Selective Visual Attention in ADHD: A Narrative Review

Abstract

Purpose of review: Attention-deficit/hyperactivity disorder is a common neurodevelopmental disorder characterized by impairing levels of inattention, hyperactivity and impulsivity that adversely impact functioning across social, academic/occupational and home settings. While the name of the disorder implies obvious difficulties in attention, research has struggled to consistently identify a precise neurocognitive marker. This article aims to characterize the functioning of selective visual attention in ADHD by reviewing previous studies that compare individuals with ADHD and healthy controls at the behavioral and neural levels using single-frame visual search tasks.

Recent findings: Past research indicates both bottom-up (stimulus-driven) and top-down (goal-driven) attention across both time and space are likely affected in ADHD. However, more research is needed to illuminate the specific mechanisms involved. Ultimately, this narrative review aims to highlight the importance of studying selective visual attention in ADHD to explain the heterogeneous symptoms and impairments of this complex disorder, as well as to build a stronger bridge between the high-level behaviors of ADHD and their underlying neurobiological mechanisms.

Keywords: ADHD; Bottom-up; Selective attention; Top-down; Visual search.

Fig. 1

Single-feature and Conjunction Search Displays and Slopes. In the single-feature search (top left), the target letter “O” appears to pop out from the green letter “O” distractors in the display. In the conjunction condition (bottom left), the target red letter “O” is more difficult to find among the green letter “O”s and red letter “Q” distractors. On the right are the typical flat and steep slopes of the RT function for these search conditions (respectively)