Erratum: My good friend and fellow Dement fellow, Jared Saletin of UC Berk, just informed me of my somewhat fallacious comments in the blog below. Severance of the corpus callosum is more symptomatic of split-brain, not aphasia. Aphasia more discreetly refers to deficits in language and comprehension resulting from damage of contralateral processing (i.e. average vocabulary,but can’t string words together in a coherent, sensible manner or average understanding of other’s speech, but can’t speak properly). Thanks Jared!
I apologize for not showcasing “Neury Thursday” as scheduled, but my cousin is getting married this weekend. This has not only been my first opportunity to use the internet since arriving in downtown Pittsburgh, but the first time I have used dial-up speed since 2000. And we’re staying in a Westin. How does that make sense?! Now on to Neury Thursday….
In this week’s Journal of Neuroscience, researchers have localized genes that are critically involved with the development of the corpus callosum (CC). The CC connects the two hemisphere. Damages and lesioning of the CC are grave; it results in aphasia, which prevents people from detecting objects on one side of the body. The most classic test for aphasia is asking an aphasic to draw a symmetrical object, such as a clock. The aphasic still possesses the capacity to illustrate, but will only illustrate half of the clock face! Particularly with vision, this neurological deficit is explanatory since vision necessitates contralateral processing; viewing objects with the left eye is processed on the the right side of the occipital cortex, and vice versa. Yep, neuroscience is awesome.