UEL Baby Dev Lab

Attentional shifting and disengagement in Rett syndrome.

Rose, S. A., Wass, S., Jankowski, J. J., Feldman, J. F., & Djukic, A. 2019. Neuropsychology

Objective. The purpose of the present study was to deepen our understanding of attention (a core cognitive ability) in Rett syndrome (RTT), an x-linked neurodevelopmental disorder caused by mutations in the MECP2 gene. We focused on two key aspects of visual orienting--shifting and disengaging attention--both of which are critical for exploring the visual world. We used gaze-based measures and eye-tracking technology to minimize demands on the limited verbal and motor abilities associated with RTT. Method. Shifting and disengaging attention were examined in 31 children (2-12 years) with Rett Syndrome (RTT) and 31 age-matched typically-developing (TD) controls. Using the gap-overlap paradigm, the frequency/speed of shifting attention from a central to peripheral target were compared on Baseline trials, where the central stimulus disappears as the peripheral target appears, and Overlap trials, where the central stimulus remains, thus requiring disengagement. Results. Our findings revealed that children with RTT had more ‘sticky fixations’(p<.001). That is, they had fewer saccades to the peripheral target than TD children, and this was true on both baseline (77% vs 95%), and overlap trials (63% vs 90%); the younger ones also had slower saccadic reaction times (SRTs)(p=.04). Within the RTT group, SRTs correlated with symptom severity. Surprisingly, disengagement cost (the relative difference between gap and overlap SRTs) did not differ across groups. Conclusion. Our results suggest that children with Rett have difficulty shifting attention and, to a lesser extent, disengaging attention, whereas with other disorders, problems with disengagement are paramount.

Training attention control of very preterm infants: protocol for a feasibility study of the Attention Control Training (ACT).

Perra, O., Wass, S., McNulty, A., Sweet, D., Papageorgiou, K., Johnston, M., ... & Alderdice, F. 2020. Pilot and Feasibility Studies

Background: Children born preterm may display cognitive, learning, and behaviour difficulties as they grow up. In
particular, very premature birth (gestation age between 28 and less than 32 weeks) may put infants at increased risk
of intellectual deficits and attention deficit disorder. Evidence suggests that the basis of these problems may lie in
difficulties in the development of executive functions. One of the earliest executive functions to emerge around 1
year of age is the ability to control attention. An eye-tracking-based cognitive training programme to support this
emerging ability, the Attention Control Training (ACT), has been developed and tested with typically developing
infants. The aim of this study is to investigate the feasibility of using the ACT with healthy very preterm (VP) infants
when they are 12 months of age (corrected age). The ACT has the potential to address the need for supporting
emerging cognitive abilities of VP infants with an early intervention, which may capitalise on infants’ neural plasticity.
Methods/design: The feasibility study is designed to investigate whether it is possible to recruit and retain VP infants
and their families in a randomised trial that compares attention and social attention of trained infants against those
that are exposed to a control procedure. Feasibility issues include the referral/recruitment pathway, attendance, and
engagement with testing and training sessions, completion of tasks, retention in the study, acceptability of outcome
measures, quality of data collected (particularly, eye-tracking data). The results of the study will inform the development
of a larger randomised trial.
Discussion: Several lines of evidence emphasise the need to support emerging cognitive and learning abilities of
preterm infants using early interventions. However, early interventions with preterm infants, and particularly very
preterm ones, face difficulties in recruiting and retaining participants. These problems are also augmented by the
health vulnerability of this population. This feasibility study will provide the basis for informing the implementation of
an early cognitive intervention for very preterm infants.

Very preterm infants engage in an intervention to train their control of attention: results from the feasibility study of the Attention Control Training (ACT) randomised trial.

