Androgens and eye movements in women and men during a test of mental rotation ability

Testosterone and lean mass show a positive correlation with the technical performance of footballers

BACKGROUND

Monitoring technical performance during a soccer match has become an indispensable practice, since the players perform different functions within the tactical system adopted by the team, resulting in specific technical actions that are fully responsive to the individual technical level of each player. Thus, current study aimed to investigate the possible direct and mediating relationship between salivary testosterone and the technical performance of semi-professional footballers during a training game.

METHODS

To characterize the sample, the anthropometric profile, body composition, biological maturation, lower limb power, speed, estimation of maximum oxygen consumption, and physical performance were used. To determine testosterone concentrations, saliva was collected before and after the training game, for subsequent measurement using enzyme immunoassay (ELISA) and Salimetrics Kits. For quantification of technical performance and participation with the ball during the training game, scout software was used from the footage of the training game. The reliability of the technical performance analyses was determined through the repetition test of two attempts (Cohen's Kappa agreement index).

RESULTS

The direct relationship between post-game testosterone and total participation with the ball in the second half; the direct relationship between the percentage of lean mass with post-game testosterone and an apparent relationship between percentage of lean mass and total participation with the ball from the set of relations mediated by post-game testosterone concentrations.

CONCLUSIONS

The results suggest that testosterone concentrations combined with high levels of lean mass may have a important role in the technical performance and participation with the ball of semi-professional footballers.

Testosterone and the Brain: From Cognition to Autism

Sex and gender matter in all aspects of life. Humans exhibit sexual dimorphism in anatomy, physiology, but also pathology. Many of the differences are due to sex chromosomes and, thus, genetics, other due to endocrine factors such as sex hormones, some are of social origin. Over the past decades, huge number of scientific studies have revealed striking sex differences of the human brain with remarkable behavioral and cognitive consequences. Prenatal and postnatal testosterone influence brain structures and functions, respectively. Cognitive sex differences include especially certain spatial and language tasks, but they also affect many other aspects of the neurotypical brain. Sex differences of the brain are also relevant for the pathogenesis of neuropsychiatric disorders such as autism spectrum disorders, which are much more prevalent in the male population. Structural dimorphism in the human brain was well-described, but recent controversies now question its importance. On the other hand, solid evidence exists regarding gender differences in several brain functions. This review tries to summarize the current understanding of the complexity of the effects of testosterone on brain with special focus on their role in the known sex differences in healthy individuals and people in the autism spectrum.

Influence of the stimulus material on gender differences in a mental-rotation test

Gender differences in mental-rotation tests with cube figures as rotational material are well examined and robust. Besides biological or socialization factors, task characteristics could partly be responsible for men's advantage in mental rotation. Therefore, we investigated in two studies the influence of different rotational materials on the gender differences in mental-rotation performance. In the first study, 134 undergraduate students (89 women, 45 men) participated using a mental-rotation test with either cube or pellet figures. Significant gender differences in favour of men but no interaction of gender and material were found. In the second study, 189 undergraduate students (110 women, 79 men) solved a mental-rotation test with either male or female-stereotyped objects. Significant gender differences appeared only when male-stereotyped objects were used as rotational material, but not for female-stereotyped material. A significant interaction of gender and material appeared. Hence, some rotational objects seem to have an influence on participants' mental-rotation performance and the gender differences in this task while others do not affect performances of women and men.

The development of mental rotation ability across the first year after birth

Mental rotation (MR) is the ability to imagine the appearance of an object from a different perspective. This ability is involved in many human cognitive and behavioral activities. We discuss studies that have examined MR in infants and its development across the first year after birth. Despite some conflicting findings across these studies, several conclusions can be reached. First, MR may be available to human infants as young as 3 months of age. Second, MR processes in infancy may be similar or identical to MR processes later in life. Third, there may be sex differences in MR performance, in general favoring males. Fourth, there appear to be multiple influences on infants' MR performance, including infants' motor activity, stimulus complexity, hormones, and parental attitudes. We conclude by calling for additional research to examine more carefully the causes and consequences of MR abilities early in life.

Spatial Thinking in Infancy: Origins and Development of Mental Rotation Between 3 and 10 Months of Age

Mental rotation (MR) is the ability to transform a mental representation of an object so as to accurately predict how the object would look from a different angle (Sci 171:701-703, 1971), and it is involved in a number of important cognitive and behavioral activities. In this review we discuss recent studies that have examined MR in infants and the development of MR across the first year after birth. These studies have produced many conflicting results, yet several tentative conclusions can be reached. First, MR may be operational in infants as young as 3 months of age. Second, there may be sex differences in MR performance in infancy, in general favoring males, as there are in children and in adults. Third, there appear to be multiple influences on infants' MR performance, including infants' motor activity, stimulus or task complexity, hormones, and parental attitudes. We conclude by calling for additional research to examine more carefully the causes and consequences of MR abilities early in life.

