Episodic And Declarative Memory

Front 1

What is episodic memory?

What is semantic memory?

What does the hippocampus create?

What does spatial context possible act as?

Representations of what are bound during encoding to the representation of a specific spatial context?

What might reinstatement of spatial context help to retrieve

Back 1

Memory for a unique event, or event sequence involving the binding together of several stimuli such as face, names or actions

Knowledge, facts, rules (not skills) often learnt through repetition/ structured by semantic similarities and differences

Different representations for different spatial contexts

May act as a scaffold for episodic memory

Objects, people, smells and sounds or states such as fear, hunger or elation

Other elements of an episodic event experienced within that spatial context

Front 2

What did Miller et al 2013 investigate?

What were participants told to do?

What was the hypothesis?

What did the study find?

Back 2

Neural activity in human hippocampal formation in relation to spatial context and retrieved memories

Freely explore a virtual town, place cells were recorded during this sample period, noting the place fields, then go to different shops and buildings where an object is presented to them outside a shop, i.e. a ring outside a sweet shop, then asked to freely recall the objects they had been presented with during the task

Place cells with place fields near each shop will activate when subjects recall the item from that location

Place cell activity during free object recall did reinstate the spatial location associated with the object as infield place cells fired during the onset of vocalisation of the object in that area

Front 3

What does the hippocampus create?

What increases when many spatial contexts are created?

What can be better distinguished by being bound to different contextual representations?

What does pattern completion underly?

Back 3

Different representations of different spatial contexts allowing events to be distinguished based on the place they occurred

Memory capacity because it reduces interference

Similar events with overlapping people, ideas and objects

Recall of spatial context and items in context

Front 4

What did Gadian et al 1997 study?

What damage did these patients have?

What deficits did these patients have?

What did they attain low to average competency in?

What do the findings support?

Back 4

3 patients with brain ages that were acquired aged 0-9 years,

All had bilateral hippocampal damage,

All had episodic memory amnesia

Competency in speech, literacy and factual knowledge

Only episodic memory being fully dependent on the hippocampus and this memory component being dissociable

Front 5

What spatial memory deficits did they all have?

"Temporal memory deficits

"Episodic

Back 5

- None of the patients could find their way around familiar settings, remember where objects are or where they have placed them

- None are well orientated on date or time, had to be frequently reminded about appointments/events

- None can provide a reliable account of the days activities, remember phone conversations, messages, stories, visitors and tv programmes

NONE CAN BE LEFT ALONE

Front 6

What are the five networks involved in episodic memory?

What happens to the hippocampal formation in ahlziemers disease and dementia?

Back 6

1. Anterior Thalamus
2. PFC
3. Parietal Cortex
4. Posterior Cingulate Cortex
5. Hippocampal formation including hippocampus, entorhinal cortex, parahipocampl corticies

Typically the first to degenerate, as the first symptom of loss of episodic and spatial memory

Front 7

Brain Structure Differences in episodic memory tasks:

What did Winocur et al 2002 do?

What did they find?

What did they also find?

What did head et al 2008 do?

What were the three findings?

What did Rosen et al 2003 do?

What did they find?

Back 7

Got young and older adult to recall events from five life periods

Young adults were biased towards episodic details and older adults preferred somatic details

Hippocampal volume increases then decreases with age

Measured age related differences in episodic memory taking measures of brain volume, executive functions and processing speed

-Age was linked to reduction in brain volumes --Cognitive performance Hippocampal shrinkage directly affected episodic memory,
-Poorer temporal processing directly effected episodic memory

14 subjects with age appropriate memory levels 2 years prior, those lower than the median had low memory, those above had high memory

Those with low memory had smaller left hippocampal volumes and left hippocampal volume positively correlated with scores on delayed and immediate recall tasks

Front 8

GENETIC DIFFERENCES:

What is the BDNF gene?

What does it code for?

What did Linnarson et al 1997 find?

Back 8

Is a gene in which different polymorphisms of it effect episodic memory

A factor implicated in growth processes and synaptic plasticity and the highest expression of this is within the hippocampus

Reduced BDNF expression in mice impaired spatial memory in Morris Water Maze

Front 9

What did Egan et al 2003 investigate?

