Executive functions among youth with Down Syndrome and co-existing neurobehavioural disorders

The burden of epilepsy on long-term outcome of genetic developmental and epileptic encephalopathies: A single tertiary center longitudinal retrospective cohort study

BACKGROUND

This retrospective cohort analysis highlighted neurodevelopmental outcome predictors of genetic developmental and epileptic encephalopathies (DEE).

PATIENTS AND METHODS

Patients' demographic, clinical and molecular genetics data were collected. All patients underwent clinical, developmental, and neuropsychological assessments.

RESULTS

We recruited 100 participants (53 males, 47 females) with a mean follow-up lasting 10.46 ± 8.37 years. Age at epilepsy-onset was predictive of poor adaptive and cognitive functions (VABS-II score, r = 0.350, p = 0.001; BRIEF control subscale, r = -0.253; p = 0.031). Duration of epilepsy correlated negatively with IQ (r = -0.234, p = 0.019) and VABS-II score (r = -0.367, p = 0.001). Correlations were found between delayed/lacking EEG maturation/organization and IQ (r = 0.587, p = 0.001), VABS-II score (r = 0.658, p = 0.001), BRIEF-MI and BRIEF-GEC scores (r = -0.375, p = 0.001; r = -0.236, p = 0.033), ASEBA anxiety (r = -0.220, p = 0.047) and ADHD (r = -0.233, p = 0.035) scores. The number of antiseizure medications (ASMs) correlated with IQ (r = -0.414, p = 0.001), VABS-II (r = -0.496, p = 0.001), and BRIEF-MI (r = 0.294, p = 0.012) scores; while age at the beginning of therapy with ASEBA anxiety score (r = 0.272, p = 0.013). The occurrence of status epilepticus was associated with worse adaptive performances. The linear regression analysis model showed that delayed/lacking EEG maturation/organization had a significant influence on the IQ (R2 = 0.252, p < 0.001) and the BRIEF-GEC variability (R2 = 0.042, p = 0.036). The delayed/lacking EEG maturation/organization and the duration of epilepsy also had a significant influence on the VABS-II score (R2 = 0.455, p = 0.005).

CONCLUSIONS

Age at seizure-onset, EEG maturation/organization, duration of epilepsy, occurrence of status epilepticus, age at the introduction and number of ASMs used are reliable predictors of long-term outcomes in patients with genetic DEE.

Implications of Using the BRIEF-Preschool With School-Age Children With Down Syndrome

This study evaluated the appropriateness of scoring the Behavior Rating Inventory of Executive Function-Preschool (BRIEF-P) using age-equivalent scores generated from multiple measures of cognition and language among school-age children with Down syndrome (DS). Subscale T scores for 95 children with DS were contrasted using standard scoring on the Behavior Rating Inventory of Executive Function-Second edition (BRIEF-2; based on chronological age) to alternate scoring using the BRIEF-P (based on age-equivalent) for patterns of subscale intercorrelations, differences in mean scores, and agreement on findings from clinical cut-off scores. Results with children with DS suggested using (1) the BRIEF-P for children ages 2-5 years old, (2) the BRIEF-2 with chronological-age scoring or the BRIEF-P with age-equivalent scoring (with some caveats) for research on children ages 5-10 years old, and (3) the BRIEF-2 for children ages 11 and older.

The Association between Executive Function and Performing Instrumental Daily Activities in People with Intellectual Disabilities

Institutionalized individuals with intellectual disabilities have few opportunities to participate in instrumental activities of daily living (IADLs), which probably affects higher cognitive functions, or vice versa. The objectives of this study were to evaluate the possible difference in the ability to perform IADLs and executive functioning between individuals with and without intellectual disabilities and to determine if executive functions are associated with the performance of IADLs in people with intellectual disabilities. This was a multi-center cross-sectional study, conducted between July 2019 and May 2020. Participants with intellectual disabilities were recruited from four centers for people with intellectual disabilities. Adults without these disabilities were gathered from several community centers. The sample consisted of 90 individuals with moderate intellectual disabilities and 79 individuals with no intellectual disability. Executive functions were evaluated using the Wechsler Adult Intelligence Scale-WAIS-IV, the INECO Frontal Screening test, the Semantic Verbal Fluency Test, and the Behavioural Assessment of the Dysexecutive Syndrome-BADS-Scale. The performance of the IADLs was assessed by the Lawton and Brody Scale. The results showed that the higher the function in instrumental activities, the lower the impairment of executive functions. Executive functions accounted for 81% of the total variance in the ability to perform the IADLs. In conclusion, individuals with moderate intellectual disabilities demonstrated limitations in executing the IADLs, which were partially associated with low performance in executive functions. This information could help in the development of evidence-based intervention programs and facilitate the formulation of appropriate support strategies to enhance participation in these activities.

