ABSTRACT
There is a long chain of logical and inferential steps between neural codes and cognitive activity. These range from the microneuronal level of networks to the macroneural, cumulative macroscopic images produced by brain imaging technology. The general idea behind macroneuronal theories of cognition is that by appropriately activating some aspect of cognition, it can localize regions of the brain that are in some way responsible for coding the cognitive process. The second case, assumes that certain brain areas are related to certain cognitive states then attempts to manipulate those cognitions by stimulating the brain locales with electrical stimuli. Both approaches are based on the same fundamental namely the cognitive processes that are mediated by specific macroscopic brain locations. Work using transcranial Direct Current Stimulation (tDCS), has blossomed in the last decade with suggestions that electrical stimulation of the brain can have profound effects on cognitive functions and psychiatric problems of one kind or another.
