WEEK 1 READINGS

Do implementation conditions for reconsolidation of memory translate easily from rodent to human studies?

Implementation conditionings for the reconciliation of memory does not translate easily for rodents to human studies.

What is memory reconsolidation?

The idea that after retrieval (recall of a memory) , previously consolidated memories can become established and require more protein synthesis for long-term storage.
Theory suggests that this can occur via volitional control or after a cue that serves as a reminder.

How can memory reconsolidation research be used practically in therapy/psychology?

Nadar and colleagues suggest that targeting specific aspects of memory during reconsolidation could help in treating anxiety, trauma-related and addiction disorders. They suggest that these interruptors can be behavioural or pharmacological

Contrast extinction and reconsolidation as methods to reduce fear.

Extinction is the processing of repeatedly presented CS without CR, thereby allowing the participant to confront CS without a conditioned fear response – this is a method that is problematic as processes of spontaneous recovery, reinstatement and renewal still exist.
Blockade of reconsolidation, on the other hand, can target the proteins that may rebuild memory as old memories are re-retrieved. For example, Nader's work used a pavlovian fear conditioning paradigm to show that when an inhibitor of protein synthesis was administered after memory retrieval, CR was reduced the next day

What is the retrieval-extinction paradigm?

aims to take advantage of the principles of reconciliation and extinction combined.
In the paradigm, tone-alone (retrieval only) trials begin, rodents are left alone, allowing for the memory to destabilise before extinction trials begin. This type of paradigm is said to encourage the altering of memory rather than create a new extinction memory.
The retrieval-extinction effect - describes how memories are more easily altered in the context of a retrieval extinction paradigm → which takes advantage of the idea of memory reconsolidation

What are some factors affecting memory modification via reconsolidation?

The length and presence of an interval between retrieval and the beginning of the extinction session
Prediction error is not necessary for behavioural updating during reconsolidation.
Associative memories may be impacted less by reconsolidation methods

What are some aspects of reconsolidation modifications?

Bidirectionality → reconsolidation can both improve and decrease the strength of emotional memories
Finite Windows → the opportunity to modify memories is finites
Specificity → the reconsolidation blockade can be both CS and US-specific, but there is some evidence to suggest that treatment effects may be generalisable across a range of conditioned stimuli.
Robust and persistent → modifications can be robust and persistent
Erasure → reconsolidation modifications is not erasure
Differences in mechanisms between standard and retrieval extinction exist but we don’t quite know what they are.

What does the research on the pharmacological blockade of reconsolidation generally conclude?

Generally, the use of propranolol, Sirolimus, has been found to have positive effects in altering CS-US cues in humans in the context of PTSD and substance use disorders.

What does research around behavioural updating during reconsolidation generally conclude?

Using the retrieval extinction paradigm, with animal research representing robust findings, but mixed findings in humans.
Lots of different types with or without behavioural interference mechanisms – e.g pharmacology etc.

What was the issue presented in the early memory field?

Incapacity to separate models to pinpoint specific causal mechanisms inside neurons by which memory was developed and modified.

What was an example of a clear structural change in both presynaptic and postsynaptic cells?

In Aplysia, studies have found that long-term memory changes have clear structural effect on the storage of long term memory in the gill-withdrawal reflex.
Sensory neurons in the experimental condition make more connections to motor neurons than control animals, compared to controls. The effect of structural changes is also prevalent in the dendrites of postsynaptic motor neurons as they also grow and remodel to accommodate additional sensory input.

What do the findings on structural changes inside the cells demonstrate about procedural memory?

That memory storage, even for elementary procedural memories, is distributed amongst multiple sites and that a single synaptic connection is capable of being modified in multiple ways in multiple different periods of time.
This had implications in psychology research because psychological concepts could now reflect their underlying cellular and molecular mechanisms.

When did discoveries around LTP emerge (changes in declarative memory)?

In the 1970s, various researchers concluded the importance of ‘cells that fire together, wire together’ – by the start of the 1990s, people had concluded that LTP is expressed by both changes in the presynaptic and postsynaptic neurons.

What did molecular biology allow for in the development of a procedural memory model that considered the switch between short term and long term memory?

Allowed for the observation that long term memory requires the synthesis of a new protein .
Additionally, found that the synthesis connection is also constrained by memory suppressor genes.

What occurred in the 1980s and 1990s around the genetic analysis of learning?

Found that gene alternation can also influence the learning and behaviour of mice and other.
Used the capacity for gene alternation to allow for specific insights into the storage vs. development of memory (e.g. when a mice’s capacity to process memory storage was blocked, LTP was inhibited, linking these two things together. )

An increase in —- is one general means of memory formation.

synaptic strength

Long term memory is — and can only occur —-, in spite of the finding that long term memory and synaptic plasticity can be influenced by —.

They found that long-term memory is indeed synapse-specific, can occur only at synapses that are marked (activated), and can capture and use productively gene products shipped to all synapses. In spite of the finding that long-term memory and synaptic plasticity can be influenced by gene expression.

Memory needs to be —.

Memory needs to be actively maintained, in order to stabilize and store memory.

Describe the hippocampus’s grid cells?

A later iteration of the idea of ‘spatial cells’ – grid cells (like place cells), are space-encoding cells that have grid-like, hexagonal receptive fields and convey information to the hippocampus about position, direction and distance.