Human Memory and Learning Exam 1

memory

• engram

• mental process used to acquire, store, retrieve info

• location where memory is kept, as in a storehouse of info

• three distinct “stages:

  • encoding

  • storage

  • retrieval

  • successful learning requires optimization of all three stages

engram

the representation that holds the contents of experience, as in a memory trace

learning

relatively permanent change in behavior that results from experience

optimized encoding

what is needed:

• attention

  • divided attention is bad for learning!

  • undivided attention needed for long-term memory!!

• intention

  • intentional vs. unintentional learning

• meaning

  • encoding success reflects ability to map new info onto existing knowledge

  • performance best when processing the words at the level of their meaning

  • performance not simply determined by what storage info is in (STM/LTM)

  • critical how info is processed at the time of encoding

• timing

intentional learning

active learning in anticipation of future recall demands this

incidental learning

passive learning as a byproduct of exposure

• repeated, incidental exposure doesn’t necessarily improve memory

trace decay

fading of stored info over time

interference

memory for one event hinders recovery of another

proactive interference

old memory makes it difficult to remember new memory

encoding variability minimizes interference

• memory continues to decline as proactive interference accumulates across lists

• release from proactive interference scales w/ category distinctiveness

• vary study habits to minimize proactive interference

Simonides

• Greek poet who relied on memory to recite his work/works of others

• recognized that memory benefits from orderly arrangement following tragedy in Thessaly

• developed what would later be called “method of loci”

franz Joseph gall

• “each brain region has a particular function, but they influence each other”

• anticipated modern view of localization + interaction

• legacy overshadowed by ridicule (carnival phrenology)

William James

• distinguished habits from primary (short-term/working) vs. secondary memory (long-term/episodic)

• anticipated multiple memory systems

Herman ebbinghaus

• philosopher in Berlin

• inspired by lawfulness of psychophysics data

• performed experiments on himself/published results in “Memory: a Contribution to Experimental Psychology”

• shorter lists are easier to learn

• forgetting curve and everything that comes w/ it

• pioneered systematic and controlled scientific study of memory

• created controlled stimulus material

forgetting curve

• rapid, nonlinear rate of forgetting that slows over time

• ways to slow this down:

  • overlearning - slows forgetting (studying beyond point of criterion)

  • savings - reduction in time required to relearn previously mastered list

  • distinguished learning - associated w/ increased savings

behaviorism

• emergence began w/ John Watson

• reaction to introspection: mental thoughts cannot be observed, behavior can

• subject matter: observable behavior

  • studied behavioral responses to stimuli

  • interested in stimulus-response relationships

• Pavlov (classical), Thorndike (puzzle box)/Skinner (Skinner box) (operant)

e.c. tolman

• learning’s not driven by reinforcement, but by curiosity of environment/seeking knowledge

• cognitive theory - animals possess cognition that will guide expression of learned behavior

• “more than one kind learning”

• rats in a maze experiment

  • latent learning

Frederic Bartlett

• combined experimental psychology w/ rich theory

• influential book → Remembering: a Study in Experimental and Social Psychology

• rejected Ebb’s methodology + idea of mere association, more generally

  • argued that memory is a constructive process that’s critically shaped by meaning

• introduced schema knowledge

endel tulving

• argued for a distinction of kinds of LTM

  • consciousness

  • content

• memory

  • episodic memory (autonomic consciousness; specific to you/own thoughts) builds upon

  • semantic memory (noetic consciousness; thinking/aware) builds upon

  • non-declarative (procedural) memory (anoretic consciousness; no thinking/process)

John o’keefe

• hippocampal place cells → specific cells mapping out space

Karl Lashley

• trained rats to run a maze then removed part of their brain

• subsequent maze performance was unaffected by localization of the lesion, instead it was the size of the lesion that mattered

• lead to the idea of “equipotentiality”

patient h.m.

• anterior temporal lobes (bilateral amygdala, hippocampus, some cortex) removed

• severe anterograde amnesia

• Brenda Milner and Susan Corkin

• procedural/working memory still intact → suggests there’s different kinds of memory/learning

  • long-term storage relies on a different brain region

implicit/nondeclarative memory

• procedural learning - skills/habits

  • riding a bike, typing on a keyboard, etc.

• priming - prior exposure shapes response

  • recognizing a word faster if you saw it earlier

• conditioning - learned associations/responses

  • feeling anxious when hearing a dentist’s drill

• statistical/pattern learning - picking up regularities w/out awareness

  • babies learning language rhythms

  • adults sensing something “feels off” in a melody/visual pattern

law of effect

• thorndike

• consequence of responses determine whether it is strengthened/weakened

  • reward → strengthened

  • no reward → weakened

  • punishment → very weakened

operant response

• skinner

• action that operated on the environment to produce some consequence; different environments will encourage different behaviors

latent learning

type of learning can occur w/out reinforcement

cognitive map

example of latent learning

• internal representation (or image) of an external environmental feature or landmark

prefrontal cortex lesions

selectively impairs working memory performance

medial temporal lobe lesions

selectively impaired associative memory performance

long-term memory

• declarative (explicit)

