Thorough Research: Dr. Hurley's Talk

Dr. Hurley's talk on progressive primary aphasia was a reinforcement on a very important concept that we have been learning since the beginning of the Cognitive Neuroscience class: that the brain consists of numerous pathways and no one region is solely responsible for a task. In Dr. Hurley's CaLLS model the visual and auditory pathways integrate in the temporal pole which he found evidence for using PET.  When participants of his study were naming objects, the PET scans showed metabolism in the temporal lobe, but the fMRI scans are not showing activation in that region during the same task.  Dr. Hurley believes that the lack of activation in the fMRI scan could be due to the air pockets around the temporal lobe, so the resolution around that area is not as good.  In order to show that there are differences in the integration of incoming information in PPA patients, the study uses a paradigm that pairs different stimuli together (picture with picture, picture with word) and looks if PPAs experience the same surprise when the pair doesn't match as the control.  The surprise, or comprehension, is marked by the N400 ERP.  There is a difference between the control's and the PPA's N400 that would suggest that the there is a difference in the way the two groups process incoming information.
However, there is still the question of why Dr. Hurley is not seeing activation in the temporal lobe.  In his perseverance, Dr. Hurley added another study that paired a picture with sound, so that another type of sensory information can be examined.  Even with the extra study added, Dr. Hurley is worried that there may be another cause for the difference in the N400: the Disconnection Syndrome.  In this case it would be the white matter that between the visual and language systems that has been disconnected in PPAs.  This would cause the same result in the N400 as the CaLLS theory.  I thought it was great that Dr. Hurley was honest that there could be another cause for the difference.  He is a great example of being a good researcher because even though he would like to be correct in his theory, he did not reject the idea that he could be wrong.  Instead, he added another study to his research (sound and olfactory), and he is even starting studies with intracranial recordings on epilepsy patients.  He is conducting thorough research instead of pretending that there isn't another potential explanation or giving up. It is important to remember that it is better to use multiple methods in your research so you have more evidence, whether it supports your hypothesis or not.  Even when your hypothesis is not supported, you should not be discouraged because your research may lead to other discoveries further down the line.