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Prosopagnosia
Published in Alexander R. Toftness, Incredible Consequences of Brain Injury, 2023
The difference between the two types of prosopagnosia that I have mentioned seems to lie in a brain region called the fusiform gyrus, located in the temporal lobe. In people with acquired prosopagnosia, this region is physically and permanently damaged (Barton, 2008). In people with developmental prosopagnosia, research suggests that this brain region has fewer brain cells, leading to a diminished face recognition ability (Garrido et al., 2009). To be a bit more specific, there are at least three different regions of the brain that respond to faces—sometimes called the fusiform face area, the occipital face area, and the face-selective superior temporal sulcus—and when a person looks at faces, those regions respond in somewhat different ways, showing that they have different jobs in the process of face identification (Liu et al., 2010). On average, damage to the right-side fusiform area is more likely to cause prosopagnosia than damage to the left-side fusiform area, and the evidence suggests that there are variants of prosopagnosia depending on the specific location of the damage, such as whether or not it's more of a vision or more of a memory issue (Albonico & Barton, 2019). That may sound straightforward, but trust me, it is not. While most researchers agree that damage to those brain regions, especially the fusiform gyrus, can lead to prosopagnosia, researchers certainly do not agree about the boundaries of the condition. That is: what exactly is prosopagnosia?
Action Evaluation and Discrimination as Indexes of Imitation Fidelity in Autism
Published in Elizabeth B. Torres, Caroline Whyatt, Autism, 2017
With respect to the fMRI results, the overall effects of imitate over mismatch revealed few effects, but most interestingly, these were located in the occipital face area (OFA). The OFA has been implicated in facial emotion recognition (Winston et al. 2003), and application of transcranial magnetic stimulation to OFA has been shown to impair emotion recognition (Pitcher et al. 2008). Furthermore, the occipital cortex has been shown to be sensitive to motor activity (Astafiev et al. 2004) and have mirror neuron properties using multivoxel pattern analysis (Oosterhof et al. 2013). These latter studies have identified a slightly more lateral and rostral region with these properties but have focused on manual actions. It is predicted that OFA will be sensitive to motor input, but studies have not yet been directed specifically to that question (Pitcher et al. 2011). Conversely, it also seems quite possible that the OFA could be sensitive to input from other areas concerned with emotional processing, including the orbitofrontal cortex and inferior frontal gyrus. The study by Braadbart et al. also suggests that many of the effects of imitation over mismatch are relatively small and only become detectable when sample sizes are sufficiently large.
Face Expertise and Category Specialization in the Human Occipitotemporal Cortex
Published in Jon H. Kaas, Christine E. Collins, The Primate Visual System, 2003
the two effects. One argument against models that postulate a stage of face detection that precedes that of identification comes from the work of Tanaka,80 who showed that faces are recognized at the individual level (“Brian”) as fast as they are recognized as faces. This is thought to be due to our expertise with faces: similarly, bird and dog experts identify stimuli outside of their domain of expertise fastest using basic categorical level (e.g., “bird” or “car,” more similar to “face”) but for objects within their domain of expertise, they can recognize objects as fast at the subordinate or individual level as at the basic level (e.g., a bird expert could recognize an object equally fast as a “jay” than as a “bird”).81 This argues against an early stage of processing for detection of faces. Neuroimaging results also suggest that the FFA, as well as the “occipital face area” (OFA) in the lateral occipital lobe, processes faces at the individual level.82 Even the earliest neurophysiological signature of face selectivity in the human brain, the N170 potential, which peaks around 170 ms poststimulus onset, is influenced by manipulations that limit face identification (e.g., inversion)59 and is sensitive to expertise at identifying nonface objects individually.1067× At this point, clear evidence for a separate face detection stage is lacking, which is problematic for the suggestion that a given face-selective area or face potential is primarily involved in this processing stage.
Gestalt Perception in Children With Visual Impairments: Item-Specific Performance and Looking Behavior
Published in Developmental Neuropsychology, 2019
Ymie J. van der Zee, Marlou J. G. Kooiker, Marisabel Talamante Ojeda, Johan J. M. Pel
It has been shown that processing of either animate or inanimate pictures can be selectively impaired in patients with damage to anterior visual areas (Caramazza & Shelton, 1998; Hillis & Caramazza, 1991; Warrington & Shallice, 1984). More recently, fMRI studies found clusters of voxel population vectors that were associated with animate and inanimate categories located anterior to retinotopic visual areas (Kriegeskorte et al., 2008; Naselaris, Stansbury, & Gallant, 2012). However, in these studies, images of hundreds of well-defined objects were presented to the subjects. In the present study, visual processing of each item involved perceptually grouping of closely projected elements to visualize a complete object, even when presented incomplete information. To our surprise, we found a significantly worse performance for naming the animate items in children with confirmed or suspected brain damage. We could not find any support for our finding in literature. At this point, we do not know if the differences we found between animate and inanimate object recognition in children with cerebral visual impairments are related to possible damage to the associated processing areas in the brain, e.g., the occipital face area (OFA) and the extrastriate body area (EBA) (Naselaris et al., 2012). The available imaging data lack the detailed information that is required to obtain insight in these specific regions.