Secrets of the Mind
I’m going to use this entry to provide a quick overview of the events of the video to inform your discussions, since you have no text to which you can refer back. Of course I’m brimming w/ interpretations and connections, but I’ll try and resist the temptation to dive in for the moment. You, on the other hand, should have at it. What do these dysfunctions tell us about normal consciousness and awareness?
Neurologist : V.S. Ramachandran
Phantom Limb Sensations following amputation. Pain and sensation of a limb which is gone. (the sensory neurons which delivered information from the limb to the brain survive the loss of the limb, any activation of those neurons is perceived as occurring at the limb) Reassignment of the somato-sensory cortex region from arm to cheek
Blind Sight. Perception of motion, but no conscious awareness of an object's shape, color, size etc. Ramachandran uses the phenomenon to illustrate that our brain can be receiving visual information without our being aware of it. I find it a better demonstration that the various components of vision (color, shape, motion, …) travel by different pathways and then are reassembled for conscious awareness in the primary visual cortex in the rear of the cerebrum (occipital lobe). He talks about “What” pathways by way of the temporal lobe which are involved in the identification of objects and “How” pathways which are more concerned with how we move through the environment (the visual cues that you use to ride a bicycle or hit a baseball or duck an oncoming tree limb). When is consciousness helpful, when is it detrimental? Peggy was the woman whose stroke in the parietal lobe interfered w/ her awareness of the left visual field including her memories and her daisy drawings
Capgras Delusion: Impostor Syndrome. David thinks that his parents are impostors. When he only hears their voices he acknowledges them as his parents. Ramachandran proposes that the delusion stems from an injury in the connection between the “What” visual center in the temporal lobes with the Amygdala which is the area where visual info enters the Limbic System, the source of your emotional reactions.
Temporal Lobe Epilepsy: epilepsy is a disease in which there are episodes of uncontrolled brain activity resulting in seizures. In this specific case the patient experiences periods of enlightenment or rapture following the seizures in which he perceives a wide range of events as having profound, even religious, significance. Ramachandran points out the areas affected include the links between the Amygdala and the Temporal Lobe.
