The randomness and complexity of urban traffic scenes make it a difficult task for self-driving cars to detect drivable areas, Inspired by human driving behaviors, we propose a novel method of drivable area detection ...The randomness and complexity of urban traffic scenes make it a difficult task for self-driving cars to detect drivable areas, Inspired by human driving behaviors, we propose a novel method of drivable area detection for self-driving cars based on fusing pixel information from a monocular camera with spatial information from a light detection and ranging (LIDAR) scanner, Similar to the bijection of collineation, a new concept called co-point mapping, which is a bijection that maps points from the LIDAR scanner to points on the edge of the image segmentation, is introduced in the proposed method, Our method posi- tions candidate drivable areas through self-learning models based on the initial drivable areas that are obtained by fusing obstacle information with superpixels, In addition, a fusion of four features is applied in order to achieve a more robust performance, In particular, a feature called drivable degree (DD) is pro- posed to characterize the drivable degree of the LIDAR points, After the initial drivable area is characterized by the features obtained through self-learning, a Bayesian framework is utilized to calculate the final probability map of the drivable area, Our approach introduces no common hypothesis and requires no training steps; yet it yields a state-of-art performance when tested on the ROAD-KITTI benchmark, Experimental results demonstrate that the proposed method is a general and efficient approach for detecting drivable area.展开更多
The effects of γ-aminobutyric acid (GABA) and its antagonists bicuculline and 2-hydroxysaclofen on neuronal firings in the nucleus of basal optic root (nBOR) in pigeons were studied by using extracellular recording a...The effects of γ-aminobutyric acid (GABA) and its antagonists bicuculline and 2-hydroxysaclofen on neuronal firings in the nucleus of basal optic root (nBOR) in pigeons were studied by using extracellular recording and microiontophoretic techniques. The results suggest that GABA may be an inhibitory neurotransmitter or modulator within nBOR, functioning by means of main mediation of GABAA receptors and of minor mediation of GABAB receptors. Furthermore, GABA and its GABAA receptors are involved in the modulation of directional selectivity in part of nBOR neurons.展开更多
In this study postsynaptic potentials responding to the electrical stimulation of the optic nerve and the nucleus isthmipars parvocellularis (Ipc) were intracellularly recorded from 86 tectal cells in pigeons, 13 of w...In this study postsynaptic potentials responding to the electrical stimulation of the optic nerve and the nucleus isthmipars parvocellularis (Ipc) were intracellularly recorded from 86 tectal cells in pigeons, 13 of which were marked with Lucifer yellow (LY). According to types of postsynaptic potentials and their succesion, the postsynaptic responses could be classified into four types: excitatory postsynaptic potential (EPSP)-inhibitory postsynaptic potential (IPSP) sequence (EI type), E, I and IE types.Among them, E or EI responses were mainly produced to the optic nerve stimulation, while the electrical stimulation of the lpc elicited I responses in more than half the recorded cells.LY-marked tectal cells included five ganglionic cells, four pyramidal cells, two bipolar cells and two stellate cells.The ganglionic cells were mainly located in tectal layers Ⅲ and Ⅳ, whereas the others were in layer Ⅱ.It appears from both intracellular recordings and fluorescent markings that there is some correlation betwe n the morphological features and the postsynaptic response types of tectal cells.展开更多
The columnar organization is a ubiquitous feature in the cerebral cortex.In this study,a neural network model simulating the cortical columns has been constructed.When fed with random pulse input with constant rate,a ...The columnar organization is a ubiquitous feature in the cerebral cortex.In this study,a neural network model simulating the cortical columns has been constructed.When fed with random pulse input with constant rate,a column generates synchronized oscillations,with a frequency varying from 3 to 43 Hz depending on parameter values.The behavior of the model under periodic stimulation was studied and the input-output relationship was non-linear.When identical columns were sparsely interconnected,the column oscillator could be locked in synchrony.In a network composed of heterogeneous columns,the columns were organized by intrinsic properties and formed partially synchronized assemblies.展开更多
It has been established that the nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus parabigeminalis, receive input from the ipsilateral tectum and project back ipsilaterally in teleosts a...It has been established that the nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus parabigeminalis, receive input from the ipsilateral tectum and project back ipsilaterally in teleosts and birds, or bilaterally in amphibians, reptiles and mammals.The nucleus receives visual excitation from the ipsilateral tectum. while it mainly exerts inhibition on cells recorded from the ipsilateral tectum. A recent study by Wang and coworkers shows that the nucleus isthmi pars magnoceUularis (Imc) and展开更多
The present study describes the effects of gamma-aminobutyric acid (GABA) and its antagonists, bicuculline and 2-hydroxysaclofen, on visual responses of neurons in the pigeon nucleus lentiformis mesencephali (nLM). Th...The present study describes the effects of gamma-aminobutyric acid (GABA) and its antagonists, bicuculline and 2-hydroxysaclofen, on visual responses of neurons in the pigeon nucleus lentiformis mesencephali (nLM). The results indicate that GABA significantly reduces both spontaneous activity and visual responsiveness, and GABAA antagonist bicuculline but not GABAB antagonist 2-hydroxysaclofen enhances visual responses of nLM cells examined. Furthermore, inhibition produced by motion in the null-direction of pretectal neurons is diminished by bicuculline but not by 2-hydroxysaclofen. It is therefore concluded that the null-direction inhibition of directional cells in the pigeon nLM is predominantly mediated by GABA and GABAA receptors. This inhibition may at least in part underlie directional asymmetry of optokinetic responses.展开更多
基金This research was partially supported by the National Natural Science Foundation of China (61773312), the National Key Research and Development Plan (2017YFC0803905), and the Program of Introducing Talents of Discipline to University (B13043).
