Measuring Methods in Memory Research

Designing a Sensory Memory Experiment

~ a very brief memory system... that holds 'perceptual' information to allow cognitive processing

***focus is typically on quantifying capacity

sensory registers

visual, auditory, or haptic

sensory memory involves...

short-term storage

Designing a Working Memory Study

~ allows us to actively maintain information in consciousness

~ research Q focuses on either... capacity, duration, or the control mechanism

What happens in the memory during a working memory study?

short-term storage is manipulated through control processes (rehearsal / elaboration/ etc.) and then subject interacts with the world (using whatever information remembered)

How can one design a working memory study?

~ digit span tasks/ assessment

~ N-back task

~ spatial span

Digit Span Task

designed to answer the Q of how many items can be held in working memory (OR the capacity of one's working memory)

~ visual or auditory stimulus

~ CAN ALSO be word span!

spatial span task

designed to answer the Q of how many locations can be held in working memory (the capacity)

N-back Task

a working memory task; the participant must decide whether the currently presented stimulus is the same as the one presented immediately before (1-back) or two items before (2-back) or three items before (3-back), etc

What are the requirements for accurate performance of the N-back task?

requires; maintenance of a rule, ...i.e. digit / letter / number span, monitoring, and updating

Designing a Long-Term Memory Study

system that allows us to encode, store, and retrieve information about prior experiences for an indefinite amount of time.

The Modern Long-Term Memory Paradigm - GENERAL FRAMEWORK

~ vary conditions in a particular stage of memory (ID variable)

~ measure memory performance (D variable)

3 stages in experiment: encoding (study phase), storage (retention interval), and finally the retrieval (test phase)

BREAKDOWN of Long-term Memory Study

Phase 1) Encoding (study phase)

Phase 2 / INTERVAL) Storage (retention interval)

Phase 3) Retrieval (test phase)

The Modern Memory Paradigm - The Encoding Phase

~ material that is to BE-REMEMBERED is presented (either intentionally or incidentally) to the participant

~ the "study phase"

Encoding Manipulations (the Modern Mem. Paradigm)

demands of orienting task ->

- intentional vs incidental encoding

- levels of processing

*materials (i.e., stimuli) to be remembered

Intentional Encoding (condition)

participant KNOWS a memory test is coming

~ therefore, they intentionally try to remember the items

Incidental Encoding

~ participant does NOT know a memory test is coming

📌 This is incidental encoding because memory happened incidentally, not on purpose.

Encoding Conditions - Levels of processing

1) shallow encoding

2) deep encoding

THEN participants are Tested either being =

1a) un-cued or

2a) cued

Rote Rehearsal

retaining information in memory simply by repeating it over and over

ex) apple, book, hockey, sing, -> repeat apple, book, sing, hockey -> repeat

~ brain treating words like sound/symbols NOT creating a connecting meaning / experience to them

shallow encoding

~ focus on surface features / little or no meaning involved

***** "rote rehearsal"

Image using / doing

picture yourself (ex: eating an apple, reading a book, singing, playing hockey)

~ the brain is creating mental images... linking words to prior knowledge (engages emotion / context / and experience)

Deep Encoding

~ focus on meaning / participant actively thinking about what the word means

**techniques = image using / doing

The test phase

(how memory is measured)

- unncued test (free recall)

OR

-a cued test (recognition)

uncued test

"tell me as many words as you can remember"

(free recall)

-no hints / harder

cued test

~ discriminate between words you studied and words that you did NOT

example: "hockey" = target

whereas "soccer" = lure

~~ both are sports, this is the "trick"... lure words test recognition accuracy... NOT only memory strength

Storage Phase

~ ( retention interval ) ~

the delay between the presentation of the material (encoding) and the memory test (retrieval)

Retrieval Phase

(the test phase).... the participant makes a response (direct or indirect) which involves the use of the intially studied material

Variety in Memory of material that participants are asked to remember

- memory is NOT equal across stimulus material

- item frequency impacts memory differently for recall vs recognition

The INFLUENCE OF the stimuli chosen for a LTM Study

-concreteness effect

-picture superiority effect

- emotional > neutral stimuli (words with meaning stick better)

- Polyanna principle / positivity bias

Concreteness effect in Memory

concrete words > (mean more) than abstract words

Picture superiority effect

picture > words

~pictures are remembered better than words

Polyanna principle / positivity bias)

~ positive emotions > negative emotions

(positive association = better memory/recall)

Item Frequency effects on the recall of material to be remembered

~common items = easier recall (b/c there are more retrieval routes)

~uncommon items = easier to recognize (less competition... our memories compete!!!)

Retention Interval Manipulation

-duration

-intervening task

**main Q = how long info is kept in memory before it's tested

retention interval: duration

= the delay before the test

-variations in delays... different groups will wait different amounts of time ...

