Spatial scaling in congenitally blind and sighted individuals: similarities and differences

Spatial scaling refers to the ability to map distances between different-sized spaces. This ability has been predominantly investigated in sighted individuals using map-reading tasks. Studies with blind individuals using similar tasks were less informative with respect to spatial scaling. Therefore, the current study examined spatial scaling systematically in congenitally blind and blindfolded sighted individuals (N = 46, aged 8.5-45.0 years). Participants were presented with embossed maps containing a target and asked to indicate the similar position in a referent space. Scaling factors were systematically manipulated by varying the sizes between these spaces. Results indicated that blind participants performed less accurately than sighted individuals. After correcting for reversal errors, this difference disappeared. Our results support previous research showing differences between blind and sighted individuals when using maps, while at the same time qualifying these studies by suggesting that these differences may result from blind individuals' propensity to interchange left-right directions.