TY - GEN A1 - Chen, Siyi A1 - Glasauer, Stefan A1 - Müller, Hermann J. A1 - Conci, Markus T1 - Surface filling-in and contour interpolation contribute independently to Kanizsa figure formation T2 - Journal of Experimental Psychology Y1 - 2018 U6 - https://doi.org/10.1037/xhp0000540 SN - 1939-1277 SN - 0096-1523 VL - 44 IS - 9 SP - 1399 EP - 1413 ER - TY - GEN A1 - Salmasi, Mehrdad A1 - Loebel, Alex A1 - Glasauer, Stefan A1 - Stemmler, Martin T1 - Short-term synaptic depression can increase the rate of information transfer at a release site T2 - PLoS Computational Biology N2 - The release of neurotransmitters from synapses obeys complex and stochastic dynamics. Depending on the recent history of synaptic activation, many synapses depress the probability of releasing more neurotransmitter, which is known as synaptic depression. Our understanding of how synaptic depression affects the information efficacy, however, is limited. Here we propose a mathematically tractable model of both synchronous spike-evoked release and asynchronous release that permits us to quantify the information conveyed by a synapse. The model transits between discrete states of a communication channel, with the present state depending on many past time steps, emulating the gradual depression and exponential recovery of the synapse. Asynchronous and spontaneous releases play a critical role in shaping the information efficacy of the synapse. We prove that depression can enhance both the information rate and the information rate per unit energy expended, provided that synchronous spike-evoked release depresses less (or recovers faster) than asynchronous release. Furthermore, we explore the theoretical implications of short-term synaptic depression adapting on longer time scales, as part of the phenomenon of metaplasticity. In particular, we show that a synapse can adjust its energy expenditure by changing the dynamics of short-term synaptic depression without affecting the net information conveyed by each successful release. Moreover, the optimal input spike rate is independent of the amplitude or time constant of synaptic depression. We analyze the information efficacy of three types of synapses for which the short-term dynamics of both synchronous and asynchronous release have been experimentally measured. In hippocampal autaptic synapses, the persistence of asynchronous release during depression cannot compensate for the reduction of synchronous release, so that the rate of information transmission declines with synaptic depression. In the calyx of Held, the information rate per release remains constant despite large variations in the measured asynchronous release rate. Lastly, we show that dopamine, by controlling asynchronous release in corticostriatal synapses, increases the synaptic information efficacy in nucleus accumbens. Y1 - 2019 UR - https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1006666 U6 - https://doi.org/10.1371/journal.pcbi.1006666 SN - 1553-7358 SN - 1553-734X VL - 15 ER - TY - GEN A1 - MacNeilage, Paul R. A1 - Glasauer, Stefan T1 - Perceiving gravity: the role of the cerebellum T2 - Current Biology Y1 - 2018 U6 - https://doi.org/10.1016/j.cub.2018.09.053 SN - 1879-0445 SN - 0960-9822 VL - 28 IS - 22 SP - 1296 EP - 1298 ER - TY - JOUR A1 - Glasauer, Stefan T1 - Ferrè, Elisa Raffaella (Hrsg.): Vestibular Cognition. Leiden [u.a.] Boston : Brill, 2017 JF - Perception Y1 - 2018 SN - 1468-4233 VL - 47 IS - 7 SP - 799 EP - 801 ER - TY - GEN A1 - Kupferberg, Aleksandra A1 - Iacoboni, Marco A1 - Flanagin, Virginia A1 - Huber, Markus A1 - Kasparbauer, Anna A1 - Baumgartner, Thomas A1 - Hasler, Gregor A1 - Schmidt, Florian A1 - Borst, Christoph A1 - Glasauer, Stefan T1 - Fronto-parietal coding of goal-directed actions performed by artificial agents T2 - Human Brain Mapping Y1 - 2018 U6 - https://doi.org/10.1002/hbm.23905 SN - 1097-0193 SN - 1065-9471 VL - 39 IS - 3 SP - 1145 EP - 1162 ER - TY - GEN A1 - Choi, Jeong-Yoon A1 - Glasauer, Stefan A1 - Zee, David S. A1 - Kim, Ji-Soo T1 - Characteristics and Mechanism of Apogeotropic Central Positional Nystagmus T2 - Brain Y1 - 2018 U6 - https://doi.org/10.1093/brain/awx381 SN - 1460-2156 SN - 0006-8950 VL - 141 IS - 3 SP - 762 EP - 775 ER - TY - GEN A1 - Dieterich, Marianne A1 - Glasauer, Stefan A1 - Brandt, Thomas T1 - Why acute unilateral vestibular midbrain lesions rarely manifest with rotational vertigo: a clinical and modelling approach to head direction cell function. T2 - Journal of Neurology Y1 - 2018 U6 - https://doi.org/10.1007/s00415-018-8828-5 SN - 0340-5354 SN - 1432-1459 VL - 265 IS - 5 SP - 1184 EP - 1198 ER - TY - GEN A1 - Oguz, Ozgur S. A1 - Zhou, Zhehua A1 - Glasauer, Stefan A1 - Wollherr, Dirk T1 - An Inverse Optimal Control Approach to Explain Human Arm Reaching Control Based on Multiple Internal Models T2 - Scientific Reports Y1 - 2018 U6 - https://doi.org/10.1038/s41598-018-23792-7 SN - 2045-2322 VL - 8 ER - TY - GEN A1 - Anggraini, Dian A1 - Glasauer, Stefan A1 - Wunderlich, Klaus T1 - Neural signatures of reinforcement learning correlate with strategy adoption during spatial navigation T2 - Scientific Reports Y1 - 2018 U6 - https://doi.org/10.1038/s41598-018-28241-z SN - 2045-2322 VL - 8 ER - TY - GEN A1 - Hausmann, Peter A1 - Daumer, Martin A1 - MacNeilage, Paul R. A1 - Glasauer, Stefan T1 - Ecological momentary assessment of head motion: Towards normative data of head stabilization T2 - Frontiers in Human Neuroscience N2 - Head stabilization is fundamental for balance during locomotion but can be impaired in elderly or diseased populations. Previous studies have identified several parameters of head stability with possible diagnostic value in a laboratory setting. Recently, the ecological validity of measures obtained in such controlled contexts has been called into question. The aim of this study was to investigate the