-> then they are tested after delay (ex: 5 minute delay, 5 day delay, 5 week delay) "tell me as many words as you can remember"

MAIN TAKEAWAY FROM THE RETENTION INTERVAL

Memory declines as the retention interval increases... (pattern is called forgetting over time... think of Ebbinghaus' forgetting curve)

Retention Interval: Delay Task

~ an activity performed during the retention interval that prevents rehearsal and may introduce interference BEFORE a memory test

example of a delay task / DURING THE RETENTION INTERVAL

delay task = one group asked to read; other group asked to complete a maze

- reading = verbal -> interferes w/ word memory

- maze = not verbal -> less interference w/ word memory

***new information interferes with previously learned info

MAIN TAKEAWAY FOR DELAY TASKS DURING THE RETENTION INTERVAL

Memory performance does NOT only depend on the length of the retention interval, BUT ALSO on the amount and type of interference experienced during the delay

The Two Retrieval Conditions for the M.M.P

-explicit

or

-implicit

Retrieval Conditions - Explicit

~ free / cued recall

~ old-new / Forced-choice recognition

~ source judgements

Retrieval Conditions - Implicit

stem completion

picture naming

degree of retrieval support

1) free recall

2) cued recall

3) recognition

What type of recall receives less external support?

free recall = less external support

What type of recall receives MORE external support?

recognition

Free Recall

open ended memory report with NO cues

~ no hints/prompts = highest cognitive demand

**typically poorest performance

Ex) "tell me about an event from your past"

Cued Recall

memory retrieval with a cue that helps narrow the search

~partial info provided =

*better performance than free recall

~~~still requires active remembering (not recognition)

ex) "what did you do one NYE 2020?"

Dependent Variables of Free recall and cued recall

-amount of info recalled

-kind of info recalled

-intrusions

-recall order

types of recognition retrieval support

- old/new

-forced choice

Dependent Variables for Recognition

-proportion correct

-error type

-response time

-bias

Old/New recognition

A form of recognition test in which a person is to indicate whether each item is either old (remembered) or new (not remembered)

Forced-Choice Recognition

person must identify the answer from among a series of possible answers

"which item did you study during the encoding session?"

Source Judgement

trying to determine the source of a particular piece of information

~ "where or from who did we learn something from?"

example: "how did you learn about your college acceptance" via letter? email?

Source Judgement on a LTM Study

participants given x amount of encoding lists, source judgement = deciding which list you saw the target word

Dependent Variables of Source judgement

-source accuracy

-reaction time

-error type

Implicit Memory condition

prior experience can shape behavior without conscious awareness

What do Implicit Memory Test Reveal?

evidence of stem completion, picture naming

Dependent Variable = proportion target response, reaction time

Neuropsychology

the study of patients with brain damage

-localization of function

Localization of Function

correlate the specific area of brain damage with the cognitive or behavioral deficits

CAVEATS TO LESION STUDIES

-RARELY small/specific enough to affect just one brain area

-may spare enough tissue that function is preserved... making it seem like that brain region is not involved in the behavior

**deficits MUST be carefully + precisely characterized

Medial Temporal Lobe Amnesia

occurs when patient has preserved intellectual function and mnemonic deficits

-> ability to form implicit memories but NOT explicit

~~~~ repetition-priming tests

~~~~ indicates flexibility of memory systems

Anterograde Amnesia

inability to form new memories after onset of a disorder

= hippocampal damage

Retrograde Amnesia

loss of memories formed BEFORE a trauma (ex: accident/surgery)

= disconnect between hippocampus and storage site

What is the Importance of Human and Animal Research?

~ underlying mechanism of behavior are similar across species

**the Institutional Animal Care and Use Committee (IACUC) and an Institutional Review Board and Protection of Human Subjects that oversees and determine acceptable procedures

Methods of Cognitive Neuroscience

- eye tracking

- pupillometry

- skin conductance

- brain scans/tests

Eye Tracking Method

trask the fixations and patterns of eye movements for encoding strategies

Pupillometry Method

measure pupil dilation during task; linked to arousal, surprise / novelty

Skin Conductance

sweat (often in fingers); linked to arousal, surprise / novelty

EEG (electroencephalogram)

electrodes record the brains electrical activity

can record: event-related potential (ERP) and neural oscillations

Event-related Potential (ERP)

changes in electrical activity related to a specific task stimulus / event

Neural Oscillations

waves of coordinated rhythmic activity; can measure how coupled (in sync) rhythms are between brain regions

Positron Emission Tomography (PET) SCAN

inject radioactive tracer into bloodstream

~indicates regions of the brain that are active and/or where certain molecules are in the brain

Magnetic Resonance Imaging (MRI)

safe + quick method of generating images of the structure and function of the brain

fMRI (functional MRI)

measures blood flow as an indirect measure of neuronal activity

Diffusion MRI****

measures water molecules along axons to assess structural connections

Level if Activation (fMRI analyses)

contrast levels of activity during different task demands/cognitive processes

Patterns and reinstatement (fMRI analyses)

compare patterns of activity

Functional Connectivity (fMRI analyses)

how correlated are activity levels between brain regions over time

Brain Stimulation Techniques

Modulate/interact with brain activity and measure the effects on neural processes and behavior

Transcranial Magnetic Stimulation (TMS)

pulses of magnetic field induce electric currents in brain; elicits action potentials in neurons at the cortical surface

Transcranial direct current stimulation (tDCS)

continuous low intensity electric current delivered via electrodes on scalp

Deep Brain Stimulation (DBS)

implanted device sends electrical impulses to brain

Direct electrical stimualtion

directly stimulate neurons via surgically implanted electrodes (clinical purposes?)

Spatial Resolution

how precisely can you measure something in space; .... ability to distinguish two points from each other

Temporal Resolution

how precisely can you measure something in time; ... ability to distinguish events happening in time