Week 4-6 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is the relationship between brain mass and intelligence?

A

Larger brain mass means a wider range of intelligent behaviour.
However absolute size does not indicate intelligence - rather the proportion of brain to body mass is more important.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the Encephalisation quotient?

Why is this useful?

A

The size of the brain relevant to body mass.

Indicates high species IQ.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where is the cerebral cortex?

How is this different between humans and other animals?

A

The outer most layer of the brain.
Made up mostly of grey matter.

Has folds - small mammals have smooth cerebral cortices.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What brain functions is the cerebral cortex involved in?

A
Attention
Perception
Awareness
Thought
Memory
Language
Consciousness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some ways we can understand the relationship between the brain and behaviour?

A

Investigate what happens when the brain is damaged or impaired - can be caused by trauma, disease, accidents, or experiments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why are accidents and disease a limited approach to understanding the function of brain areas?

A

The show what damage to certain parts of the brain will do to function, but can’t be controlled or replicated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are examples of invasive techniques?

A

Ablation
Surgical modification
Psychosurgery
Deep brain stimulation (DBS) - electrodes inserted into the brain to stimulate different areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are examples of non-invasive techniques?

A

EEG - electroencephallography
TMS - Transcranial Magnetic Stimulation
Transcranial Direct Current Stimulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When would it be appropriate to use electroencephalography (EEG)?

A

EEG records brain activity using electrodes placed in various locations on the scalp.

Useful for:
Seizure disorders
Sleep disorders
Changes in behaviour
After severe head injuries

Pro: Can see brain responses very quickly
Con: Offers poor spatial resolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is MRI?

What is it useful for?

What are the pros / cons?

A

Magnetic resonance imaging
Powerful magnetic fields to measure different kinds of tissue in the body - white matter, grey matter, cerebral / spinal fluid

Useful for:
Tumour
Soft tissue injuries like ligaments
Joint injuries
Spinal injuries
Internal organs

Pro: Bold contrast - get definition!
Con: Poor temporal resolution - blood takes time to reach brain regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is PET?

A

Positron emission tomography
Radioactive materials injected intravenously that bind with molecules in the body such as water.
Can scan before and after treatments to see which brain regions show changes.

Con: Poor temporal resolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is TMS?

A

Transcranial magnetic stimulation
Attach electrodes to the scalp to induce electric currents inside the brain

Pro: Relatively painless

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is DBS?

What is it used for?

What are the pros / cons?

A

Direct brain stimulation
Electrodes inserted into the brain.
Relatively new technique.

Used for:
Parkinson's
Essential trmor
Depression
OCD

Cons: Invasive brain surgery! Used only in new cases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the parts of the Hindbrain?

A

Medulla oblongata
Pons
Cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the medulla oblongata?

A

Passes messages from spinal cord and brain.

Located at the base of brain where it connects to spinal cord.

Responsible for:
Cardiovascular system
Respiratory system (coughing, sneezing)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the pons?

A

Relays signals from the forebrain to the cerebellum.
Sends information from the face, eyes, and ears to the brain.
Largest part of the brainstem.

Located above the medulla and below the midbrain.

Responsible for:
Sleep
Respiration
Swallowing
Bladder control
Hearing
Equilibrium
Taste
Eye movement
Facial expressions
Facial sensations
Posture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the cerebellum?

A

Means ‘little brain’
Works unconsciously on aspects of motor control, gait and posture

Located below the cortex and behind the brainstem

Responsible for:
Motor control
Balance
Movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the three parts of the midbrain?

A

Colliculi
Tegmentum
Cerebral peduncles

Responsible for visual and auditory input and processing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the superior colliculus?

A

Transforms sensory input into movement output.

Responsible for:
Receiving input from the eyes
Orientation of eyes and head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the inferior colliculus?

A

Main auditory centre of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the cerebral peduncles?

A

Connect the midbrain to the brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which part of the brain is associated with “higher order” or more “human” features?

A

Forebrain

Evolutionarily newer part of the brain which has evolved to help humans solve problems within our environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the parts of the forebrain?

