Interaction between mechanism of attention selection in space and time: Behavioural and electrophysiological evidence

The study of mechanisms involved in spatial attention is one of the most investigated field inmodern neuroscience, but in the last years a growing interest has been devoted to unveil themechanisms concerning also the temporal aspects of attention. In this thesis three experiment arereported that tried to cast more light on the temporal aspects of attention and on the relationshipbetween spatial and temporal attentional mechanisms.In the first experiment the relationship between spatial and temporal deficit in selective visualattention has been investigated in a group of neglect patients using a temporal order judgement task(TOJ). The main finding is a stronger impairment in temporal selection for spatial position in whichthe attention selection is more impaired, suggesting an interaction between the two aspects in themodulation of the deficit.The second and the third experiment investigated temporal expectations generated by a regularrhythm. In particular, the impact of exogenous and endogenous temporal expectation has beencompared in a discrimination task, revealing the pervasive effect of regularity of movement andspeed in orienting attention in time. Moreover, it has been confirmed the combined effect of spatialand temporal expectations in modulation of electrophysiological response.These results suggest the existence of an interaction between spatial and temporal mechanisms ofattention.