The effect of visuo-spatial organisation in recognition-memory tasks.

We investigated whether recognition memory benefits when stimuli are organised in a visuo-spatial array. Three different memory tasks were compared: (a) verbal task (what); (b) spatial task (where); (c) combination task, where both verbal and spatial informations were combined together (what/where). We hypothesised that when visual stimuli are organised in a spatial array the recognition is better. Recognition memory was assessed by quantifying the speed of correct responses and the total number of correct responses in a group of male volunteers (N = 20). Subjects' task was to recognise a stimulus probe from sequences (one versus three) of stimuli. All stimuli appeared randomly in one of nine locations on a 3 x 3 grid. The results show that subjects were faster and more accurate when they had to recognise only spatial information (where) than when they had to recognise verbal information (what) or the combination of both verbal and spatial information (what/where). Additionally, when the stimuli were presented in a spatial array there were benefits for the spatial task, whilst verbal and combination tasks were unaffected. Additionally, asymmetry between left and right hemifields has been found. These findings are discussed with regard to different memory processes that operate independently.