CNS + Bio basis for learning

lec 3

what is bio psyche?

application of bio principles to study of mental processes and behaviour

what does William James (1890) argue about bio psyche?

the scientific psychology should be grounded in bio understanding

name the research methods for bio psyche

lesion studies, animal studies, enhancing neural function, measuring neural activty, genetic manipulations

who made the theory of reflex action 1662

Descartes

explain descartes theory of reflex action

hydraulic model of causation and brain function i.e. fluid comprises animal spirits, Fire (A) is the stimulus causing a chain of processes between the foot (B) continuing up the nerve tube to a cavity in the brain (F), the opening of tthis cavity allows fluid to enter the nerve tube resulting in the reflex action 1.e. pulling foot away

explain spinal reflex

stimulus ‘triggers’ electrical activity in neuron, multiple parallel pathways act simultaneously, these sequence of actions = relay/circuit, results inn sensation of pain

label spinal reflex

what is an action potential

info is transmitted along neurons as sharp impulses of electricity, this triggers activity/activation (produces action potential)

what model from which school of psychology demontrates action potential and looks at neurons

the connectivist model of cognitive and bio psyche

label the structure of a typical neuron

label the excitability of neurons and muscle cells

summarise neuron activity in the brain (how is neuron activity defined)

neuronal activity in the brain is often described in abstract terms e.g. info (in bio terms its callled action potential)

explain the use of this info/ neuron activity in brain

info is the correlation of socially meaningful content and neuronal signals, info can also be a spinal reflex registered in the brain

how does communication function between neurons

the synapse is the region where one neuron communicatees with another, synapse consists of part of the cell and the small gap between. action potentials dont cross generally from one neuron to another, communication between neurons works by neurotransmitters (chemical)

label image of synapse region

explain the function of neurotransmitters

in response to the arrival of action potentials, the neurotransmitter is released at the terminal of the presynaptic neuron influencing the activity of the postsynaptic neuron. molecules termed ‘receptors’ are influenced by neurotransmitters creating new action potential

lebel image of synaptic transmission

explain neurotransmitters and behaviour (4)

• mediates connections between neurons and control behaviour and mental processes

• e.g.- emotional states are influenced by the release of neurotransmitter (e.g serotonin and GABA)

• drugs can artificually manipulate the activity of neurons to target certain synapses e.g. pyschopharmacology

• mood altering drugs indicate the interdependence between mental states and phsycial events in the brain e,g. anti-depressants

label the cerebrum

label the cerebral lobes

label brain

label Brodmann’s areas

label white, grey matter and the ventricle

explain information processing (4)

• the brain is a super system of systems composed of an elaborate interconnection of small but macroscopic cortical regions and sub cortical nuclei

• these are made up of microscopic local circuits (neurons) which are connected by synpases

• the brain makes decisions based on internal and external events

• different parts of the brain process different types of info

summarise the connectionist neural net

• parallel distributed processing (PDP)

• has important theoretical practical consequences

• items of info are not stored at specific sites; they are distributed throughout the whole net

whats included in the bio basis of learning

non-associative habituation/sensitization, associatiive learning (conditioning)

explain learning by Toates (2011)

• acquisition of knowledge ot skill triggered in a particular situation

• bahaviour that results in potential to change behaviour

• results in physical changes in the brain

what are the 2 types of learning according to Toates 2011

1. non-associative learning: habituation and sensitisation

2. associative learning: conditioning

explain non-associative learning: habituation

• most basic learning form

• decoupling of association

• progressive decline of response to stimulus

• facilitates attention to new stimuli

• consequence of change at the neural level

explain sensitization

• progressive response following repeated exposure to stimulus

• efficient firing on neuron (LTP)

• both adaptive and maladaptive

• e.g. pain response=adaptive

• e.g. drug sentivity = maladaptive

label image of synapses in habituation and sensitisation

what is classical conditioning as associative learning

-pairing of 2 stimuli results in behaviour change

what does LTP stand for

long term potentiation

explain LTP

• Bliss and Lomo 1973 dicovered a persistent strangthening of synapses in the hippo of anesthetized rabbits

• electrical stimulation in the hippo produced an increased response (potentiation) in the connecting synapse - a phenomenon they called LTP

how can LTP be associative

• activity in the presynaptic neurons also infleunced the ‘sensitivity’ of nearby synapses

• if weak and steong synapses are active simuktaneously then the weak synpase will be potentiated

what is opererant c

• learning behaviour can be shaped by external cues and responses

what can a random response to a particular sitch be a connsequence of?

• reinforcement

• punishment

• positive reinforcement

• negative reinforcement

• positive punishment

• negative punishment

whats does hebbs law state in hebbian learning

‘neurons that fire together wire together’

what is Hebb’s law explaining

-when axon of cell A is near enough to excite cell B and repeatedly takes part in firing it, some growth process ot metabolic change takes place in one ot both cels such that A’s efficiency, as one of the cells firing B is increased.

what does Hebbs (1949) suggest is the organisation of behaviour

• learning involved the strengthening of connections between neurons

• events are represented as activity flow through neuronal loop

• repeated activation of two neurons leads to formation and stregthening of a functional link

whats does repeated stimulation of synapse result in

it results in pre-synpatic and post-synaptic change

label repeated synapse stimulation

whats are hebbian implications for learning

it highlights role of synatic plasticity in learning as strictural changes in neuronal connectivity

what is the hebb synapse

• synapse which has increased strength due to learning

• transformation of a neutral stimulus to a conditioned stimulus

• describes the process of long-term changes (LTP)

what is involved in synaptic pruning

branching and weeding (neuronal pruning'/neuro-structural reassembly)

explain synaptis pruning

• refers to changes in the neural sturcture by reducing the overall number of neurons/connections, leaving more efficient synaptic configurations

• used to describe amturation of behaviour and cog intelligence in kids as ‘weeding out’ lesser used synapses

label image of synaptic density from newborn to adults hood