Lecture 4 - LTM Encoding

What is encoding?

the acquisition of information into LTM

What is storage?

the maintenance of information in LTM over; memory is in a state of availability

What is retrieval?

accessing the information stored in LTM

What is the total time hypothesis?

• the more practice you have learning a list on Day 1, the faster you will be to relearn it the next day

• the amount learned is a direct function of study time

What is distributed vs massed practice?

typing skills in postal workers

• 2 × 1 hour practice blocks per day

• or 1 × 2 hour practice block or day

better learning with distributed practice

What is the levels of processing effect (LOP)?

incidental encoding of words at different LOP, then a recognition test

• deeper and more meaningful processing leads to better memory

• maintenance rehearsal: repeating an item at a shallow level not very effective

• elaborative rehearsal: processing an item to a deeper level very effective

What is the organization effect?

participants studied 3 lists of 15 words that varied in how organized/related they were

• memory recall test

• organization increases recall

• organizing materials yourself is most effective as well as relating new information to prior knowledge (schemas)

• fMRI scans while encoding schema-related organized info v unrelated info

• the ventromedial prefrontal cortex (vmPFC) was more active for schema-related encoding

• the vmPFC is important for linking new info to organized knowledge structures

What is the attention effect?

• study list of words + card sorting task with varying complexity (sorting into 2,3, or 4 categories)

• memory recall test

• focused attention increases memory

• LTM encoding is reduced when attention is divided (multitasking)

• encoding under full attention vs divided attention conditions

• d1PFC and d1-parietal cortex activity is reduced under divided attention

• attentional networks are important for encoding

What is the distinctiveness effect?

• study sequential list of letters (one at a time)

  • memory recall test

• better memory for distinctive/novel items

• due in part to better encoding by enhanced attention but also reduced interference/competition at the time of retrieval

• participants studied novel (distinctive) and pre-familiarized (non-distinctive) pictures/words, followed by a recognition test

  • frontal and medial temporal lobe regions were more activated for distinctive than non-distinctive items (frontal attentional networks contribute to novelty affects)

  • patients with lesions to their frontal lobe or MTL do not show distinctiveness effects

What is the emotion effect?

• study negative and neutral images while tracking eye movements

• recognition memory testt

• after a delay, negative images are remembered better than neutral images

  • negative images led to more centrally clustered eye movements (more focused attention) and subsequently better encoding

• fMRI can during recognition memory task for emotional and neutral images

• emotional items: more amygdala activity

• neutral items: more medial temporal lobe (MTL) activity

• memory for emotions relies on a specialized set of brain regions that incudes the amygdala, which is known as the fear and emotion center

Distinctiveness vs Emotion effects

• distinctiveness and emotion both increase memory

• emotion, but not distinctiveness reduces memory for surrounding items (AKA the weapon focus effect)

What is the reward effect?

• effects of high (S1) vs low (1c) reward for correct recognition after short and long delays

• reward cue → target → distractor task → repeat

• recognition memory test

• delayed memory is. better for high reward items

  • immediate memory is not affected by reward

What is the testing effect?

study word pairs by generating or study word pairs by reading

• cued recall test

• better memory for actively generated items than for read items

fMRI scan during encoding by generating vs reading

• recognition memory was greater for generated than read words

• multiple encoding processes and a widespread network of brain regions are engaged by generation

at a short delay additional study time was best, but at a long delay repeated testing was best

• testing involves generation plus focused encoding on what you don’t know yet

What is the multimodal encoding effect?

study words, additional encoding methods, delayed recognition test after 1 day

• better memory wit multimodal elaborative encoding

What factors facilitate LTM encoding in the medial temporal lobe (MTL)?

• study time

• distributed practice

• multimodal encoding

What factors facilitate LTM encoding in the fronto-parietal network?

Prefrontal Cortex (PFC)

• attention

• semantics

• organization/schemas

• distinctiveness/novelty

• emotion (amygdala)

What factors facilitate LTM encoding in the substantia nigra?

reward

What factors facilitate LTM encoding in multiple networks?

generation and multimodal encoding