8b - Memory encoding processes

how do memory stages tend to be represented?

encoding → consolidation +storage → retrieval

Zeigarnik effect

the tendency to remember uncompleted/interrupted tasks better than completed ones

what is the total time hypothesis

Ebbinghaus → learnt a list of nonsense syllables every day, practise makes perfect

• practice drives brain plasticitiy

outline evidence for how practice might change brain plasticity

• London taxi drivers required to take ‘the knowledge’ test → posterior hippocampus of the taxi drivers was consistently larger, correlated with how much time they spent as taxi drivers

• medical students scanned at 3 intervals, before, during and after extensive exams → increase in gray matter volume in the parietal cortex and posterior hippocampus (remained even after 3 months of studying

what is the relationship between repetition and learning

generally, repetition improves learning (repetition effect), but simple repetition with no attempt to organise the material might not lead to learning especially if information is complex and not percieved as useful

• memory and attention are very selective

what is spaced repetition

distributing learning trials sparsely across a period of time, leads to faster improvement rates of learning and less forgetting

• allows for consolidation between trials → memory becomes more firmly established

• HOWEVER: does take more time which isn’t always practical or convenient

what is some experimental evidence for spaced repetition

Kornell & Bjork : when students tried to learn the style of 12 artists, they were much more effective when interleaved, even when tested on novel paintings by the artists

outline testing effect

testing yourself produces better learning than simply reviewing/re-studying materials

• errors in recall when training may affect later recall unless corrective feedback is provided

• erroneous retrieval may be strengthened in memory

• delayed feedback (end of test) produces highest retention rates

what did Karpicke and blunt find about testing

4 groups studied a science text, studying the text and testing it immediately produced superior memroy in a test a week later than other forms of studying

• also helped with being able to answer inferential questions from the text

what are 2 ways in which motivation might make learning more efficient

• automatically: external (e.g. reward,novelty) or internal (e.g. curiosity) motives prior to exposure to stimuli improves memory even when time spent studying or strategies used are controlled

  • e.g. Gruber et al found curiosity made memory better

• strategically: people use deeper and more elaborate memorisation strategies for high value items

how might novelty enhance memory

being in a novel environment can facilitate enhanced memory encoding

• this is facilitated by dopaminergic release in the ventral tegmental area (VTA) that engages hippocampal encoding of the novel informstion

• like curiosity, novelty also has a long-lasting effect that can improve encoding of unrelated information

what is some experimental evidence for novelty

• memory in school children was improve by an unrelated novel experience before or after being taught a story

• ballarini et al (2013)

how do we know the hippocampus is encoding?

meta-analysis of 72 studies → areas more active during encoding for items later remembered compared to items later forgotten (Brewer et al)

what did Tulving find regarding organisarion

memory is benefitted by subjective organisation - chunking together seperate words for recall even if not encoded together

• items chunked together if they are linked to a common associate, come from the same semantic category, form a logical hierarchical structure or matrix

what did Bartlett find about meaning

ascribing meaning to a stimuli can modulate encoding of information and hot it is stored in memory, studied using abstract or ambiguous stimui that can be interpreted in different wats

what is Paivio’s dual-coding hypothesis

more imageable words (e.g. concrete nouns) are more memorable

• high imageability = apple, church etc, → can be encoded in terms of verbal meaning and visual appearance

• low imageability = history, silence, hope → can ONLY be encoded in terms of verbal meaning

what is Craik & Lockhart’s levels of processing model

challenges traditional memory theories that separate memory into short-term and long-term stores.

Instead, it emphasizes how information is processed rather than where it is stored, suggesting that the depth of mental engagement during encoding determines memory retention

the lowest level is visual (most forgettable), then phonological (acoustic) and semantic (meaning)

evidence for craik and lockharts levels of processing model

pps presented with different words to rememeber

• visual: is TABLE in uppercase

• phonological: does dog rhyme with log

• semantic: does field fit in the sentence: …

remembered them in that order

what are limitations in the levels of processing model

• difficult to define and measure

  • deeper is not always more memorable

what are schemas

structured representation of knowledge about the world, events, people or actions

• can be used to make sense of new material, to store and later recall them

• influenced/determined by social and cultural factors

experimental evidence for schemas

• pps learned to associate visual objects to specific locations within an array over almost a year

• on 2 occaisions, they were exposed to 4 new objects in new locations

• these were presented either in the schematised array or empty

• novel objects learned within the learned array were recalled better than those within the empty array

experimental evidence for the effect of prior knowledge on learning

• prior-knowledge triggers an additional evaluatiove smenatic or episodic-binding process that supports encoding

• when pps encoded associations between faces and houses they remembered double the amount of pairs when the faces were famous, compared to not

• this integration of new information with prior knowledge is supported by interactions between vmPFC and hippocampus