Saccadic and smooth pursuit eye movements have been postulated to play a role in organizing and integrating visual forms in the environment. The delay in voluntary occulomotor navigation reflects deficits in the neural systems that underlie the executive control of eye movements. Habeyck et al. (2006) found that children of fathers with an AUD exhibited a higher rate of saccadic errors on the most difficult tasks associated with antisaccadic eye movement. A follow-up neuro-imaging study of youth at high risk for developing SUD found that the inhibition of eye movement response was related to activation in the frontal cortex (McNamee et al. 2008). Likewise, a number of studies investigating eye movements in subjects with ADHD have identified deficits in inhibiting responses (i.e. premature saccades; Ross et al. 1994), directional movement (i.e. antisaccades; Mostofsky et al. 2001), and stopping an already initiated response (i.e. countermanding saccade task; Hanisch et al. 2006). Dysfunction in oculomotor control has been identified in boys with ADHD and their unaffected brothers, suggesting that saccade deficits may be a potential endophenotype for ADHD (Rommelse et al. 2008).
