This thesis looks at the central processing of two unpleasant sensations, itch and pain, and how these sensations can be modulated using psychological tools. The initial section focuses on the induction and modulation of thermal noxious stimuli and the way in which this is represented in the brain. It is well known that pain can be modulated by distraction, and also which areas of the brain are frequently activated by noxious stimuli. The research reported here expands upon this knowledge. The first study found that when subjects were engaged in a cognitively demanding task (the Counting Stroop task) their attention was distracted away from thermal painful stimuli. They reported a significantly (p=0.006) lower pain intensity rating for stimuli during the interference (more cognitively demanding) task compared to the neutral (less cognitively demanding) task. The interference task was confirmed to be more difficult than the neutral task by significantly increased reaction times in the former compared to the latter. The reduced perception of painful thermal stimuli applied during the interference task compared with those felt in the neutral task was accompanied by a reduced activation in some key components of the pain matrix (insula, mid-cingulate, thalamus). Some key pain processing regions showed an increase in signal during the interference task compared with the neutral task (perigenual cingulate, orbitofrontal regions). [continued in main text ...]