The combination of psychological and neural approaches involves several key methodologies: Neuropsychological which refers to the study the behavior of human adults who have sustained brain damage (usually through stroke or head injury) which selectively affects their ability to carry out these processes. For example, some patients are impaired at recognizing faces (prosopagnosia), some are impaired at recognizing objects (visual object agnosia) and some are unable to represent visuospatial information (hemispatial neglect). By examining patterns of associations and dissociations among abilities after brain damage, one can make inferences about the functional and structural organization of the brain. Psychophysical studies, which refers to the detailed measurement and characterization of the processes under investigation using response latencies and accuracies, as well as other analytic and computational approaches Computational simulations of artificial neural networks, which may be used to model these visual processes, their development and their breakdown following brain-damage. Detailed structural and functional neuroimaging including magnetic resonance imaging, evokes response potential and magnetoencehalography.