AREA OF STUDY 2 MEMORY UNIT 3 THE CONSCIOUS SELF.

AREA OF STUDY 2

MEMORY

UNIT 3THE CONSCIOUS SELF

ROLE OF THE NEURON IN MEMORY FORMATION


NEURON: A nerve cell that is specialised to receive, process and/or transmit information to other cells within the body

DENDRITES: Thin extensions of a neuron that receive information from other neurons and transmit it to the soma

SOMA: Integrates the neural information received from dendrites and sends it to the axon. Contains the nucleus

AXON: A single tube-like extension that carries neural information away from the soma towards other neurons

AXON TERMINAL: The terminal button is a small structure like a sac that stores and secretes neurotransmitter


MYELIN SHEATH: Serves a similar function as the insulation around electrical wire. Helps prevent interference from the activity of other nearby neurons

SYNAPTIC GAP: Tiny space between the pre-synaptic neuron and the post-synaptic neuron which the

neurotransmitter travels across

NEUROTRANSMITTER: A chemical substance produced by a neuron that carries a message to other neurons or cells in muscles and organs. They attach themselves to receptor sites on the post-synaptic neuron that are specialised to receive that specific neurotransmitter

Some neurotransmitters are excitatory, some are inhibitory


CHANGES IN FUNCTION & STRUCTURE OF NEURONS

Creating memories changes the structure and function of neurons

Changes in the function of neurons is evident in:

•An increase in the amount of neurotransmitter produced and released by the pre-synaptic neuron

•Greater effects of neurotransmitter at its receptor sites on the post-synaptic neurons



DIFFERENT NEUROTRANSMITTERS HAVE DIFFERENT ROLES IN MEMORY FORMATION

GLUTMATE (Glu): the main excitatory neurotransmitter. Makes post- synaptic neurons more likely to fire. Key role in

structural change in growth and strengthening of synaptic connections. NMDA and AMPA receptors have to be present for glutamate to work. These are found in abundance in the hippocampus, a structure involved in the formation of LTM

DOPAMINE (DA): Has a role in attention, initiation of voluntary movement, the experience of pleasure and

reward based learning. Contributes to the strengthening of synaptic connections in the brain. As dopamine

increases or decreases, so can the functioning of working memory



DIFFERENT NEUROTRANSMITTERS HAVE DIFFERENT ROLES IN MEMORY FORMATION

ACETYLCHOLINE (ACh): Involved in learning, attention, sleeping, dreaming and motor control. Low level in the brains of people suffering from Alzheimer’s disease. Drugs that inhibit the activity of Ach can cause temporary loss of memory

NOREPINEPHRINE (NE): Has a role in the encoding and retention of memories for emotionally significant experiences. Also called noradrenaline. Secreted automatically during times of heightened emotional arousal. Influences the activities of the amygdala and hippocampus



Creating memories changes the structure and function of neurons

Changes in the structure of neurons is evident in:

•Growth and strengthening of synaptic connections•Number of dendritic spines increases – dendrites become ‘bushier’•This increases the surface area of dendrites which allows for extra synapses•‘Synaptic growth’ allows for more synaptic connections between adjacent neurons in a memory circuit

LONG TERM POTENTIATION is the long-lasting strengthening of synaptic connections of neurons, resulting in better

communication between neurons and more responsive post-synaptic neurons

HOMEWORK

LEARNING ACTIVITY 7.1 (pg.288)LEARNING ACTIVITY 7.2 (pg.288)

ROLE OF THE TEMPORAL LOBE IN MEMORY FORMATION

Research conducted on H.M. (Henry Molaison)

•Had brain surgery to treat severe epilepsy•Split-brain treatment did not work•His medial temporal lobe was removed•This surgery was successful in stopping seizures•His personality was unchanged and all cognitive functions remained unaffected• HM could not remember things that happened leading up to the

surgery• Memory loss was ‘total’ in period of 2 years leading up to surgery• Memory loss was ‘partial’ in period of 10 years leading up to surgery• Short-term memory was relatively normal but…• He could not form new episodic or semantic memories• Procedural memory was relatively normal


THE ROLE OF THE HIPPOCAMPUS

A medial temporal lobe structure that is crucial for long-term

memory formation

•Has a role in encoding new declarative explicit memories

•Does not appear to have a role in forming or retrieving procedural memories

•Believed that the hippocampus does not store long-term memories

•Instead the hippocampus transfers memories to other cortical areas for long-term storage


THE ROLE OF THE HIPPOCAMPUS

A medial temporal lobe structure that is crucial for long-term

memory formation

•People with damage to the hippocampus also tend to have trouble remembering the location of objects

•This indicates that the hippocampus is also important for spatial memory

HOMEWORK

LEARNING ACTIVITY 7.4 (pg.291)


THE ROLE OF THE AMYGDALA

A small structure located next to and interconnected with the hippocampus in the medial

temporal lobe

•Role in processing and regulating emotional reactions (fear & anger)

•Involved in the encoding and storage of memories that have a significant emotional component

•Amygdala contributes to the formation of explicit declarative memories ‘flashbulb memories’


THE ROLE OF THE AMYGDALA

A small structure located next to and interconnected with the hippocampus in the medial

temporal lobe

•Particularly important for the learning and memory of fear responses involving implicit memory

•People with damage to the amygdala are unable to acquire a conditioned fear response

HOMEWORK

LEARNING ACTIVITY 7.5 (pg.294)

AREA OF STUDY 2 MEMORY UNIT 3 THE CONSCIOUS SELF.

Documents

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memory formationrole

memory formationneuron

memory formationacetylcholine

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postsynaptic neuronsrole

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function of neuronschanges