Quality, not quantity, matters most for our memory

The capacity of our working memory is better explained by the quality of memories we can store than by the quantity, claims research.

Researchers tried to clarify a long-standing debate in psychology about the capacity of our working memory.

"Our findings show that we don't simply store a set number of items and then recall them near-perfectly," said Weiji Ma, an associate professor in New York University's Department of Psychology.

"Rather, we try to memorise all relevant objects but the quality of these recollections is uneven and gets worse as we have to remember more," added Ma, senior author of the study.

Working memory (WM) has a similar function as random access memory (RAM) in computers but its mechanisms are not nearly as well understood.

In recent years, psychology researchers have come to contrasting conclusions on the limits of working memory.

Some have said there is a fixed number of memories we can store - for example we may be able to store the positions of only four different cars in our working memory at any given time.

But others have maintained that working memory's storage is not defined by the number of items it can hold and that its limits are better defined by the quality of memories.

In an effort to resolve this debate, Ma and colleagues examined data from 10 previously conducted experiments.

In a typical experiment, participants were asked to recall one of up to eight colours they had seen a few seconds ago - a well-established measurement for gauging memory.

Their analysis showed that working memory capacity is best explained in terms of quality of memories.

This quality gradually diminished as participants were asked to recall more and more colours.

"Our results certainly do not mean that you always remember everything that matters. However, 'remembering everything a little bit' seems much closer to the truth than 'remembering a few things perfectly and others not at all'," added Ma.

The findings appeared in the journal Psychological Review.