scholarly journals Hippocampal replay of experience at real-world speeds

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Eric L Denovellis ◽  
Anna K Gillespie ◽  
Michael E Coulter ◽  
Marielena Sosa ◽  
Jason E Chung ◽  
...  
Keyword(s):  
Real World ◽  
Critical Role ◽  
State Space Model ◽  
Movement Speed ◽  
Clear Understanding ◽  
Space Model ◽  
Movement Dynamics ◽  
Decision Making Processes ◽  
Past Experiences ◽  
Spatial Trajectories

Representations related to past experiences play a critical role in memory and decision-making processes. The rat hippocampus expresses these types of representations during sharp-wave ripple (SWR) events, and previous work identified a minority of SWRs that contain ‘replay’ of spatial trajectories at ∼20x the movement speed of the animal. Efforts to understand replay typically make multiple assumptions about which events to examine and what sorts of representations constitute replay. We therefore lack a clear understanding of both the prevalence and the range of representational dynamics associated with replay. Here, we develop a state space model that uses a combination of movement dynamics of different speeds to capture the spatial content and time evolution of replay during SWRs. Using this model, we find that the large majority of replay events contain spatially coherent, interpretable content. Furthermore, many events progress at real-world, rather than accelerated, movement speeds, consistent with actual experiences.

scholarly journals Hippocampal replay of experience at real-world speeds

2020 ◽  
Author(s):  
Eric L. Denovellis ◽  
Anna K. Gillespie ◽  
Michael E. Coulter ◽  
Marielena Sosa ◽  
Jason E. Chung ◽  
...  
Keyword(s):  
Decision Making ◽  
Real World ◽  
Critical Role ◽  
State Space Model ◽  
Clear Understanding ◽  
Space Model ◽  
Movement Dynamics ◽  
Decision Making Processes ◽  
Spatial Trajectories ◽  
Spatial Content

Representations of past and possible future experiences play a critical role in memory and decision-making processes. The hippocampus expresses these types of representations during sharp-wave ripple (SWR) events, and previous work identified a minority of SWRs that contain “replay” of spatial trajectories at ~20x real-world speeds. Efforts to understand replay typically make multiple assumptions about which events to examine and what sorts of representations constitute replay. We therefore lack a clear understanding of both the prevalence and the range of representational dynamics associated with replay. Here we develop a state space model that uses a combination of movement dynamics of different speeds to capture the spatial content and time evolution of replay during SWRs. Using this model, we find that the large majority of replay events contain spatially coherent, interpretable content. Furthermore, most events progress at real-world, rather than accelerated, movement speeds, consistent with actual experiences.

scholarly journals Looking for Semantic Similarity: What a Vector Space Model of Semantics Can Tell Us About Attention in Real-world Scenes

2021 ◽  
Author(s):  
Taylor R. Hayes ◽  
John M. Henderson
Keyword(s):  
Vector Space ◽  
Semantic Similarity ◽  
Real World ◽  
Critical Role ◽  
Vector Space Model ◽  
Semantic Knowledge ◽  
Space Model ◽  
Strong Positive Relationship ◽  
Space Semantic ◽  
The Relationship

The visual world contains more information than we can perceive and understand in any given moment. Therefore, we must prioritize important scene regions for detailed analysis. Semantic knowledge gained through experience is theorized to play a central role in determining attentional priority in real- world scenes but is poorly understood. Here we examined the relationship between object semantics and attention by combining a vector space model of semantics with eye movements in scenes. Within this approach, the vector space semantic model served as the basis for a concept map, an index of the spatial distribution of the semantic similarity of objects across a given scene. The results showed a strong positive relationship between the semantic similarity of a scene region and viewers’ focus of attention, with greater attention to more semantically related scene regions. We conclude that object semantics play a critical role in guiding attention through real-world scenes.

scholarly journals Looking for Semantic Similarity: What a Vector-Space Model of Semantics Can Tell Us About Attention in Real-World Scenes

2021 ◽  
pp. 095679762199476
Author(s):  
Taylor R. Hayes ◽  
John M. Henderson
Keyword(s):  
Vector Space ◽  
Semantic Similarity ◽  
Real World ◽  
Critical Role ◽  
Vector Space Model ◽  
Semantic Knowledge ◽  
Space Model ◽  
Strong Positive Relationship ◽  
Space Semantic ◽  
The Relationship

The visual world contains more information than we can perceive and understand in any given moment. Therefore, we must prioritize important scene regions for detailed analysis. Semantic knowledge gained through experience is theorized to play a central role in determining attentional priority in real-world scenes but is poorly understood. Here, we examined the relationship between object semantics and attention by combining a vector-space model of semantics with eye movements in scenes. In this approach, the vector-space semantic model served as the basis for a concept map, an index of the spatial distribution of the semantic similarity of objects across a given scene. The results showed a strong positive relationship between the semantic similarity of a scene region and viewers’ focus of attention; specifically, greater attention was given to more semantically related scene regions. We conclude that object semantics play a critical role in guiding attention through real-world scenes.