The Executive Function Account of Repetitive Behavior: Evidence From Rubinstein-Taybi Syndrome

In this study, we focus on Rubinstein-Taybi syndrome (RTS) to explore the associations between executive function deficits and repetitive behaviors. Thirty individuals with RTS completed direct assessments of inhibition, working memory and set-shifting. Informants completed repetitive behavior and executive function questionnaires. Repetitive questions were associated with poorer inhibition and working memory. Stereotypy was associated with poorer inhibition. Adherence to routines was associated with poorer set-shifting, but only on the parental report measure. No other associations were evident. There is evidence of an association between specific repetitive behaviors and executive functioning in RTS, suggesting executive dysfunction may underpin behavioral difference in RTS. The findings point towards specific associations that are of interest for further research across populations in which repetitive behaviors are present.

Executive functions and adaptive behaviour in individuals with Down syndrome

BACKGROUND

Previous research has explored executive functions (EFs) and adaptive behaviour in children and adolescents with Down syndrome (DS), but there is a paucity of research on the relationship between the two in this population. This study aims to shed light on the profile of EFs and adaptive behaviour in DS, exploring the differences by age and investigating the relationship between these two domains.

METHOD

Parents/caregivers of 100 individuals with DS from 3 to 16 years old participated in the study. The sample was divided into preschoolers (3-6.11 years old) and school-age children (7-16 years old). Parents/caregivers completed either the Preschool Version of the Behaviour Rating Inventory of Executive Function (for children 2-6.11 years old) or the Second Edition of the same Inventory (for individuals 7 + years old). Adaptive behaviour was assessed with the Vineland Adaptive Behaviour Scale - Interview, Second Edition.

RESULTS

Findings suggest that individuals with DS have overall difficulties, but also patterns of strength and weakness in their EFs and adaptive behaviour. The preschool-age and school-age children's EF profiles differed slightly. While both age groups showed Emotional Control as a relative strength and Working Memory as a weakness, the school-age group revealed further weaknesses in Shift and Plan/Organise. As concerns adaptive behaviour, the profiles were similar in the two age groups, with Socialisation as a strength, and Communication and Daily Living Skills as weaknesses, but with a tendency for preschoolers to obtain intermediate scores for the latter. When the relationship between EFs and adaptive behaviour was explored, Working Memory predicted Communication in the younger group, while in the older group the predictors varied, depending on the adaptive domains: Working Memory was a predictor of Communication, Inhibit of Daily Living Skills, and Inhibit and Shift of Socialisation.

CONCLUSION

As well as elucidating the EF profiles and adaptive behaviour in individuals with DS by age, this study points to the role of EFs in adaptive functioning, providing important information for targeted interventions.

Executive functions and their relationship with intellectual capacity and age in schoolchildren with intellectual disability

BACKGROUND

There is certain empirical evidence of, on the one hand, a positive correlation between executive functions (EFs) and intelligence in people with intellectual disability (ID) and, on the other hand, a slower rate of development of EFs in these people relative to people without ID. This evidence is not, however, unequivocal, and further studies are required.

METHODS

We analysed the relationship between development of EFs and both age and intellectual capacity, in a sample of 106 students with either ID or borderline intellectual functioning (BIF) at a special education centre [63 boys and 43 girls, 11-18 years old, mean total intelligence quotient (TIQ) of 59.6]. We applied nine instruments to evaluate both neuropsychological development (working memory, inhibitory control, cognitive flexibility, planning, processing speed and verbal fluency) and behavioural development [teachers' perceptions of the EFs of their students by Behavior Rating Inventory of Executive Function - Second Edition (BRIEF-2) School]. ID and BIF groups were statistically compared in terms of mean performance measures in EF tests. We looked at the correlation between EFs and age, and correlations between EFs and intelligence: TIQ, fluid intelligence [measured by the perceptual reasoning (PR) sub-index of Wechsler Intelligence Scale for Children-IV (WISC-IV)] and crystallised intelligence (measured by the verbal comprehension (VC) sub-index of WISC-IV). Regression models were built for variables with strong correlation.