A
Cerebrum
Thalamus
Hypothalamus
Pineal gland
Limbic system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the cerebrum?

A

Largest part of the brain

Responsible for:
Initiation of movement
Coordination of movement
Touch
Temperature
Vision
Hearing
Judgment
Reasoning
Problem solving
Emotions
Learning
Reading
Writing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the thalamus?

A

Relays motor and sensory signals to the cerebral cortex.

Responsible for:
Sensory inputs (vision, hearing, touch, taste)
Regulation of consciousness and alertness
Memory
Emotion
Arousal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the hypothalamus?

A

Links the nervous system to the endocrine system via the pituitary gland

Responsible for:
Eating
Drinking
Stress regulation
Temperature regulation
Memorizing
The Four Fs (fighting, fleeing, feeding, "mating")
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the substantia nigra?

A

Damage is implicated in movement disorders such as Parkinson’s

Responsible for:
Motor control
Motor learning
Executive functions
Emotions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the hippocampus?

A

Responsible for:
Consolidating short term memories into long term memory store
Spatial recognition and memory (map reading, navigation)

Damage affects memory acquisition - still able to form physical or motor skill acquisition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the amygdalae?

How do we know what they are responsible for?

A

Responsible for:
Fight or flight response
Memory
Fear and aggression responses in animals

Case study with damage to amygdalae claimed that she was afraid of certain things but showed no fear responses to them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the sulci and gyri?

A

Sulci - valleys of the wrinkles in the brain

Gyri - Bulgy parts of wrinkles in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The brain is split into hemispheres connected by what structure?

Why might you sever this?

What happens when you do?

A

Corpus collosum
Allows info from one hemisphere to be shared with the other

Split brain surgery may be used for severe epilepsy that travels from one side of the brain to the other

People recover well but may suffer side effects such as spatial neglect syndrome. Patients may still respond subconsciously to the object on the bad side.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the four lobes of the cortex?

A

Frontal
Parietal
Temporal
Occipital

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Where is the primary motor cortex?

A

Centre top of the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What order is your motor cortex organised in?

A

Upper part controls feet, legs, groin and torso

Lower part controls hands, arm, face, and tongue muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Which body parts have larger representation in the motor cortex?

Why?

A

Hands and face

Humans tend to use these a lot more for fine motor movements than legs or torso

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What techniques might you use to understand the motor cortex?

A

Brain injury
Neuroimagery
Non-invasive stimulation such as TMS - targeting the upper reaches will get twitches in the feet, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

The dorsal lateral pre-frontal cortex (DLPFC) is involved in what types of cognitive functions?

A
Executive functions:
Cognitive processes
Problem solving
Holding items in working memory
Deep thoughts
Engaging in rules
Future planning
Inhibiting inappropriate responses
E.g. Planning a dinner party, sitting an exam
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Where is the somatosensory cortex?

A

Top middle/back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does the somatosensory cortex do?

How do we know?

A

Perception of touch (pressure, pain, temperature)
Spatial navigation through environment - brain makes a map of our bodies in relation to our environment - avoids interactions with objects like walls and furniture

Penfield and Boldrey (1937)
Operations on patients with serious issues - electrical stimulation of parts of the cortex - patients would report different sensations in different parts of their bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

How is the somatosensory cortex comparable to the motor cortex?

A

Also organised in a hierarchical manner:
Legs, torso, and feet represented higher
Hands, face, and neck represented lower down
Larger area associated with hands and face

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What does the parietal lobe do?

A

Processing of sensory info - touch and limb position

Spatial navigation and awareness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Where does visual information get processed in the brain?

A

Through the thalamus to the occipital lobe / primary visual cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is cortical blindness?

What makes it different to other forms of blindness?

A

Patient will be unable to see anything at all

Damage to the occipital lobe rather than anything to do with the eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Where does auditory information get processed in the brain?

A

Auditory cortex / temporal lobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What’s the name of the brain region involved in face detection?

A

Fusiform gyrus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Damage to the temporal lobes can cause a few different conditions. Name and describe some of them.

