L5

Question 1

which area of the brain is activated when you are processing colour

Answer 1

V4

Question 2

what happens when you damage V5

Answer 2

akinetopsia (cant see moving things)

Question 3

monkeys have a similar area to V5. what is this

Answer 3

MT

Question 4

describe the cells in V5

Answer 4

these cells respond to movement in different parts of the visual field. some of these cells also respond to the speed of the object

they change their firing rate

Question 5

what use is motion detection

6

Answer 5

Captures attention

Segments foreground from background. (eg in the car things close to you are moving faster)

Helps in computing the 3D shape of an object.

Allows estimation of the direction in which you are heading within the scene. (optic flow)

Allows recognition of actions

Helps compute the distance to various objects in the scene

Question 6

what is optic flow

Answer 6

If you fixate on something in the direction that you are moving in the periphery will flow past you. This is called optic flow. The NS uses this to detect what direction you are moving in

Question 7

what is the definition of looming

Answer 7

change in visual angle as you approach an object

Question 8

what is looming

Answer 8

Looming is when you get closer to an object that that object rapidly gets bigger in your visual field

This is not a linear relationship

This happen when you fixate on an object that you are walking toward. The object will be the same size until you get really close to it and then it will expand rapidly

Question 9

what is the binding problem

Answer 9

this is the question of how your brain attaches a particular feature to an object

Question 10

what is one potential solution to the binding problem

Answer 10

temporal binding

Question 11

what is temporal binding

Answer 11

Distributed neural responses are tied together by the coordinated timing of their firing patterns.

This synchrony is often associated with repeated, oscillatory activity

Cells firing in synchrony form “cell assemblies” that collectively represent a given object at a moment in time

This shared timing tags specific cells as sharing the same “message” and links the features of an object together

Question 12

what is proof of temporal binding

Answer 12

ambiguous figures

you can see 2 different images in the same image

the image is not changing which means that infoder for you to see the other image something in your brain must have changed

Question 13

if you are preceaving thing at different time (temporal binding theory) then how come you still see a whole image and not just the thing you are looking at

Answer 13

being spread out over time does not mean you brain looks at one thing and then it looks at another it means that the pathways in the brain are active at different times

eg you have 2 networks firing in the brain. these are firing at the same time but the pathways have different firing rates meaning that the cell in those networks are not active at the same time

Question 14

what is schizophrenia

Answer 14

A disorder characterized by abnormalities in perception,

cognition and emotion

Question 15

what are the +ive symptoms of schizophrenia

Answer 15

hallucinations, delusions

Question 16

what are the -ive symptoms of schizophrenia

Answer 16

apathy, lack of motivation

Question 17

what are the cognitive symptoms of schizophrenia

Answer 17

bad memory, disorganised thinking

Question 18

what are some examples of thought and language disorder in schizophrenia

Answer 18

clang
derailment
word salad

Question 19

what is clang

Answer 19

inappropriate rhyming

eg “I said the bread and read the shed and fed Ned at the head”

Question 20

what is derailment

Answer 20

when the statement starts off good but as time goes on the person gets more and more off topic/makes less sense

Question 21

what is word salad

Answer 21

the extreme form of derailment

Question 22

what are some risk factors for schizophrenia

Answer 22

Genetic (concordance in monozygotic (identical) twins is 30-40%; dizygotic 5-10%

Older age of father

Complications during pregnancy or at birth

Season of birth (winter and spring)

Urban living

Socioeconomic factors (stress)

Drug use in teens and young adulthood

Question 23

if you were to look at the brain of a schizophrenic person what would you expect to see

Answer 23

Enlarged ventricles

Reduction in size of several regions including frontal cortex and medial temporal
lobes

Reduction of activity in frontal cortex and medial temporal lobes

Excessive subcortical dopaminergic activity with increased DA release,
synthesis and storage.

Decreased activity in GABAergic, inhibitory systems

Decreased activity at the NMDA subtype of glutamate receptors.

Question 24

what is the dopamine hypothesis of schizophrenia

Answer 24

that schizophrenia is caused by dopamine

Question 25

what is some evidence that supports the dopamine hypothesis

Answer 25

Drugs that enhance dopamine (DA) release or effects produce some of the positive effects of schizophrenia in healthy individuals

Dopamine super-sensitivity and elevated dopamine D2 receptors have been reported in patients

Antipsychotic drugs like chlorpromazine block DA receptors

Question 26

what is the glutamate hypothesis of schizophrenia

Answer 26

Inhibitory neurons modulate excitation via NMDA receptors

(excitatory release glutamate, inhibitory release GABA)

What we think happens in schizophrenia is that we think the GABA receptor (NMDA) is desensitised which reduced the brake on the excitatory neuron

Question 27

what is some evidence that supports the glutomate hypothesis

Answer 27

Negative and cognitive symptoms are not responsive to dopamine blockade

Antagonists of the NMDA subtype of glutamate receptor, such as ketamine and PCP, produce a psychosis that resembles
schizophrenia and generate the negative and cognitive
symptoms.

Dysfunction may occur where the NMDA receptor is involved in communication between excitatory and inhibitory neurons

Question 28

what is the difference between when you present a mooney face to a normal brain to a schizophrenic brain

(a mooney face is one of those black and white images that is heart to make out)

Answer 28

you see changes in the way that the brain oscillates

When you present the picture to the control, about 100ms after presented you will see very large and bright gamma bands (high frequency brain oscillations).

In schizophrenic the response is suppressed which suggests that there must be something wrong with the circuits

this is also the same for beta bands but beta band is even lower

Question 29

what is transcranial magnetic stimulation (TMS)

Answer 29

This is when you put a coil of wire over the top of your skelp which activates the neurons underneath it

Question 30

which area of the brain has the largest reduction in frequency of oscillations in schizophrenia

Answer 30

the prefrontal cortex

Question 31

what is the PANSS score

Answer 31

positive and negative syndrome scale

the higher the score the more symptoms you have

Question 32

what is the relationship between the PANSS score and oscillation frequency

Answer 32

higher the score the lower the frequency

Question 33

in the prefrontal cortex what did a low frequency relate to

Answer 33

poor memory

Question 34

in schizophrenic brains, what would you see if you were to look at the hippocampus

Answer 34

you would see (in a scan) that there is less GABA receptor (A5) avalibilty in the hippocampus