learning and memory Flashcards
what is learning?
a process by means of which organisms acquire new knowledge or skills
what is memory?
the maintenance of learning across time
inference of behavioural change (rescorla, 1988)
t1= subject exposed to an experience
t2= subject assessed whether t1 has modified behvaiour
experimental paradigms: a single stimulus (s1) without any other event
habituation and sensitisation
experimental paradigm: s1 presented with another stimulus (s2)
classical conditioning
experimental paradigm: s1 presented in such a way so as to reinforce a certain behaviour
instrumental/operant conditioning
what is habituation?
a decrease in the behvaioural response following repeated exposure to a threatining stimulus e.g habituation of the startle response
what is sensitisation?
an increase in the behvaioural response following repeated exposure to a threatining stimulus
often characterised by sensitisation to a whole class of stimuli, in addition to the one that has been repeated
what is classical conditioning?
the process by which a response normally elicited by one stimulus comes to be controlled by the other
(unconditioned/neutral/conditioned)
what is operant conditioning?
the process by which a behaviour is affected by its outcomes
positive reinforcement and negative reinforcement
simple model of memory processing
input of incoming information (aquisition via perception and encoding)
holding in a memroy store (consolidation, maintenance)
output performance (retrieval/recall/recognition)
multiple-trace hypothesis of memory (mcgaugh, 1968)
temporal stages of memory
mediated intracellularly by different processes
short-term, immediatiate-term and long-term memory
what is short-term memory?
memories held for a few minutes (<30 mins although no strict definition)
vulnerable to interference
severeal stores
working memory model (baddeley and hitch 1974)
a multi-component short-term memory store
allows information to be held and manipulated over a short period of yime until required to complete a task
what is the central executive?
attentional store
what is the visuospatial sketchpad?
temporary store for the remembrance and manipulation of visual information
what is the phonological loop?
temporary store for verbal information
inner voice and ear
regional activation during working memory (chen et al, 2013)
the greater the demandson working memory, the greater the number of brain regions activated
what is consolidation?
information in the STM is transferred to the LTM
what is synaptic consolidation?
early, fast process that stabilizes a memory at the level of individual synapses
occurs within the first few hours after learning or encoding
depends on synaptic plasticity mechanisms - - long lasting strengthening of the synapse e.g long term potentiation
- long lasting weakening of the synpase e.g long term depression
what is systems consoldiation?
initially, new episodic memories (like “what you did yesterday”) rely heavily on the hippocampus
over time, the memory becomes less dependent on the hippocampus and is stored more diffusely in the neocortex, especially in areas related to the memory content
appears to depend on deep sleep
what is memory consolidation/reconsoidation?
transfer STM to LTM
recent research has challenged the view that consolidated memory traces are permanent
it has been suggested that recativation (retrieval) of a memory returns it to an unstable state- the memory can be reconsolidated if it to persist
this leaves more room for interference and inaccurate memory recall (altered)
therapeutic applications of memory reconsolidation
dysregulated signalling of the stress-related neurotransmitter noradrenaline has been identified as a key biomarker underlying PTSD symptomatology (giustino et al 2016)
administration of propanolol (non-selective noradrenline β receptor antagonist) at the time of memory reactivation has been shown to block the magnitude of physiological responses to a remembered event
what is long-term memory?
memories lasting longer than 30 mins (altough no strict definition)
robust and enormous capacity
memory stroage requires structural/biochemical changes in neurons and neural netowkrs
synaptic plasticity mechanisms- LTP and LTD
