Coding, capacity and duration

Cognitive psychology is the study of how people learn, structure, store and use knowledge eg perception, memory and language.

Coding= The way in which information is stored in memory and it is modal specific.

Capacity= The maximum amount of information that can be retrained in memory.

Duration= How long a memory can be held for before it is forgotten.

Sensory register

Coding= Crowder(1993) found that the SR only retains information in the iconic store for a few milliseconds, but for 2-3 seconds in the echoic store. This supports the idea of sensory information being coded into separate stores and suggests they have different durations

Capacity= Sperling flashed a 3×4 grid of letters onto a screen for one-twentieth of a second, and asked pots to recall the letters if one row. As the information would fade very quickly, he sounded different tones (high, medium, and low) to indicate which row needed to be recalled (1, 2, or 3). Recall of letters in the indicated row was high(3/4), which suggests all of the information was originally there since they didn’t know what row would be indicated, indicating that the capacity for SR is high.

Duration= Welsh and Thompson (1978) found that the iconic memory store has an average duration on 500 milliseconds, which decreases as individuals get older. This suggests that the duration of SR is limited and dependant on age. The duration is less than half a second.

Coding= modal specific Capacity= high or unlimited Duration= less than ½ a second

Short term memory

Coding= Baddely (1966) gave ppts four sets of words to recall in order. For STM task they had to recall them immediately to prevent rehearsal following presentation and for LTM task they had to be recalled following a longer time interval.

1.Words that sounded similar eg cat, map, cap, mat

2.Word that sounded different eg dog, bin, cup, pen

3.Words with a similar meaning eg big, large, huge, vast

4.Words with a different meaning eg huge, good, light, blue

The researchers then recorded how many mistakes were made during recall

Findings suggest that encoding is different for LTM and STM

STM= acoustically encoded

Capacity= Jacob’s measured digit span in the 1800s. The researcher gives 4 digits and the ppt has to recall these in correct order out loud. If this is correct, the researcher reads out 5 digits and so on until the ppt can’t recall the order correctly. This determines the individuals digit span. Jacob’s found that the mean span for digits across all ppts was 9.3 items and the mean span for letters was 7.3.