Franklin & Marshall College Franklin & Marshall College

Perception Laboratory

  • eye scanner

 

Perception Research Laboratory

How do we know the world?  How real and true is our experience?  These questions stand among the oldest topics of psychological science.  Investigators have studied perception from diverse points of view — epistemology, natural history, phenomenology, physiology, and psychophysics to name a few. 

Our research on perception at Franklin & Marshall has focused on vision and behavior, as we pursue two objectives:  (1) to increase our fundamental understanding of perceptual systems and related neural mechanisms, and (2) to develop new solutions for practical problems that are related to perception, such as vision in challenging conditions, transportation safety, and athletic performance.

 

About the Lab.

The Perception Research Laboratory, located at LSP-139, includes a suite of five rooms, which are equipped to investigate a wide variety visual and behavioral phenomena, including:

Visual acuity, contrast sensitivity, peripheral vision, refractive error, useful field of view, motion perception, depth perception, illusions

Control of locomotion (walking, driving), postural stability, vection (feelings  of self-motion like in an iMax theater)

Eye movements and visual attention

Driving simulator

Ocular adjustments for distance: accommodation (the eyes’ focus) and binocular vergence (crossing and uncrossing the eyes for binocular fusion)

The next section provides a sample of our research projects.

  • Simulator

 Eye tracking system and driving simulator.

  • Vection lab

 Postural stability and vection lab.

  • Xiaoyu Motion

 Xiaoyu Zhang ’11 is investigating visual perception of motion.

  • Perception Researchers

Perception Research Scholars, Summer 2010: clockwise from top-left, Xiaoyu Zhang, Johnny Lawrence, Greeshma Prasad and Alex Nalbandian.

 Perception & Action at Franklin & Marshall: Research Sampler

  • The Resting State of the Eyes

Our research has shown that every person has a characteristic resting focus, and our eyes shift toward that resting posture in difficult visual conditions.

This explains why many people become near-sighted in low-visibility conditions like fog or dim light, and it helped us understand why some people experience visual fatigue from near work.

  • Resting State of Eye
  • Publications on the Resting State of the Eyes

Owens, D. A. (1984). The resting state of the eyes.  American Scientist, 72, 378-387.

Owens, D. A. & Wolf-Kelly, K.  (1987)  Near work, visual fatigue, and variations of oculomotor tonus.  Investigative Ophthalmology & Visual Science, 28, 743-749.

Owens, D. A.  (1987)  Oculomotor information and perception of three-dimensional space. Chapter 9  in H. Heuer & A.F. Sanders (eds.) Perspectives on Perception and Action, Hillsdale, N.J.: Lawrence Erlbaum, pp. 215-248.

  • Night Vision, Selective Visual Degradation, and Road Safety

Many visual abilities – like acuity, color vision, and depth perception -- are severely degraded in low light conditions.

 This has serious consequences for road safety: for example, most motorists “over-drive their headlights” because they are not aware of their visual limitations.

We are investigating the role of “two modes of vision,” which depend on different brain mechanisms, to improve driver’s education and road safety.

     

 

  • Publications on Selective Visual Degradation and Driving

Owens, D. A.  (2003).  Twilight vision and road safety: Seeing more than we notice but less than we think. In J. T. Andre, D. A. Owens, & L. O. Harvey (eds.) Visual Perception:   The influence of Herschel W. Leibowitz, Washington, D.C.: American Psychological Association, pp. 157-180.

Owens, D. A., Antonoff, R. A., & Francis, E. L.  (1994)  Biological motion and nighttime pedestrian conspicuity. Human Factors, 36 (4), 718-732.

Owens, D. A., & Sivak, M.  (1996).  Differentiation of visibility and alcohol as contributors to twilight road fatalities.  Human Factors, 38 (4), 680-689.

Owens, D. A., & Tyrrell, R. A. (1999).  Effects of luminance, blur, and age on nighttime visual guidance:  A test of the selective degradation hypothesis.  Journal of Experimental Psychology: Applied, 5 (2), 115-128.

Owens, D. A., Wood, J. M., & Carberry, T.  (2010).  Effects of reduced contrast on the perception and control of speed when driving.  Perception, in press.

  

  • Eye Movements and Visual Attention

The Second Biggest Visual Illusion in the Universe is the false impression that we can see everything at once.  In fact, we can perceive clearly only a very small region of the visual field.  This region of clear vision corresponds to our fovea, a part of the retina that sees area about the size of our thumbnail at arm’s length. 

Eye movements are essential for normal perception.  We move our eyes rapidly and accurately, ~3 to 5 times every second, throughout every waking hour and even in our dreams. 

These eye movements are needed to point the area of clear vision toward any and every thing we want to see clearly.

We are using eye movement recordings to investigate how visual attention differs between novice and expert drivers.  Our hypothesis is that “expert” drivers are more likely to look sooner at potential hazards and, therefore, have a lower accident rate than novices.

  • Student Perception Researchers

 Student researchers, Jennifer Stevenson ‘08 and Andrew Osborne ’08, using the eye tracker to study attention of novice compared to experienced drivers.

 

  • driving simulator

 A novice driver views potentially dangerous road scenes while his eye movements are recorded.

  • driving simulator 3
  • driving simulator 2

The green lines illustrate the “scan paths” of a driver’s eyes when viewing four road scenes.

 

  •  Publications on Eye Movements, Visual Attention, and Driving

Owens, D.A., Stevenson, J., Osborn, A., & Geer, J.  (2009).  Tracking the visual attention of novice and experienced drivers. Journal of Vision, August 5, 2009 9(8): doi10.1167/9.8.384

Osborn, A. & Owens, D. A.  (2010).  Change blindness: A comparision of selective attention in novice and experienced drivers.  Journal of Vision, in press.