Authors:

DUNCAN, J.

Reference:

Year of publication:

2001

CBU number:

3772

Abstract:

Experiments on the role of frontal cortex in control of visual attention are considered in the context of the diverse, adaptable properties of frontal neurons. The first set of experiments uses positron emission tomography (PET) to measure regional cerebral activity during spatially-directed attention. Unexpectedly, the results show a region of frontal activity ipsilateral to the attended visual field. We suggest that one main role of frontal cortex in this task may be inhibiting processing of the contralateral field. The second line of work addresses relations between specific and general functions of frontal cortex. In line with monkey data, a synthesis of neuroimaging results from many different laboratories suggests that relatively well-defined regions of frontal cortex have rather general functions, adapting themselves to the solution of diverse cognitive problems. Since these are much the same regions as those activated in our own studies, our results may reflect adaptation of rather general systems to the specific problem of attentional control. In the third section of the chapter, a method is presented for measuring impairments in attentional control. The method is illustrated with the first data we have started to collect from patients with focal frontal lobe lesions.