Perra, O., Wass, S., McNulty, A., Sweet, D., Papageorgiou, K. A., Johnston, M., ... & Alderdice, F. 2021. Pilot and Feasibility Studies

Background: Very premature birth (gestational age between 28 and 31 + 6 weeks) is associated with increased risk
of cognitive delay and attention deficit disorder, which have been linked to anomalies in the development of
executive functions (EFs) and their precursors. In particular, very preterm (VP) infants display anomalies in
controlling attention and gathering task-relevant information. Early interventions that support attention control may
be pivotal in providing a secure base for VP children’s later attainments. The Attention Control Training (ACT) is a
cognitive training intervention that targets infants’ abilities to select visual information according to varying task
demands but had not been tested in VP infants. We conducted a feasibility study to test the processes we intend
to use in a trial delivering the ACT to VP infants.
Methods and design: We tested recruitment and retention of VP infants and their families in a randomised trial, as
well as acceptability and completion of baseline and outcome measures. To evaluate these aims, we used
descriptive quantitative statistics and qualitative methods to analyse feedback from infants’ caregivers. We also
investigated the quality of eye-tracking data collected and indicators of infants’ engagement in the training, using
descriptive statistics. Results: Twelve VP infants were recruited, and 10 (83%) completed the study. Participants’ parents had high
education attainment. The rate of completion of baseline and outcome measures was optimal. VP infants
demonstrated engagement in the training, completing on average 84 min of training over three visits, and
displaying improved performance during this training. Eye-tracking data quality was moderate, but this did not
interfere with infants’ engagement in the training.

Impaired visual search in children with Rett syndrome.

Rose, S. A., Wass, S., Jankowski, J. J., Feldman, J. F., & Djukic, A. 2019. Pediatric Neurology

Aim: This study aims to investigate selective attention in Rett syndrome, a severely disabling neurodevelopmental disorder caused by mutations in the X-linked MECP2 gene.
Method: The sample included 28 females with Rett syndrome (RTT) and 32 age-matched typically
developing controls. We used a classic search task, in conjunction with eye-tracking technology. Each
trial included the target and several distractors. The distractors varied in number and differed from
targets in either a "single feature" (color or shape), creating a pop-out effect, or in a "conjunction of
features" (color and shape), requiring serial search. Children searched for the target in arrays containing
five or nine objects; trials ended when the target was fixated (or 4000 ms elapsed).
Results: Children with Rett syndrome had more difficulty finding the target than typically developing
children in both conditions (success rates less than 50% versus 80%) and their success rates were little
influenced by display size or age. Even when successful, children with RTT took significantly longer to
respond (392 to 574 ms longer), although saccadic latency differences were observed only in the singlefeature condition. Both groups showed the expected slowing of saccadic reaction times for larger arrays
in the conjunction-feature condition. Search failures in RTT were not related to symptom severity.
Conclusions: Our findings provide the first evidence that selective attention, the ability to focus on or
select a particular element or object in the environment, is compromised by Rett syndrome. They
reinforce the notion that gaze-based tasks hold promise for quantifying the cognitive phenotype of RTT

Sustained attention in the face of distractors: A study of children with Rett syndrome

Rose, S. A., Wass, S., Jankowski, J. J., Feldman, J. F., & Djukic, A. 2017. Neuropsychology

Objective. The object of the present study is to advance our understanding of the cognitive
profile of Rett Syndrome (RTT), an x-linked neurodevelopmental disorder caused by mutations
in the MECP2 gene. We focus on sustained attention, which plays a critical role in driving
cognitive growth, and use an innovative, gaze-based task that minimizes demands on the limited
verbal and motor abilities associated with RTT.
Method. The task required the ability to sustain attention on a visual target (a butterfly) whilst
inhibiting a prepotent response to look to moving distractors (trees and clouds) presented in the
peripheral visual field. The sample included children with RTT (N = 32) and their typically
developing (TD) counterparts (N = 32), aged 2-12 years.
Results. Our findings revealed that children with RTT had more difficulty sustaining attention
(with the TD group averaging 60% looking at the butterfly vs only 25% for the RTT group).
Furthermore, they showed that RTT was associated with difficulties in three fundamental factors
influencing sustained attention: engagement, distractibility, and re-engagement. The RTT group
was slower to engage, more distractible, and slower to re-engage.
Conclusion. Our findings suggest there may be a fundamental disruption to sustained attention
in RTT, identifies factors related to this impairment, and points to cognitive areas that could be
assessed in evaluating the usefulness of interventions.