A

Prosopagnosia
Patients can no longer identify people that they previously knew, sometimes even extending to themselves

Visual agnosia
Inability to name or describe visible objects that were once known

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are the two areas associated with language that are described?

What are they each involved in?

A

Broca’s area - speech production

Wernicke’s area - speech comprehension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Describe and compare the two types of aphasias discussed.

A

Broca’s aphasia
Unable to produce articulate speech
E.g. Tan, who could only say the word Tan but could otherwise communicate well with gestures

Wernicke’s aphasia
Can produce speech that is fluent but nonsensical.
May use filler words when they can’t find the right word.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are some of the problems associated with taking a purely neurobiological approach to understanding the brain?

A

Description is not explanation
Correlation is not causation
We have a variety of evidence that implicates different areas in certain behaviours, but we don’t know why.
May be a modern expression of phrenology - we may know a particular area of the brain is active during certain activities, but we don’t know how it performs it.
The brain doesn’t perform in isolation - behaviours may be a function of complex, brain-wide networks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What different types of brain cells are there?

What are they called and what do they do?

A

Neurons
10-100 billion of them in the nervous system
High level of interconnectivity that allows cognitions and behaviours to arise
Communication and processing of information in the nervous system

Glial cells
Different types with different functions
Provide nutrients to neurons and structural support to the nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What different functions do neurons have?

A

Sensory neurons
Transmit info from sensory receptors to the brain for processing

Motor neurons
Transmit instructions from the brain to muscles and organs in the body
Can be very long

Interneurons
Transmit info between neurons in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What does the Axon do?

What covers the Axon?

What is it there for?

A

Carries nerve impulses away from the cell
Transmits electrical signals to the terminal buttons which then transmit across the synapse to the dendrites of the next cell.

Myelin sheath

Allows electrical impules to transmit quickly and efficiently along the cell - protects the impulse from degrading

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Where do neurons interact with each other? I.e. What are the relevant parts of the neurons? What is the junction called?

A

Synapses

Site of transmission of electric nerve impulses between two cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are the four types of neuron? Where might you find each other them?

A

Unipolar neuron
One projectoin from the cell body which can be either a dendrite or an axon, depending on its function

Bipolar neuron
Important role in visual system

Multi-polar neurons
Most common type of neuron in the brain

Pseudo-unipolar neuron
Has only one projection from the cell body, but comprises both dendrites and an axon
Commonly observed as long sensory and motor neurons traversing the length of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is grey matter made up of?

A

Cell bodies and dendrites of neurons
Where information processing occurs
Located on the outside of the brain
Some large areas deep in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is white matter?

A

Contains Axons (nerve fibres)
Most of the inner parts of the brain
Communication between inner and outer areas of grey matter
Spinal cord is also white matter

57
Q

What is the difference between intra-neuron communication (within a single neuron) and inter-neuron communication (between cells)?

A

Intra
Step A: ELECTRICAL signal from dendrites and cell body to Axon hillock
Step B: ELECTRICAL signal from Axon Hillock to terminal buttons (action potentials)

Inter
Step C: CHEMICAL signals from terminal buttons of one neuron to dendrites of another neuron across the synapse

58
Q

What is an ion?

What types are there?

A

Electrically charged molecule
Can be positively or negatively charged

Cation - positive charge
Anion - negative charge

Found naturally both inside and outside the cell

59
Q

What are diffusion and electrostatic pressure? How do they work? How do they affect ions?

A

Diffusion
Passive movement of a substance from an area of high concentration to an area of low concentration

Electrostatic pressure
Passive attraction of oppositely charge ions and repulsion of similarly charge ions

Can make ions move around depending on concentration and / or whether the area has net negative or positive charge. These processes are passive.

60
Q

What is meant by semi-permeability of the cell membrane?

What make them more or less permeable?

A

Some things can pass through while others can not.
Opening and closing of ion channels allows certain ions to pass through.

Opening and closing can be controlled by electrostatic stimulation.

61
Q

What is the resting state of the intra- and extra- cellular space? What is the “resting potential” (both definitionally and specifically)?

A

Intracellular space has overall negative charge
Extracellular space has overall positive charge

Resting potential = -70mv

62
Q

What is an excitatory potential?

