Exploring individual differences in the mental rotation of hands and their links to mental health

Past research has provided insights into mental imagery strategies applied when making judgments in same-different tasks (SDTs) and hand laterality tasks (HLT). We explored individual differences in the use of these strategies, and their relationship to anxiety and depression. University students completed an SDT and an HLT along with measures of sensory processing sensitivity (SPS), alexithymia, anxiety, and depression. Group-level results suggested the use of: a) object-based transformations in the SDT; b) visuospatial transformations for back views in the HLT, and c) motoric simulation for palm views in the HLT. However, there was considerable individual variation across conditions in both tasks. Moreover, with targets rotated 120^o, response times (RTs) for judgments regarding back views in the HLT varied as a function of sex and personality, with females and those scoring higher on SPS responding more quickly to medially than laterally rotated hands. We speculated that the link with SPS might be related to a strong tendency by high scorers to imagine that the target was the hand of a confronting "other" and to adopt that person's perspective and hand posture via a process of embodied simulation. In contrast, with targets rotated 120^o, alexithymia predicted lower accuracy in the SDT; we speculated that this might reflect problems with executive function that interfered with the confirmation stage. SPS and alexithymia also fully mediated the relationships between performance variables and depression/anxiety-offering a plausible explanation for why mental imagery and mental health outcomes have been linked in past work.