NEGLECT SINDROME FOR AVERSIVE AND PLEASANT STIMULI IN A MACAQUE MONKEY WITH PEEF LESION

Aim: The Premotor Ear-Eye Field (PEEF), rostral to dorsal premotor cortex is involved in auditory perception and in ear-eye attentional orienting processes. In this work we describe the attentional deficits provoked by an electrolytic lesion in the PEEF.Methods: A macaque monkey was previously trained for three oculomotor tasks: Fixation task, Saccade task, Peripheral attention task. After unit activity recording, we made an electrolytic lesion using direct corrent (15 mA for 20 s), accidentally provoking an epileptic attack. During the epileptic attack, we observed rapid movements of both pinnae and a rhythmic contralateral tilting of the head, trunk and arm.Results: The animal was able to execute the oculomotor tasks as well as before the epileptic attack. Moreover we observed that the animal showed a neglect only for aversive stimuli with the head free. When the head was fixed this neglect desappered. In addition, the extinction phenomenon appeared for both aversive and pleasant stimuli and in both experimental conditions: free head and fixed head.Conclusion: These data firstly confirm that the PEEF is involved in attentional processes and secondly suggest that attentional behaviour is influenced by head condition. In addition, this last point suggests an additional role of PEEF in head movement control and also it is in favour of the double control system one for the head and one for the eye.