Final answer:
Brain activity in response to visual stimuli is processed by specific regions: the parahippocampal place area for houses, and the fusiform face area for faces, as seen in fMRI scans.
Step-by-step explanation:
When observers were perceiving the house, activity increased in the parahippocampal place area (PPA); when they were perceiving the face, activity increased in the fusiform face area (FFA). These specialized regions of the brain are responsible for processing different types of visual stimuli. The PPA is involved in scene recognition and spatial navigation, while the FFA is part of the 'what pathway' and is specifically activated by facial recognition. Functional magnetic resonance imaging (fMRI) allows researchers to see which areas of the brain are more active in response to certain stimuli due to increased blood flow, which correlates with higher energy consumption in those areas.
For instance, in an experiment where a subject views photographs of faces or houses, fMRI scans can reveal differentiated patterns of activation, demonstrating the brain's intricate system for processing visual information. This task illustrates how specific regions in the brain are engaged during visual tasks and how advanced imaging techniques like fMRI help us understand the functional organization of the brain.