What is the role of the neuron?
Receive, process and transmit information
What are the roles of dendrites, soma and axon?
- 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)
What is a synapse and synaptic transmission?
- 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
What are the functions of the hippocampus?
- 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
What are the factors that affect the functioning of the hippocampus?
- Psychological factors such as stress, anxiety, depression
- Brain trauma such as head injury or stroke
- Health related conditions such as alzheimer's disease
What are the roles of the amygdala?
- 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
What is consolidation?
The process by which new memories are transferred into LTM
Describe the consolidation theory
- 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
What conditions are necessary for permanent strage of memory? (Consolidation theory)
- 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
Describe long term memory over the life span
- 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
Describe short term memory over the life span
- 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
Describe working memory over the life span
- 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
What are the reasons to explain memory decline?
- Lack of motivation: losing interest in trying to learn
- Loss of confidence in memory: Less effort in learning and remembering new material
What is amnesia?
- The inability to remember due to damage to the brain
- eg. injury, disease, stroke, seizures, drugs, alcohol
What is retrogade amnesia?
- Difficulty in recalling material learnt before the brain damage
- Causes include strokes, brain tumours, surgery and electroconvulsive therapy
What is anterogade amnesia?
- 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
What is brain trauma?
Damage to the brain caused by head injuries, disease, seizure, malnutrition, stroke, chemical damage, anoxia (lack of oxygen), surgery
What are neurodegenerative diseases?
Progressive decline in structure , activity and function of neurons in the brain
What is dementia?
- A large group of neurodegenerative diseases that affects higher mental functions and loss of memory
- Develops progressively
- eg. Alzheimer's disease
Describe 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
What are the structural changes involved with Alzheimer's disease?
- 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