The Oxford Handbook of Impulse Control Disorders

2012 ◽  
Keyword(s):  
Decision Making ◽  
Impulse Control ◽  
Treatment Options ◽  
Impulse Control Disorders ◽  
Clear Understanding ◽  
Intermittent Explosive Disorder ◽  
Normal Behavior ◽  
Assessment And Treatment ◽  
Decision Making Processes ◽  
Psychopathological Disorders

Impulsivity, to varying degrees, is what underlies human behavior and decision-making processes. As such, a thorough examination of impulsivity allows us to better understand modes of normal behavior and action as well as a range of related psychopathological disorders, including kleptomania, pyromania, trichotillomania, intermittent explosive disorder, and pathological gambling—disorders grouped under the term "impulse control disorders" (ISDs). Recent efforts in the areas of cognitive psychology, neurobiology, and genetics have provided a greater understanding of these behaviors and given way to improved treatment options. The Oxford Handbook of Impulse Control Disorders provides a clear understanding of the developmental, biological, and phenomenological features of a range of ICDs, as well as detailed approaches to their assessment and treatment. Bringing together founding ICD researchers and leading experts from psychology and psychiatry, this volume reviews the biological underpinnings of impulsivity and the conceptual challenges facing clinicians as they treat individuals with ICDs.

Multivariable modeling and control of an activated sludge process

1998 ◽  
Vol 37 (12) ◽  
pp. 149-156 ◽  
Author(s):  
Carl-Fredrik Lindberg
Keyword(s):  
Activated Sludge ◽  
Nitrate Concentration ◽  
State Space Model ◽  
Activated Sludge Process ◽  
Invariant State ◽  
Linear Quadratic ◽  
Modeling And Control ◽  
Space Model ◽  
And Control ◽  
Time Invariant

This paper contains two contributions. First it is shown, in a simulation study using the IAWQ model, that a linear multivariable time-invariant state-space model can be used to predict the ammonium and nitrate concentration in the last aerated zone in a pre-denitrifying activated sludge process. Secondly, using the estimated linear model, a multivariable linear quadratic (LQ) controller is designed and used to control the ammonium and nitrate concentration.

Development of L1-norm sliding mode observer for sensor fault diagnosis of an industrial gas turbine

2021 ◽  
pp. 095965182199617
Author(s):  
Mahyar Akbari ◽  
Abdol Majid Khoshnood ◽  
Saied Irani
Keyword(s):  
Fault Detection ◽  
State Space ◽  
Gas Turbine ◽  
Sliding Mode ◽  
State Space Model ◽  
Sensor Fault ◽  
Space Model ◽  
Decision Logic ◽  
Sensor Fault Detection ◽  
Industrial Gas Turbine

In this article, a novel approach for model-based sensor fault detection and estimation of gas turbine is presented. The proposed method includes driving a state-space model of gas turbine, designing a novel L1-norm Lyapunov-based observer, and a decision logic which is based on bank of observers. The novel observer is designed using multiple Lyapunov functions based on L1-norm, reducing the estimation noise while increasing the accuracy. The L1-norm observer is similar to sliding mode observer in switching time. The proposed observer also acts as a low-pass filter, subsequently reducing estimation chattering. Since a bank of observers is required in model-based sensor fault detection, a bank of L1-norm observers is designed in this article. Corresponding to the use of the bank of observers, a two-step fault detection decision logic is developed. Furthermore, the proposed state-space model is a hybrid data-driven model which is divided into two models for steady-state and transient conditions, according to the nature of the gas turbine. The model is developed by applying a subspace algorithm to the real field data of SGT-600 (an industrial gas turbine). The proposed model was validated by applying to two other similar gas turbines with different ambient and operational conditions. The results of the proposed approach implementation demonstrate precise gas turbine sensor fault detection and estimation.

Modeling of CCLP in koryo extract production

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ji Chol ◽  
Ri Jun Il
Keyword(s):  
Process Control ◽  
Medical Care ◽  
State Space ◽  
State Space Model ◽  
The State ◽  
Space Model ◽  
Effective Components ◽  
Counter Current

Abstract The modeling of counter-current leaching plant (CCLP) in Koryo Extract Production is presented in this paper. Koryo medicine is a natural physic to be used for a diet and the medical care. The counter-current leaching method is mainly used for producing Koryo medicine. The purpose of the modeling in the previous works is to indicate the concentration distributions, and not to describe the model for the process control. In literature, there are no nearly the papers for modeling CCLP and especially not the presence of papers that have described the issue for extracting the effective components from the Koryo medicinal materials. First, this paper presents that CCLP can be shown like the equivalent process consisting of two tanks, where there is a shaking apparatus, respectively. It allows leachate to flow between two tanks. Then, this paper presents the principle model for CCLP and the state space model on based it. The accuracy of the model has been verified from experiments made at CCLP in the Koryo Extract Production at the Gang Gyi Koryo Manufacture Factory.

Sign in / Sign up

Export Citation Format

Share Document