Accommodative response and cortical activity during sustained attention

Abstract

Greater accommodative lag and vergence deficits have been linked to attentional deficits similar to those observed in Attention Deficit Hyperactivity Disorder (ADHD). The purpose of the present study was to assess the effect of accommodative-vergence stress on a measure of sustained attention (Conners CPT) used in the diagnosis of ADHD. Twenty-seven normal non-ADHD adults completed the Conners CPT twice: wearing -2.00 D lenses and normally (without the -2.00 D lenses) in a counterbalanced order with at least 24 h between the sessions. Simultaneous recording of participants' dynamic accommodative responses was performed from the right eye using the Grand Seiko WAM-5500 auto-refractor and electroencephalographic activity (EEG) in the left prefrontal region using the Neurosky Mindset headset. The results demonstrated a significantly greater accommodative lag in the -2.00 D stress condition and a significantly poorer performance on the Conners CPT as indexed by slower reaction time, greater standard error of hit reaction time, grater response variability, poorer stimulus detectability and a greater number of perseverations. No differences were observed on measures of EEG in the theta (4-7 Hz), alpha (8-12 Hz), and beta (12-20 Hz) bands. Moreover, when directly juxtaposed with each EEG band in multiple linear regression analyses, greater accommodative lag in the stress condition was significantly associated with a greater probability of clinical classification on the Conners CPT, and was also marginally predictive of the number of omissions recorded in the stress condition. The results demonstrated that sustained attention can be influenced by such factors as accommodative-vergence stress and suggest that bottom-up processes can contribute to and potentially exacerbate attentional problems in individuals with ADHD. The study also showed that cortical dysfunction (while sufficient) may not be a necessary condition for attentional deficits.

Attention-Related Eye Vergence Measured in Children with Attention Deficit Hyperactivity Disorder

“…Many of the children with CI report attention problems [ 36 , 41 ] and recent studies demonstrate a relationship between CI and ADHD [ 19 ]. Our study supports the finding of binocular vision as an important factor in attention [ 42 ], and the idea of deficient binocular vision in ADHD children [ 19 ]. However, CI occurs at close distances whereas in our study the used target distances fall well outside the range of distances of CI for children.…”

Stereoacuity, Fusional Vergence Amplitudes, and Refractive Errors Prior to Treatment in Patients with Attention-Deficit Hyperactivity Disorder

“…8 In patients with ADHD, binocular vision changes and oculomotor deficits such as convergence insufficiency 9,10 , accommodative dysfunction 11 , reduced stereoacuity 12 , and ametropia 13 have been reported. Regarding underlying mechanisms, Poltavski et al 14 suggested a bidirectional relationship between attention and accommodation. However, the association between ADHD and oculomotor control changes such as accommodative dysfunction and convergence insufficiency is not clearly known yet.…”

Effects of a blue‐blocking screen filter on accommodative accuracy and visual discomfort

“…In order to control for any residual refractive error, the lag of accommodation was corrected by subtracting the baseline static refractive value using the equation of Poltavski et al (2012). 58 The mean residual spherical equivalent refractive error was + 0.21 AE 0.25 D (range -0.32 to + 0.57 D). The variability of accommodation and pupil diameter were obtained by calculating the standard deviation of the dynamic accommodation and pupil recordings during a 60-s period.…”