A working brain produces electrical activity that can be recorded at the scalp. An event-related potential (ERP) is a characteristic electrophysiological response to any specific category of stimulus or event. The P300 is an ERP associated with stimuli that must be attended. It has been suggested that the P300 may be a manifestation of functioning in the locus coeruleus – norepinephrine system (LC-NE system), a neuromodulatory system that is associated with arousal , vigilance and attention. A link has been suggested between cognitive deficits in the elderly and suboptimal activity in the LC-NE system. Christopher Warren is attempting to demonstrate the link between the P300 and the LC-NE system, and describe the related changes in the brain that occur with age. He is assessing the performance of elderly participants on a specific attentional task, while simultaneously recording the electrophysiological activity of their brain using electroencephalograph recording equipment. The data will be compared with a control group of younger participants. Chris is looking for specific, key differences in electrophysiological activity and behavioural performance between elderly participants and controls, which will support the link between the LC-NE system and the P300, and will allow inference as to how the LC-NE system is behaving in the elderly participants.. Chris’s results will describe, and possibly implicate suboptimal function of the LC-NE system in cognitive decline with age. This research has direct implications for understanding the cognitive decline associated with healthy aging, potentially describing the function and malfunction of the LC-NE system in aging populations. It could also generate a model that could be applied to understanding LC-NE function in people with attention deficit/hyperactivity disorder, dementia, schizophrenia, or traumatic brain injury. A comprehensive theory of the LC-NE system could inform the development of clinical strategies and tools to help elderly citizens effectively work around attention-related cognitive deficits that occur with age