Mental Rotation: The Effects of Processing Strategy, Gender and Task Characteristics on Children's Accuracy, Reaction Time and Eye Movements' Pattern

The effects of gender, strategy and task characteristics on children's mental rotation (MR) behavioral measures and eye movements were studied. Eye movements reflect thinking pattern and assist understanding mental rotation performance. Eighty-three fourth-grade children (44 boys and 39 girls) were administered the Computerized Windows Mental Rotation test (CWMR) while having their eye movements monitored and completed a Strategy Self-Report (global/local/combined) and a Spatial Span (WM) subtest. Difficulty level affected performance and was reflected in a different eye movement pattern. Boys were more accurate than girls, but they did not differ in their eye movement pattern. Eye movement pattern was related to strategy, accu-racy and reaction time, revealing that the global and combined strategy were more effective compared with local strategy. WM was found to correlate with accuracy at the easy level of the test. The usage of eye movement measures assists in elaborating our knowledge regarding MR performance among chil-dren and enable a wider understanding regarding the interaction between gender, strategy and difficulty level.

Digit ratio (2D:4D) and its behavioral correlates in infant rhesus macaques (Macaca mulatta)

2D:4D ratios are typically lower in adult human males than females and are linked to numerous sex-differentiated behaviors. 2D:4D ratios are considered an indicator of prenatal androgen exposure; if so, children's 2D:4D ratios would arguably be even better indicators of prenatal androgen exposure since children have experienced fewer postnatal influences than adults. However, sex differences in 2D:4D ratios as well as associations between 2D:4D ratios and sex-typed behaviors in children have been inconsistent. Several studies also report sex differences and behavioral correlates of 2D:4D ratios in adult non-human primates, but little is known about 2D:4D ratios in infant non-human primates. This study examined sex differences in 2D:4D ratios over the first month of life, and associations with behavioral outcomes at 12-24 weeks of age, in N = 304 infant rhesus macaques. An increase in 2D:4D ratios over the first month of life was found, as well as associations with aggression and play behaviors, but no sex differences in 2D:4D ratios were observed. These results highlight the need for future developmental studies of 2D:4D ratios in order to determine not only their stability and predictive value, but also to discern the mechanism connecting prenatal androgen exposure, 2D:4D ratios, and behavioral outcomes.

Sex differences in a chronometric mental rotation test with cube figures: a behavioral, electroencephalography, and eye-tracking pilot study

In chronometric mental rotation tasks, sex differences are widely discussed. Most studies find men to be more skilled in mental rotation than women, which can be explained by the holistic strategy that they use to rotate stimuli. Women are believed to apply a piecemeal strategy. So far, there have been no studies investigating this phenomenon using eye-tacking methods in combination with electroencephalography (EEG) analysis: the present study compared behavioral responses, EEG activity, and eye movements of 15 men and 15 women while solving a three-dimensional chronometric mental rotation test. The behavioral analysis showed neither differences in reaction time nor in the accuracy rate between men and women. The EEG data showed a higher right activation on parietal electrodes for women and the eye-tracking results indicated a longer fixation in a higher number of areas of interest at 0° for women. Men and women are likely to possess different perceptual (visual search) and decision-making mechanisms, but similar mental rotation processes. Furthermore, men presented a longer visual search processing, characterized by the greater saccade latency of 0°–135°. Generally, this study could be considered a pilot study to investigate sex differences in mental rotation tasks while combining eye-tracking and EEG methods.

Influence of sex-stereotyped stimuli on the mental-rotation performance of elderly persons

BACKGROUND

In mental-rotation tests with cube figures as rotational objects, differences in favor of men are often found (Voyer, Voyer, & Bryden, 1995). Mental-rotation performance often declines with age (Jacewicz & Hartley, 1987), but sex differences usually remain (Herman & Bruce, 1983).

METHODS

In this study, male- and female-stereotyped objects were used as rotational stimuli in a mental-rotation paper and pencil test (Ruthsatz, Neuburger, Rahe, Jansen, & Quaiser-Pohl, 2017) for elderly participants (age: 57-88 years).

RESULTS

Overall, no sex differences for mental-rotation performance were found, whereas a significant interaction of sex and stimulus material revealed better performance for own-sex objects (η² = .070). A significant negative correlation between mental-rotation performance and age could be found (r = -.384).