What did the study find?

What did they have no impairment in?

What was a clear impairment?

Back 9

How polymorphism of BDNF effects human memory and hippocampal volume in schizophrenics, their siblings and controls

Those with the met polymorphism had impaired BDNF activity dependent secretion in the hippocampus

Various non-episodic memory tasks such as the California verbal reasoning, the semantic memory test and working memory/selective executive function test

In the Wechsler memory scale revised which is a test of verbal episodic memory requiring immediate and delayed recall of information from two stories

Front 10

What did Hariri et al 2003 investigate?

What was the stimuli?

What were measured?

What was found?

What did the fMRI find?

What did it also use?

Back 10

The effect of met polymorphism on a recognition memory task

Complex visual scenes

fMRI bold signals during encoding when scenes were first presented and then again during the retrieval block which contained the original and lures of the novel scenes

Performance was worse in met carrier in recognition accuracy, the recognised old as old and new as new only 84% compared to 91% of other genotypes

Increased brain activity in the other genotypes in the right hippocampus, the right parahippocampus and bilateral parahippocampus

A regression model that found 25% of the individual differences in the recognition in the memory task was explained by met genotype status and amount of hippocampal activity

Front 11

What did Bueller 2006 investigate?

What did they find?

What are the 5 consequences of carrying the met polymorphisms?

Back 11

Met allele in relation to hippocampal volume

Those with the met genotype had 11% smaller hippocampi than the vol polymorphism

1. Less secretion of BDNF
2. Less hippocampal activation in episodic memory tasks
3. Worse episodic memory
4. Fine non episodic memory
5. Small hippocampi both left and right

Front 12

What did King et al 2015 find?

What did the study report?

What four core regions are included?

Back 12

Individual difference in episodic recollection correlate with cross regional activity in the brains recollection network

Over 3 different episodic recollection task correlations are seen between 1. recollection success 2. the degree to which core regions of a recollection network show task specific increase in connectivity with other recollection network regions

Hippocampus
Medial prefrontal cortex
Posterior parietal cortex (Angular gyrus)
Posterior cingulate cortex

Front 13

Differences in Strategies:

What is there rarely found in given tasks?

What is most ideal to use?

What happens instead?

Where is there a possible interaction?

Back 13

A unique solution

The most efficient strategy every time

People have preferred strategies and favour them sometimes even if they are not most efficient

Between different brain areas, genes and strategies

Front 14

What is caused by favouring non-hippocampal solutions?

Back 14

Weak hippocampal synaptic plasticity and fewer hippocampal neurons

Front 15

What did Kirchoff et al 2006 do?

What were the two most common strategies?

What were the results?

What did it also find?

Back 15

They asked participants to carefully study images in anticipation of an unspecified memory test, there were no other instructions which allowed individuals to adopt their own strategies, then asked participants to answer a strategy questionnaire which loaded answers to one of four strategies

1. Visual inspection (i.e. studied colours/orientations)
2. Verbal elaboration (using the starting letter of the objects names)

For both strategies there was a positive correlation between use of these strategies and performance, people who used the two strategies were more successful compared to using visual imagery and memory retrieval

Participants brain activity in the left inferior frontal cortex correlates with their use of verbal elaboration strategy but not with visual inspection, participants brain activity in the left extra-striate cortex correlated with their use of visual inspection strategy but not verbal elaboration, this is a double dissociation

Front 16

What did Miller et al 2002 argue?

What method did the study use?

What did this find about participants brain activity?

What do these result indicate?

What does this highlight?

Back 16

That neuroimaging techniques commonly basis statistical analysis on groups of subjects in order to identify activation in studies of episodic memory this may be at the detriment at understanding the true underlying cognitive activations

Neuroimaging

Brain activity for all 9 participants was very distinct, these individual patterns of activity were reliable over time

Different cognitive strategies used to produce recognition response, highlighting the importance of group and individual analysis to understand episodic memory retrieval process