Comparing cognition, behavior, and neural responses to real objects versus images
The long term goal of this research is to investigate how the human brain processes and represents real world 3-dimensional (3D) objects compared to 2-dimensional (2D) pictures of objects, and whether real objects have unique and measurable effects on cognition and behavior. In the past few decades of research in psychology and neuroscience there has been a rapid rise in the number of behavioral and imaging studies that have examined the structure and function of the visual and motor systems. The stimuli employed in these studies are diverse, ranging from basic elements to more complex stimuli such as objects, faces, and scenes. The overwhelming majority of research to date, however, have utilized 2D images as proxies for real tangible objects. The reliance on images is especially pervasive in functional magnetic resonance imaging (fMRI), mostly for practical reasons: the scanner is a constrained environment in which control over stimulus parameters, and their speed, visibility, and timing is critical-but difficult to realize using real objects. In the real world, however, we predominantly interact with real 3D objects, not 2D images, and the human brain has largely evolved to perceive and interact with real objects and environments (Gibson, 1979). Real objects differ from pictures in many respects, from the presence of additional stereo shape information, to the fact that they afford grasping and interaction - factors known to influence brain-based responses. By focusing on images alone we may compromise ecological validity and impose unnecessary limits in what science can contribute to the development of new and possibly more valid scientific procedures, technologies, diagnostic tools, and patient-based treatments. This research program examines how, and why, the format in which objects are displayed influences fundamental aspects of human cognition and action. The program is comprised of three broad aims that examine the nature of real-object effects on decision-making, attention and eye-movements, and the perception of size. The studies utilize novel and innovative paradigms and equipment designed to present real objects rapidly and efficiently, and includes convergent behavioral studies in healthy observers, neuropsychological patient-based studies, and functional neuroimaging (fMRI).