Visuospatial attention

Figure: Example of the The Posner orienting task modified from [1]. The arrow (i.e. the cue) is presented for 2360ms. The asterisk (i.e. the target) is presented for 300ms.

Visuospatial attention has been assessed along several dimensions, including visual search (i.e., cancellations tasks) and reaction time.

Star cancellation is a paper and pencil visual search test originally proposed in and part of the Behavioral Inattention Test [2]. The patient has to circle all stars printed on a large A4 piece of paper. Stars are mixed with letters and words that the patient should not circle.

Mesulam Unstructured Symbol Cancellation Test is a paper and pencil visual search test where symbolic targets are mixed with symbolic distractors [3].

The Posner orienting task is a detection paradigm initially designed by [1]. The paradigm is computerised and consists of two square frames (1° size) placed on the left and the right of a central fixation (at 3.3° of eccentricity). Trials start when the central fixation turns from red to green. After 800ms, an arrow points left or right. 1000 to 2000ms later, an asterisk appears in one of the two square frames, 75% of the time at the location indicated by the cue (valid trials). In the other 25% the asterisk appears in the opposite location (invalid trials). Patients are required to press a button when an asterisk appears on the screen with their ipsilesional hand. A pause of 2360ms separates each trial. Each patient performs 120 trials divided into one practice block and two test blocks.

Score Info
bit_coc Center of cancellation (BIT)
bit_ltot_miss Left misses (BIT)
bit_rtot_miss Right misses (BIT)
bit_tot_miss Total misses (BIT)
mes_coc Center of cancellation (Mes-USCT)
mes_l_miss Left misses (Mes-USCT)
mes_r_miss Right misses (Mes-USCT)
mes_tot_miss Total misses (Mes-USCT)
pos_acc_avg Accuracy average (Posner)
pos_acc_disengage Accuracy disengagement (Posner)
pos_acc_li Accuracy left invalid (Posner)
pos_acc_lv Accuracy left valid (Posner)
pos_acc_ri Accuracy right invalid (Posner)
pos_acc_rv Accuracy right valid (Posner)
pos_acc_validity Accuracy validity (Posner)
pos_acc_vf Accuracy visual effect (Posner)
pos_rt_avg Reaction time average (Posner)
pos_rt_disengage Reaction time disengagement (Posner)
pos_rt_li Reaction time left invalid (Posner)
pos_rt_lv Reaction time left valid (Posner)
pos_rt_ri Reaction time right invalid (Posner)
pos_rt_rv Reaction time right valid (Posner)
pos_rt_validity Reaction time validity (Posner)
pos_rt_vf Reaction time visual effect (Posner)
pos_sub_avg Subbing average (Posner)
pos_sub_disengage Subbing disengagement (Posner)
pos_sub_li Subbing left invalid (Posner)
pos_sub_lv Subbing left valid (Posner)
pos_sub_ri Subbing right invalid (Posner)
pos_sub_rv Subbing right valid (Posner)
pos_sub_validity Subbing validity (Posner)
pos_sub_vf Subbing visual effect (Posner)

BIT= Behavioural Inattention Test, Mes-USCT=Mesulam Unstructured Symbol Cancellation Test


1. Posner, M.I. and Y. Cohen, Components of visual orienting. Attention and performance X: Control of language processes, 1984. 32: p. 531-556.

2. Wilson, B., J.F. Cockburn, and P. Halligan, Development of a behavioral test of visuospatial neglect. Arch Phys Med Rehabil., 1987. 68(2): p. 98-102.

3. Mesulam, M.M., Principle of Behavioural Neurology: Tests of Directed Attention and Memory (Contemporary Neurology Series). 1985: F.A. Davis Company.