Experiments

Front 1

Clive Wearing

Back 1

Contracted viral encephalitis - it destroys parts of the temporal lobe which are used for forming new memories.

Front 2

Capacity exp of sensory mem

Back 2

Wondered how much info people can take in from briefly presented stimuli. Flashed an array of letters on screen for 50 milliseconds and asked ppl to report as many letters as possible.
Whole report method - being asked to recall as many letters as possible from the whole grid. Resulted in remembering 4.5/12 letters.
Partial report method - asked to recall only a part of the grid, so it focused memory. Immediately after the grid flashed, Sperling sounded one of three cues, indicating the row of letters to report. High, med, and low pitches to indicate the top, middle and bottom row. Remembered 3.3/4 letters.

Proved that the participants were seeing all the letters, but could only recall a few before their memory faded. Which ones they recalled did not matter.

Delayed partial report method -cue tone was delayed for a fraction of a second before they were asked to report the letters in that row. Ppl could only remember about 1/4 letter.

After a stimulus is presented, all or most of the material is available for perception. Over the next second, the memory fades. After 1 second as passed, the number of letters is about the same as the number after the whole report method.

Front 3

Duration of STM test

Back 3

Given a set of letters and numbers. Participants asked to count down from the number, then after a time recall the letters. They could remember about 80% of letters after counting for 3 seconds, but only remember 12% after 18 seconds.
After set trials, the later trials had worse and worse recall, due to proactive interference. Hearing all the previous letters and numbers got in the way of remembering the new sets.

Front 4

Capacity of STM

Back 4

Use digit span (remembering numbers), can get about 5-9 items.
Later, tested STM by flashing two arrays of colored arrays of squares. Ppl could only go well with less than 4. They thought this meant the STM could only handle 4 items at once.

Front 5

Chunking exp

Back 5

S.F. was asked to repeat sets of numbers. After 230 one hr sessions, he could repeat a sequence of up to 79 numbers due to chunking the numbers into groups of 4 or so numbers.
Also asked chess players to remove chess pieces from game then replace them. Chess masters who could chunk their positions and moves would place more in the correct spot than chess newbies who didn't know the plays

Front 6

Auditory coding

Back 6

representing items in the STM based on their sound
Ppl saw a lot of letters flashed on a screen then told to write them. Realized that errors were made because ppl were likely to mistake a target letter for one than sounded like the target. F, would be written S or X instead, but NOT E which LOOKS like the target.

Front 7

Visual coding

Back 7

Represents items visually in STM. Given a grid of partially colored squares. Then asked to fill in a blank grid. Found that people could get up to 9 squares, which proved that STM could encode visually as well as auditory

Front 8

Semantic coding

Back 8

Represents items in terms of their meanings.
Given words relating to fruit or a profession. Listened to three words of the same group, counted backwards by 15 seconds, the recalled the words. Repeated 4 times
Intentionally created proactive interference.