ACT-R/S Focal Space Action Space Coordinate System Origin Center of gaze Object Rectangle obstacles Location Vectors to obstacle edges Units Angular vectors Objects that I need to navigate around: 1.A chair 2.A table 3.A cabinet 4.Some guy Cabinet isa action-rep retinal-loc vis-loc1 right-theta 350 o right-distance 3m left-theta 300 o left-distance 3.1m region My-office Table isa action-rep retinal-loc vis-loc3 right-theta 120 o right-distance 0.2m left-theta 10 o left-distance 2.5m top-theta 105o top-distance 0.2m region My-office Chair isa action-rep retinal-loc vis-loc2 right-theta 5 o right-distance 1m left-theta 355 o left-distance 0.5m top-theta 100 o top-distance 1.05m region My-office Encoding Coordinate System Origin Upper-left of scene (ACT-R/PM) Object Feature based composite Location Screen-X, Screen-Y Units Encoding 1.No, I have no new 2.Oh, that guy is Lelyn Lelyn isa visual-object location loc-02 … Screen isa visual-object location loc-04 …. Only region with a variable extent and a non-anchored span within the visual field The majority of cognitive psychology research into vision has focused on this region It is responsible for object identification, tracking, and reading. Utilizes much of Byrne’s ACT-R/PM extension. Used for navigational representations and scene memory. We borrowed from robotic navigation to determine the functional necessities. Neuropsychology brain damage studies suggest a representation that uses landmark’s position relative to the observer’s point of gaze. Navigation is performed by trying to match up relative positions to landmarks, while avoiding other obscuring landmarks. A neurologically inspired model of spatial reasoning Anthony Harrison & Christian Schunn George Mason University & The University of Pittsburgh The spatial model is being inspired by numerous areas of spatial research: neurological, developmental, as well as traditional cognitive psychology. It is hoped that these converging lines of evidence will inform a more plausible and defensible model of spatial reasoning and processing. Data and theories from these various domains are presented briefly with respect to their impact on the model. The first structural decision for this model was the separation of visio-spatial representations into three distinct spatial representations and one visual. These divisions follow Previc’s neurological model of 3-D space. The visual representation system (focal space in Previc) already exists in ACT-R/PM, and will be modified only slightly. The remaining spatial representations are Previc’s ambient extrapersonal, action extrapersonal, and peripersonal spaces. Each of these four representational systems will have their own buffers with which to operate. This will allow the model to process incoming representations in parallel (much like the motor and basic visual system operate in parallel in ACT-R/PM). Peripersonal Space Encoding Two objects I’ve manipulated: 1.The chair 2.My umbrella Umbrella isa prp-rep geon umbrella-cylinder Chair-back isa prp-rep geon chair-back-cube Chair-seat isa prp-rep geon chair-seat-cube Region that is immediately within grasp of the individual. Spans central 60 degrees on the visual field Lower field bias Extends to the maximum arm’s reach. Neuroimaging studies show used during fine motor control and object manipulation Neuroimaging studies show used during mental rotation suggests region contains very precise three-dimensional metric representations of objects to be manipulated. (P attend-new-action-rep =goal> isa goal =visual-loc> isa visual-loc status new representation action ==> +action> isa action-rep retinal-loc =visual-loc ) (P attend-new-prp-rep =goal> isa goal =visual-loc> isa visual-loc status new depth near representation prp ==> +prp> isa prp-rep retinal-loc =visual-loc ) Coordinate System Origin Upper torso Object Accurate 3D geon Location (of object) Vector from upper torso Units Psychological cubits Other Considerations Object representations and object identities are separate entities. However, once the identity is established it is linked to the representation as long as it remains active An episodic memory system is required for most basic spatial reasoning processing. A symbolic mechanism will be used. Spatial representations are all with respect to an object and the viewer Spatial relationships allow the tying together of multiple representations within a region (focal to focal, ambient to ambient) Each region has its own buffer which capacity is limited by activation levels Coordinate System Origin Center of region Object Rough 3D geon of spatial extent Location (of self) Sector based Units Categorical Encoding Two distinct geometric regions: 1.My office 2.The hall My-office isa ambient-rep location center geon box-01 Office-hall isa ambient-rep location nil geon box-02 (P attend-new-action-rep =goal> isa goal =visual-loc> isa visual-loc status new representation action ==> +action> isa action-rep retinal-loc =visual-loc ) (P attend-new-prp-rep =goal> isa goal =visual-loc> isa visual-loc status new depth near representation prp ==> +prp> isa prp-rep retinal-loc =visual-loc ) Ambient Space Used in postural control (effectively determining which way is up) Used as general qualitative, locational encoding. Used to integrate representation across large expanses Key References Anderson, J. R., & Lebiere, C. (1998). Atomic components of thought. Mahwah, NJ: Erlbaum. Biederman, I. (1987). Recognition-by-components: A theory of human image understanding. Psychological Review, 94(2), Huttenlocher, J., Newcombe, N., & Sandberg, E. H. (1994). The coding of spatial location in young children. Cognitive Psychology, 27(2), Margules, J., & Gallistel, C. R. (1988). Heading in the rat: Determination by environmental shape. Animal Learning & Behavior, 16(4), Presson, C. C. (1982). Strategies in spatial reasoning. Journal of Experimental Psychology: Learning, Memory, & Cognition, 8(3), Previc, F. H. (1998). The neuropsychology of 3-D space. Psychological Bulletin, 124(2), Sandberg, E. H., Huttenlocher, J., & Newcombe, N. (1996). The development of hierarchical representation of two-dimensional space. Child Development, 67, Tourekzky, D. S., & Redish, A. D. (1996). Theory of rodent navigation based on interacting representations of space. Hippocampus, 6,