  • episodic

  • semantic

• non declarative (implicit)

  • conditioning

  • priming

  • skills/habits

  • associations

dendrites

• receive information

  • input zone where neurons collect/process information, either from the environment or from other cells

cell body

• integrates information

  • integration zone where the decision to produce a neural signal is made

axon

• carry information

  • conduction zone where information can be electrically transmitted over great distances

axon terminal

• transfer information

  • output zone where the neutron transfers information to other cells

synaptic plasticity

change in the structure/biochemistry of a synapse that occurs during learning

Hebb’s rule

if two connected neurons are both active simultaneously, synapse between them will be strengthened

consolidation

transfer of short-term to long-term storage

• hypothesis: experience-dependent plasticity (co-occurrence of activity) may be a neural mechanism of this concept

long-term potentiation

long-lasting strengthening in synaptic connections due to high-frequency activity

• stable/enduring stronger response in the future

• strengthens synapse

neurogenesis

new neurons being born

• in adult humans, the hippocampus/olfactory bulbs are the only brain regions where these new neurons can be born

  • thousands of new neurons are formed in the hippocampus every day

  • younger neurons have greater plasticity, so they may be important for creating new connections

limbic system

structures important to emotion, learning, and memory

• amygdala

• thalamus

• hypothalamus

amygdala

• highly connected to the hippocampus, consistent w/ its role in memory and w/ the hypothalamus

• connects features of memory w/ aspects of emotion (fear conditioning and emotional learning)

• heightened activity in PTSD

hypothalamus

• “under the thalamus"

• associated w/ basic instincts/drives (food, thirst, fight/flight, hormonal releases)

thalamus

• heavily connected to other areas of the brain

• all sensory inputs (except olfaction) routes through here before it connects to other parts of the brain regions

papez circuit

areas involved in memory formation/emotional responses

• has been further elaborated to include other regions (prefrontal cortex (PFC) and amygdala)

• he injected rabies virus into a cat’s hippocampal region

  • traced the spread of virus through this thing

hippocampal-cortical network

important for recollection and prospective memory

medial temporal lobe amnesia

• occurs when patient has preserved intellectual function/mnemonic deficits

• form implicit but not explicit memories

  • repetition - priming tests

  • indicates flexibility of memory systems

anterograde amnesia

inability to form memories after the onset of the disorder

• there’s hippocampal damage involved in this

retrograde amnesia

inability to recall memories from before the trauma (ex: accident, surgery)

• there’s a disconnect between the hippocampus and storage site

basal ganglia

• striatum + globus pallidus

• involved w/ procedural memory → the knowledge of how to do something

  • intricate reciprocal connections to the thalamus/cortex

occipitotemporal junction

• supports priming → past experiences increase the response to a given sensory stimulus

cerebellum

• involved w/ conditioning (learning of associations)

  • skill learning (procedural)

  • fear conditioning also involves the amygdala

n-back

• these tasks are commonly used in neuroimaging studies of working memory

• continues sequence of stimuli w/ a fixation delay of fixed duration

• accurate performance requires maintenance of a rule, digit/letter/number span, monitoring

source judgement

• part of retrieval

  • attribution of where/from whom we learned something

neuropsychology

study of patients w/ brain damage

localization of function

correlate specific area of brain damage w/ cognitive or behavioral deficits

• part of neuropsychology

eye tracking

track the fixations/patterns of eye movements for encoding strategies

pupillometry

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

skin conductance

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

EEG

• electrodes record the brain’s electrical activity

  • remember that action potentials are electrical signals

• scalp → electrodes placed on the skull

• intracranial → electrodes surgically placed directly on the brain

event-related potential

changes in electrical activity related to a specific task stimulus

neural oscillations

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

MEG

• measures magnetic fields emitted by the brain’s electrical activity

• noninvasive (similar to scalp eeg)

• tracks pathways of information processing

PET scan

• inject radioactive tracer in bloodstream

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

MRI

• safe/quick means of generating images of structure/function of the brain

• different molecules (ex: oxygen, hydrogen) react differently when placed in an extremely strong magnetic field

• structural → detailed picture of the brain

  • studies tissue

• functional → measures blood flow as an indirect measure of neural activity (more active regions require more blood)

• diffusion (diffusion tensor imaging) → measures water molecules along axons to assess structural connections

levels of activation

contrast levels of activity during different task demands/cognitive processes

patterns and reinstatement

• compare patterns of activity

  • do these changes repeat exactly or not during retrieval?

  • from ending → retrieval

functional connectivity

how correlated are activity levels between brain regions over time

TMS

• pulses of magnetic field induce electric currents in the brain

• elicits action potentials in neurons at the cortical surface

transcranial direct current stimulation

continuous low intensity electric current delivered via electrodes on scalp

deep brain stimulation

implanted device sends electrical impulses to the brain

direct electrical stimulation

directly stimulate neurons via surgically implanted electrodes (clinical)

spatial resolution

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

temporal resolution

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

atkinson/shiffrin

• formalized a model that captured the view common among memory researchers that memory is not a unitary process

• good heuristic and a useful way to think about information processing