Feeling Oneself Requires Embodiment: Insights From the Relationship Between Own-Body Transformations, Schizotypal Personality Traits, and Spontaneous Bodily Sensations

Subtle bodily sensations such as itching or fluttering that occur in the absence of any external trigger (i.e., spontaneous sensations, or SPS) may serve to locate the spatial boundaries of the body. They may constitute the normal counterpart of extreme conditions in which body-related hallucinations and perceptual aberrations are experienced. Previous investigations have suggested that situations in which the body is spontaneously experienced as being deformed are related to the ability to perform own-body transformations, i.e., mental rotations of the body requiring disembodiment. We therefore decided to consider whether the perception of SPS might relate to embodiment as assessed through (i) the ability to perform own-body transformations (OBT task) and (ii) schizotypal traits (Schizotypal Personality Questionnaire, or SPQ), since high degrees of schizotypy in the general population have been associated with more vivid perceptions and aberrant perceptual experiences. Then participants completed a standard SPS task. Our analysis revealed that the slower the response time in the OBT task, the more frequent the perception of SPS. This suggests that difficulties in disembodying and mentally transforming one’s own body facilitate feeling oneself. Furthermore, a greater number of correct responses in the OBT task was associated with less frequent perception of SPS. This suggests that finding it easier to disembody and perform mental own-body transformations interferes with the ability to sense oneself. The results also show that higher schizotypal traits, as assessed through the SPQ, are associated with more frequent perception of SPS. Taken together, these results provide a coherent picture and suggest that embodiment is required in order to correctly feel oneself, as expressed through the perception of SPS. The ability to easily experience disembodiment reduces the sense of feeling oneself, and proneness to schizotypal traits produces body misperceptions that enhance and amplify this feeling. The results are discussed in the light of current knowledge and theories about body representations, taking into account attention and interoception as factors that influence body awareness. We offer explanations for perceptual aberrations, body-related delusions, and hallucinations based on misperceived or misinterpreted SPS, and we discuss possible mechanisms that may contribute to feeling and misperceiving oneself.

Capturing Fluctuations in Gendered Cognition With Novel Intensive Longitudinal Measures

Cognition is often assumed to be stable, but compelling evidence shows that some skills (e.g., working memory) vary. There is limited investigation, however, of variation in gendered cognition, such as spatial skills and verbal recall, potentially because there are no validated measures for intensive longitudinal assessment. The goal of this study was to introduce and validate new 75-occasion measures of three-dimensional mental rotations and delayed paired verbal recall. This was accomplished by studying cognitive fluctuations over 75 days in an intensive longitudinal study of 121 participants, focusing on 54 (27 women) who were matched for gender, age, and language. Results from psychometric analyses suggest that both measures show parallel forms reliability, including expected gender differences, and validity (i.e., performance with respect to a standard measure or item difficulty), although results are more consistent for mental rotations than verbal recall. Results also suggest there are significant daily fluctuations in both mental rotations and verbal recall. Findings encourage future clinical work on the antecedents and consequences of cognitive fluctuations with the newly developed, freely available measures.

Investigating sex differences, cognitive effort, strategy, and performance on a computerised version of the mental rotations test via eye tracking

Mental rotation tests (MRTs) have previously shown one of the most prominent sex differences in cognitive psychology, marked by a large male performance advantage. However, debate continues over the reasons for these sex differences. Previously, we used pupillometry to demonstrate sex differences in the cognitive effort invoked during the original MRT. Here, we evaluated the magnitude of sex differences during performance on a computerized version of the Vandenberg and Kuse MRT. Secondly, we examined whether fixation metrics could illuminate strategy use by participants. Finally, we used pupillometry to investigate whether cognitive effort differed between sexes and trials of different difficulty. While our results demonstrate no performance differences between sexes on the computerized MRT, fixation patterns provided evidence that gaze strategy was associated with performance on different parts of the test. Moreover, we show the cognitive demand of the V&K MRT, evidenced by large task dependent increases in participants’ pupil diameters.

Selective facilitation of egocentric mental transformations under short-term microgravity

ABSTRACTUnderstanding the impact of microgravity on human cognitive performance is crucial to guarantee the safety and success of future long-term manned missions. The effects of weightlessness on key mental processes such as spatial abilities are in particular not fully characterized. In this study, we examine the influence of microgravity on perspective-taking abilities—a type of mental operation especially relevant in the context of collaborative teamwork between ‘free-floating’ astronauts. Twelve subjects performed a cooperative task in virtual-reality under both normal and short-term microgravity conditions during a parabolic flight. The task involved various degrees of mental transformations, and required subjects to perform actions instructed by a fellow astronaut aboard a virtual spacecraft. The experimental design allowed us to control for nuisance variables, training effects, and non-gravity related factors of parabolic flights. Overall, our results indicated that microgravity has a facilitatory effect on perspective-taking abilities. Notably, this facilitation was selective to conditions requiring subjects to rotate their perspective around their line of sight, i.e., for mental rotations in the frontal plane. Moreover, microgravity affected subjects differently depending on their visual field dependence, as determined via a classic rod-and-frame test. Specifically, improvement in performance was more pronounced in field-independent subjects. Together, these results shed light on a long standing debate about the impact of microgravity on egocentric mental imagery, and have direct operational consequences for future long-term missions.

Fundamentally Distributed Information Processing Integrates the Motor Network into the Mental Workspace during Mental Rotation

The manipulation of mental representations in the human brain appears to share similarities with the physical manipulation of real-world objects. In particular, some neuroimaging studies have found increased activity in motor regions during mental rotation, suggesting that mental and physical operations may involve overlapping neural populations. Does the motor network contribute information processing to mental rotation? If so, does it play a similar computational role in both mental and manual rotation, and how does it communicate with the wider network of areas involved in the mental workspace? Here we used multivariate methods and fMRI to study 24 participants as they mentally rotated 3-D objects or manually rotated their hands in one of four directions. We find that information processing related to mental rotations is distributed widely among many cortical and subcortical regions, that the motor network becomes tightly integrated into a wider mental workspace network during mental rotation, and that motor network activity during mental rotation only partially resembles that involved in manual rotation. Additionally, these findings provide evidence that the mental workspace is organized as a distributed core network that dynamically recruits specialized subnetworks for specific tasks as needed.

Gymnasts and Orienteers Display Better Mental Rotation Performance Than Nonathletes

The aim of this study was to examine whether athletes differ from nonathletes regarding their mental rotation performance. Furthermore, it investigated whether athletes doing sports requiring distinguishable levels of mental rotation (orienteering, gymnastics, running), as well as varying with respect to having an egocentric (gymnastics) or an allocentric perspective (orienteering), differ from each other. Therefore, the Mental Rotations Test (MRT) was carried out with 20 orienteers, 20 gymnasts, 20 runners, and 20 nonathletes. The results indicate large differences in mental rotation performance, with those actively doing sports outperforming the nonathletes. Analyses for the specific groups showed that orienteers and gymnasts differed from the nonathletes, whereas endurance runners did not. Contrary to expectations, the mental rotation performance of gymnasts did not differ from that of orienteers. This study also revealed gender differences in favor of men. Implications regarding a differentiated view of the connection between specific sports and mental rotation performance are discussed.