Acquisition of skilled visual search performance following severe closed-head injury.

This study used a semantic-category visual search task to investigate skill acquisition and automatic process development in a severe closed-head injured (CHI) population. Eighteen severe CHI participants (> I year post injury) and 18 matched controls completed over 3600 trials of training in both consistent mapping (CM) and varied mapping (VM) training situations. Transfer conditions were also used to test for development of an automatic attention response (AAR) that was independent of general, task-related learning. For both the severe CHI and control group, CM training, where individuals always responded in the same way to a specific class of stimuli, resulted in dramatic performance improvements and the development of an AAR. In the VM training condition, where individuals could not respond in the same way to a class of stimuli from one stimulus exposure to the next, there was little performance improvement and continued reliance on controlled processes. The visual search rates of the CHI participants also remained slower than those of controls following extended VM but not extended CM practice. These results indicate that skill acquisition training guidelines can be used to teach severe CHI patients to develop a new automatic skill.