RESULTS

In most of the tests used to evaluate EFs, the ID subgroup performed significantly worse than the subgroup with BIF. In general, teachers' thought that participants had 'medium-low' levels of EFs. TIQ, by WISC-IV scale, correlated significantly with scores in all tests for all EFs. The PR sub-index correlated significantly with 14 of the tests for EFs; 35% of the variation in PR can be explained by variation in performance in Picture Span (working memory) and Mazes (planning). The VC sub-index correlated weakly with seven of the EF tests. We found significant correlations in the ID group between age and scores in all tests of working memory and inhibitory control. Age - considering all participants - did not correlate with any of the variables of teachers' perception except for working memory, and this correlation was not strong.

CONCLUSIONS

The results of our study are consistent with descriptions of the typical population: (1) fluid intelligence is more related to EFs than crystallised intelligence is; and (2) working memory capacity is the EF most strongly related with general, fluid and crystallised forms of intelligence. The results suggest that as children and adolescents with ID/BIF get older, their capacities for working memory and inhibitory control increase; development of the other EFs studied was less evident. Teachers' perceptions of the EFs of children with ID or BIF were independent of intellectual capacity and age. More research is needed to delve further into the development of EFs in people with ID/BIF.

Factor structure of the BRIEF-P teacher version in a sample of Bosnian preschool children with intellectual disability

Executive functions (EF) play a key role in child's development as they are necessary prerequisites for everyday functioning and later academic success. Much research has been directed at examining whether EF are unidimensional or multidimensional construct. In this study, we tested two theoretically driven models and one mathematically driven EF model based on the Behavior Rating Inventory of Executive Functions - Preschool Edition (BRIEF-P). The sample for this study consisted of 102 children with intellectual disability (77 boys, 25 girls), aged 40-71 months (mean age- 62.1 months, SD- 7.6 months). Early childhood special education teachers completed the BRIEF-P Teacher Version. Confirmatory Factor Analysis was used to assess the validity of different EF models. The original BRIEF-P, with a second-order, three-factor model and one-factor model were not a good fit to the data. Mathematically driven one-factor model, with the addition of correlated errors between the scales of working memory and shift, and working memory and plan/organize was a good model fit. The current study indicates that EF differentiation begins to emerge at preschool age in children with intellectual disabilities. Understanding EF structure in children with intellectual disability will help create better intervention programs for this population.

Attachment representations among school-age children with intellectual disability

BACKGROUND

Research data documenting a high risk of insecure and disorganized attachment among children with intellectual disability (ID) in infancy and early childhood raises the question of mutual influences between ID and attachment in later childhood.

AIMS

The objectives of the present study were to examine attachment among school-age children with ID and whether attachment varies according to level of intellectual functioning, adaptative functioning, and presence of a genetic syndrome (i.e. Down syndrome).

METHODS

Attachment among 54 children with ID aged 8-12 years (30 with Down Syndrome, 24 with non-specific ID) was assessed using the Attachment Story Completion Task, and compared with that of 108 typically developing children, 54 of the same chronological age and 54 of the same mental age.

OUTCOMES

Results show (1) less security among children with ID than among same-age controls (2) more disorganization among children with ID compared to the two control groups, (3) a link between attachment disorganization and level of adaptive functioning among children with ID and (4) no difference in attachment between children with DS and children with non-specific ID.

CONCLUSIONS

Children with ID remain vulnerable to disorganization during late childhood. More research is needed to understand the factors underlying disorganized attachment representations.

Relationship Between Parent and Teacher Reported Executive Functioning and Maladaptive Behaviors in Children With Down Syndrome

The current study evaluates the concurrent relationship between parent ratings of executive functioning and maladaptive behavior among children and adolescents with Down syndrome and then repeats this evaluation using teacher reports. Parents and teachers of 63 school-age children with Down syndrome rated the child's executive functioning (Behavior Rating Inventory of Executive Function) and behaviors (Achenbach Child Behavior Checklist). For parent and teacher ratings, elevated behavior dysregulation predicted higher levels of rule-breaking, aggressive, and externalizing behavior. For teacher ratings, elevated behavior dysregulation also predicted higher levels of inattention problems. Among both parent and teacher ratings, greater metacognitive difficulties predicted challenges with attention. Understanding the relationship between these constructs has important implications for targets of intervention and developing preventative strategies.

