Much of the work in the Brain and Cognition Laboratory investigates how people navigate in the very near environment. Imagine turning out the light at night and then attempting to "navigate" in the room when it's dark. People are generally able to do this pretty well. This shows that people remember their environment and can keep track of their own body motions. In the Brain and Navigation Laboratory, we study the psychological and neural processes that allow us to perform tasks such as these.
Medial temporal lobectomy: Sometimes when people have injuries in and around the medial temporal lobe, the way they keep track of nearby objects and their own body motions changes. These changes are seldom bothersome, but they are important for understanding how the brain monitors body and object motions. In research funded by the National Institute for Neurological Disorders and Stroke, we are testing the ability of people who have had brain surgery in these regions to keep track of simple body motions.
Philbeck, J.W., Behrmann, M., Biega, T., & Levy, L. (2006). Asymmetrical perception of body rotation after unilateral injury to human vestibular cortex. Neuropsychologia, 44, 1878-1890.
Philbeck, J. W., Behrmann, M., Levy, L. & Potolicchio, Jr., S. J., & Caputy, A. J. (2004). Path integration deficits during linear locomotion after human medial temporal lobectomy. Journal of Cognitive Neuroscience, 16(4), 510-520.
Philbeck, J. W., O'Leary, S., & Lew, A. L. B. (2004). Large errors, but no depth compression, in walked indications of exocentric extent. Perception & Psychophysics, 66(3), 377-391.
Philbeck, J. W., Klatzky, R. K., Behrmann, M., Loomis, J. M., & Goodridge, J. (2001). Active control facilitates non-visual navigation. Journal of Experimental Psychology: Human Perception and Performance, 27, 141-153.
Philbeck, J. W., Behrmann, M., & Loomis, J. M. (2001). Updating of locations during whole-body rotations in patients with hemispatial neglect. Cognitive, Affective, & Behavioral Neuroscience, 1, 330-343.
Philbeck, J. W., Behrmann, M., Black, S. E., & Ebert, P. (2000). Intact spatial updating during locomotion after right posterior parietal lesions. Neuropsychologia, 38, 950-963.
How do we use our eyes to find out where things are?
In the Brain and Navigation Laboratory, we use a variety of different methods for measuring people's perception of the distance and direction of nearby objects. Some of these methods are "action-based", such as walking or aiming a pointer at an object (see pictures above). These are useful ways of measuring perception, because they do not rely upon people's familiarity with numbers.
Gajewski, D.A., Philbeck, J.W., Chichka, D.F. & Pothier, S.G. (2008). Exploring the time course of egocentric distance perception with visual masking of a real-world environment. Annual meeting of the Vision Sciences Society, Naples, FL, May 12, 2008.pdf
Philbeck, J.W., Dopkins, S., Sargent, J. & Arthur, J. (2008). Large manual pointing errors, but accurate verbal reports, for indications of target azimuth. Perception, 37, 511-534
Loomis, J. M., Philbeck, J. W., & Zahorik, P. (2002) Dissociation between location and shape in visual space. Journal of Experimental Psychology: Human Perception and Performance, 28, 1202-1212.
Loomis, J. M., & Philbeck, J. W. (1999). Is the anisotropy of perceived 3-D shape invariant across scale? Perception & Psychophysics, 61, 397-402.
Philbeck, J. W., Loomis, J. M., & Beall, A. C. (1997). Visually perceived location is an invariant in the control of action. Perception & Psychophysics, 59, 601-612.
Philbeck, J. W., & Loomis, J. M. (1997). Comparison of two indicators of perceived egocentric distance under full-cue and reduced-cue conditions. Journal of Experimental Psychology: Human Perception and Performance, 23, 72-85.
Loomis, J. M., Da Silva, J. A., Philbeck, J. W., & Fukusima, S. S. (1996). Visual perception of location and distance. Current Directions in Psychological Science, 5, 72-77.
How do we keep track of objects when we move?
Keeping track of objects during body rotations
When we move around in the world, we can often use our eyes to keep track of where things are. But sometimes vision is not available. How do we keep track of objects then? We study this using a computer-controlled turntable, shown above. Using this table, we can rotate people by various amounts to see how well they keep track of nearby objects.
Philbeck, J. W. & O'Leary, S. (2005). Remembered landmarks enhance the precision of path integration. Psicologica, 26, 7-24.
Behrmann, M., & Philbeck, J. W. (2001). Spatial representation and updating: Evidence from neuropsychological investigations. In D. R. Montello (Ed.), Spatial information theory: Foundations of geographic information science, pp. 352-370. Proceedings of COSIT '01. Lecture Notes in Computer Science, 2205. Berlin: Springer-Verlag.