Daisy, Daisy, Give Me Your Answer Do! Case Studies of Left Visual Neglect in Patients with Acute Cerebral Lesions

Abstract

Patients with acute brain lesions often demonstrate dramatic forms of visual neglect; however their unstable medical conditions and rapidly changing neglect make it impossible to carry out rigorous experimentation to test theories of neglect. Careful assessment of their disorders can, however, inform rehabilitation strategies, and stimulate tentative neglect hypotheses that can later be tested more rigourously on the much rarer patients who have persisting neglect. The neglect behaviours of two patients with acute lesions are described in terms of environment-centred and object-based frames of reference. TT, with a right parietal glioma, has difficulty describing unexpected details on the left sides of pictures, in contrast to SM, with a right frontal abscess, who describes pictures accurately. Both patients, however, show left-sided neglect when copying pictures. When asked to copy daisy pictures, including half daisies, TT copied half daisy heads, including half of the half daisies, but SM missed only whole daisy heads to the left of other daisies. Their different responses to these daisy pictures is tentatively explained in terms of their ability to perceive whether or not half daisies appear “ridiculous”. SM also embellished the right sides of her drawings, suggesting an interaction between this dysexecutive behaviour and neglect.