Aim of the present study is to verify the hypothesis that phasic and tonic attention disorders, often observed in heminattention, are responsible of the heminattentive syndrome, and that reduction of heminattention after rehabilitation treatment is chiefly due to reduction of selective attention deficit.

A group of chronic right brain damaged heminattentive patients has been submitted to an evaluation of heminattention and selective attentive deficit before and after being submitted to a specific treatment for heminattention (Pizzamiglio et al., 1992).

Heminattention tests included Bells test (Gauthier, 1989), Letter cancellation (Pizzamiglio et al., 1992), Word and No-word reading (Vallar et al., 1996).

Attentive tests included Go-nogo and Alertness tests (Zimmermann and Fimm, 1992).

Statistical comparison between performances before and after rehabilitation showed a clear effect of the rehabilitation treatment on visuo-spatial scanning (Bells test: F=4,73, p<.01; Letter cancellation: F= 2,80, p>.05; Word and No-word reading: F=2,81, p<.01) and the absence of any effect on attentive tests (Alertness omissions: F=0,17, n.s.; Alertness reaction time: F=1,06, n.s.; Go-nogo omissions: F=0,83, n.s.; Go-nogo reaction time: F=0,82, n.s.).

Since the rehabilitation treatment specifically acts only on heminattention disorders and doesn’t affect selective attention deficits.

These data strongly support the hypothesis that heminattention and selective attention are double dissociated, being due to lesions in adjacent but independent neural areas.

Present results also suggest the need to associate specific treatment for selective attention deficits to rehabilitation treatment of heminattention.