Practice makes perfect, but a question that still remains a mystery is why it is so difficult to transfer learning from a trained to an untrained task? Why are we no better at remembering faces when we have been training our memory for words? Scientists at Umea University and Karolinska Institutet in Sweden now show in the journal Science that the answer lies in the brain areas activated by each task.
The scientists studied the brain activity of healthy subjects as they performed a task that was part of a training program and two untrained tasks. Their performance on the trained task and one of the untrained tasks improved. What these two tasks had in common was the activation of the striatum, a cluster of neuronal nuclei in midbrain.
The study involved a group of older (over 65 years) and younger (20-30 years old) subjects, who were asked to participate in a training program to update information in working memory. After five weeks, both groups showed clear improvement on the trained tasks. The transfer effect was limited, but in the younger group transfer was observed to another test involving memory updating.
To examine the neural systems involved, the scientists studied their subjects' brains using functional magnetic resonance imaging before and after training. During scanning, they performed a verbal updating task from the training program, a non-trained numerical task, which also required updating, and a non-trained task that did not require this skill. All tasks activated areas in the frontal cortex before training. In the younger group, the striatum was also activated during the updating tasks. After training, the striatum was activated during the trained task in both groups, and during the non-trained updating task in the younger group.