Opportunities, barriers, and recommendations in down syndrome research

BACKGROUND

Recent advances in medical care have increased life expectancy and improved the quality of life for people with Down syndrome (DS). These advances are the result of both pre-clinical and clinical research but much about DS is still poorly understood. In 2020, the NIH announced their plan to update their DS research plan and requested input from the scientific and advocacy community.

OBJECTIVE

The National Down Syndrome Society (NDSS) and the LuMind IDSC Foundation worked together with scientific and medical experts to develop recommendations for the NIH research plan.

METHODS

NDSS and LuMind IDSC assembled over 50 experts across multiple disciplines and organized them in eleven working groups focused on specific issues for people with DS.

RESULTS

This review article summarizes the research gaps and recommendations that have the potential to improve the health and quality of life for people with DS within the next decade.

CONCLUSIONS

This review highlights many of the scientific gaps that exist in DS research. Based on these gaps, a multidisciplinary group of DS experts has made recommendations to advance DS research. This paper may also aid policymakers and the DS community to build a comprehensive national DS research strategy.

Executive function in down syndrome children in Bogotá, Colombia

The study aim was to characterize executive function in 114 children with Down syndrome from a reference institution in Bogotá, Colombia. Children were screened with the Battelle Developmental Inventory to establish their developmental age. Eighty children with an equivalent mental age of 2–5.11 years were allocated to groups of 20 according to their mental age. Parents and teachers then completed the Behavior Rating Inventory of Executive Function-Preschool Version. We found a high variability and a low correlation between parent and teacher ratings. In general, children showed a specific profile characterized by weakness in the domains of working memory, shifting, planning, and organization, and strengths in the emotional control domain. These findings indicate a characteristic pattern of executive function in children with Down syndrome. This profile could form the basis for the planning of clinical assessment programs.

Systematic Review of Recent Pediatric Down Syndrome Neuropsychology Literature: Considerations for Regression Assessment and Monitoring

OBJECTIVES

To conduct a systematic review of recent pediatric Down syndrome (DS) neuropsychology research that may be useful to clinicians and researchers examining regression in this population.

METHODS

We reviewed original peer-reviewed articles published between 2013 and 2018 studying neuropsychological profiles in DS.

RESULTS

Thirty-one articles (of 1231 included in the original search) passed all inclusion criteria, were evaluated for bias, and were included in the analysis.

CONCLUSION

Findings argued against a single "DS profile" and revealed multiple within-group differences as well as expected and unexpected differences relative to typically developing children and children with other intellectual and developmental disabilities. Areas identified as most germane to regression monitoring included working memory, inhibition, letter and word identification, navigational route learning, motor skills (when strong at baseline), single word receptive/expressive vocabulary, and adaptive function.

Different abilities needed at home and school: The relation between executive function and adaptive behaviour in adolescents with Down syndrome

Studies have shown that executive function abilities are related and have predictive power over adaptive behaviour in both typical and atypical populations. This study examined the relationship between executive functioning and adaptive behaviour in adolescents with Down syndrome, as it has not been studied before in this population. We propose and test a model of how each core EF (i.e., working memory, inhibition, and flexibility) contributes to each domain of AB (i.e., conceptual, social, and practical). We found that parent reported Conceptual skills were related to working memory, while teacher reported Conceptual and Practical skills were related to inhibition and flexibility. We hypothesise that these findings are related to the different requirements and expectations of the home and school environments: the more predictable home environment requires the adolescent to rely on working memory for his everyday activities, while the changing and challenging school environment requires the inhibition common behaviours and to flexibly change actions to be successful.

Reliability of Informant-Report Measures of Executive Functioning in Children With Down Syndrome

The current study evaluates the psychometric properties of the Behavior Rating Inventory of Executive Function (BRIEF) with children with Down syndrome. Caregivers of 84 children with Down syndrome rated their child's behavior with the BRIEF. Teacher ratings were obtained for 57 children. About 40% of children with Down syndrome were reported by parents, and 70% by teachers, to exhibit clinically significant challenges with executive functioning. Distribution of scores was normal, internal consistency for subscales was questionable to primarily excellent, and inter-rater reliability was poor to good. Normative data conversions controlled for age, IQ, and gender differences, with some exceptions. The study findings suggest that the BRIEF and its subscales generally performed in a psychometrically sound manner among children with Down syndrome.

