Visual processing in reading disorders and attention-deficit/hyperactivity disorder and its contribution to basic reading ability

Abstract

Whether visual processing deficits are common in reading disorders (RD), and related to reading ability in general, has been debated for decades. The type of visual processing affected also is debated, although visual discrimination and short-term memory (STM) may be more commonly related to reading ability. Reading disorders are frequently comorbid with ADHD, and children with ADHD often have subclinical reading problems. Hence, children with ADHD were used as a comparison group in this study. ADHD and RD may be dissociated in terms of visual processing. Whereas RD may be associated with deficits in visual discrimination and STM for order, ADHD is associated with deficits in visual-spatial processing. Thus, we hypothesized that children with RD would perform worse than controls and children with ADHD only on a measure of visual discrimination and a measure of visual STM that requires memory for order. We expected all groups would perform comparably on the measure of visual STM that does not require sequential processing. We found children with RD or ADHD were commensurate to controls on measures of visual discrimination and visual STM that do not require sequential processing. In contrast, both RD groups (RD, RD/ADHD) performed worse than controls on the measure of visual STM that requires memory for order, and children with comorbid RD/ADHD performed worse than those with ADHD. In addition, of the three visual measures, only sequential visual STM predicted reading ability. Hence, our findings suggest there is a deficit in visual sequential STM that is specific to RD and is related to basic reading ability. The source of this deficit is worthy of further research, but it may include both reduced memory for order and poorer verbal mediation.

Sex‐related differences in behavioral and amygdalar responses to compound facial threat cues

“…For example, females are more often affected by anxiety disorders (Mclean, Asnaani, & Litz, ) and depression (Abate, ) that are associated with deficits in face processing and emotion perception. On the other hand, males have a higher risk of developing autism spectrum disorders (Werling & Geschwind, ) that show impaired emotional perception and are more vulnerable to attention deficit hyperactivity disorders (ADHD; Ramtekkar, Reiersen, Todorov, & Todd, ) that are related to attention, working memory, executive functioning deficits (Kibby et al, ) and reduced perception of anger (Manassis, Tannock, Young, & Francis‐John, ). Thus, investigating sex‐related differences in behavioral and neural responses, as well as brain structure, in larger samples of healthy observers will have important implications for identifying such sex differences in these psychiatric disorders.…”

The structure of preliteracy competence in children aged five to seven years

“…Lin et al (2016) have demonstrated that visual-spatial abilities in kindergarten are associated with reading performance in first, second and third grade of primary school. M. Kibby et al (2015) emphasise that reading difficulties are related to visual processing problems. Kavale and Fornes (2000) argue that visual memory and visual discrimination are the best predictor of general reading ability.…”

“…Stronger visual discrimination abilities were also positively associated with better phonemic awareness skills, presumably because of the association between letter knowledge and phonemic skills, or letter-sound correspondence. Kibby et al (2015) found that visual processing might be intact in reading disabilities when measured with tasks of untimed discrimination and visual short-term memory that do not require sequential processing or allow easy labelling.…”

“…This means that the child is able to distinguish each individual character, as well as patterns or symbols (Magajna, Kavkler, Čačinovič Vogrinčič, Pečjak, & Bregar Golobič, 2008). The type of visual processing affected is also debated, although visual discrimination and visual shortterm memory may be more commonly related to reading (Kibby et al, 2015). Many studies (Ortiz et al, 2014, Woodrome & Johnson, 2009 have been conducted to evaluate the extent to which visual discrimination plays a role in developing letter identification abilities, which are essential in learning to read.…”

Spatial Ability in children with Attention-Deficit/Hyperactivity Disorder (ADHD) and its Impact on Executive Functions.

“…Several behavioral studies have focused on SA impairments in children with ADHD (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37), although some of the studies did not show the existence of any differences in spatial tasks between the performance quality of children with ADHD and typically developing children (38)(39)(40)(41)(42). The reason for many inconsistencies might be due to the fact that not only the unity of SA is not precisely de ned, but also not even a single appropriate test is used to measure these factors in various researches.…”