--- In FairfieldLife@yahoogroups.com, "George DeForest" <[EMAIL PROTECTED]> wrote: > . > > > > Patrick Gillam wrote: > > > > people are advised to face east, > > for instance by orienting desks to face east. > > What's that all about? Seems to me it has > > some connection with orienting one's brain > > to energies that flow from east to west. > > yes, the Sun mainly. here is a clip from > http://www.alltm.org/pages/neil.html -- > > "scientific studies in the Journal of Neuroscience (1) > show that the neurons in our brain actually fire > differently depending on the direction we are facing. > There are also "place neurons" in the brain which > signal our body's orientation in a room or environment. > Thus, the way we face influences brain and body functioning.
Um, the cited journal article does all that? Here is the abstract, followed by he article's Generaliions and Conclusions. Can you explain more precisely how the article "show[s] that the neurons in our brain actually fire differently depending on the direction we are facing." and how "there are also "place neurons" in the brain which signal our body's orientation in a room or environment. Thus, the way we face influences brain and body functioning." By the way, one of the co-authorsis Bruce L. McNaughton. Is that the blond headed guy that used to teach TM in Detroit in mid 70's? ================ Abstract Path Integration and Cognitive Mapping in a Continuous Attractor Neural Network Model Received Feb. 24, 1997; revised May 14, 1997; accepted May 15, 1997. Alexei Samsonovich and Bruce L. McNaughton Arizona Research Laboratories Division of Neural Systems, Memory and Aging, The University of Arizona, Tucson, Arizona 85749 A minimal synaptic architecture is proposed for how the brain might perform path integration by computing the next internal representation of self-location from the current representation and from the perceived velocity of motion. In the model, a place-cell assembly called a "chart" contains a two-dimensional attractor set called an "attractor map" that can be used to represent coordinates in any arbitrary environment, once associative binding has occurred between chart locations and sensory inputs. In hippocampus, there are different spatial relations among place fields in different environments and behavioral contexts. Thus, the same units may participate in many charts, and it is shown that the number of uncorrelated charts that can be encoded in the same recurrent network is potentially quite large. According to this theory, the firing of a given place cell is primarily a cooperative effect of the activity of its neighbors on the currently active chart. Therefore, it is not particularly useful to think of place cells as encoding any particular external object or event. Because of its recurrent connections, hippocampal field CA3 is proposed as a possible location for this "multichart" architecture; however, other implementations in anatomy would not invalidate the main concepts. The model is implemented numerically both as a network of integrate-and-fire units and as a "macroscopic" (with respect to the space of states) description of the system, based on a continuous approximation defined by a system of stochastic differential equations. It provides an explanation for a number of hitherto perplexing observations on hippocampal place fields, including doubling, vanishing, reshaping in distorted environments, acquiring directionality in a two-goal shuttling task, rapid formation in a novel environment, and slow rotation after disorientation. The model makes several new predictions about the expected properties of hippocampal place cells and other cells of the proposed network. Generalizations The above picture of the hippocampal model of space argues for a general concept of an attractor-map-based internal cognitive model. Many cognitive tasks can be represented effectively on the basis of abstract mathematical models such as graphs (e.g., Muller et al., 1996) and manifolds and therefore may require internal "mapping." According to this concept, the underlying attractor map of the cognitive model is presumed to preexist, and representations of particular memory items may become bound to it. For example, in analogy to the multichart architecture for space, it is possible to conceive of attractor map primitives for egocentric space or even for objects such as chairs or people, which exist in a synaptic matrix without yet having been bound to particular exemplars. To navigate around the map, it is necessary to have a sense of possible local transitions. This can be provided by another attractor map, in analogy with the spatial map and the head direction map in the model of this paper. A related concept was proposed by Droulez and Berthoz (1991). Therefore, attractor maps are likely to be found in various brain areas in addition to the hippocampus; e.g., they may underlie cortical mental rotations (Georgopoulous et al., 1989; 1993) and motion control (Sparkes and Neson, 1987; Sparks et al., 1990; Droulez and Berthoz, 1991; Munoz et al., 1991; Fikes and Townsend, 1995). Conclusions Hippocampal spatial representations can be described efficiently in terms of charts and self-localized activity packets. This representation inspires a new concept of an attractor map, which may have broad applications elsewhere. The attractor map concept together with the path integration concept lead to a plausible connectionist model (MPI) of the hippocampal spatial representation system, which uses previously suggested ideas of multiple wired charts (Muller et al., 1991; McNaughton et al., 1996). Numerical simulations of this theory confirm intuitive assumptions about its dynamics. The proposed point of view, although incomplete, leads to a straightforward explanation of many available experimental facts and currently seems to be the most inclusive among alternative theories of hippocampal place-cell dynamics. To subscribe, send a message to: [EMAIL PROTECTED] Or go to: http://groups.yahoo.com/group/FairfieldLife/ and click 'Join This Group!' Yahoo! 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