Adaptive behaviour, executive function and employment in adults with Down syndrome

BACKGROUND

Individuals with Down syndrome (DS) demonstrate difficulties with aspects of executive function (EF) and adaptive behaviour across the lifespan. There is a current lack of information regarding how these difficulties relate to employment outcomes in adulthood. This study evaluated the adaptive behaviour and EF profiles of individuals with DS during early adulthood and the association between these areas of functioning and employment status.

METHODS

Parents or caregivers of primarily young adults with DS (n = 31; mean chronological age = 25.9 years; SD = 5.92) completed the Vineland Adaptive Behavior Scales - Second Edition the Behavior Rating Inventory of Executive Function - Adult version and a demographic questionnaire that requested information regarding adult employment status.

RESULTS

Findings indicated a distinct pattern of relative strengths and challenges in adaptive behaviour and EF. In addition, the EF sub-domain of working memory was a significant predictor of employment status.

CONCLUSIONS

Specific aspects of the DS cognitive profile may have an important influence on employment status in primarily young adults with DS. Implications for interventions are discussed.

A cross-sectional analysis of executive function in Down syndrome from 2 to 35 years

BACKGROUND

Previous research has indicated a unique profile of executive function (EF) in children and adolescents with Down syndrome (DS). However, there is a paucity of research on EF in adults with DS. This study aimed to gain a broader understanding of strengths and weaknesses in EF in DS from 2 to 35 years.

METHOD

Parents of 112 individuals with DS between 2 and 35 years participated in this study. Parents either completed the Behaviour Rating Inventory of Executive Function - for individuals 6+ years - or the Behaviour Rating Inventory of Executive Function Preschool Version - for children 2-5 years.

RESULTS

Results suggest not only overall difficulties but also patterns of strength and weakness within EF for individuals with DS. For the 2 to 5-year-old group, emotional control and shift were relative strengths, planning/organisation and inhibit were intermediate skills, and working memory was a relative weakness. For the 6 to 18-year-old group, emotional control and organisation of materials were relative strengths, inhibit and initiate were intermediate skills, and working memory, monitor, planning/organisation, and shift were relative weaknesses. Most abilities were consistent from 2 to 18 years, except shift, which decreased in preadolescence before beginning to recover in adolescence. Across the full age range (2-35 years), composite scores indicated quadratic trends in inhibit, working memory, and planning/organisation, and a cubic trend in shift, with EF abilities generally declining in middle childhood before recovering in adulthood.

CONCLUSIONS

This study extends previous research on EF in DS by providing an initial description of EF profiles across the lifespan. More longitudinal and behavioural research is needed to further characterise the development of EF in DS.

Executive functioning in Cornelia de Lange syndrome: domain asynchrony and age-related performance

BACKGROUND

The aim of this study was to examine executive functioning in adolescents and adults with Cornelia de Lange syndrome (CdLS) to identify a syndrome and age-related profile of cognitive impairment.

METHODS

Participants were 24 individuals with CdLS aged 13-42 years (M = 22; SD = 8.98), and a comparable contrast group of 21 individuals with Down syndrome (DS) aged 15-33 years (M = 24; SD = 5.82). Measures were selected to test verbal and visual fluency, inhibition, perseverance/flexibility, and working memory and comprised both questionnaire and performance tests.

RESULTS

Individuals with CdLS showed significantly greater impairment on tasks requiring flexibility and inhibition (rule switch) and on forwards span capacity. These impairments were also reported in the parent/carer-rated questionnaire measures. Backwards Digit Span was significantly negatively correlated with chronological age in CdLS, indicating increased deficits with age. This was not identified in individuals with DS.

CONCLUSIONS

The relative deficits in executive functioning task performance are important in understanding the behavioural phenotype of CdLS. Prospective longitudinal follow-up is required to examine further the changes in executive functioning with age and if these map onto observed changes in behaviour in CdLS. Links with recent research indicating heightened responses to oxidative stress in CdLS may also be important.

The Behavior Rating Inventory of Executive Function and Continuous Performance Test in Preschoolers with Attention Deficit Hyperactivity Disorder

OBJECTIVE

The aim of this study is to examine performance-based measures and behavioral ratings of executive functions (EF) as a component of preschool attention deficit hyperactivity disorder (ADHD).