文摘The randomness and complexity of urban traffic scenes make it a difficult task for self-driving cars to detect drivable areas, Inspired by human driving behaviors, we propose a novel method of drivable area detection for self-driving cars based on fusing pixel information from a monocular camera with spatial information from a light detection and ranging (LIDAR) scanner, Similar to the bijection of collineation, a new concept called co-point mapping, which is a bijection that maps points from the LIDAR scanner to points on the edge of the image segmentation, is introduced in the proposed method, Our method posi- tions candidate drivable areas through self-learning models based on the initial drivable areas that are obtained by fusing obstacle information with superpixels, In addition, a fusion of four features is applied in order to achieve a more robust performance, In particular, a feature called drivable degree (DD) is pro- posed to characterize the drivable degree of the LIDAR points, After the initial drivable area is characterized by the features obtained through self-learning, a Bayesian framework is utilized to calculate the final probability map of the drivable area, Our approach introduces no common hypothesis and requires no training steps; yet it yields a state-of-art performance when tested on the ROAD-KITTI benchmark, Experimental results demonstrate that the proposed method is a general and efficient approach for detecting drivable area.
基金Project supported by the National Natural Science Foundation of China and Amherst College.
文摘The effects of γ-aminobutyric acid (GABA) and its antagonists bicuculline and 2-hydroxysaclofen on neuronal firings in the nucleus of basal optic root (nBOR) in pigeons were studied by using extracellular recording and microiontophoretic techniques. The results suggest that GABA may be an inhibitory neurotransmitter or modulator within nBOR, functioning by means of main mediation of GABAA receptors and of minor mediation of GABAB receptors. Furthermore, GABA and its GABAA receptors are involved in the modulation of directional selectivity in part of nBOR neurons.
基金Project supported by the National Natural Science Foundation of China.
文摘In this study postsynaptic potentials responding to the electrical stimulation of the optic nerve and the nucleus isthmipars parvocellularis (Ipc) were intracellularly recorded from 86 tectal cells in pigeons, 13 of which were marked with Lucifer yellow (LY). According to types of postsynaptic potentials and their succesion, the postsynaptic responses could be classified into four types: excitatory postsynaptic potential (EPSP)-inhibitory postsynaptic potential (IPSP) sequence (EI type), E, I and IE types.Among them, E or EI responses were mainly produced to the optic nerve stimulation, while the electrical stimulation of the lpc elicited I responses in more than half the recorded cells.LY-marked tectal cells included five ganglionic cells, four pyramidal cells, two bipolar cells and two stellate cells.The ganglionic cells were mainly located in tectal layers Ⅲ and Ⅳ, whereas the others were in layer Ⅱ.It appears from both intracellular recordings and fluorescent markings that there is some correlation betwe n the morphological features and the postsynaptic response types of tectal cells.
基金supported by the National Natural Science Foundation of China(Grant Nos.39893340-06,30170231 and 62075023)Brain-Mind Research Center in the Chinese Academy of Sciences.
文摘The columnar organization is a ubiquitous feature in the cerebral cortex.In this study,a neural network model simulating the cortical columns has been constructed.When fed with random pulse input with constant rate,a column generates synchronized oscillations,with a frequency varying from 3 to 43 Hz depending on parameter values.The behavior of the model under periodic stimulation was studied and the input-output relationship was non-linear.When identical columns were sparsely interconnected,the column oscillator could be locked in synchrony.In a network composed of heterogeneous columns,the columns were organized by intrinsic properties and formed partially synchronized assemblies.
基金Project supported by the National Natural Science Foundation of China
文摘It has been established that the nucleus isthmi (NI) in lower vertebrates and its mammalian analogue, the nucleus parabigeminalis, receive input from the ipsilateral tectum and project back ipsilaterally in teleosts and birds, or bilaterally in amphibians, reptiles and mammals.The nucleus receives visual excitation from the ipsilateral tectum. while it mainly exerts inhibition on cells recorded from the ipsilateral tectum. A recent study by Wang and coworkers shows that the nucleus isthmi pars magnoceUularis (Imc) and
文摘The present study describes the effects of gamma-aminobutyric acid (GABA) and its antagonists, bicuculline and 2-hydroxysaclofen, on visual responses of neurons in the pigeon nucleus lentiformis mesencephali (nLM). The results indicate that GABA significantly reduces both spontaneous activity and visual responsiveness, and GABAA antagonist bicuculline but not GABAB antagonist 2-hydroxysaclofen enhances visual responses of nLM cells examined. Furthermore, inhibition produced by motion in the null-direction of pretectal neurons is diminished by bicuculline but not by 2-hydroxysaclofen. It is therefore concluded that the null-direction inhibition of directional cells in the pigeon nLM is predominantly mediated by GABA and GABAA receptors. This inhibition may at least in part underlie directional asymmetry of optokinetic responses.