A

If electrostatic pressure or diffusion causes the cell to depolarise (become less negative)

63
Q

What is an inhibitatory potential?

A

If a cell becomes more negative - hyperpolarised

64
Q

What happens if a cell receives an inhibitatory potential at the same time as an equally large excitatory potential

A

They cancel each other out

65
Q

Where do the graded potentials converge?

A

Post-synaptic dendrite

66
Q

What are some differences between graded potentials and action potentials?

A

Graded potentials
Move from Dendrites to axon hillock
Involve changes in ion concentration and membrane potential

Action potentials = +40mv
Move from axon hillock to terminal buttons
Involve changes in ion concentration and membrane potential

67
Q

What is the threshold of excitation? What happens when it is reached?

A

If there is enough excitatory potential, the neuron will ‘fire’ and the signal will continue on to the neurons it is communicating with.

When membrane potential reaches -55 to -65mv

If threshold is not reached, nothing happens.

68
Q

What are depolarisation, repolarisation, and hyperpolarisation?

When do these happen?

A

Depolarisation
When an ion becomes less negative

Repolarisation
When an ion regains negativity

Hyperpolarisation
When an ion becomes more negative

Stimulus > depolarisation > threshold of excitation > repolarisation > refractory period / hyperpolarisation > resting state

Refer diagram

69
Q

Why can action potential only go one way?

A

There is an inbuilt refractory period in an ion to ensure they do not open in a backwards direction

70
Q

Where do action potentials occur? What is this process called?

A

Nodes of Ranvier
Periodic gaps in the myelin sheath of certain neurons to facilitate the rapid conduction of nerve impulses

Saltatory conduction

71
Q

What is interneuronal communcation?

A

Chemical interaction that occurs only in the synapse

72
Q

What are neurotransmitters?

A

Chemicals that are released by the pre-synaptic neuron to the post-synaptic neuron to cause EPSPs and IPSPs

Glutamate
Y-aminobutyric acid (GABA)
Dopamine (DA)
Serotonin (S-HT)
Acetylcholine (ACh)
Endorphins
73
Q

What is a graded potential?

A

Potential that can vary in amplitude and direction

74
Q

Whats the relationship between neurotransmitters and graded potentials?

A

For sensory receptors (e.g. taste, retina) graded potentials in their membranes result in the release of neurotransmitters at synapses with sensory neurons.

75
Q

What does pre-synaptic and post-synaptic refer to?

A

Pre-synaptic
Neuron sending the chemical signal

Post-synaptic
Neuron receiving the chemical signal

76
Q

Where does the decision for a neuron to fire occur?

A

Axon hillock

77
Q

What is an EPSP?

A

Excitatory post-synaptic potential

Depolarises the membrane (makes it more positive)

78
Q

What is an IPSP?

A

Inhibitory post-synaptic potential

Polarises the membrane (makes it more negative)

79
Q

In general terms, hjow do psychoactive chemicals affect our brains (and therefore our experience)?

A

Either increase or decrease neurotransmitters and their networks

80
Q

What determines whether a neurotransmitter will bind to a post-synaptic receptor?

A

Specific neurotransmitters bind to their specific receptors.
‘Lock and key’ principle
Molecular structure of a neurotransmitter can only bind to a receptor that can receive that structure
E.g. Dopamine by dopamine receptors

81
Q

Do you think inter-neuronal transmission is faster or slower than intra-neuronal communication? Why?

A

Slower - required chemical reaction, rather than energy transfer?

82
Q

How do neurons “know” to stop releasing neurotransmitters?

A

Neurotransmitters can bind to receptors to create a feedback loop that tells the pre-synaptic neuron to stop releasing the neurotransmitter.
All excess neurotransmitter also needs to be removed from the synapse, either by re-uptake sites in the pre-synaptic neuron and / or by degradation by enzymes in the synapse so that the neurotransmitter can be recycled.

83
Q

In a little more detail now, how can drugs affect our neurotransmission process?

