Working memory load elicits gender differences in mental imagery

Findings concerning gender differences in solving imagery tasks are controversial: sometimes they show that men outperform women and sometimes they show no difference between them. These findings have been interpreted by considering personality factors and evolutionary theories about the use of different strategies to solve imagery tasks. To interpret these results, the visuo-spatial working memory (VSWM) load required to perform these tasks should be considered. According to Coluccia and Louse (2004), the VSWM load could be a determining factor in increasing or levelling off individual differences. But, until now few studies have considered this explanation of gender differences. The aim of this study was to determine whether women perform worse than men on tasks requiring a high VSWM load, as proposed by Coluccia and Louse. Specifically, based on Kosslyn’s model (1995) we analyzed three different aspects of mental imagery ability, that is, generation, inspection and transformation, involving different VSWM loads. The Visual Mental Imagery Battery (VMIB) was performed by 190 participants (95 males; 95 females); it includes two generation tasks, two inspection tasks and three transformation tasks. We found no significant gender differences in performance of either the generation or the inspection tasks. On the transformation tasks, however, men outperformed women in both mental rotation and mental folding. Thus, on the basis of these results gender differences were absent on tasks with a lower VSWM load (i.e., generation and inspection), but men outperformed women on tasks with a higher VSWM load (i.e., transformation tasks), which involve elaborating and comparing mental images. Therefore, further investigation of VSWM would be useful to clarify the controversial results reported in imagery task studies.