Latent Inhibition and Asymmetrical Visual-Spatial Attention in Children with ADHD

Abstract

The research was designed to determine whether the purported hemispheric asymmetries that are associated with attention deficit/hyperactivity disorder (ADHD) affect performance on a selective attention visual search task, and whether any obtained asymmetry will be modulated by methylphenidate. Two groups of children (8-15 years) with ADHD, one with methylphenidate treatment (ADHD+) and one without (ADHD+), were compared to matched controls on a two-stage visual search task. The task assessed right-left visual field asymmetries and the effects of changing a previous distractor into a target. Such a procedure, related to latent inhibition (LI; poorer performance to a previously irrelevant stimulus than to a novel one), can provide evidence for dysfunctional processing of irrelevant stimuli. All three groups exhibited the LI effect. The ADHD group, however, exhibited less LI for left- than right-side targets, an effect absent in the control and ADHD+ groups, suggesting a lateralized attentional deficit for ADHD+ that was normalized by methylphenidate.

Brain lateralization and self-reported symptoms of ADHD in a population sample of adults: a dimensional approach

“…The result of group comparison analyses (categorical approach) is consistent with the clinical studies on children and adults with ADHD showing a compromised reaction time performance on the LVF ( Carter et al, 1995 ; Epstein et al, 1997 ; Lubow et al, 2005 ; Geeraerts et al, 2008 ; Chan et al, 2009 ). Consequently, atypical lateralization at the behavioral level might be a characteristic of clinical ADHD as far as inattention type is concerned.…”

Inhibitory Control of Proactive Interference in Adults With ADHD

“…Further analysis revealed that semantic facilitation was greater for targets presented to the LVF (M = 26.74 ms of semantic facilitation) versus targets presented to the RVF (M = 10.66 ms of facilitation), t(63) = 2.98, p < .01. This result suggests that verbal PI is more pronounced for targets presented to the LVF and processed in the right hemisphere, consistent with right-lateralized attentional and inhibitory deficits in ADHD (Carter et al, 1995;Lubow et al, 2005).…”

“…Thus, adults without ADHD were expected to show normal semantic inhibition on the semantic IOR task (e.g., , whereas adults with ADHD were expected to show semantic facilitation on this task. In addition, adults with ADHD were expected to show variable performance on both IOR tasks as a function of VF of target presentation, consistent with ADHD-related deficits in visual-spatial attention and inhibition associated with the right hemisphere (e.g., Carter et al, 1995;Lubow et al, 2005).…”

Peculiarities of Latent Inhibition Formation in SHR Rats in Conditioned Task of Different Complexity

“…To test the ability for attention switch, the phenomenon of latent inhibition (LI) is used, which is characterized by the delay of condition reaction formation in healthy subjects as a result of multiple preexposure (PE) of conditioned stimulus before training [5]. LI is known to be affected in children with attention defi cit hyperactivity syndrome [6]. The same result was obtained in attempt to form LI in SHR rats [3].…”