Biological psychology

Question 1

How many neurons are in the brain?

Answer 1

About 100 billion, connecting to 10,000 others

Question 2

Relative charge inside axon to outside

Answer 2

~-70mv

Question 3

Threshold of excitation

Answer 3

Decrease past this and voltage is further decreased, which affects permeability of membrane nearby (like a tube). ALL OR NONE. Positive feedback or permeability and voltage

Question 4

Action potential

Answer 4

Temporary wave of depolarisation

Question 5

How long does it take to traverse the brain?

Answer 5

~50ms, slow as time needed to recover

Question 6

Why are action potentials metabolically costly?

Answer 6

Glucose and O2 requires, extracted from blood - so we can measure blood flow, blood oxygenation/glucose conc to measure brain activity

Question 7

Why does a myelin sheath speed up an action potential?

Answer 7

Acts as an insulator and action potential can hop from node of Ranvier to node of Ranvier by saltatory conduction

Question 8

EPSP

Answer 8

Excitatory post-synaptic potential (excitatory input) which decreases voltage

Question 9

IPSP

Answer 9

Inhibitory post-synaptic potential increases voltage difference

Question 10

Summation

Answer 10

Temporal and spatial - more = more action potentials = bigger effect on effector

Question 11

How does a synapse work?

Answer 11

1. Ca2+ ions (due to AP arrival) release NT
2. Vesicles fuse with bouton membrane and release contents
3. Bind with post-synaptic membrane receptors which change permeability

Question 12

How can drugs affect the role of specific NT systems?

Answer 12

Modify transmitter systems 
Facilitate transmitter release
Mimic transmitter
Block uptake of enzyme
Mimic transmitter at autoreceptor

Question 13

Neutal coding: labelled lines

Answer 13

One neuron signals one property e.g. colour - Muller’s law of specific nerve energies

Question 14

Rate coding

Answer 14

Firing rate of neutron increases as the intensity of the stimulus increases (Lord Adrian)
Non-linear - refractory period 2-5ms - max rate 200 AP/sec
Must be logarithmic to cover large range e.g. candle for away vs v bright lights

Question 15

Distributed/population coding

Answer 15

Type and value of things coded e.g. arm movements have different firing rates on a number of neurons to achieve desired angle - “tuned” to a specific stimulus
Distributed coding of high level properties e.g. face types - “grandmother cell”

Question 16

Time coding

Answer 16

Precise timing of APs may carry - 200ms across brain, not enough time for APs to travel down each axon to make a rate code

Question 17

Anatomical classification of the brain

Answer 17

Colour: grey (substantial rubsosa), white (substantial nigra), red, stripy (corpus striatum)
Shape: seahorse (hippocampus), almond (amygdala)
Position: front (caudal), back (rostral), side (lateral), middle (medial), top, bottom (ventral)

Question 18

Cell chemistry in the brain

Answer 18

Shapes: pyramidal, stellate
Connectivity: cranial nerves
Chemistry: dopaminergic system, cytochrome oxidase blobs (stained with)

Question 19

Cytoarchitectonics

Answer 19

Organisation of cell types in the brain

Question 20

Hindbrain

Answer 20

Cerebellum, medulla, reticular formation

Question 21

Midbrain

Answer 21

Superior colliculus, susbtantia nigra

Question 22

Diencephalic forebrain

Answer 22

Limbic systems, basal ganglia, thalamus

Question 23

Thalamic forebrain

Answer 23

Thalamus, hypothalamus, pituitary gland

Question 24

Cerebral cortex

Answer 24

Lobes (frontal, parietal, occipital, temporal), brodmann areas, sulci (valley folds), gyri (hills)

Question 25

Function of hindbrain

Answer 25

Reticular formation - arousal, habituation, pain modulation, motor control
Medulla oblongata - cardiovascular control
Cerebellum - precise control of direction, force, velocity, amplitude

Question 26

Function of midbrain

Answer 26

Superior colliculus - control of eye movements
Other visual midbrain structures: focus, pupil diameter, circadian rhythm
Substantia nigra - gating motor commands
Periaqueductal grey - survival functions

Question 27

Functions of diencephalic forebrain

Answer 27

Hypothalamus - CNA and endocrine via pituitary - homeostatic
Thalamus - axons from retina synapse on cells in dorsal lateral geniculate nucleus ) (DLGN) that project to cereal cortex - visual replays
Amygolata and hippocampus - spatial memory (unable to learn new facts - cant encode new memories)

Question 28

Visual areas on cortex and striate cortex

Answer 28

Smaller = less blindness e.g. 1/2, 1/4
SC = visual area, retinotopic organisation

Question 29

Motor and somatosensory cortex

Answer 29

Representation of body in primary motor and somatosensory areas (distorted but adjacency preserved)

Question 30

Cortex: Broca’s area

Answer 30

Speech production

Question 31

Cortex: Wenicke’s area

Answer 31

Language understanding

Question 32

Phineas Gage

Answer 32

Frontal cortex damaged - affected “personality”

Question 33

Why is biological psychology important?

Answer 33

Mechanism that might underlie understanding others

Insights into cognitive and behavioural development

Question 34

Amygdala

Answer 34

Emotional faces - different parts response to different emotions even when not consciously seeing stimuli

Question 35

Development of brain

Answer 35

Newborn brain v small, uneven in maturity, only spinal cord and brain stem well developed - periods of myelination, synaptic growth and synaptic pruning which related to stages of visual, motor and cognitive development in children