CONCLUSIONS

It seems to be easier to perform mental-rotation with objects that persons are more familiar with. There is a decrease in mental-rotation accuracy as well as in the processing speed for the older participants.

Gender differences in mental rotation strategy depend on degree of autistic traits

Participants with low, medium, and high autistic traits completed a mental rotation task while their eye movements were recorded. Men were more accurate than women (F(1, 102) = 4.36, P = 0.04, η²_p  = 0.04), but there were no group differences in reaction time. In terms of eye movements, all participants tended to rely on top corners of cube figures for most angles of rotation, and bottom corners of cube figures for 0 and 90 degree rotations (duration: F(8, 816) = 21.70, P < 0.001, η²_p  = 0.18; count: F(8, 816) = 24.42, P < 0.001, η²_p  = 0.19) suggesting a shift in strategy with rotation angle. Eye movements to corners of cube figures also varied by autistic traits group and gender (duration: F(4, 204) = 2.44, P = 0.05, η²_p  = 0.05; count: F(4, 204) = 2.47, P = 0.05, η²_p  = 0.05). Participants with low and medium autistic traits tended to rely more often on the top corners, whereas women with high autistic traits relied on both the top and bottom corners and men with high autistic traits relied on all corners equally. These results suggest mental rotation strategies may vary by both gender and autistic traits. Autism Res 2018, 11: 1024-1037. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

The current study looked at eye movements to assess adults' strategies when mentally rotating three-dimensional cube figures. Adults with varying levels of autistic traits differ in their mental rotation strategies. In addition, gender differences in strategies are observed in adults with the highest level of autistic traits.

The association between the disruption of motor imagery and the number of depressive episodes of major depression

BACKGROUND

Mental rotation performance may be used as an index of mental slowing or bradyphrenia, and may reflect, in particular, speed of motor preparation. Previous studies suggest depressive patients present the correlates of impaired behavioural performance for mental rotation and psychomotor disturbance. The aim of this study is to compare the mental rotation abilities of patients with a first episode of depression, recurrent depression and healthy control subjects with regard to hand tasks.

METHODS

We tested 32 first episode of depression, 38 recurrent depression and 36 healthy control subjects by evaluating the performance of depressed patients with regard to the hand mental rotation tasks.

RESULTS

First, the first episode and recurrent depression subjects were significantly slower and made more errors than controls in mentally rotating hands. Second, the first depressive episode but not the recurrent depression displayed the same pattern of response times to stimuli at various orientations relative to control subjects in the hand task. Third, in particular, recurrent depression subjects were significantly slower and made more errors during the mental transformation of hands than first depressive episode relative to control subjects and the differences were significantly larger in female than male subjects in the mental rotation hand task.

LIMITATIONS

Patients were on antidepressant medication.

CONCLUSIONS

These results suggest that the impaired behavioural performance for mental representation processing are related to the number of previous episodes. Moreover, the recurrent major depressive episodes may contribute to the reinforcement of cognitive impairments and further the development or maintenance of mental representation dysfunctions, especially in female patients. A deficit on mental rotation in the depressive patients may be potential biomarkers for recurrence chronically.

Dimensional transformation in tests of spatial and environmental cognition

In previous research, it has been argued that spatial performance on psychometric tests might be accounted for, in part, by the need for test-takers to transform mentally two-dimensional (2-D) test items into a three-dimensional (3-D) representation. With this in mind, the Landscape Perception Test (LPT) was designed to isolate the 2-D to 3-D (and vice versa) transformational aspect of spatial cognition. Gender differences were used as an indirect means to examine the contribution of the 2-D to 3-D transformation to spatial performance. Since the LPT was designed by means of an image relevant to geospatial cognition, measures of environmental cognition, as well as experience in various activities, were also examined. One hundred thirty undergraduate students (66 females and 64 males) completed the Childhood Activities Questionnaire, the Santa Barbara Sense of Direction Test, the Visualization of Views (VV) Test, the Perspective Taking/Spatial Orientation Test, and the LPT. Results showed higher scores for men than for women on LPT items requiring 2-D to 3-D conversion (LPT23), but not on those requiring the reverse operation. In addition, only the LPT23 produced significant indirect effects of gender on VV Test performance. Performance on the tests was also correlated with environmental cognition and previous experience with spatial activities. The results suggest that dimensional transformation might be a factor significantly contributing to spatial performance. Psychometric aspects of the LPT are also discussed.

