Table 1).

Studies of attention and WM performance in PD, schizophrenia, and ADHD.

Author	Task	Disease, treatments	Performance change
(Mathis, Wynn, Breitmeyer, Nuechterlein, & Green, 2011)	Attentional blink	Schizophrenia	Patients show an exaggerated attentional blink effect compared to healthy controls, with significantly lower detection of the second target. Results suggest deficits in both visual processing and general attentional deficits.
(Javitt, Doneshka, Grochowski, & Ritter, 1995)	WM, auditory oddball task	Schizophrenia	Impaired mismatch negativity, increased reaction time and decreased number of correct detections
(Stablein et al., 2016)	WM, visual motion task	Schizophrenia	Decreased task accuracy, attributed to visual deficits and impaired attention in patients
(Clementz, Wang, & Keil, 2008)	Target identification sustained attention	Schizophrenia	Abnormal target identification in patients, attributed to visual deficits in schizophrenia
(Fuller et al., 2006)	Visual search tasks, four types	Schizophrenia	Rates of search were slower in patients, especially when the task required precise attentional control. Results suggest primary impairment of attention in schizophrenia
(Slagter et al., 2016)	Attentional blink	Parkinson’s disease on and off dopaminergic therapy (levodopa and agonists).	Patients exhibited poorer performance than healthy controls. An optimum level of dopamine for cognitive function is suggested
(R Cools & D’Esposito, 2011)	Review, tower of London, WM task, attentional set-shifting	Parkinsons’ disease on and off medication	PD patients had deficits on the Tower of London planning task, WM and attentional set-shifting tests
(Rodriguez-Oroz et al., 2009)	Review of tasks in which shifting of attention is impaired in PD	Parkinson’s disease	Issues when switching attention, and double task demands
(Bulens, Meerwaldt, Vanderwildt, & Vandeursen, 1987) (Hutton, Morris, & Elias, 1993)	Contrast sensitivity test	Parkinson’s disease on and off levodopa treatment	Loss of contrast sensitivity in patients. Levodopa improves contrast sensitivity function, close to normal levels
(Lange et al., 1992)	Tower of London and spatial WM task	Parkinson’s disease; on and off L-dopa medication	L-dopa withdrawal dramatically impaired performance in the tower of London test, with times slower than baseline condition (on L-dopa). Increase of errors in the spatial WM task during L-dopa withdrawal
(Moustafa et al., 2008)	WM task, continuous performance AX-CPT	Parkinson’s disease; on and off dopaminergic medications (L-dopa and agonists)	PD patients showed deficits for ignoring distractors and attentional shifting
(Kempton et al., 1999)	Cambridge Neuropsychological Test Automated Battery (CANTAB)	ADHD; stimulant methylphenidate, D-amphetamine	Medicated ADHD children did not show impairment in most of the executive function tasks, except the spatial recognition memory task. These results suggested that stimulant medication improved executive function performance
(Karatekin & Asarnow, 1998)	Dot test of visuospatial WM and digit span subtest of the Wechsler intelligence scale (digit recall)	Childhood onset schizophrenia and ADHD	Normal children were able to recall more digits than children with schizophrenia and ADHD. Both schizophrenic and ADHD children had greater distance error on the dot test.