Executive Function
Executive function (EF) is a broad domain that includes skills to guide
goal-directed behavior, including the ability to shift tasks, update
information into working memory, and inhibit
responses.47-48 EF has been well-researched in
children with SDB.11,14,16-17,20,21,46 Compared to
normative data, most studies report average abilities to plan and
monitor tasks,11,17,21 think
flexibly,16 problem-solve
effectively,20 and sequence tasks.21Other studies reported impairments in these same
domains.14,46 One recent study reported that children
with SDB fell in the bottom 25% on tasks that measured mental
flexibility and problem solving compared to normative
data.46 Another study supported these results with
findings of reduced problem-solving abilities in children with SDB,
compared to normative data.14
Multiple studies that included a control group reported differences in
EF capabilities for children with and without SDB. In some studies, SDB
groups performed worse than controls in general attention/EF
domains,17,19 specific planning and monitoring
tasks,9,17 and efficiency tasks.14Other studies found no differences on measures of
planning,14,21 organization,14,21and verbal fluency.14 A recent meta-analysis
investigated differences in EF between children with SDB and controls.
They reported a medium effect size in the domain of
generativity.49 No significant differences were found
on standardized measures of inhibition, working memory, shifting, or
vigilance.49
Studies that investigated the influence of SDB severity level on EF
reported more errors on cancellation tasks in children with mild,
compared to moderate SDB,16 and greater impairment on
problem-solving tasks in individuals with severe compared to moderate or
mild SDB.11 Others reported no differences across SDB
severity levels for sequencing,21 planning,11,14 and organizing.11,14Therefore, preliminary research suggests that children with all levels
of EF severity may demonstrate reduced executive abilities in domains
including but not limited to planning, organizing, inhibition, and
problem solving.
Numerous studies investigated associations between SDB respiratory
parameters and EF deficits. Some studies reported no association between
respiratory parameters and EF.5,14 Other studies
reported that a higher arousal index was associated with decreased
mental flexibility,20 planning,17organization,17 difficulty solving complex
tasks,46 and increased reaction
time.46 Additional respiratory parameters such as
AHI,20 slow wave activity,46 and
oxygen desaturation46 have also been related to
executive dysfunction in this population. Taken together, the literature
indicates that sleep duration and indices of respiratory status are
associated with executive dysfunction across multiple domains in
children with SDB.
Kaihua et al50 investigated indicators of executive
dysfunction in children with SDB using event related potentials (ERP).
Using an electroencephalograph (EEG), the authors measured two
constituents of ERP (N2 and P3 amplitude and latency) while children
were completing a Go/No Go task.50 During the Go task,
children with SDB demonstrated elevated amplitude and latency of P3,
indicating a higher level of attentional investment and delayed response
time compared to controls.50 During the NoGo task,
children with SDB demonstrated reduced N2 amplitude and increased P3
latency, indicating reduced impulse inhibition and longer response time
compared to controls.50 This suggests that children
with SDB require additional time and additional attentional capacity to
complete inhibitory tasks, compared to children without
SDB.50 The authors conjectured that intermittent sleep
and hypoxia might influence neural circuitry in children with SDB,
contributing to the increasing amplitude and latency of P3 and decreased
amplitude of N2.50
There were large discrepancies in the literature regarding the impact of
SDB on EF. These discrepancies were likely influenced by limited sample
sizes,16,20,50 a large variety of EF measures, wide
ranging discrepancies in SDB definitions and criteria, and lack of
control for important covariates including BMI16 and
SES.11 In addition, multiple studies recruited
participants at-risk for SDB through clinical
referrals,14,16,20,46,50 rather than the
community.11,17,19