Keeping time and rhythm by replaying a sensory-motor engram

Imagine practicing a piece of music, or a speech, solely within the mind, without any sensory input or motor output. Our ability to implement dynamic internal representations is key for successful behavior, yet how the brain achieves this is not fully understood. Here we trained primates to perceive, and internally maintain, rhythms of different tempos and performed large-scale recordings of neuronal activity across multiple areas spanning the sensory-motor processing hierarchy. Results show that perceiving and maintaining rhythms engage multiple brain areas, including visual, parietal, premotor, prefrontal, and hippocampal regions. Each area displayed oscillatory activity that reflected the temporal and spatial characteristics of an internal metronome which flexibly encoded fast, medium, and slow tempos on a trial-by-trial basis. The presence of widespread metronome-related activity across the brain, in the absence of stimuli and overt actions, is consistent with the idea that time and rhythm are maintained by a mechanism that internally replays the stimuli and actions that define well-timed behavior.

P.016 Hypertensive disorders in pregnancy are associated with future development of vascular dementia: A systematic review and meta-analysis

Background: We aimed to evaluate the association between hypertensive disorders in pregnancy (HDP) and future risk of cognitive impairment and dementia. Methods: Systematic searches were performed in MEDLINE and EMBASE up to April 27th, 2020. Exposure of interest included the different types of HDP. Outcomes of interest included dementia incidence, dementia subtype, and cognitive testing. Results: On qualitative review, 4/9 studies showed impaired memory, visual motor processing speed, executive function, and verbal testing in previously preeclamptic women. 2/4 studies showed impaired visual motor processing and subjective cognitive complaints in previously eclamptic women. Six cohort studies involving >2.6 million women were included in the meta-analysis. Pooled hazard ratios (aHR) with 95% confidence intervals were generally adjusted for age at delivery ethnicity, and vascular risk factors. Women with a history of gestational hypertension were more likely to develop vascular dementia (aHR 2.02 [1.45-2.83],I2:0%), but not Alzheimer disease (1.24 [0.93-1.66],single-study). Women with a history of preeclampsia were also more likely to develop vascular dementia (2.17 [1.20-3.91],I2:61.1%), but not Alzheimer dementia (1.19 [0.83-1.69],I2:69.9%). Conclusions: Whereas studies of neuropsychological testing in previously preeclamptic and eclamptic women have been heterogeneous, a history of HDP is associated with developing vascular dementia in later life.

Perspectives on Perception for Optimal Performance

To enhance understanding of the audiomotor performance art that is singing, as well to optimize healthy performance, this article focuses the lens of neuroscience on perceptual-motor processing and the neural anatomy that links mind and body.

Neural dynamics of illusory tactile pulling sensations

The sensation of directional forces and their associated sensorimotor commands are inextricably intertwined, complicating the identification of brain circuits responsible for tactile pulling sensations. One hypothesis is that, like tactile frequency discrimination, pulling sensations are generated by early sensory-frontal activity. Alternatively, they may be generated later in the somatosensory association cortex. To dissociate these accounts and uncouple the pulling sensation from unrelated but correlated sensory and motor processing, we combined high-density EEG with an oddball paradigm and asymmetric vibration, which creates an illusory sensation of the hand being directionally pulled. Oddballs that created a pulling sensation in the opposite direction to common stimuli were compared to the same oddballs in the context of neutral common stimuli (symmetric vibration) and to neutral oddballs. Brain responses to having directional pulling expectations violated by directional stimuli were therefore isolated. Contrary to the sensory-frontal account, frontal N140 brain activity was actually larger for neutral than pulling oddballs. Instead, pulling sensations were associated with amplitude and latency modulations of midline P200 and P3b potentials, and specifically, to contralateral parietal lobe activity 280ms post-stimulus. The timing of this activity suggested pulling sensations involve spatial processing, such as tactile remapping between coordinate frames. Source localization showed this activity to be centered on the postcentral sulcus, superior parietal lobule and intraparietal sulcus, suggesting that pulling sensations arise via the processing of body position, tactile orientation and peripersonal space. Our results demonstrate how tactile illusions can uniquely disambiguate parietal contributions to somatosensation by removing unrelated sensory processing.

