Mechanisms of learning and behaviours not dependent on learning
What is learning?
A relatively permanent change in behaviour and knowledge that occurs as a result of experience
What are 3 behaviours not dependent on learning?
Fixed action patterns
Behaviour dependent on maturation
What are reflex actions? Provide an example
Reflex actions innate, automatic and involuntary reactions to environmental stimuli, which
do not require prior experience and conscious processing by the brain.
They involve a simple, rapid response to a specific stimulus and
are adaptive for survival.
eg. Blinking in response to having air blown into your eyes
What are fixed action patterns? Provide an example
Fixed action patterns are inborn, predispositions to behave in a certain way when appropriately stimulated. They are complex, sequential behavioural responses that are unique to a particular species where every member of the species inherits the behaviour
eg. A funnel web spider creates its characteristic tubular web
What are behaviours dependent on maturation? Provide an example
Behaviours dependent on maturation are behaviours that are genetically predetermined to occur at certain stages of an organism’s lifespan; they require the organism to be sufficiently mentally and/or physically developed before the action can be undertaken
eg. Humans cannot walk until they are sufficiently developed mentally and physically
What are neural pathways?
An interconnected group of neurons organised as a network that is active during the learning process
When learning, a new neural pathway is either created or existing ones are strengthened
What is a synapse?
The junction where the axon terminals of the presynaptic neuron comes into close proximity with the dendrites of post synaptic neurons
What is synaptogenesis?
The formation of new synapses and change in neural pathways, particularly during the early brain development
What are neurotransmitters? Provide examples
Chemical substances that carry information between neurons
Glutamate: An excitatory neurotransmitters that strengthens connections of synapses. It makes pre-synaptic neurons more likely to fire
Dopamine: Prompts the growth of dendritic spines in the post synaptic neuron
What does plasticity of the brain refer to?
Refers to the way the brain changes is response to stimulation form the environment. Occurs at the synaptic connections in the brain
What is developmental plasticity?
Refers to the brain's ability to modify synaptic connections as a result of learning and experiences during the growth or development of its neural structure.
What are the 5 stages of plasticity?
1. Proliferation: where unborn baby cells become neurons and divide and multiply
2. Migration: newly formed neurons move to their destined location
3. Circuit formation: the axons of the new neurons form synapses with target cells
4. Circuit pruning: Where neurons who have not made a connection die and connections are either strengthened or weakened based n whether the neurons fire together
5. Myelination: Where the axons of the neurons become covered in myelin. It protects axons from interference and speeds up the transmission. Begins from occipital lobes to frontal lobes
What is adaptive plasticity and reorganisation?
Refers to changesin the neural stucture of the brain to enable adjustments to experiences and to compensate and/or maximise remaining functions in the event of brain damage
Reorganisation: a shift in neural connections that alter the function of a particular area of the brain
What are sensitive periods?
A specific time in development when an organism is more responsive to learning than any other time of development
What is experience expectant and dependent learning?
Experience expectant learning: Occurs during sensitive periods and refers to experiences necessary for learning to occur. eg. Learning to speak the native tongue as a child
Experience dependent learning: A form of learning that can occur at anytime eg, learning to read or write in one's native tongue
What are critical periods?
A very narrow period of time in an animal's development in which the animal is preprogrammed for learning to occur
eg. Young birds imprinting to the first moving object they see after they hatch from an egg
Brain development during adolescence
Cerebellum: increase in the number of neurons and synapses in the cerebellum.
more active during adolescence.
Corpus callosum: thickens and there is an increase in the number of connections between the two
Frontal lobe (prefrontal cortex): motor
movement and higher order thinking.
What is rerouting and sprouting to compensate for loss of function due to brain damage
Rerouting: when an undamaged neuron that has lost connection with an active neuron due to damage, it seeks a new active
neuron to connect with instead.
Sprouting: growth of new, bushier connections on a neuron’s dendrites.
What is LTP?
The long-lasting strengthening of synaptic connections between neurons, resulting in enhanced/more effective neural functioning.
Functional and structural changes include:
Increased levels of neurotransmitters produced and released (pre synaptic)
Increase in dendrites – formation of new synaptic connections