Research on Forgetting and Human Memory

Research on Forgetting and Human Memory

The actual term forgetting is the inability to recall or recognize

information. Forgetting may occur because the information no longer

exists in memory and so is not available for retrieval. Alternatively

it can occur because it cannot be found and so is not accessible (cue

dependent forgetting). Forgetting is more likely with information that

needs to be recalled, as recognition is usually easier than recall.

Explanations for forgetting are different for short term memory and

long-term memory.

Since STM are likely to be due to lack of availability it has

disappeared, rather than accessibility (being able to find it).

Trace decay is involved in the many reasons that we forget. This is

the actual physical disappearance of a memory trace from the brain.

Trace decay is one reason for forgetting. It should be distinguished

from cue-dependent forgetting, in which the memory trace has not

decayed but is hard to find. Peterson and Peterson provided evidence

that data in STM disappears.

Peterson and Petersons study was to test the hypothesis that

information held in STM disappears within about 20 seconds if

rehearsal is prevented. If participants are allowed to repeat

information, this maintains information indefinitely. An accurate

reading of STM requires no rehearsal. Participants were given trigrams

to remember such as TVG. After each trigram they were given a

three-digit number and asked to count backwards in 3s and 4s. This was

to prevent rehearsal. Each trial they stopped at different times: 3,

6, 9, 12, 15, or 18. This is called the ‘Brown-Peterson technique’ the

findings of their experiment were that if participants had to wait 3

seconds before recalling the trigram they could recall the trigram

correctly 80% of the time; if they had to wait 6 seconds, 50% were

recalled; and after 18 seconds, recall was down to 2%.

This suggests that STM is limited to a maximum of 18 seconds when

rehearsal is prevented. This supports the idea that STM and LTM are

very different types of memory as STM has a limited duration.