Brain and molecular mechanisms of vigilant attention
Vigilant attention is the capacity to maintain alert responding to unchallenging or monotonous stimuli under conditions where novelty, challenge or emotionality do not externally activate attention. This brain system has evolved for the detection of rare but important stimuli, or for the avoidance of error in during routine behaviour. In this paper I will demonstrate the brain bases for this capacity, via fMRI, PET and ERP, and show how this system interacts with midbrain arousal systems in maintaining the balance between exogenous and endogenous mechanisms of maintaining alert responding. I will also show how this system interacts with the right hemisphere spatial orienting system of the brain, and will demonstrate this particularly in the context of Attention Deficit Disorder - the only neuropsychological disorder which is defined primarily in terms of deficits in the brains' attentional systems. I will show, via this model system, a possible molecular genetic basis for different aspects of vigilant and spatial attention, particularly in relation to the DAT1, DBH and DRD4 genotypes.