Pre-study saliva collection is completed at home by participants early in the morning. This provides a biochemical marker which aims to support both cognitive findings and the results from the Bond Lader mood questionnaire completed during the computer testing. Instructions are given to participants for saliva collection and the samples analysed for cortisol and cortisone. Participants are instructed to have their usual breakfast except for coffee or tea. Blood pressure is taken pre and post study on visits 2 and 3.