Exploring the Dimensions of Movement-Specific Reinvestment From Personal Characteristics Perspectives

The purposes of the present study were three-fold: to examine (a) if the movement-specific reinvestment responses should be represented as two dimensional constructs, (b) whether dichotomization of the movement-specific reinvestment responses are appropriate, and (c) how the two dimensions are associated with relevant psychological concepts. To conduct a comparative examination of the MSRS structure in two Asian samples, participants were 236 Japanese university students (136 men, 100 women; Mage = 18.0, SD = 1.6) and 328 Singaporeans (167 men, 161 women; Mage = 21.8, SD = 1.8). After examining the factor structure of the movement-specific reinvestment responses for the first purpose, latent class factor analysis was conducted for both samples for the second purpose. For the third purpose, correlation analysis and mediation analysis were conducted for a part of the Singaporean sample. Through a series of latent class factor analysis, four and three classes were identified for the Japanese and Singaporean samples, respectively. For both samples, the patterns of the item-average scores for the two movement-specific reinvestment dimensions were parallel among the classes. Conscious Motor Processing was positively associated with mental toughness, intrinsic regulation, integrated regulation, mastery-approach and task goal orientations, and dispositional flow, whereas Movement Self-Consciousness was positively related with stress and mastery-avoidance goal orientation. The findings of the study supported (a) the two-dimensional representation of the movement-specific reinvestment responses, but did not fully support (b) the practice of dichotomization of the movement-specific reinvestment responses, and indicated that (c) at the trait level, Conscious Motor Processing and Movement Self-Consciousness were associated with positive and negative psychological constructs, respectively.

Visual perturbation of balance suggests impaired motor control but intact visuo-motor processing in Parkinson's disease

Postural instability marks one of the most disabling features of Parkinson's disease (PD), but only reveals itself after affected brain areas have already been significantly damaged. Thus, there is a need to detect deviations in balance and postural control before visible symptoms occur. In this study, we visually perturbed balance in the anterior-posterior direction using sinusoidal oscillations of a moving room in virtual reality at different frequencies. We tested three groups: individuals with PD under dopaminergic medication, an age-matched control group, and a group of young healthy adults. We tracked their centre of pressure and their full-body motion, from which we also extracted the centre of mass. We investigated sway amplitudes and applied newly introduced phase-locking analyses to investigate responses across participants' bodies. Patients exhibited significantly higher sway amplitudes as compared to the control subjects. However, their sway was phase-locked to the visual motion like that of age-matched and young healthy adults. Furthermore, all groups successfully compensated for the visual perturbation by phase-locking their sway to the stimulus. As frequency of the perturbation increased, distribution of phase-locking (PL) across the body revealed a shift of the highest PL-values from the upper body towards the hip-region for young healthy adults, which could not be observed in patients and elderly healthy adults. Our findings suggest an impaired motor control, but intact visuo-motor processing in early stages of PD, while less flexibility to adapt postural strategy to different perturbations revealed to be an effect of age rather than disease.

Design Heuristics For In-Crisis Users

Any interface designed for in-crisis users needs to address their state of mind and physiological arousal. However, to date no clear guidance exists for the specific needs of in-crisis users. An opportunity to redesign a regional domestic abuse website inspired us to adapt Nielsen’s 10 heuristics by including three heuristics for in-crisis users, specifically domestic abuse victims. Given the lack of research we used existing research to address users’ cognitive and motor processing impairments during high anxiety and arousal. To see how well current domestic abuse websites follow these heuristics, we evaluated a pseudo-randomly selected set of 98 domestic abuse helplines. The result showed overall poor results. Irrelevant information, poor readability, and failure to highlight crucial information were among the main contributors for the poor assessment. The data illustrates the need for improved design guidelines to create a safe and effective option for in-crisis users.

No evidence for three functionally specialized subregions in the subthalamic nucleus: A model-based 7 T fMRI study

The subthalamic nucleus (STN) is a small, subcortical brain structure. It is a target for deep brain stimulation, an invasive treatment that reduces motor symptoms of Parkinson's disease. Side effects of DBS are commonly explained using the tripartite model of STN organization, which proposes three functionally distinct subregions in the STN specialized in cognitive, limbic, and motor processing. However, evidence for the tripartite model exclusively comes from anatomical studies and functional studies using clinical patients. Here, we provide the first experimental tests of the tripartite model in healthy volunteers using ultra-high field 7 Tesla (T) functional magnetic resonance imaging (fMRI). 34 participants performed a random-dot motion decision-making task with a difficulty manipulation and a choice payoff manipulation aimed to differentially affect cognitive and limbic networks. Moreover, participants responded with their left and right index finger, differentially affecting motor networks. We analysed BOLD signal in three subregions of equal volume of the STN along the dorsolateral-ventromedial axis, identified using manually delineated high resolution anatomical images. Our results indicate that all segments responded equally to the experimental manipulations, and did not support the tripartite model.