Bodies and occlusion: item types, cognitive processes, and gender differences in mental rotation

The aim of the current study was to reexamine previous findings in which the magnitude of the male advantage in mental rotation abilities increased when participants mentally rotated occluded versus nonoccluded items and decreased when participants mentally rotated human figures versus blocks. Mainly, the study aimed to address methodological issues noted on previous human figure mental rotations tests as the items composed of blocks and human body were probably not equivalent in terms of their cognitive requirements. Our results did not support previous research on embodied cognition as mental rotation performance decreased among both men and women when mentally rotating human figures compared to block items. However, for women, the effect of occlusion was decreased when mentally rotating human figures. Results are discussed in terms of task difficulty and gender differences in confidence and guessing behaviour.

The association between 2D:4D ratios and sociosexuality: a failure to replicate

Researchers investigating the role of biological factors in the development and maintenance of interest in uncommitted sexual activity (i.e., sociosexuality) have reported that greater prenatal androgen action in women, as inferred by the ratio of the 2nd to 4th digit, is associated with greater interest in uncommitted sexual relationships, as measured by scores on the Sociosexuality Orientation Inventory (SOI) (Clark, 2004). This evidence suggesting a rather extensive role for prenatal factors in human mating behavior has been cited over 20 times in the literature. However, despite this indication of the impact of the research results on theories of human sex differences, there are no published replications of the original finding. For that reason, the association between 2D:4D ratios and sociosexuality was evaluated in two studies. In the first study, using methodology similar to the original report, no significant association between 2D:4D ratios and SOI scores was found either in women (n = 25) or men (n = 25). Next, to test the possibility that moderating factors, such as menstrual cycle phase and circulating testosterone levels, influence the strength of the association between 2D:4D ratios and sociosexuality, salivary hormone levels and behaviors were measured during the early follicular and mid-luteal phase of the menstrual cycle in women not using hormonal contraceptives (n = 40) and at two time points in women using oral contraceptives (n = 44) and in men (n = 42). Women and men in this study showed the expected sex differences in hormone levels and behavior. However, circulating hormones and 2D:4D ratios were unrelated to measures of sociosexuality obtained at the two test sessions. In sum, these data suggest that factors other than prenatal and circulating hormones explain the sex differences in self-reports of sociosexuality.

Scientometric analysis and bibliography of digit ratio (2D:4D) research, 1998-2008

A scientometric analysis of modern research on the second-to-fourth digit ratio (2D:4D), a widely studied putative marker for prenatal androgen action, is presented. In early 2009, this literature totalled more than 300 publications and, since its initiation in 1998, has grown at a rate slightly faster than linear. Key findings included evidence of publication bias and citation bias, incomplete coverage and outdatedness of existing reviews, and a dearth of meta-analyses in this field. 2D:4D research clusters noticeably in terms of researchers, institutions, countries, and journals involved. Although 2D:4D is an anthropometric trait, most of the research has been conducted at psychology departments, not anthropology departments. However, 2D:4D research has not been predominantly published in core and specialized journals of psychology, but rather in more broadly scoped journals of the behavioral sciences, biomedical social sciences, and neurosciences. Total citation numbers of 2D:4D papers for the most part were not larger than their citation counts within 2D:4D research, indicating that until now, only a few 2D:4D studies have attained broader interest outside this specific field. Comparative citation analyses show that 2D:4D research presently is commensurate in size and importance to evolutionary psychological jealousy research, but has grown faster than the latter field. In contrast, it is much smaller and has spread more slowly than research about the Implicit Association Test Fifteen conjectures about anticipated trends in 2D:4D research are outlined, appendixed by a first-time bibliography of the entirety of the published 2D:4D literature.

Blocks and bodies: sex differences in a novel version of the Mental Rotations Test

A novel version of the Mental Rotations Test (MRT) that alternated the standard block figures with three-dimensional human figures was administered to 99 men and 129 women. Women and men differed predictably in their retrospective reports of childhood play and digit ratios, a putative measure of prenatal androgen action. Compared to the block figure items, human figure items on the modified MRT were associated with an improvement in performance in both sexes. However, consistent with the study hypothesis, the enhancing effect of the human figure condition on performance as measured by conventional scores was smaller in men compared to women and not at all evident in men when performance was measured by ratio scores. A closer inspection of the human figures effects on test scores showed performance in women improved for both male and female figure items. In contrast, relative to scores on block figure items, performance in men improved when stimuli were male figures but did not improve when stimuli were female figures. These results add to the evidence that the magnitude of sex differences in scores on the MRT may vary according to the test content and item properties. The findings suggest that online measures of cognitive processing in response to different classes of test stimuli (e.g., animate vs. inanimate objects, self-relevant vs. neutral stimuli) may prove useful in research aimed at understanding the hormonal and social factors contributing to the sex difference in performance on the MRT.