A

Increase or decrease synthesis of neurotransmitters in the cell.
Alter how much neurotransmitter is released by the cell.
Influence how much neurotransmitter is in the synapse at any one time by manipulating re-uptake of the neurotransmitter or the enzymes that break it down.
Increase or decrease the amount of neurotransmitter receptors in the post-synaptic neuron.
Introduce chemicals that “pretend” to be neurotransmitters with the effect of increasing the number of receptors in the post-synaptic neuron that are activated, or block access to the receptor without activating it

84
Q

What type of neurotransmitter is glutamate? What is it implicated in?

A

Most prevalent excitatory neurotransmitter in the nervous system!
Very commonly involved in producing EPSPs in post-synaptic neurons.
Implicated in the pathophysiology of epilepsy and seizures. I.e. Uncontrollable excitation in the brain.
Important for learning and memory; particularly implicated in the forming of long term memories in “long term potential”.

85
Q

What type of neurotransmitter is GABA? What is it implicated in?

A

Gamma amino buteric acid
Most prevalent inhibitory neurotransmitter in the brain.
Directly influence by alcohol; alcohol bings to GABA receptors and activates GABA receptor sites; has a molecular structure that can be received by GABA receptors.

86
Q

What kind of neurotransmitter does alcohol affect and how?

A

GABA
Involved in inhibition of neuronal fireing; consumption inhibits frontal lobes of the brain which control behaviour.
Excessive consumption can cause the brain to shut down - sleep / coma / death.

87
Q

Alcohol, Xanax, and Valium all work on what neurotransmitter network?

A

GABA

They cause reduced activity of the brain and reduced anxiety.

88
Q

What neurotransmitter and associated network is associated with drugs of dependence? Why might this be the case?

A

Dopamine
Activates reward pathways in the brain.
They make you feel good!

89
Q

What kinds of things does dopamine affect in the brain and body?

A

Emotions
Motivation
Arousal
Movement

90
Q

What kinds of conditions may be present in those with too much dopamine?

A

Schizophrenia
Methamphetamines
Cocaine

91
Q

What happens when you don’t have enough dopamine?

A

May be a result of Parkinson’s

92
Q

What symptoms can treatment of schizophrenia cause?

A

May reduce dopamine and cause symptoms similar to Parkinson’s
Vice versa when treating Parkinson’s - potential for psychotic symptoms to occur

93
Q

What neurotransmitter is involved in sleep, mood, empathy, and arousal regulation?

A

Serotonin

Low serotonin = depression

94
Q

What does MDMA / ecstacy do neurologically? What can this tell us about the role of this neurotransmitter network?

A

Increases activity of serotonin neurotransmitters.

Causes users to feel a heightened sense of empathy.

95
Q

What is Actylcholine involved in? What disorder is treated by addressing this network?

A

Learning, memory, movement, muscle coordiantion

Linked to Alzheimer’s

96
Q

What role do endorphins play?

A

Mood

Reducing pain

97
Q

What drugs are associated with endorphins?

A

Morphine

Heroin

98
Q

What is the difference between sensation and perception?

A

Sensation
Detect information from patterns of physical activity in the environment

Perception
Involves organisation of sensory information into percepts, and integrating them with cognition

99
Q

Define the term absolute threshold and explain how one might go about estimating this value from a graph of performance (% correct) as a function of stimulus intensity?

A

Absolute threshold
How much of a stimulus is required for us to detect a sensation
More precisely - the degree of stimulus required to correctly detect that stimulus 50% of the time

100
Q

Explain the Weber-Fechner (Law) and understand the nature of the relationship between the Weber fraction and the difference threshold

A

Weber-Fechner Law
It is easier to detect change in low amounts of a stimulus that in high amounts

Equation:
delta(i) 
/
i
=
K

Difference threshold
How much of a difference in stimulus is required to be able to tell that it has changed

101
Q

Explain the distinction in signal-detection theory between sensitivity and response bias

A

Sensory sensitivity is limited by the quality of your sense organs

Response bias is someone’s decision making; may be influenced by confidence, motivation, and most importantly the desire to not miss a stimulus versus the desire to avoid incorrectly detecting it

See diagram

102
Q

What is sensory transduction?

