Retrieval and Forgetting

How is the frontal lobe is involved in memory accessibility

frontal damage hinders recall of memories, but recall improves with increased cues regardless of frontal damage

It mediates the accessibility

general principles of retrieval

target trace is the particular memory we want to retrieve, retrieval cues are little pieces of info allowing access to the target trace

Memories exist as patterns of activation not as individual entities

Cortical reinstatement

patterns of activity that the hippocampus and cortex need to be able to recreate them

Recall vs retrieval vs encoding

actual performance vs the task of remembering vs the task of committing to memory

Disrupting attention with what type of stimuli worsens outcomes

test-congruent stimuli, especially during encoding

Encoding specificity

The more similar the cues available at retrieval are to the conditions present at encoding, the more effective the cues will be (think of the best buy example)

State-dependent memory

If your physiological state matches the state of encoding, you will remember better

e.g., You are always intoxicated in class, you will perform better on the exam if you are intoxicated

Mood-dependent memory

Same as state depended, if you learn while sad, you will test better when sad

Mood-congruent memory

when you are happy, you are more likely to remember happy things and when you are sad, you are more likely to remember sad things (implications for depression)

Including multiple of these improves memory recall

cues (especially those related to the target recall)

The activity of what brain areas during encoding is positively correlated with memory performance

the hippocampus and surrounding areas, if encoding does not happen than memeory performance even with cues is not going to be sucesful

The role of different retrieval strategies have of ‘unearthing' different memories

We often have all the information we need accessible to us, but using a specific frame helps us pick what matters most in that moment. The burglar example, remember things from the house as either a home buyer or a burglar

episodic memory

Memories for specific episodes or events that are tied to the time and place in which the information was learned

Accompanied by an awareness of the past event, and a subjective re-experiencing of that event

The Recognition Memory Paradigm

Participants must identify 'old' information as such (Stimuli present during encoding AND test = targets, stimuli NOT present during encoding but present at test = lures)

Forced Choice recognition: Lures and targets shown together and identify which ones were on the study list, which ones were not

Yes/No recognition: One item shown at a time with targets and lures intermixed

Signal Detection Theory

We all have a cutoff where we say something is old or new. You can have a liberal (lower) threshold or a a high threshold of familiarity

SDT: HIT

target word was shown, and the participants say it was on the list they studied (correct)

SDT: Correct Rejection

They show a lure word, the participant says it was not on the list (correct)

SDT: False Alarm

Lure is show, participant say it was on the list they studied (wrong)

SDT: Miss

Target was shown to participant, they say it was not on the list when it was (wrong)

Lures have lower familiarity but

but by some chance might have higher level of familiarity than others

where do misses exist on the chart?

In between, they fall below threshold for saying something is familiar, and some lures have a abnormally high familiarity that are past response criteria and you will say there were on the list

If you have low familiarity threshold you will have more false alarms

strengths of signal detection theory

Allows for quantification of recognition

Allows for quantification of individual biases

Accounts for guessing

Weaknesses of signal detection theory

Does not explain recognition perfectly

Frequent words in a given language are recognized less often compared to infrequent words (Word frequency effect and cannot be explained by signal detection theory)

Dual Process Theory - familiarity

Is the perception of a memory’s strength

Not tied to contextual details

Rapid & automatic

Exists on a continuum

Dual Process Theory - Recollection

The subjective re-experiencing of a memory

Contextual

Slow & effortful

Binary (can recall or you cant)

How does the dual process theory employ remember-know methodology + what supports the dual process theory

Using a remember/know task, participants are asked if they remember seeing the stimuli or know they saw the stimuli (familiarity)

Hippocampal activity is greater during encoding for stimuli that were subsequently rated as ”remembered” vs. those that were rated as ”known.”

what is the hippocampus important for in terms of remembering

binding contextual details together for subjective re-experiencing

Process-dissociation procedure (PDP)

Uses context queries to discern familiarity and recollection

Do you remember seeing this word?

Do you remember seeing this word on the left-hand side of the screen?

Hippocampal and parahippocampal activity during encoding is greater when the source (context) is correctly recalled

To successfully retrieve the memories you work so hard to encode, you should

Pay attention to cues

Match your learning and test contexts as much as possible (Both internally and externally!)

Frame recall appropriately

Appreciate the importance of recognition

Forgetting Can Be Either a Failure of

Availability Or Accessibility

Jost's Law

If two memories are of the same strength, the older will decay more slowly than the newer one

Memories are more vulnerable at first, but then enter a stable state that increases over time

what process underlies remembering and forgetting

Long Term Potentiation

Memories are vulnerable until they are re/consolidated

3 Factors Underlie Incidental Forgetting

1. Trace Delay

2. Contextual fluctuation

3. Interference

Trace delay

The activation of specific memory traces may diminish over time, associations with specific stimuli and cues may also become weaker.

Changing context and trace delay

Context (even the very classroom we are in) is always changing!

Retrieval is partially dependent on the congruency of cues present at encoding and retrieval

Decreases over time

Interference

Recall success decreases as the number of targets associated with a cue increases

If you have one memory with a cue (a car) you will remember it well, but the more memories you accumulate the harder it is to recall just one memory

○ Cue overload

Proactive interference

The tendency for earlier memories to disrupt the retrieval of more recent memories (cue overload)

This can only happen if the two items are related to each other (e.g., psychology and neuroscience)

Retroactive interference

The tendency for more recent memories to disrupt the retrieval of earlier memories (competition assumption)

How is Part-Set Cueing is an Example of Retrieval-Induced Forgetting

People do worse at recalling the rest of the items on a list when they are given a few items on the list. This is weird because cues normally aid recall

This happens because when you try to recall all the other items on the list, they compete with each other, and the provided cues make it harder to access the uncued related items

This is specific, it only relates to related memories (fruit) but does not affect unrelated categories (fish)

How is Part-Set Cuing is Best Explained by Inhibition

It assumes that unpracticed traces have lower activation regardless of cue-target association

When you try to recall a target item (like plum), your brain actively suppresses the activation level of the competing items (like apple or banana).

This reduced activation happens inside the memory trace itself, not in the cue-target link, So even if you later use a completely different but related cue, the suppressed items are still at a low activation level and are still hard to retrieve.

vlPFC role in retrieval induced forgetting

During retrieval practice, activity in the VLPFC increases to suppress competing memories, subsiding in later trials

Suppressing competing memories early on reduces future interference!