Development and validation of the Arizona Cognitive Test Battery for Down syndrome

Abstract

Neurocognitive assessment in individuals with intellectual disabilities requires a well-validated test battery. To meet this need, the Arizona Cognitive Test Battery (ACTB) has been developed specifically to assess the cognitive phenotype in Down syndrome (DS). The ACTB includes neuropsychological assessments chosen to 1) assess a range of skills, 2) be non-verbal so as to not confound the neuropsychological assessment with language demands, 3) have distributional properties appropriate for research studies to identify genetic modifiers of variation, 4) show sensitivity to within and between sample differences, 5) have specific correlates with brain function, and 6) be applicable to a wide age range and across contexts. The ACTB includes tests of general cognitive ability and prefrontal, hippocampal and cerebellar function. These tasks were drawn from the Cambridge Neuropsychological Testing Automated Battery (CANTAB) and other established paradigms. Alongside the cognitive testing battery we administered benchmark and parent-report assessments of cognition and behavior. Individuals with DS (n = 74, ages 7–38 years) and mental age (MA) matched controls (n = 50, ages 3–8 years) were tested across 3 sites. A subsample of these groups were used for between-group comparisons, including 55 individuals with DS and 36 mental age matched controls. The ACTB allows for low floor performance levels and participant loss. Floor effects were greater in younger children. Individuals with DS were impaired on a number ACTB tests in comparison to a MA-matched sample, with some areas of spared ability, particularly on tests requiring extensive motor coordination. Battery measures correlated with parent report of behavior and development. The ACTB provided consistent results across contexts, including home vs. lab visits, cross-site, and among individuals with a wide range of socio-economic backgrounds and differences in ethnicity. The ACTB will be useful in a range of outcome studies, including clinical trials and the identification of important genetic components of cognitive disability.

Does the Cambridge Automated Neuropsychological Test Battery (CANTAB) Distinguish Between Cognitive Domains in Healthy Older Adults?

“…Alzheimer's disease (Saunders & Summers, 2010), epilepsy (Torgersen et al, 2012), ADHD (Gau & Shang, 2010), Down syndrome (Edgin et al, 2010), and various central nervous system diseases (Roque et al, 2011) and on the basis of clinical cut-off scores in those with epilepsy (Torgersen et al, 2012). However, as CANTAB tests were not specifically designed with the purpose of measuring discrete cognitive functions, it is not surprising that not all of the tests included in the current battery coalesce with the cognitive domains from a traditional battery.…”

Obstructive sleep apnea syndrome and cognition in Down syndrome

“…The range of IQ (median=42.00, interquartile range [IQR]=9.0) was similar to previous studies of Down syndrome. 16 Each child was monitored with PSG off-site at his or her place of residence. Tests selected from the ACTB were administered within 3 months of the sleep measurements by research staff.…”

“…In the present study we used PSG to examine the correspondence between OSAS, defined by AHI, and cognition in children with Down syndrome as measured by the Arizona Cognitive Test Battery (ACTB), a battery specifically designed for this population. 16 We also examined which aspects of sleep physiology are most influenced by OSAS in Down syndrome. We hypothesized that OSAS would relate to areas of cognition shown to be impaired in previous studies, including executive function, memory, and verbal learning.…”

“…hippocampal and prefrontal dependent) that are described fully elsewhere. 16 Each participant was assessed by a trained psychometrician blind to the OSAS diagnosis. The following measures from the ACTB were included.…”

Cognitive mechanisms underlying Armoni: A computer-assisted cognitive training programme for individuals with intellectual disabilities

“…Because the measurement of cognitive abilities using conventional normative data is inappropriate for persons with ID due to substantial floor effects (Palmer, 2006;Edgin et al, 2010), only the direct scores on the neuropsychological tests and the outcome scores of the activities were considered for statistical analyses.…”