Our model of the spatial and temporal aspects of place cell firing, and their role in rat navigation is reviewed. The model provides a can- didate mechanism, at the level of individual cells, by which place cell information concerning self-localization could be used to guide navi- gation to previously visited reward sites. The model embodies specific predictions regarding the formation of place fields, the phase coding of place cell firing with respect to the hippocampal theta rhythm, and the formation of neuronal population vectors downstream from the place cells that code for the directions of goals during navigation. Re- cent experiments regarding the spatial distribution of place cell firing have confirmed our initial modeling hypothesis, that place fields are formed from Gaussian tuning curve inputs coding for the distances from environmental features, and enabled us to further specify the functional form of these inputs. Other recent experiments regarding the temporal distribution of place cell firing in 2-dimensional environ- ments have confirmed our predictions based on the temporal aspects of place cell firing on linear tracks. Directions for further experiments and refinements to the model are outlined for the future.

A robotic platform controlled by a neuronal simulation is presented for studying the mechanisms underlying the firing of hippocampal place cells and how they support navigation. The sensors on the robot provide visual, odometric and short-range proximity information which are combined to estimate the distance of the walls of the enclosure from the robot and its current heading direction. These inputs drive a neuronal simulation of the hippocampus in which the robot's location is represented as the firing of place cells. If a goal location is encountered, connection strengths are incremented between active place cells and a set of 'goal cells' which guide subsequent navigation (Burgess et al., 1994), allowing the robot to return to goal locations. The system shows good agreement with actual place cell firing, and makes predictions regarding the firing of cells in the subiculum and the locus of search of rats after deformation of their environment.

Perception is an intentional action through space in time by which the finite brain explores the infinite world. By acting, the brain thrusts its body into the future spacetime of the world while predicting the sensory consequences. Through perceiving its actions and their results, it remembers its predictions, its actions, and their consequences. To perform these operations the brain, through chaotic dynamics, constructs and uses finite perceptual matrices of spacetime and infers causation. Perceived time differs from world time in ways that are determined by the neural mechanisms of intentionality. In particular, perception of the self in action, through the mechanism of preafference, gives structure and content to the concepts of continuity, contiguity, duration, temporal order, cause, and effect. Perceptual scales are expanded beyond kinesthesia by conversion of time into space, such as by clocks and calendars. Remembered time differs from perceived time in being dependent on awareness, which makes it episodic, fragmentary, and subject to large variations in rates of time lapse in the flow of meanings. The attribution of causal agency to objects and events in the world results from anthropomorphization in accordance with the neural mechanisms of the internal perception of intentional action.

The essential task of brain function is to construct orderly patterns of neural activity from disorderly sensory inputs, so that effective actions can be mounted by the brain, a finite state system, to deal with the world's infinite complexity. Two schools of thought are described, that characterize distinctive sources of the order within brains, one passive, the other active. These schools have profoundly influenced ways two groups of contemporary neuroscientists design their experiments and process their data, so that they have very different perspectives on the roles of noise and chaos in brain function.

Emotion is defined as a property of intentional behavior. The widespread practice of separating emotion from reason is traced to an ancient distinction between passive perception, which is driven by sensory information from the environment, and active perception, which begins with dynamics in the brain that moves the body into the environment in search of stimuli. The neurodynamics of intentional behavior is reviewed, with emphasis on the limbic system that controls the autonomic and neuroendocrine systems in the brain and body, directing them for the support of the musculoskeletal system that is executing the behavior. An essential part of intentionality is learning from the sensory consequences of one's own actions. The perception of emotional states through awareness involves global states of cooperative activity in the forebrain, which have internal contributions from the many parts of the brain that join in making these states, and inevitably there are contributions from the sensory systems of the body that implement and signal emotional states. The distinction between "rational " versus "emotional " behaviors is made in terms of the constraint of high-intensity chaotic activity of components of the forebrain by the cooperative dynamics of consciousness versus the escape of subsystems owing to an excess of chaotic fluctuations in states of strong arousal. Aquinas.txt 2 Walter J Freeman

Perception is an intentional action by which the finite brain explores the infinite world. By acting, the brain thrusts its body into the future spacetime of the world while predicting the sensory consequences. By perceiving its actions and their results, it remembers its predictions. To perform these operations the brain, through chaotic dynamics, constructs and uses finite perceptual matrices of space, time and causation. Perceived time differs from world time in ways that are determined by the neural mechanisms of intentionality. In particular, perception of the self in action, through the mechanism of preafference, gives structure and content to the concepts of contiguity, duration, temporal order, cause, and effect. Remembered time differs from perceived time in being dependent on awareness, which makes it episodic, fragmentary, and subject to large variations in rates of time lapse in the flow of meanings.

Perception is an intentional action through space in time by which the finite brain explores the infinite world. By acting, the brain thrusts its body into the future spacetime of the world while predicting the sensory consequences. Through perceiving its actions and their results, it remembers its predictions, its actions, and their consequences. To perform these operations the brain, through chaotic dynamics, constructs and uses finite perceptual matrices of spacetime and infers causation. Perceived time differs from world time in ways that are determined by the neural mechanisms of intentionality. In particular, perception of the self in action, through the mechanism of preafference, gives structure and content to the concepts of continuity, contiguity, duration, temporal order, cause, and effect. Perceptual scales are expanded beyond kinesthesia by conversion of time into space, such as by clocks and calendars. Remembered time differs from perceived time in being dependent on awareness, which makes it episodic, fragmentary, and subject to large variations in rates of time lapse in the flow of meanings. The attribution of causal agency to objects and events in the world results from anthropomorphization in accordance with the neural mechanisms of the internal perception of intentional action. Time and Causation 2 Walter J Freeman