Item	Item-total correlation (all subjects)	Item-total correlation (prHD subjects)	Item-total correlation (HD subjects)
Concentration	0.585	0.622	0.410
Odor detection	0.245	0.281	0.173
Social cognition	0.484	0.614	0.188
Interpersonal awkwardness	0.514	0.478	0.619
Multitasking (concurrent tasks)	0.655	0.716	0.622
Multitasking (switching)	0.623	0.727	0.464
Planning	0.580	0.563	0.617
Prospective memory	0.640	0.666	0.710
Keeping track of time	0.517	0.557	0.469
Problem solving	0.602	0.717	0.296
Expressing thoughts verbally	0.524	0.616	0.372