Sensory, Short-term & Working Memory

Partial Report

-Tone presented after grid offset signals which of the 3 rows to report -Delay between matrix offset & tone onset varied between 0 & 100msec (ISI) -An estimate of the actual # of letters available can be made by the formula: # reported x # of rows Conclusion- average 3.3-4 letters. Ps could report *any* of the rows. Estimated span depended on the delay of the tone 82% available during zero delay from tone

The modal model of memory

3 types sensory memory short-term memory long-term memory

Span of Apprehension

4-5 items perceived in a brief visual presentation (50 msec)

How does expertise affect chunking?

Chase & Simon (1973) tested STM for chess pieces on a board IVs: Expertise- chess masters vs. beginners Piece Organization- Pieces positioned for all real chess game (dif in ability, masters are better) vs. randomly positioned (no dif in ability) DVs: reposition of the board

How does chunking affect STM?

Ericsson et al. (1989) trained a college student w/ average memory ability to use chunking. S.F. had an initial digit span of 7 After 230 one-hour training sessions, S.F. could remember up to 79 digits. Chunks them into meaningful units

Decay or Interference?

Keppel & Underwood (1962) decay stays relatively the same Performance on the Peterson & Peterson Task is relatively good early on & nearly perfect on the first trial Performance get much worse after many trials Evidence for proactive *interference.* Info learned previously interferences w/ learning new info

Measuring the Duration of STM

Perterson & Peterson (1959) How long does *non-rehearsed* info stay in STM? Present 3 letters followed by 3 #s. ex. PIR-393 Keep the letters in memory while counting backward by 3's from the # (metronome) Measure recall accuracy as a function of the time spent counting (recall interval)

What is memory?

Processes involved in (encoding) retaining, retrieving, & using info about stimuli, images, events, ideas, & skills after the original info is no longer present. how past experiences influence present thought and behavior

Measuring the Capacity & Duration of Sensory Memory

Sperling (1960) How much info is held in sensor memory & how long it is held? *capacity & duration* A Complex Stimulus-3X4 grid of letters, displayed for 50 msec. on a tachistoscope IV Report method and delayed partial report -Whole Report- report as many letters as possible from the grid -Partial report- tone presented after grid offset signals which of the 3 rows to report --Delayed partial report- interval btwn matrix offset and tone onset 0 to 1000 DV- an estimate of the actual # of the letters available can be made by the formula: # reported x # of rows Estimated- span of apprehension was 4.5

Sensory Memory

The retention, for a brief period of time, of the effects of sensory stimulation holds *large amount* of info for a very *short period* of time -Collects info -Holds info for initial processing -Fills blanks and info decays rapidly

Control processes

active processes that can be controlled by the person Rehearsal Strategies used to make a stimulus more memorable Strategies of attention that allow focus on specific stimulus

long-term memory

can hold a large amount of info for years or even decades

How does stimuloi complexity affect chunking?

colored squares Chinese characters random polygons shaded cubes lowest to highest for ability to chunk

short-term memory

holds 5-7 items for about 15-20 seconds

sensory memory

initial stage that holds all incoming info from seconds or fractions of a second

Retroactive interference

learning new info interferes w/ remembering old info

Results of Duration of STM

rate of mem trace decay When rehearsal is prevented, STM duration is about 15-18 sec. ~50% loss of info in the STM after 3 seconds of counting After 18 secs performance at 10%

Chunking

small units are combined into larger meaningful units chunk- a collection of elements strongly associated w/1 another, but weakly associated w/ elements in other chunks recoding it

Echoic Memory

Breif sensory memory of the things that we hear -responsible for presistence of sound

Short-term memory

Info disappears relatively quickly this is when you're conscious (unlike sensory) 3 processes could be responsible for forgetting info in STM Displacement- close together info? Decay- fades away Interference- before or after can conflict

Proactive Interference

Info learned previously interfers w/ learning new info

Sensory Memory Sperling

Sperling: little analysis of stimuli took place in visual sensory memory (iconic memory) large capacity & very short duration Later research: there may be some basic analysis of info -letter combinations resembling words reported better than random letter combinations report by category is possible

What is the Capacity of STM?

What is the capacity and how many items can STM hold? Miller's Magical # 7, plus or minus 2 -# of "slots" for storing info in STM is around 5-9 -new info *displaces* old Digit Span: how many digits a person can remember. typical result:5-8 items, what is an item?

Iconic Memory

brief sensory memory of the things tat we see -Responsible for the persistence of vison --retention for the perception of light

Persistence of a stimulus representation Sensory Memory

something analogous to original stimulus remains present for a short period of time (gives time) giver perceptual system additional time to extract info from sensory input "fills in blanks" this is a memory phenomenon