Spatio-temporal properties of oculomotor activation by multiple, simultaneous peripheral stimuli

2021 ◽  
Vol 188 ◽  
pp. 251-261
Author(s):  
John Christie ◽  
Matthew D. Hilchey ◽  
Raymond M. Klein
Author(s):  
Tengfei Li ◽  
Jing Liu ◽  
Haiying Sun ◽  
Xiang Chen ◽  
Lipeng Zhang ◽  
...  

AbstractIn the past few years, significant progress has been made on spatio-temporal cyber-physical systems in achieving spatio-temporal properties on several long-standing tasks. With the broader specification of spatio-temporal properties on various applications, the concerns over their spatio-temporal logics have been raised in public, especially after the widely reported safety-critical systems involving self-driving cars, intelligent transportation system, image processing. In this paper, we present a spatio-temporal specification language, STSL PC, by combining Signal Temporal Logic (STL) with a spatial logic S4 u, to characterize spatio-temporal dynamic behaviors of cyber-physical systems. This language is highly expressive: it allows the description of quantitative signals, by expressing spatio-temporal traces over real valued signals in dense time, and Boolean signals, by constraining values of spatial objects across threshold predicates. STSL PC combines the power of temporal modalities and spatial operators, and enjoys important properties such as finite model property. We provide a Hilbert-style axiomatization for the proposed STSL PC and prove the soundness and completeness by the spatio-temporal extension of maximal consistent set and canonical model. Further, we demonstrate the decidability of STSL PC and analyze the complexity of STSL PC. Besides, we generalize STSL to the evolution of spatial objects over time, called STSL OC, and provide the proof of its axiomatization system and decidability.


2010 ◽  
Vol 5 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Alice Rokszin ◽  
Zita Márkus ◽  
Gábor Braunitzer ◽  
Antal Berényi ◽  
Marek Wypych ◽  
...  

AbstractOur study compares the spatio-temporal visual receptive field properties of different subcortical stages of the ascending tectofugal visual system. Extracellular single-cell recordings were performed in the superficial (SCs) and intermediate (SCi) layers of the superior colliculus (SC), the suprageniculate nucleus (Sg) of the posterior thalamus and the caudate nucleus (CN) of halothane-anesthetized cats. Neuronal responses to drifting gratings of various spatial and temporal frequencies were recorded. The neurons of each structure responded optimally to low spatial and high temporal frequencies and displayed narrow spatial and temporal frequency tuning. The detailed statistical analysis revealed that according to its stimulus preferences the SCs has markedly different spatio-temporal properties from the homogeneous group formed by the SCi, Sg and CN. The SCs neurons preferred higher spatial and lower temporal frequencies and had broader spatial tuning than the other structures. In contrast to the SCs the visually active SCi, as well as the Sg and the CN neurons possessed consequently similar spatio-temporal preferences. These data support our hypothesis that the visually active SCi, Sg and CN neurons form a homogeneous neuronal population given a similar spatio-temporal frequency preference and a common function in processing of dynamic visual information.


1997 ◽  
Vol 111 (5) ◽  
pp. 867-872 ◽  
Author(s):  
Salvatore Aglioti ◽  
Nicola Smania ◽  
Andrea Atzei ◽  
Giovanni Berlucchi

Author(s):  
Muthukumaran Ramasubramanian ◽  
Chaity Banerjee ◽  
Debashri Roy ◽  
Eduardo Pasiliao ◽  
Tathagata Mukherjee

Author(s):  
Haixiao Wang ◽  
Fang Liu ◽  
Jinjun Tang

Using taxi GPS trajectories data is of very importance to explore Spatio-temporal features of human mobility in transportation designing and planning. The data were collected from taxi GPS devices in Harbin city during a week. The taxi trips are extracted from GPS data, and travel distance and time in occupied and vacant states are firstly used to investigate the human mobility. Then, the urban area is divided into 400 grids. Furthermore, travelling network corresponding to taxi trips are designed to further examine the dynamics of mobility, in which the grid are considered as nodes and edge weights are defined as total number of trips among nodes. We observe some basic statistical features of network: degree, edge weights, clustering coefficients and network structure entropy. We also use the correlation between strength and degree to analyze the significance of nodes. Based on network analysis, we select two grids, a central business district and a residential district with high degree and strength, to study the spatial and temporal properties of trips that start from and end at these two grids. Finally, the correlation between trip volume and operation efficiency is explored and we find that hourly trip volume express negative correlation with operation efficiency.


2004 ◽  
Vol 279 (44) ◽  
pp. 46242-46252 ◽  
Author(s):  
Larry E. Wagner ◽  
Wen-Hong Li ◽  
Suresh K. Joseph ◽  
David I. Yule

Regulation of Ca2+release through inositol 1,4,5-trisphosphate receptors (InsP3R) has important consequences for defining the particular spatio-temporal properties of intracellular Ca2+signals. In this study, regulation of Ca2+release by phosphorylation of type 1 InsP3R (InsP3R-1) was investigated by constructing “phosphomimetic” charge mutations in the functionally important phosphorylation sites of both the S2+ and S2- InsP3R-1 splice variants. Ca2+release was investigated following expression in Dt-40 3ko cells devoid of endogenous InsP3R. In cells expressing either the S1755E S2+ or S1589E/S1755E S2- InsP3R-1, InsP3-induced Ca2+release was markedly enhanced compared with nonphosphorylatable S2+ S1755A and S2- S1589A/S1755A mutants. Ca2+release through the S2- S1589E/S1755E InsP3R-1 was enhanced ∼8-fold over wild type and ∼50-fold when compared with the nonphosphorylatable S2- S1589A/S1755A mutant. In cells expressing S2- InsP3R-1 with single mutations in either S1589E or S1755E, the sensitivity of Ca2+release was enhanced ∼3-fold; sensitivity was midway between the wild type and the double glutamate mutation. Paradoxically, forskolin treatment of cells expressing either single Ser/Glu mutation failed to further enhance Ca2+release. The sensitivity of Ca2+release in cells expressing S2+ S1755E InsP3R-1 was comparable with the sensitivity of S2- S1589E/S1755E InsP3R-1. In contrast, mutation of S2+ S1589E InsP3R-1 resulted in a receptor with comparable sensitivity to wild type cells. Expression of S2- S1589E/S1755E InsP3R-1 resulted in robust Ca2+oscillations when cells were stimulated with concentrations of α-IgM antibody that were threshold for stimulation in S2- wild type InsP3R-1-expressing cells. However, at higher concentrations of α-IgM antibody, Ca2+oscillations of a similar period and magnitude were initiated in cells expressing either wild type or S2- phosphomimetic mutations. Thus, regulation by phosphorylation of the functional sensitivity of InsP3R-1 appears to define the threshold at which oscillations are initiated but not the frequency or amplitude of the signal when established.


2011 ◽  
Vol 53 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Akihiko Tanimura ◽  
Akiko Shitara ◽  
Yosuke Tojyo

2021 ◽  
Author(s):  
Alessia Calafiore ◽  
Nombuyisielo Murage ◽  
Andrea Nasuto ◽  
Francisco Rowe

This paper leverages on the opportunities presented by individual level GPS data to study human mobility. It develops a methodology to understand the spatio-temporal properties of collective movements using network science. Through a spatially-weighted community detection approach, we derived functional neighbourhoods from human mobility patterns from GPS data and analyse the extent to which they vary across time. The results show that while the overall city structure remains stable, functional neighbourhoods tend to contract and expand over the course of the day. This work proposes a methodological framework and emphasises the importance of detecting short-term structural changes in cities based on human mobility.


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