal representation of the absorption process- it is our interpretation of he wavelength ranges in our retina

Front 20

What is red?

Back 20

Red is subjective colour hitch can e interpreted based on the I divisible experience / perception/ unique retinal structure

Front 21

What reason may you Haverfordwest expecting the photoreceptors to be physically anchored on the retina despite the observation that there is a neural matter between the light source and the photoreceptor?

Back 21

The spatial arrangement of photoreceptors

The presence of a blind spot in the retina due to converging neural material in front rod e retina

An inverted retina also allows photoreceptors to receive blood and nutrients from the retinal pigment epithelium, which absorbs most of he light bit captured by the retina. Because its at the back, no reflections, has more time to pass through

Front 22

What reason may you Have for expecting the photoreceptors to be physically anchored on the retina despite the observation that there is a neural matter between the light source and the photoreceptor?

Back 22

The spatial arrangement of photoreceptors

The presence of a blind spot in the retina due to converging neural material in front rod e retina

An inverted retina also allows photoreceptors to receive blood and nutrients from the retinal pigment epithelium, which absorbs most of he light bit captured by the retina. Because its at the back, no reflections, has more time to pass through

Front 23

Orthogonally in the vector representation of signal coding confers which of the following properties upon that stage of the system

Back 23

A property that allows overlapping stimulus coding e.g. Location and quality. Components are independent of one another as altering one would not affect the other

Front 24

Which statement best describes a receptive field?

Back 24

Description of the sensitivity profile of a sensory neurone

Sensitivity range and are over which a neurone responds

Or a space comprising of many neurones which is capable of detecting changes in the light intensity over a set area in space

A section if the world that a neurone is responsive to

Abstract concept that describes the sensitivity of a sensory neurone - spatial, temporal, wavelength

Front 25

What is the most likely format of the first spatially structured or differentiated receptive fields in the visual system?

Back 25

Two neurones adjacent from each other
Capable of detecting change in light intensity between the two of them
Centre surround organisation circle
Positive and negative response
Photoreceptors, bars of light
Centre surround organisation 2D donut shape- receptive field with ON receptors (excitatory) in the middle and OFF receptors (inhibitory) in the periphery. Increasing events in the centre of the receptive field increases the output and vice versa

Front 26

The receptive fields referred to in question 12 confers what properties to the system?

Back 26

A way in which to identify edges of objects- sensitivity to change rather than absolute levels of excitation
Opponency of the cones / because increasing events in the centre of the surround receptive field increases the output and vice versa

Front 27

Why when considering the processing of he neural signal, is the actual physical location of any visual neurone other than the photoreceptors, arbitrary?

Back 27

It is the photoreceptors that detect the signals and thus their physical location is important, other neurones in the visual system merely relay and interpret the signal thus they can be spatially arrange any way as long as the correct connections are maintained
Fragmented at photoreceptors reassembled at the brain
Photoreceptors just detect change and neurones send messages to brain
All receptive fields in the visual systems have the same x,y,t space that constitutes the axis of the visual input- they actually sit well away from the world you are looking at

Front 28

Why however is the relative location of any sensory neurone potentially important

Back 28

They are involved in interpreting and relaying the sensory information and thus the correct connections are essential
To make sure they link up properly, each has one area of the receptive field it attends to will either be excited or inhibited

important because relative location of neurone is maintained in some ordered relationship to the input map of the world ; the multiple retinotipic maps

Front 29

The term phase coherence refers to the hypothesis that...

Back 29

An edge: border is signalled consistently across all scales of analysis

Front 30

The idea of modularity in visual processing refers to...

Back 30

Visual modularity is an organisational concept concerning how vision works. Theory is: different properties of the visual world e.g. Colour, motion, form, require different computational solutions which are implemented in anatomically/ functionally distinct regions that operate independently that is, in a modular fashion

Front 31

What reason may you have for questioning the assumption that the LGN is just a station for signals travelling from the retina to the cortex?

Back 31

There are more connections carrying signals from the cortex back to the LGN ( lateral geniculate nucleus-in the thalamus) than from the LGN to the cortex

Front 32

What reason may you have for questioning the assumption that the LGN is just a station for signals travelling from the retina to the cortex?

Back 32

There are more connections carrying signals from the cortex back to the LGN ( lateral geniculate nucleus-in the thalamus) than from the LGN to the cortex

Front 33

Taken as a population, primary visual cortical (v1) neurones have what critical property ?