A
The conversion of physical energy into neural / electrochemical activity.
Performed by special class of cells called sensory receptors.
103
Q

What types of sensory receptors are there?

A

Simple receptors
Free nerve endings that are simply exposed to the environment.
E.g. Pain and touch receptors

Encapsulated receptors
Coated nerve endings that are more specifically sensitive
E.g. Temperature

Specialised receptors
Nerves with dendrites specialised to detect specific types of stimuli
E.g. Light, sound, smell

104
Q

Explain the relationship between wavelength of light and perceived colour

A

Wavelength determines perceived colour

105
Q

What are rods and cones? Why do we have them?

A

Two classes of receptors.
Transduce electromagnetic energy (photons of light) into neural activity.
When photons of light strike these receptors, it can result in a chemical reaction with the receptor cell that causes that cell to change its electrical potential.

106
Q

What are cones?

A

Three different types, each sensitive to a particular wavelength of light (either blue, green, or red)
More densely situated in the centre of the retina

107
Q

What are rods?

A

More sensitive to light, particularly flickering lights

More prevalent at the periphery of the retina

108
Q

Describe the role the cornea and lens play in focusing light on the rods and cones of the retina

A

Light is focused (refracted) by the cornea >
Enters the eye through the pupil >
Is refracted again by the lens in order to cast a clear and focused image of objects onto the retina at the back of the eye

109
Q

What is “accomodation”?

A

The ability of the lens to adjust its thickness, thereby altering its refractive power

110
Q

Explain the functional significance of neurons of visual cortex as basic visual feature detectors

A

Receive and integrate inputs from thalamic cells, giving these neurons complex response properties
I.e. Their activity reflects the combined activities of several thalamic inputs

111
Q

What are myopia, hyperopia, and presbyopia? What causes them?

A

Myopia
Short-sightedness
Cornea and / or lens are too strong or eyeball is too large

Hyperopia
Far-sightedness
Cornea and / or lens are too weak or eyeball is too small

Presbyopia
Unable to see nearby objects
Lens is unable to increase its thickness and thereby increase refractive power as an object moves closer

112
Q

Describe the trichromacy theory and opponent-process theory of colour

A

Trichromacy theory
Colour we perceive an object to be depends on relative activity of the three types of cones
Relative activity of cones can be uniquely coded for 16 million different colours

Opponent process theory
Colour we perceive depends on relative activity of three pairings of colour-sensitive neurons. Activity of one member of each pair inhibits activity of the other member.
Pairings are red-green, blue-yellow, black-white

113
Q

Describe the Gestalt organisational principles governing the perception of form

A

Group features into figure vs ground object perceptions
Group features that are similar in shape into coherent objects
Group features that are close together into coherent shapes
Group features in a way that favours continuity of an object
Fill in apparent gaps between features in order to complete and object

114
Q

Describe how monocular cues for depth (including pictorial, physiological, and motion cues) can provide information about three dimensions despite our eyes only being able to extract two-dimensional visual information

A
Pictorial cues:
Relative position / height
Relative size
Linear perspective
Light and shadow
Interposition / occlusion
Aerial perspective or relative clarity

Physiological cues:
Accommodation

Relative movement (motion parallax)

Depth information from utilisation of and comparisons between two eyes

Convergence / divergence - extent to which our eyes need to ‘cross’ in order to focus on one subject

115
Q

How can binocular disparity provide information about object in three dimensions?

A

Comparison of visual information between the eyes

Convergence / divergence

116
Q

What are motion sensitive neurons and how do they account for the beta effect and the phi phenomenon?

A

Beta effect
Series of still images in quick succession gives the impression of movement

Phi phenomenon
Two separated images that flicker on and offer in alternation

117
Q

What is the ‘persistence of vision’?

A

Perception of motion happens automatically, mechanistically, without cognitive intervention, simply because the pattern of visual stimulation activates motion detectors in the cortex

118
Q

What are the relationships between the amplitude of a sound wave and its perceived intensity, and the frequency of a soundwave and its perceived pitch?

