Lecture 2

The brain, central nervous system and the biological basis of learning

Biological psychology

The application of the principles of biology to the study of mental processes and behaviour

Research methods in biological psychology

Lesion studies, animal studies, enhancing neural function, measuring neural activity, genetic manipulations

Lesion studies

The study of the brain after a person has died → Phineas Gage

Animal studies

The study of the brain of animals using animal subjects → ethical issues

Enhancing neural function

Transcranial Magnetic Stimulation (TMS) → temporary enhancement or disruption of brain functions

Deep Brain Stimulation (DBS) → surgical treatment for movement disorders

Measuring neural activity

Frick et al. (2022)

Genetic manipulations

Comparing identical and fraternal twins in human studies

The nervous system

Works with the endocrine system to sense the environment around us and bring about the necessary response as a result of this environment

Central nervous system

Spinal cord and brain

Peripheral nervous system

Everything else

Descarte’s theory of reflex action (1662)

Argued that bodily responses were all impulsive

Thought of reflexes as working like water pipes - using fluid to transmit information

Spinal reflex

Stimulus triggers electrical activity in the neuron

Multiple pathways acting simultaneously

Sequence of events in a relay

Results in sensation of pain

Action potential

The electricity pulses that travel along the neuron and transmit the information

Structure of the typical neuron

Sensory neuron

Motor neuron

Dendrite

Axon

Synapses

Sensory neurone

Afferent - receptor to the CNS

Motor neurone

Efferent - CNS to effector

Dendrite

Accepts the signal

Axon

Sends the signal on

Synapses

Where the neurones connect

Pyramidal neurons

Found in prefrontal cortex - primarily excitatory - involved in complex thinking and executive functions

Excitability of neurons and muscle cells

Action potentials are about fluctuations in voltage

Communication between neurones

Gap between dendrite and axon is a synapse

Action potential sent chemically - neurotransmitters

Brain structure

The cerebrum

The cerebral cortex

The cerebellum

The pons

The cerebrum

Largest part of the brain - consists of 2 hemispheres - contains the cerebral cortex

The cerebral cortex

Plays a role in higher cognition like memory, language and thought

The cerebellum

Little brain - responsible for balance, movement, motor controls

The pons

Bridge - part of the brain stem that delivers information to the cerebellum

Cerebral lobes

Frontal lobe

Parietal lobe

Temporal lobe

Occipital lobe

Frontal lobe

Contains most dopamine sensitive neurones

Associated with reward and attention - planning and following through a task

Parietal lobe

Associated with bodily sensation like touch - earlier than frontal lobe

Temporal lobe

One either side of the brain - responsible for hearing, language comprehension, memory, learning etc.

Occipital lobe

Devoted to visual processing - only one function

Brodman’s areas

Anotehr way of classifying the brain - divided cerebral cortex into 52 sections

White matter

Connects the grey matter together

Grey matter

Contains the dendrites and cell bodies - regions of the brain where information is processed

Biological basis of learning

Non-associative learning

Associative learning

Non-associative learning

Habituation

Sensitization

Habituation

Most basic form of learning - decoupling of association

Sensitization

Progressive response following repeated exposure to stimulus

Associative learning

Classical conditioning

Operant conditioning

Classical conditioning

Involves the pairing of 2 stimuli to result in a change in behaviour → Pavlovian conditioning

Operant conditioning

Learning and behaviour can be shaped by external cues and responses

Hebbian learning

Suggested that learning involved the strengthening of connections between neurones

Synaptic pruning

Changes in neural structure by reducing the overall number of connections, learning more efficient synaptic configurations