Visual Integration Test procedure.

Note. The Visual Integration Test consisted of three conditions: the identification, localization and integration conditions, administered in four sequential blocks. The identification condition (block 1) required visual processing of identity: the target was digit ‘6’ or ‘9’ presented in the center of the screen and subjects were required to press the left or right button on a response box, respectively. The localization condition (block 2 and 3) required visual processing of the location of targets that were presented on the left or right side of the screen. In block 2, the target was ‘6’ and the required response was compatible with the target location. In block 3, the target was '9' and the required response was incompatible with the target location. The integration condition (block 4) required processing of the visual identity as well as location of targets presented on the left or right of the screen, measuring visual integration. The targets were either '6' or '9', and they required compatible and incompatible responses, respectively. In other words, a ‘6’ presented on the right side of the screen required a right button response, whereas a ‘9’ presented on the right side of the screen required a left button response, and vice versa. ISI = inter-stimulus interval.