Final 29 variables included in the Principal components analysis.

* ‘Trail Completion Difference’ was measured as the difference in completion times between the two trails of the SOAT; ‘Maze Trial Time’ is the time taken to complete the trial twice consecutively without error; ‘Path Learning Time’ is the time taken to learn the path prior to completing the trial twice consecutively without error (i.e. the time taken from the start of the first trial till the end of the last trial with one or more errors).# The letter ‘A’ or ‘L’ is added to the end of each ERP component to denote amplitude (A) or latency (L), for example ‘N1A’ denotes fronto-central N1 amplitude.