ecological validity of previously described parameters of head stabilization in a real-world setting. Ten healthy subjects participated in the study. Head and trunk movements of each subject were recorded with inertial measurement units (IMUs) for a period of at least 10 h. Periods of locomotion were extracted from the measurements and predominant frequencies, root mean squares (RMSs) and bout lengths were estimated. As parameters of head stabilization, attenuation coefficients (ACs), harmonic ratios (HRs), coherences, and phase differences were computed. Predominant frequencies were distributed tightly around 2 Hz and ACs, HRs, and coherences exhibited the highest values in this frequency range. All head stability parameters exhibited characteristics consistent with previous reports, although higher variances were observed. These results suggest that head stabilization is tuned to the 2 Hz fundamental frequency of locomotion and that previously described measures of head stability could generalize to a real-world setting. This is the first study to address the ecological validity of these measures, highlighting the potential use of head stability parameters as diagnostic tools or outcome measures for clinical trials. The low cost and ease of use of the IMU technology used in this study could additionally be of benefit for a clinical application. Y1 - 2019 U6 - https://doi.org/10.3389/fnhum.2019.00179 SN - 1662-5161 VL - 13 ER - TY - GEN A1 - Glasauer, Stefan T1 - Sequential Bayesian updating as a model for human perception T2 - Progress in Brain Research N2 - Sequential Bayesian updating has been proposed as model for explaining various systematic biases in human perception, such as the central tendency, range effects, and serial dependence. The present chapter introduces to the principal ideas behind Bayesian updating for the random-change model introduced previously and shows how to implement sequential updating using the exact method via probability distributions, the Kalman filter for Gaussian distributions, and a particle filter for approximate sequential updating. Finally, it is demonstrated how to couple perception to action by selecting an appropriate action based on the posterior distribution that results from sequential updating. Y1 - 2019 U6 - https://doi.org/10.1016/bs.pbr.2019.04.025 SN - 1875-7855 SN - 0079-6123 VL - 249 SP - 3 EP - 18 ER - TY - GEN A1 - Salmasi, Mehrdad A1 - Stemmler, Martin A1 - Glasauer, Stefan A1 - Loebel, Alex T1 - Synaptic Information Transmission in a Two-State Model of Short-Term Facilitation T2 - Entropy N2 - Action potentials (spikes) can trigger the release of a neurotransmitter at chemical synapses between neurons. Such release is uncertain, as it occurs only with a certain probability. Moreover, synaptic release can occur independently of an action potential (asynchronous release) and depends on the history of synaptic activity. We focus here on short-term synaptic facilitation, in which a sequence of action potentials can temporarily increase the release probability of the synapse. In contrast to the phenomenon of short-term depression, quantifying the information transmission in facilitating synapses remains to be done. We find rigorous lower and upper bounds for the rate of information transmission in a model of synaptic facilitation. We treat the synapse as a two-state binary asymmetric channel, in which the arrival of an action potential shifts the synapse to a facilitated state, while in the absence of a spike, the synapse returns to its baseline state. The information bounds are functions of both the asynchronous and synchronous release parameters. If synchronous release facilitates more than asynchronous release, the mutual information rate increases. In contrast, short-term facilitation degrades information transmission when the synchronous release probability is intrinsically high. As synaptic release is energetically expensive, we exploit the information bounds to determine the energy–information trade-off in facilitating synapses. We show that unlike information rate, the energy-normalized information rate is robust with respect to variations in the strength of facilitation. Y1 - 2019 U6 - https://doi.org/10.3390/e21080756 SN - 1099-4300 VL - 21 IS - 8 ER - TY - GEN A1 - Glasauer, Stefan A1 - Dieterich, Marianne A1 - Brandt, Thomas T1 - Computational neurology of gravity perception involving semicircular canal dysfunction in unilateral vestibular lesions T2 - Progress in Brain Research N2 - Unilateral peripheral vestibular lesions not only lead to vertigo, nystagmus and imbalance, but also to a bias in the perception of verticality, which can be measured as tilt of the subjective visual vertical (SVV). Previously, this tilt has been assumed to be caused by a residual otolith bias, for example, because unequal numbers of active haircells on both sides of the utricular striola might result in an imbalance of the firing rates of central otolith neurons. Here we propose that a tilt of the subjective visual vertical might as well be caused by a vertical semicircular canal bias in the roll axis after unilateral peripheral lesions. The canal bias, acting similar to angular velocity stimuli, influences the SVV via the central gravity estimator, which under normal circumstances resolves a perceptual tilt-translation ambiguity. To illustrate our hypothesis, we compare model predictions to data on SVV measurements in patients with unilateral vestibular lesions while being tilted or being rotated eccentrically. We further embed the model of peripheral processing in a neural network that implements the idiotropic bias and represents the direction of gravity as population code in a three dimensional spherical topography. Y1 - 2019 U6 - https://doi.org/10.1016/bs.pbr.2019.04.010 SN - 1875-7855 SN - 0079-6123 VL - 248 SP - 303 EP - 317 ER -