Female advantage in verbal processing extends into many memory tasks which are not explicitly verbal.1 In this session of review, we included studies of human spatial ability and verbal memory with sex-favored components (Table 1). The concept of mental rotation (spatial rotation) as a cognitive behavior was introduced by Shepard and Metzler2 in 1971. It requires the dynamic spatial transformation of objects with respect to their internal spatial structure. Furthermore, mental rotation is involved in problem solving,3 acquiring mathematical
knowledge,4 and academic thinking.5 Studies using eye movement measurements, direct recording from electrodes implanted in the brain, functional magnetic resonance imaging (fMRI), and transcranial magnetic stimulation suggested that mental rotation involves motor and visual processes and related brain regions.6 selleck chemicals llc The typical test of mental rotation involves distinguishing BMN 673 manufacturer a shape or an object that has been rotated from a similar, rotated shape or object, often a mirror image. There are simple (2-dimensional stimuli) and complex (3-dimensional stimuli) tasks as shown in Fig. 1. The rotation of simple 2-dimensional stimuli can lead to greater activation of the left parietal area of brain rather than the right parietal area, while the complex 3-dimensional
rotations are associated with more right parietal activation than left parietal activation.7 Studies showed that the analogy between physical and mental processes requires activation of parietal area which is linked to angle of rotation.8 Research on the early development appears that the mental rotation may appear as early as 4 months of age,9 and 10 and reach near-adult level around the age of 6–7 years.11 and 12 Mental rotation has great sex differences, particularly males usually perform
better on mental rotation tasks than do females.13 However, the sex differences in mental rotation only appear in adults.7 Interestingly, sex differences in mental rotation are also confirmed by brain imaging studies that showed different networks activating during mental rotation tasks for men and women, such as increased activation in the parietal lobules in men, and increased activity in Suplatast tosilate frontal areas in women.14, 15 and 16 The unique brain regional activities between males and females may be interpreted as evidence of a different cognitive strategy between men and women to solve mental rotation problems. While it is unclear whether the sex difference in mental rotation is regulated or dependent on sex steroids, some studies showed that sex hormones play direct role in mental rotation. For example, in females, low estradiol during normal menstrual cycle was found to be associated with significantly better accuracy on the mental rotation task with large angles of rotation by 2-dimensional object, while estrogen showed no effects on small angles of rotation.