Jason G. Fleischer
J:
Research Fellow
in Theoretical Neurobiology
T:
+1 (858) 626-2069
P:
The Neurosciences Institute
800 Silverado St #302
La Jolla, California 92037
USA
E:





Curriculum Vitae      Research Info     Publications




RESEARCH



Neuroscience     Robotics

Robotics is a natural complement to computational neuroscience. Neural models that are embodied in real world devices receive more varied inputs than simulated models, and the consequences of an embodied model's actions are less predictable --- what some dismiss as the inherent "noisiness" of the real world may in fact be a key component in how biological neural systems learn. This is one of the reasons why I feel that neural models that have physical bodies are more convincing than those that are implemented in simulation. And neuroscience models can in turn help build more capable robots. A better understanding of how animals learn motor control and cognitive abilities will produce a new set of tools for building robots that need those same skills.

My work is part of the Brain-Based Device (BBD) program here at The Neurosciences Institute. BBDs are large-scale neural models with an emphasis on realistic neuroanatomy and neurophysiology. A BBD's simulated nervous system is embodied in a robotic device, which interacts with the environment while engaged in a behavioral task.






Neuroscience

My main research interest is in the computational modelling of medial temporal lobe (MTL) function. The MTL, including the hippocampus, is a brain region that is known to be involved in memory formation in humans and other mammals. One of the most striking features of hippocampal activity is the existence of place fields, where a cell's discharge rate is strongly correlated with the animal's location. Some place fields occur regardless of context, and others depend on the path the animal took in the past or will take in the future. Place fields in animals have been also been shown to be dependent on multiple sensory modalities.

I have been building, testing, and analyzing the Darwin X and XI BBDs, which have models of MTL plus selected cortical areas (~100K simulated neuronal units, 1.2M synapses) and perform maze-navigation tasks. Activity in the simulated hippocampus has been shown to be place specific, journey dependent and multimodal in its responses. Analysis of the neural pathways leading to place activity have pointed to differential involvement of the perforant path versus the trisynaptic loop in early versus late training place fields, and in journey-dependent versus -independent place fields. When lesioning sensory streams to the simulated MTL, changes in the pathways leading to place activity during the lesion are larger in the entorhinal cortex than in the hippocampus, which is consistent with pattern-completion theories of hippocampal function.

The work with Darwin X and XI has shown that BBDs simulating anatomical and physiological details of the MTL and surrounding regions can support the formation of spatial memory, episodic memory, and associative memory. The results using these models may have heuristic value in analyzing findings from studies of behaving animals.






Robotics

I have been working on a soccer-playing robot based on the Segway scooter that implements a neural simulation for visual processing and uses algorithms based on psychophysical data to perform obstacle avoidance and ball-handling. The Neurosciences Institute ran demonstrations in conjunction with Carnegie Mellon University, who also have a Segway robot, at both the 2004 and 2005 RoboCup American Open tournaments (BBC news blurb). This is part of a newly-proposed RoboCup league where each team consists of both human players, mounted on Segway scooters, and Segway robots. This new league highlights the problem of human-robot interaction, which has become an important research topic since robots are becoming more common in the everyday world.

Previously I have worked in the area of AI robotics, investigating issues of reliable landmark detection using predictive sensor models, symbol grounding on robotic agents, and route communication between robots.





PUBLICATIONS



Journal Articles






Full-text








Full-text








Full-text








Full-text








Full-text





Book Chapters



  •  JG Fleischer, JL McKinstry, DE Edelman, and GM Edelman.   The Case For Using Brain-Based Devices To Study Consciousness.  In, JL Krichmar and H Wagatsuma (Eds.),   Neuromorphic and Brain-Based Robots: Trends and Perspectives ,  Cambridge University Press,  pp. 303--320,  2011.



Full-text








Full-text








Full-text





Refereed Conference Papers



  •  JG Fleischer, B Szatmáry, DB Hutson, DA Moore, JA Snook, GM Edelman, and JL Krichmar.  A neurally controlled robot competes and cooperates with humans in Segway Soccer.  In Proceedings of the IEEE International Conference on Robotics and Automation,  pp.3673--3678,   2006.



Full-text





  •  B Szatmáry, JG Fleischer, DB Hutson, DA Moore, JA Snook, GM Edelman, and JL Krichmar.  A Segway-based human-robot soccer team.  In Proceedings of the IEEE International Conference on Robotics and Automation, pp.4436--4438,  2006.



Full-text





  •  JG Fleischer.  Imitation is not enough for lexicon learning  In From Animals to Animats VIII. Proceedings of the Eighth International Conference on Simulation of Adaptive Behavior,  pp.477--486,  2004.



Full-text





  •  JG Fleischer and SR Marsland.  Learning to autonomously select landmarks for navigation and communication. In From Animals to Animats VII. Proceedings of the Seventh International Conference on Simulation of Adaptive Behavior,  pp.151--160,  2002.



Full-text





  •  JG Fleischer and UDF Nehmzow.  Towards robots that give each other navigational directions: Learning symbols for perceptual categories.  In Towards Intelligent Mobile Robots 01. Proceedings of the 3rd British Conference on Autonomous Mobile Robots,  Technical Report UMCS-01-4-1,  University of Manchester Computer Science Department,  2001.



Full-text





  •  JG Fleischer and WO Troxell.  Biomimicry as a tool in the design of robotic systems. In Proceedings of the 3rd International Conference on Engineering Design and Automation, 1999.



Full-text





Posters






AbstractPoster








AbstractPoster





Theses


  •  Route Communication Between Mobile Robots Using Adaptive Landmark Symbols.  Ph.D. thesis, University of Manchester (U.K.), 2004.



AbstractFull-text





  •  Biomimetic design of a cooperative mobile robot system for a foraging task, M.S. thesis, Colorado State University, 1999.



AbstractFull-text