Motor expertise facilitates the accuracy of state extrapolation in perception

Ludolph N, Plöger J, Giese MA, Ilg W. Motor expertise facilitates the accuracy of state extrapolation in perception. PLOS ONE. 2017;12(11): e0187666

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe

Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders

Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe

Interacting Learning Processes during Skill Acquisition: Learning to control with gradually changing system dynamics

Ludolph N, Giese MA, Ilg W. Interacting Learning Processes during Skill Acquisition: Learning to control with gradually changing system dynamics. Scientific Reports. 2017;7(1): 13191

Validation of enhanced kinect sensor based motion capturing for gait assessment

<div><p>Optical motion capturing systems are expensive and require substantial dedicated space to be set up. On the other hand, they provide unsurpassed accuracy and reliability. In many situations however flexibility is required and the motion capturing system can only temporarily be placed. The Microsoft Kinect v2 sensor is comparatively cheap and with respect to gait analysis promising results have been published. We here present a motion capturing system that is easy to set up, flexible with respect to the sensor locations and delivers high accuracy in gait parameters comparable to a gold standard motion capturing system (VICON). Further, we demonstrate that sensor setups which track the person only from one-side are less accurate and should be replaced by two-sided setups. With respect to commonly analyzed gait parameters, especially step width, our system shows higher agreement with the VICON system than previous reports.</p></div

Reconstruction of the body surface and averaged skeleton.

<p>(A, B) Three-dimensional reconstruction of the body surface and the corresponding skeleton reconstruction using two sensors. The surface was estimated based on the 3d point clouds using the marching cubes algorithm in MeshLab [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175813#pone.0175813.ref032" target="_blank">32</a>]. Surface areas tracked by only one of the two sensors are highlighted in red (right) and blue (left). Corresponding Kinect skeleton joint positions estimates of the two sensors are shown as red and blue dots. The spatially averaged skeleton is indicated as black stick figure. (B) Magnification of the left lower leg. Notice, that the joint position estimates of the left sensor (blue) are closer to the surface which is only tracked by the left sensor (blue), correspondingly for the joint position estimates of the right sensor. (C) Averaged skeleton and joint position trajectories during walking obtained using six sensors.</p

Motor control and visual familiarization task.

<p>(A) Visualization of the cart-pole system for both tasks. In the visual familiarization blocks the force was indicated as red arrow (like in the extrapolation task). The reward (blue number) that we presented during the motor control blocks (MF subjects) was not shown during the visual familiarization (VF subjects). We did not show the arrow during the motor control blocks. (B) The input device, which was used for controlling the system during the motor control blocks. The knob of the input device can be shifted left and right, which was used to control the virtual force that is applied to the cart from either side. (C) Phases of each trial during the visual familiarization. During the observation phase, a balancing attempt was shown that lasted up to 30 seconds. Afterwards, subjects rated the attempt on a scale from one (very bad) to five (very good). BD: balancing duration, RT: response time.</p

Comparison of the two groups based on the model lh_cVEL and parameter h*.

<p>Inter-quartile range (box) and median (dot) of the fitted <i>h*</i> for the motor familiar (MF) and visually familiar (VF) subjects in block T4. The median <i>h*</i> for subjects in the group MF is significantly higher and therefore closer to the perfect model (h = 900ms).</p