Back 33

V1 represents everything that one is able to see as all visual input to the cortex enters at this point

Front 34

What is the binding problem

Back 34

Refers to how the brain pre consciously determines and combines visual features like colour and shape to create coherent mental equivalents

The way each component within out system works independently in terms of processing information from the external world e.g., auditory system, visual system... Yet we experience a holistic unified experience rather than segments

Front 35

What is the problem wig the binding problem

Back 35

Lack of knowledge on whether the different components do in fact come together or if they need to at all in order for us to make sense if the world as we do

Front 36

What is the problem wig the binding problem

Back 36

Lack of knowledge on whether the different components do in fact come together or if they need to at all in order for us to make sense if the world as we do

Front 37

An example of context dependency bin colour vision is...?

Back 37

Colour is dependent in context

Front 38

What is the problem wig the binding problem

Back 38

Lack of knowledge on whether the different components do in fact come together or if they need to at all in order for us to make sense if the world as we do

Front 39

An example of context dependency bin colour vision is...?

Back 39

Colour is dependent in context

Front 40

An attentionally motion system may

Back 40

gives the number circumstances doesn't make us may allow isolation of a particular aspect motion . a good example would be how turning our heads doesn't make us dizzy but we are still able to distinguish objects in our field of vision

Front 41

What is the problem wig the binding problem

Back 41

Lack of knowledge on whether the different components do in fact come together or if they need to at all in order for us to make sense if the world as we do

Front 42

An example of context dependency bin colour vision is...?

Back 42

Colour is dependent in context

Front 43

An attentionally motion system may

Back 43

gives the number circumstances doesn't make us may allow isolation of a particular aspect motion . a good example would be how turning our heads doesn't make us dizzy but we are still able to distinguish objects in our field of vision

Front 44

The visual system appears to dissociate motion signals elicited by eye movement from retinal motion by...

Back 44

Inflow hypothesis- feedback from eye movement
Outflow hypothesis- big eyes use the same signal to account for motion of the eye
Disassociation of what is in the system and how we actually see the world

Front 45

What is the problem wig the binding problem

Back 45

Lack of knowledge on whether the different components do in fact come together or if they need to at all in order for us to make sense if the world as we do

Front 46

An example of context dependency bin colour vision is...?

Back 46

Colour is dependent in context

Front 47

An attentionally motion system may

Back 47

gives the number circumstances doesn't make us may allow isolation of a particular aspect motion . a good example would be how turning our heads doesn't make us dizzy but we are still able to distinguish objects in our field of vision

Front 48

The visual system appears to dissociate motion signals elicited by eye movement from retinal motion by...

Back 48

Inflow hypothesis- feedback from eye movement
Outflow hypothesis- big eyes use the same signal to account for motion of the eye
Disassociation of what is in the system and how we actually see the world

Front 49

Adaptation refers to...?

Back 49

Reduced sensitivity to stimulation as a result of repeated exposure to stimulus

Front 50

What is meant by the term 'parallel processing'

Back 50

The ability of the brain to do many things/ process simultaneously e.g. Identifying an object requires colour , depth, form , motion etc.. A black car is only seen as one when there is a combination of various inputs from different parts of the visual system

Front 51

The term M and P in the context of the visual system refer to...?

Back 51

M= magnocellular, or parasol
P= parvocellular, or midget

M cells do not exhibit colour opponency- smaller centre surround receptive fields that are sensitive to colour an shape - make transient responses. They fire action potentials when a stimulus is introduced but quickly fade If stimulus does not changed

P cells also exhibit colour opponent responses: their firing Is also dependent on the wavelength of light in their receptive field . Give sustained responses to stimuli in their receptive field- large centre surround receptive fields sensitive to depth, indifferent to colour and rapidly adapt to stimuli

Front 52

A vector is...?

Back 52

A quantity having direction as well as magnitude, especially as determine the position of one point in space relative to another

Direction+ magnitude = a single directional signal

Front 53

The theoretical hierarchy established by David Marr is...

Back 53

Problem> algorithm> implementation

Front 54

Retinal cortical expansion refers to...

Back 54

Where there is a large number of neurones corresponding to the centre of the visual field compared to the peripheral

Front 55

The two most likely kind of motion detectors in the human visual system are ...?

Back 55

Delay/ compare
Fly and beetle detector
Spatiotemporal detector

Front 56

Three critical dimensions of vision are ...

Back 56

X axis, Y axis and T - time

Front 57

The term biological motion describes..?

Back 57

Movements made by biologically active stimuli. Dots fill gaps of biological movement

Front 58

Interaction between V1 orientation selective receptive fields follows what laws?

Back 58

Aligned V1 receptive cells positively interact whilst orthogonal receptive cells negatively interact

Front 59

What is synesthesia?

Back 59

A condition in which sense get cross wired. E.g. May see colours when hearing a sound or actually taste words. Stimulation of one sense causes an inappropriate stimulation in another