UNIT 4 BRAIN, BEHAVIOUR & EXPERIENCE

1. UNIT 4BRAIN, BEHAVIOUR & EXPERIENCE AREA OF STUDY 1 LEARNING

2. NEURAL PROCESSES INVOLVED IN LEARNING • Neurons are soft, flexible, living cells • They can change their size, shape, function and connections with other neurons • They are influenced by biological processes and environmental experiences

3. DEVELOPMENT OF NEURAL PATHWAYS When learning occurs, physical changes take place in the brain at a neuronal level • The most prominent change is at the synapse • Learning changes the strength of connections between neurons at the synapse • Learning can cause new synapses to form • Neurotransmitter forms the basis of these connections

4. DEVELOPMENT OF NEURAL PATHWAYSROLE OF SYNAPSES • DONALD HELB (1949) • ‘Neurons that fire together, wire together’ • Credited with the idea that learning involves the establishment and strengthening of neural connections at the synapse • Learning results in the creation of ‘cell assemblies’ (interconnected groups of neurons that form networks or pathways) • When neurotransmitter is repeatedly sent across the synaptic gap, the pre-synaptic neuron and the post-synaptic neuron are repeatedly activated at the same time • This changes the chemistry of the synapse, strengthening the connections between neurons • This makes them more likely to fire together again

5. DEVELOPMENT OF NEURAL PATHWAYSLONG-TERM POTENTIATION • DONALD HELB (1949) • ‘Neurons that fire together, wire together’ • These synaptic changes that occur in a neural pathway during learning are believed to have long-term potentiation • Repeated stimulation causes a post-synaptic neuron to be more responsive to the pre-synaptic neuron • LTP makes learning possible in humans and all animals with nervous systems • The exact role of LTP is yet to be extensively investigated

6. DEVELOPMENT OF NEURAL PATHWAYSNEUROTRANSMITTERS INVOLVED IN LEARNING • GLUTAMATE • Has a crucial role in learning • Glutamate initiates activity in post-synaptic neurons • Its repeated release is believed to contribute to synaptic formation and strengthen connections at the synapse during learning • DOPAMINE • Contributes to the strengthening of synaptic connections during learning • Has been researched for its role in reward-based learning • When you do something you like, dopamine is secreted within a specific neural pathway in the brain • The release of dopamine provides a pleasurable experience • This motivates the individual to repeat the behaviour

7. HOMEWORK LEARNING ACTIVITY 10.4 (pg.380)

8. PLASTICITY & EFFECTS OF EXPERIENCE ON THE BRAIN Plasticity is the ability of the brain’s neural structure or function to be changed by experience throughout the lifespan Our genes govern the overall architecture of our brain, but experience guides, sustains and maintains the details The brain of a developing individual is more plastic than an adult DEVELOPMENTAL PLASTICITY ADAPTIVE PLASTICITY

9. PLASTICITY & EFFECTS OF EXPERIENCE ON THE BRAINDEVELOPMENTAL PLASTICITY • Developmental plasticity refers to changes in the brain’s neural structure in response to experience during its growth and development • This type of plasticity is pre-determined and influenced by genes, but subject to experience • Forming new synapses = synaptogenesis • Occurs rapidly during the first year of life • Eliminating synaptic connections = synaptic pruning • Number of synapses in an adult is 40% less than the number of synapses in a three year old

10. PLASTICITY & EFFECTS OF EXPERIENCE ON THE BRAINADAPTIVE PLASTICITY • Adaptive plasticity refers to changes occurring in the brain’s neural structure to enable adjustment to experience, to compensate for lost function and/or to maximise remaining functions in the event of brain damage • Most evident when the brain has experienced damage through either inflicted or acquired injury through re-organising the structure of the brain • The way that the brain responds depends upon the location, degree and extent of the damage, and the age at which the damage is experienced • Can be done at neuronal level, larger areas of brain tissue or at hemispheric level • Rerouting = an undamaged neuron that has lost a connection with an active neuron may seek a new active neuron and connect with it instead • Sprouting = the growth of new bushier nerve fibres with more branches to make new connections. Sprouting also involves rerouting

11. PLASTICITY & EFFECTS OF EXPERIENCE ON THE BRAINTIMING OF EXPERIENCES

12. PLASTICITY & EFFECTS OF EXPERIENCE ON THE BRAINTIMING OF EXPERIENCES Sensitive Periods of Development A period of development when an organism is more responsive (or sensitive) to certain environmental stimuli or experiences ‘Windows of opportunity for learning’ They are the optimal, or best possible, times for relevant learning to occur EXPERIENCE-EXPECTANT LEARNING = the brain encounters the experience that is expected, ideally in a sensitive period. The particular experience then contributes to the brain’s development. Occurs at infancy EXPERIENCE-DEPENDENT LEARNING = Learning that ‘depends’ on exposure to specific ‘experience’. Occurs at any time during an individual’s development

13. PLASTICITY & EFFECTS OF EXPERIENCE ON THE BRAINTIMING OF EXPERIENCES • Critical Periods of Development • A specific period of development during which an organism is most vulnerable to the deprivation or absence of certain environmental stimuli or experience • Have identifiable start and end times • For example, if after birth, one eye is kept closed, or does not function properly, the eye will be forever blind • Imprinting is an example of a critical period (a period when an attachment is formed directly after birth)

14. HOMEWORK LEARNING ACTIVITY 10.6 (pg.393)

15. CHAPTER 10 CHAPTER 10 – TRUE OR FALSE QUIZ (pg.393) CHAPTER 10 – MULTIPLE CHOICE TEST (pg.394-395) CHAPTER 10 – SHORT ANSWER TEST (pg.395-396)