Objects with strong contextual associations by these definitions were found to elicit greater responses than objects with weak contextual associations in the parahippocampal place area (PPA) and retrosplenial complex (RSComp), brain regions that are known to respond strongly during the visual perception of scenes 17, 18. Previous neuroimaging studies have attempted to meet this challenge 11, 12, 13, 14 One approach has been to operationalize context as a one-dimensional rating that reflects how strongly an object brings to mind a particular context 11, 15 or whether or not an object is associated with other objects or locations 16. Thus, identifying the brain mechanisms that support the representation of contextual knowledge is an important challenge for cognitive neuroscience. Moreover, theoretical accounts suggest that contextual facilitation might be evidence for a general cognitive mechanism by which the mind makes predictions about the world in order to support adaptive behavior 5, 6, 7, 8, 9, 10. Previous behavioral work has demonstrated that the visual system uses contextual knowledge to facilitate object recognition 1, 2, 3 and visual search 4. This type of contextual knowledge can help people identify their surroundings and generate expectations for the other objects they might encounter. For example, fire hydrants are often found with traffic lights and mailboxes on city sidewalks, while tea kettles are found with mugs and stoves in kitchens. Many objects have a natural place in the world-a setting in which they and other co-occurring objects are typically encountered. Together, these findings show that the sensory coding of objects in the human brain reflects the latent statistics of object context in visual and linguistic experience. In contrast, a language-based statistical model of the co-occurrence of object names in written text predicted responses in neighboring regions of object-selective visual cortex. We found that cortical responses to single objects were predicted by the statistical ensembles in which they typically occur, and that this link between objects and their visual contexts was made most strongly in parahippocampal cortex, overlapping with the anterior portion of scene-selective parahippocampal place area. We identified low-dimensional representations that capture the latent statistical structure of object co-occurrence in real-world scenes, and we mapped these statistical representations onto voxel-wise fMRI responses during object viewing. Here we use machine learning and fMRI to test the hypothesis that object co-occurrence statistics are encoded in the human visual system and elicited by the perception of individual objects. If only the reading portion dropped to it’s lowest levels ever, wouldn’t that point to the fact that our kids aren’t reading for pleasure? Studies show that only about half read for pleasure.A central regularity of visual perception is the co-occurrence of objects in the natural environment. Some say it’s because of diversity with more and more kids from all backgrounds taking the test, but I wonder if it’s not more than that. The class of 2011 had the lowest SAT critical reading score (497)ever recorded. Because of so many distractions, this generation of kids is more distracted than ever, and it’s not by school work. Take a look at this short video for some highlights.ĭuring the segment, Melanie Hastings and I also talked about the lure of technology. Scientists are just beginning to study brain changes by looking at MRIs to determine if constant texting, facebooking, tweeting (you name it!) is changing brains. Today, I appeared on News Channel 8’s Let’s Talk Live discussing how technology is impacting this generation of students.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |