Final answer:
Nancy Kanwisher used neuroimaging techniques to test hypotheses about the brain's visual processing, focusing on whether certain brain regions like the FFA were specialized for recognizing faces rather than performing low-level feature extraction.
Step-by-step explanation:
The student's question pertains to the experimental methods used by Nancy Kanwisher to test alternative hypotheses related to the process of low-level feature extraction in the brain. This line of research did not focus on feature extraction itself but rather on the identification and functioning of certain areas of the human brain, such as the fusiform face area (FFA) that are specialized for recognizing specific categories of objects. Kanwisher and colleagues utilized neuroimaging techniques like fMRI to investigate these regions and determine if they were responsible for general visual processing or dedicated to specific tasks. To test alternative hypotheses, they compared activation patterns when subjects performed different visual recognition tasks involving faces, objects, and places to discern whether the FFA was exclusively processing faces or merely complex objects at a low-level. By showing high levels of FFA activation specifically when subjects viewed faces as compared to other stimuli, Kanwisher provided evidence against the low-level feature extraction hypothesis in favor of face-specific processing.