Learning and Memory Flashcards
1
Q
How can changes caused by experience be observed?
A
- in behaviour
- in neurons
- in synapses (density/efficiency and interactions between neurons)
2
Q
What does brain damage cause?
A
- memory loss for earlier events (retrograde amnesia)
- within a limited time period
3
Q
What happened to patient HM?
A
- had severe epilepsy so underwent bilateral medial temporal lobotomy
- afterwards suffered from anterograde amnesia (long term memory loss for new events/newly learnt info)
- hippocampus, amygdala, subcortical regions, entorhinal cortex was damages but some parts spared. parahippocampal cortex was fully removed
4
Q
How does HM show different brain areas are involved in memory formation?
A
- cognitive abilities were largely preserved, as well as short-term memory and episodic memories of pre-operation
- could acquire new motor skills but not recall having performed the task
5
Q
Definition of memory engram and what were the findings of Karl Lashley of them?
A
- localised trace of memory in the cortex
- series of experiments to show link between lesions and changes in behaviours with mice/rats
- found more errors made during relearning with higher percentage of cerebral cortex removed
- concluded learning and memory aren’t located in single area but widely distributed
- as lesions were made all over, shows isn’t specific part that needs to be spared to perform with little errors as possible
6
Q
What are the major limitations of investigating causal relations in human beings?
A
- ethical considerations of brain manipulations and measurements
- number of patients with lesions is small, difficult to generalise
- expensive research-quality data
7
Q
What are the benefits of using animal models?
A
- overcome some ethical limitations
- replication and precision of lesions
- availability and sample sizes
- systematic study of wider range of methods, behaviours and psychological processes allowing insight at circuit/synaptic level
8
Q
How do surgical lesions vary in precision?
A
- neurons are ablated using physical or pharmacological methods (neurotoxins or high concentrations of neurotransmitter)
- loss of neurons is permanent, significant damage of non-target tissues in surrounding areas
9
Q
What is optogenetics?
A
- precise temporary inactivation of neurons done through genetic engineering
- light-sensitive molecules inserted in membrane using genetic transgenic lines to investigate specific circuits
- functional control of targeted cell types using light of specific wavelength
- high spatial and temporal precision with microstimulations
- reversible temporary manipulations allow within-subject comparisons
10
Q
Definition of human episodic memory?
A
- recall of unique experiences explicitly located in past as conscious experience
- language-based reports (allows for argument that it’s only possible for humans)
11
Q
Do animals have episodic-like memories?
A
- ability to form and recall memories for events personally experienced in the past are tight to specific context
- novelty and familiarity judgements
- retrieval of when/where/what memories in the learning of context-dependent tasks in scrub jays
12
Q
What are the functions the medial temporal lobe is responsible for?
A
- hippocampus involved in encoding specific items in context during long-term memory formation
- perirhinal cortex is important for sense of familiarity
- parahippocampus encodes context representations
13
Q
What did Squire and Zola-Morgan (1991) find?
A
- when monkeys had lesion in hippocampus they performed nearly as well as control when learning from previous experiences
- when the lesion extended to include entorhinal cortex and parahippocampal cortices they performed significantly worse
- when the lesion extended to anterior entorhinal and perirhinal cortices the performance was the worst
14
Q
What are the 2 types of memory and the related brain regions?
A
- declarative (factual,episodic, how events and facts relate to familiarity): medial temporal lobes, particularly the hippocampus, are important
- non-declarative (procedural, knowing how to do things): striatum is important
15
Q
Definition of learning?
A
- process of acquiring new information
- in 2 forms on how they’re exposed to stimuli, intervals and if it interacts with stimuli or it’s passive exposure (e.g. priming)
16
Q
What is non-associative learning?
A
- habituation and sensitisation
- experience of repeated exposure to stimuli and responding in adaptive fashion rather than associating response with something
- involves brain stem and cerebellum
- habituation: response weakens with repeated stimulus presentation but not due to adaptation of senses or fatigue, not extinction of associations
17
Q
Definition of appetitive association and temporal contiguity?
A
- degree of coincidence of CS and US determine learning outcome
- reinforcement is most effective if reward coincides/follows CS
