Relationships between ovarian hormone concentrations and mental rotations performance in naturally-cycling women

Circulating gonadal hormones have been linked to variation in the structure and function of the adult human brain, raising the question of how cognition is affected by sex hormones in adulthood. The impacts of progestogens and estrogens are of special interest due to the widespread use of hormone supplementation. Multiple studies have analyzed relationships between ovarian hormones and mental rotation performance, one of the largest known cognitive sex differences; however, results are conflicting. These discrepancies are likely due in part to modest sample sizes and reliance on self-report measures to assess menstrual cycle phase. The present study aimed to clarify the impact of progestogens and estrogens on visuospatial cognition by relating mental rotation task performance to salivary hormone concentrations. Across two studies totaling 528 naturally-cycling premenopausal women, an internal meta-analysis suggested a small, positive effect of within-subjects changes in progesterone on MRT performance (estimate = 0.44, p = 0.014), though this result should be interpreted with caution given multiple statistical analyses. Between-subjects differences and within-subject changes in estradiol did not significantly predict MRT. These results shed light on the potential cognitive effects of endogenous and exogenous hormone action, and the proximate mechanisms modulating spatial cognition.

Bilateral sensory and motor as well as cognitive differences between persons with and without musculoskeletal disorders of the wrist and hand

BACKGROUND

Sensory and motor disturbances are characteristic of musculoskeletal injuries and conditions. Rehabilitation interventions aimed at remediating these disturbances are traditionally exclusively targeted to the affected area. However, there is some evidence of bilateral changes in sensory and motor function associated with unilateral injuries and conditions suggesting central changes. Deficits on specific cognitive tasks have also been documented in persons with chronic pain.

PURPOSE

The purpose of the present study was to determine if participants with unilateral pain arising from heterogeneous wrist/hand injuries and conditions demonstrate bilateral changes in sensory and motor functions as well as cognitive deficits.

DESIGN/METHODS

Sensory (Pressure Pain Thresholds, Two Point Orientation Discrimination), Motor (grip strength and Purdue Pegboard), and Cognitive function (Stroop test and mental rotation task) were measured in 30 participants with wrist/hand pain and 30 healthy control participants in an observational cross-sectional study.

RESULTS

Participants with unilateral wrist/hand pain demonstrated differences in cognitive function measured with the Stroop test (p = 0.03). They also demonstrated bilateral sensorimotor differences in pressure pain thresholds (p = 0.03), grip strength (p = 0.00) and Purdue pegboard test (p = 0.03) results compared to healthy control participants.

CONCLUSION

Cognitive as well as bilateral alterations in sensory and motor function in participants with musculoskeletal injuries and conditions suggest central changes are involved in their pathophysiology. These findings in persons with heterogeneous injuries/conditions suggest that these changes are not specific to an injury/condition. Bilateral sensorimotor changes have important implications with regards to the pathophysiology of musculoskeletal disorders of the wrist/hand, for rehabilitative interventions and research.

Mental rotation task specifically modulates functional connectivity strength of intrinsic brain activity in low frequency domains: A maximum uncertainty linear discriminant analysis

Neuroimaging studies have highlighted that intrinsic brain activity is modified to implement task demands. However, the relation between mental rotation and intrinsic brain activity remains unclear. To answer this question, we collected functional MRI (fMRI) data from 30 healthy participants in two mental rotation task periods (1st-task state, 2nd-task state) and two rest periods before (pre-task resting state) and after the task (post-task resting state) respectively. By combining the spatial independent component analysis (ICA) and voxel-wise functional connectivity strength (FCS), we identified FCS maps of 10 brain resting state networks (RSNs) within six different bands (i.e., 0-0.05, 0.05-0.1, 0.1-0.15, 0.15-0.2, 0.2-0.25, and 0.01-0.08Hz) corresponding to the four states for each subject. The maximum uncertainty linear discriminant analysis (MLDA) method showed that the FCS within the low frequency bandwidth of 0.05-0.1Hz could effectively classify the mental rotation task state from pre-/post-task resting states but failed to discriminate the pre- and post-task resting states. Discriminative FCSs were observed in the cognitive executive-control network (central executive and attention) and the imagery-based internal mental manipulation network (default mode, primary sensorimotor, and primary visual). Imagery manipulation is a stable mental element of mental rotation, and the involvement of executive control is dependent on the degree of task familiarity. Together, the present study provides evidence that mental rotation task specifically modifies intrinsic brain activity to complement cognitive demands, which provides further insight into the neural basis of mental rotation manipulation.