Children who have trouble with reading comprehension despite average word recognition ability may have deficits in executive function, says a recent study in the Journal of Learning Disabilities.
A team of researchers from the Kennedy Krieger Institute at the Johns Hopkins University School of Medicine found that children with specific reading comprehension deficit (S-RCD) performed worse in tests measuring planning, organization and self-monitoring than controls and children who had word recognition deficits.
Both children with S-RCD and children who have deficits in word recognition demonstrated poorer response inhibition and verbal working memory compared to controls. In children with known word recognition deficits, however, executive dysfunction appears to be partly linked to weaknesses in phonological processing, the researchers write.
“In an effort to understand more about the various skills that contribute to reading comprehension, particularly beyond those that are well established (i.e., word recognition and oral language), researchers have begun to examine the role of various executive function skills in reading comprehension,” the researchers write.
The 86 children who participated in the study were tested for executive function with a battery of 8 tests measuring 3 core skill areas: working memory, planning/spatial working memory and response inhibition. Students were divided into 3 groups: Controls, students with word recognition deficits (WRD) and children with S-RCD, who had reading comprehension problems but average word recognition abilities.
Three tests measured planning and spatial working memory. These were:
- Elithorn Perceptual Maze Test (WISC-III-Pl) —requires the child to choose a path through a maze without backtracking
- Trail Making (Letter/Number Sequencing, D-KEFS0) —requires the child to switch back and forth between connecting numbers and letters in sequence
- Tower (Total Achievement; D-KEFS) —measures child’s ability to build a tower by moving disks varying in size across 3 pegs, a test of planning and organization.
Three tests measured working memory:
- Sentence Span—child must remember the last word in a sentence from a set of sentences read by examiner.
- Spatial Span Backward Span (WISC-IV)—child must recall the sequence in which 10 blue cubes are tapped by examiner, both forward and backward.
- Digit Span (WISC-IV)—child must repeat a sequence of numbers he or she hears, both forward and backward.
Two tests measured response inhibition.
- Conflicting motor response—the child is told to show a fist when the examiner shows a finger and to show a finger when the examiner shows a fist for a total of 48 trials
- Contralateral motor response—with eyes closed, participants are asked to lift their right hand when touched on the left hand and vice versa for a total of 48 trials.
After controlling for socioeconomic status and ADHD symptom severity, there were no significant differences between the WRD and S-RCD groups on response inhibition and verbal working memory, the researchers report. However, there was a trend for the S-RCD group to perform more poorly than the WRD group on the planning/spatial memory tests.
Participants in the study were 86 children between the ages of 10 and 14 years with the youngest being in the 4th grade, the stage at which the emphasis in instruction shifts from decoding to comprehension or “learning to read.” The students were recruited through mailings to directors of learning disability organizations and clinics and notices posted in the community.
Children who met criteria for ADHD, Oppositional Defiant Disorder and/or Adjustment Disorders were included in the study. However, children were excluded from participating if they had an intellectual disability or pervasive developmental disorder (mental retardation), uncorrectable visual impairment, hearing loss of 25 decibels or more, history of neurological disorder, psychiatric disorder other than ADHD that involved treatment with psychotropic medications, Verbal Comprehension Index and Perceptual Reasoning Index scores below 80 or Full Scale IQ scores above 130.
Children with ADHD were included in the study because of the hypothesized relationship between reading comprehension deficits and executive dysfunction in children with intact word recognition skills. Children who were being treated with medications other than stimulants were excluded from this study and those taking stimulants were asked to stop taking them the day before and for the 2 days during the testing.
“Executive Dysfunction Among Children With Reading Comprehension Deficits,” by Gianna Locascio et al., Journal of Learning Disabilities, 2010, Volume 43, Number 5, pps. 441-454.