Brain damage studies

Used to help determine the functions of parts of the brain; a person with damage to a specific brain area often shows deficits in specific abilities (e.g., damage to the hippocampus leads to deficits in memory).  One of the salient features of such studies in recent times has been an interest the neuroprotective factors of hormones.  One such hormone is ghrelin, which has been suggested it protects, for example, against neuronal damage induced by glucose-oxygen deprivation in the hypothalamus and cortex, and neurons in the hippocampus and cortex against cerebral ischemia.  Functional deficits are not always a consequence of (acquired) brain damage as the case of Jason Padgett demonstrates.  He was subjected to a mugging that involved being knocked to the ground and kicked repeatedly in the head.  After recovering from concussion, his perception of the world changed dramatically, manifesting synesthesia: he now saw the world (e.g., the flow of water) in terms of fractal dimensions.  He was invited to Finland for a session of brain-imaging under the direction of the neuroscientist Berit Brogaard.  In a series of functional magnetic resonance imaging recordings, Padgett’s left parietal and frontal areas became active when he was subjected to mathematical formulae and that gave rise to synesthetic fractals, but bilateral activation when exposed to nonsense formulae.  Subsequent transcranial magnetic stimulation (TMS) deprived him of these experiences.  What this case study suggests is that synesthetic imagery is generated by cortical areas not typically involved in visual imagery.  As he describes in his book Struck by genius (2014), written together with Maureen Seaberg, these ‘idiot savant’-like capacities came at a cost: post-traumatic syndrome disorder, obsessive-compulsive disorder, and social anxiety.  His remarkable story has led to the claim the application of TMS can temporarily boost creativity and memory.                  

See Basal ganglia (disorders), Cerebellum (disorders), Cerebral cortex (or pallium), Cerebral cortex (disorders), Double dissociation, Fractals, Frontal cortex, Functional magnetic resonance imaging (fMRI), Hippocampus, Hormones, Hypothalamus, Ischemia, Methyl mercury, Obsessive-compulsive disorder (OCD), Parietal cortex, Synesthesia, Transcranial magnetic stimulation (TMS)