Training 'plastic' memory in people may help them become more intelligent than what they were blessed with at birth, scientists have found.
Most of the IQ tests attempt to measure two types of intelligence--crystallized and fluid intelligence.
While crystallized intelligence draws on existing skills, knowledge and experiences to solve problems by accessing information from long-term memory, fluid intelligence draws on the ability to understand relationships between various concepts, independent of any previous knowledge or skills, to solve new problems.
Headed by Swiss postdoctoral fellows Susanne M. Jaeggi and Martin Buschkuehl, working at the University of Michigan in Ann Arbor, the research indicates that this fluid part of intelligence can be improved through memory training.
"When it comes to improving intelligence, many researchers have thought it was not possible. Our findings clearly show this is not the case. Our brain is more plastic than we might think," says Jaeggi. "."
The researchers reasoned that just like crystallized intelligence is dependent on long-term memory; fluid intelligence relies on short-term memory, or what one calls the "working memory," which people use to remember a phone number or an e-mail address for a short time. But beyond that, working memory refers to the ability to both manipulate and use information briefly stored in the mind in the face of distraction.
For the study, they recruited four groups of volunteers and trained their working memories using a complex training task called "dual n-back training," which presented both auditory and visual cues that participants had to temporarily store and recall.
The training was provided during a half hour session held once a day for 8, 12, 17 or 19 days. For each of these training periods, researchers tested participants' gains in fluid intelligence. The results were compared against those of control groups to ensure that the volunteers actually improved their fluid intelligence, and not just their test-taking skills.
Surprisingly, the results indicated that the control groups made gains, apparently because they had practice with the fluid intelligence tests, while the trained groups improved considerably more than the control groups. In fact, the longer the participants trained, the larger were their intelligence gains.
"Our findings clearly show that training on certain memory tasks transfer to fluid intelligence. We also find that individuals with lower fluid intelligence scores at pre-test could profit from the training," says Jaeggi.
This is important as improved fluid intelligence scores could bring about improved general intelligence as measured by IQ tests. General intelligence is a key to determining life outcomes such as academic success, job performance and occupational advancement.
In fact, researchers concluded by saying that this same type of memory training may help children with developmental problems and older adults who face memory decline.
"Even though it currently appears very hard to improve these conditions, there might be some memory training related to intelligence that actually helps. The saying 'use it or lose it' is probably appropriate here," said Jaeggi.