Mechanism of Memory Formation

Receive, process and transmit information

• Dendrites: receive info from other neurons
• Soma: Controls the metabolism and maintenance of the cell
• Axon: A nerve fiber that carries info away from the soma. Has terminal buttons at ends that secrete neurotransmitters (a chemical substance that transmits nerve impulses)

• Synaptic transmission: The process of neurons communicating with other neurons
• Synapse: the junction between two neurons where the terminal buttons of the presynaptic neuron comes into close proximity with the receptor sites on the dendrites of a post synaptic neuron

• Formation of explicit memories
• The process of consolidating of explicit memories
• Transfer new memory to other parts of the brain for permanent storage
• Linking emotion to memory through the close relationship with amygdala

• Psychological factors such as stress, anxiety, depression
• Brain trauma such as head injury or stroke
• Health related conditions such as alzheimer's disease

• Regulates emotions such as fear and aggression
• Memory for emotions shown on faces
• The emotions it regulates enhances the memorability of an event
• Has a role in activating the hippocampus

The process by which new memories are transferred into LTM

• Proposes that memory is permanently stored through a process where there are physical changes to the neurons
• Ongoing process
• Retrieved memory must be reconsolidated to allow it to be refined, corrected or modified

• Physical change: there must be a physical change to the synapses
• No disruption: LTM is unlikely to form of process is disrupted due to head injury, level of attention, arousal level due to anxiety)
• Time: Consolidation takes time; the more time neural connections have to strengthen, the less vulnerable they are to disruption or change

• Declarative memory: Semantic memory are at the same level however may require more time to encode and retrieve.
• Episodic memory is affected the most- declines rapidly after middle age.
• Procedural memory: No significant decline

• For simple tasks, STM does not deteriorate with age
• Verbal recency memory is most affected by age
• Visual recency memory is less likely to be affected by age

• Elderly people are more likely to perform more poorly than younger people on complex working memory tasks
• Prefrontal cortex—responsible for working memory—is less active and efficient

• Lack of motivation: losing interest in trying to learn
• Loss of confidence in memory: Less effort in learning and remembering new material

• The inability to remember due to damage to the brain
• eg. injury, disease, stroke, seizures, drugs, alcohol

• Difficulty in recalling material learnt before the brain damage
• Causes include strokes, brain tumours, surgery and electroconvulsive therapy

• The inability to encode and store new memories
• Able to retrieve memories prior
• Often related to damage to temporal lobe and hippocampus
• Often accompanied by retrogade amnesia

Damage to the brain caused by head injuries, disease, seizure, malnutrition, stroke, chemical damage, anoxia (lack of oxygen), surgery

Progressive decline in structure , activity and function of neurons in the brain

• A large group of neurodegenerative diseases that affects higher mental functions and loss of memory
• Develops progressively
• eg. Alzheimer's disease

• Most common form of dementia 
• Hippocampus and prefrontal cortex are affected therefore experiences retrogade and anterogade amnesia
• Symptoms include mood and personality changes, impaired ability to recall words and names, semantic and procedural memories decline

• Presence of amyloid plaques (protein that form among axon terminals) interferes with communication between neurons
• Neurofibrillary tangles (build up of protein)- associated with death of brain cells
• Brain shrinks when hippocampus loses cells