METHODS

Twenty-one 4-to-6-year-old children with ADHD and 52 children with no psychopathology, matched on age, gender, socioeconomic status, and parental education, were enrolled. Parents were interviewed with the use of The Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime version. The Conners' Kiddie Continuous Performance Test (K-CPT) was administered to the children, and the Behavior Rating Inventory of Executive Function-Preschool version (BRIEF-P) and the Conners' Parent Rating Scale-Revised/Short Form (CPRS-R/S) were filled out by the parents.

RESULTS

All BRIEF-P and CPRS-R/S scores, the K-CPT measures of inattention and impulsivity were higher in the ADHD group. The CPRS-R/S ADHD index was strongly correlated with inhibition and related indexes in the BRIEF-P and was moderately correlated with inattention measures in the K-CPT.

CONCLUSION

The current study is one of the few to investigate the features of preschool ADHD with the use of behavioral ratings of EF and a performance-based measure. Our results suggest that the BRIEF-P was able to identify behavioral difficulties in inhibition and working memory and that the K-CPT identified difficulties indicating inattention. The findings of this study support the use of a combination of methods for a complete evaluation of preschoolers with inattentive and hyperactive/impulsive behavior, the application of rating scales for screening ADHD symptoms, and the measurement of behavioral correlates of EF, along with performance-based measures.

The Arizona Cognitive Test Battery for Down Syndrome: Test-Retest Reliability and Practice Effects

A multisite study investigated the test-retest reliability and practice effects of a battery of assessments to measure neurocognitive function in individuals with Down syndrome (DS). The study aimed to establish the appropriateness of these measures as potential endpoints for clinical trials. Neurocognitive tasks and parent report measures comprising the Arizona Cognitive Test Battery (ACTB) were administered to 54 young participants with DS (7-20 years of age) with mild to moderate levels of intellectual disability in an initial baseline evaluation and a follow-up assessment 3 months later. Although revisions to ACTB measures are indicated, results demonstrate adequate levels of reliability and resistance to practice effects for some measures. The ACTB offers viable options for repeated testing of memory, motor planning, behavioral regulation, and attention. Alternative measures of executive functioning are required.

Physiological substrates of executive functioning: a systematic review of the literature

Executive function (EF) is a multifaceted construct that has been defined as a set of higher-order cognitive processes that allow for flexibility, self-regulation, strategic planning, and goal-directed behaviors. EFs have been studied in numerous clinical disorders using a variety of neuropsychological tasks and, more recently, neuroimaging techniques. The underlying physiological substrates of EF were historically attributed to the frontal lobes; however, recent studies suggest more widespread involvement of additional brain regions. The purpose of the present study was to conduct a systematic review (using PRISMA 2009 guidelines) of neuroimaging studies employing functional magnetic resonance imaging and diffusion tensor imaging methods investigating the physiological substrates of EFs in attention-deficit/hyperactivity disorder compared to other clinical groups and non-clinical participants. Research articles were retrieved using PsycINFO, PsycARTICLES, MEDLINE, and ScienceDirect, beginning February 2015 through May 2016. A total of 42 studies met eligibility. Of those 42 studies, 22 studies included clinical participants and 20 studies included non-clinical participants. Results revealed increased activation of the frontal brain region in the majority of non-clinical studies and approximately 50% of the clinical studies, albeit with some inconsistencies across subregions, tasks, and age groups. Implications, methodological limitations, and suggestions for future research are discussed.

Longitudinal measures of cognition in the Ts65Dn mouse: Refining windows and defining modalities for therapeutic intervention in Down syndrome

Mouse models have provided insights into adult changes in learning and memory in Down syndrome, but an in-depth assessment of how these abnormalities develop over time has never been conducted. To address this shortcoming, we conducted a longitudinal behavioral study from birth until late adulthood in the Ts65Dn mouse model to measure the emergence and continuity of learning and memory deficits in individuals with a broad array of tests. Our results demonstrate for the first time that the pace at which neonatal and perinatal milestones are acquired is correlated with later cognitive performance as an adult. In addition, we find that life-long behavioral indexing stratifies mice within each genotype. Our expanded assessment reveals that diminished cognitive flexibility, as measured by reversal learning, is the most robust learning and memory impairment in both young and old Ts65Dn mice. Moreover, we find that reversal learning degrades with age and is therefore a useful biomarker for studying age-related decline in cognitive ability. Altogether, our results indicate that preclinical studies aiming to restore cognitive function in Ts65Dn should target both neonatal milestones and reversal learning in adulthood. Here we provide the quantitative framework for this type of approach.