A

Amplitude
How intensely loud a sound is
High amplitude = louder sound

Frequency
Higher frequency = higher pitch
Humans can hear from 20Hz to 20,000Hz

119
Q

What is the purpose of hair cells? Where are they located?

A

Mechanoreceptors sensitive to vibrations

120
Q

How are the neurons of the auditory cortex process organised?

A
Hair cells receive vibrations
Info is passed to auditory nerves
Auditory nerves > brainstem
Brainstem > Thalamus
Thalamus > auditory cortex (in temporal lobes)

Arranged tonotopically:
Higher pitches trigger neurons towards the back of the brain

121
Q

Explain the difference between conductive hearing loss and sensorineural hearing loss in terms of the locus of the condition

A

Conductive
Inability of the tympanic membrane to vibrate

Sensorineural
Damage to hair cells (tinnitus)
Damage to vestibulocochlear nerve
Damage to auditory cortex

122
Q

How do we perceive the three-dimensional location of a sound?

A

Binaural neurons - comparison between the two ears.

123
Q

Compare the frequency theory and the place theory of pitch perception

A

Frequency
Frequency of oscillation of the basilar membrane corresponds to the soundwave frequency
Direct 1 to 1 correspondence
However hair cells have frequency limits of up to 100Hz

Volley theory
Groups of cells collectively detect frequencies up to 4000Hz

Place theory
Basilar membrane detect different frequencies of sound
Lower frequencies are detected at the apex
Higher frequencies are detected at the base
Detects up to 20,000Hz frequencies

124
Q

If light is the stimulus for sight, what are the stimuli for smell and taste?

A

Chemicals on the tongue and olfactory bulbs

125
Q

What is the process by which smell and taste information is transduced?

A

Chemoreceptors are specific to particular chemicals.

Lock and key mechanisms - certain receptors respond to certain chemicals

126
Q

In the cortex, how are taste and smell organised and represented?

A

See diagram

127
Q

Taste and smell regions are connected to other areas in your brain. What other regions?

What purpose does this serve?

What impacts does this have on our experiences?

A

Regions that specialised in processing spatial information.

Strong link to disgust and fear

Identify dangerous or good foods
Recognise friend or foe

128
Q

What are the body senses?

A

Touch - somatosensation

Body position - proprioception

Balance - equilibrium
Vestibular areas in the Thalamus and cortex help keep us oriented
Processed by semicircular canals in ears

Pain - nocioception
Processed in multiple places
Need to be able to responde in various ways depending on nature of the pain

129
Q

How do we experience touch, balance, and pain?

A

Proprioceptors respond to position movement and strain experience by body parts

130
Q

What are the receptor types described for the body senses? Where are they located?

A

Muscle spindle organs

Golgi-tendon organs

131
Q

How are reflexes processed?

A

Signals receive an immediate response directly from the spinal cord

132
Q

What is meant by the gate control theory of pain?

A

All touch senses compete for perception.
Presence of non-painful touch stimulus can inhibit pain stimulus.
E.g. Holding onto a body part that is experience pain

133
Q

Why do we integrate perceptual information with cognition?

A

Perception is the ability to capture, process, and actively make sense of the info that our senses receive.
It is the cognitive process that makes it possible to interpret our surroundings with the stimuli that we receive throughout sensory organs.

134
Q

What is agnosia?

A

Inability to process sensory information

135
Q

What is visual agnosia specifically?

A

Inability to process visual information

136
Q

What are the differences between apperceptive and associative visual agnosias?

A

Apperceptive
Difficulty recognising things due to limitations in integrating visual information into object percepts.
Can be hard to diagnose.
E.g. Can’t achieve object constancy, difficulty identifying objects in cluttered environments, difficulty identifying heavily shadowed objects

Associative
Limited by linking perception with cognition.
Can recognise the outline of an object and deal with object rotation.
Can’t name or classify objects.
E.g. Can’t draw from memory, can’t match objects according to common function

137
Q

What is prosoagnosia?

A

Face blindness - can see facial features but can’t recognise who it is

138
Q

What are the main features of auditoria agnosia and tactile agnosia?

A

Unawareness of inability

E.g. Stroke patients may not recognise that they are unable to move their arm!