This study was aimed at identifying the impaired attentional component
s in patients who had sustained a severe CHI several years before. A g
roup of 14 CHI patients and a Control group (matched for age, sex and
education) were tested. Experiment 1 used a dual-task paradigm (Umilta
et al., 1992). The double task-single task difference was greater for
the CHI group, indicating a specific damage at a central executive st
age where decision are made and responses are coordinated. Experiment
2 used a task-shifting paradigm (Morra and Roncato, 1986). The cost of
shifting from one task to the other was greater for the CHI group, bu
t only in the Short Series Condition where a new task-program could be
pre-activated. Experiment 3 studied visual selective attention using
Navon paradigm (1977); in this case, there was no difference between p
atients and controls.