Signalling changes to individuals who show resistance to change can reduce challenging behaviour

Background & objectives Several neurodevelopmental disorders are associated with resistance to change and challenging behaviours – including temper outbursts – that ensue following changes to routines, plans or expectations (here, collectively: expectations). Here, a change signalling intervention was tested for proof of concept and potential practical effectiveness. Methods Twelve individuals with Prader-Willi syndrome participated in researcher- and caregiver-led pairing of a distinctive visual-verbal signal with subsequent changes to expectations. Specific expectations for a planned subset of five participants were systematically observed in minimally manipulated natural environments. Nine caregivers completed a temper outburst diary during a four week baseline period and a two week signalling evaluation period. Results Participants demonstrated consistently less temper outburst behaviour in the systematic observations when changes imposed to expectations were signalled, compared to when changes were not signalled. Four of the nine participants whose caregivers completed the behaviour diary demonstrated reliable reductions in temper outbursts between baseline and signalling evaluation. Limitations An active control group for the present initial evaluation of the signalling strategy using evidence from caregiver behaviour diaries was outside the scope of the present pilot study. Thus, findings cannot support the clinical efficacy of the present signalling approach. Conclusions Proof of concept evidence that reliable pairing of a distinctive cue with a subsequent change to expectation can reduce associated challenging behaviour is provided. Data provide additional support for the importance of specific practical steps in further evaluations of the change signalling approach.

Discovery of relict subglacial lakes and their geometry and mechanism of drainage

Recent proxy measurements reveal that subglacial lakes beneath modern ice sheets periodically store and release large volumes of water, providing an important but poorly understood influence on contemporary ice dynamics and mass balance. This is because direct observations of how lake drainage initiates and proceeds are lacking. Here we present physical evidence of the mechanism and geometry of lake drainage from the discovery of relict subglacial lakes formed during the last glaciation in Canada. These palaeo-subglacial lakes comprised shallow (<10 m) lenses of water perched behind ridges orientated transverse to ice flow. We show that lakes periodically drained through channels incised into bed substrate (canals). Canals sometimes trend into eskers that represent the depositional imprint of the last high-magnitude lake outburst. The subglacial lakes and channels are preserved on top of glacial lineations, indicating long-term re-organization of the subglacial drainage system and coupling to ice flow.

Characteristics of change triggered temper outbursts in children with PWS and ASD and how these may impact on the efficacy of behavioural intervention strategies.

Background
Temper outbursts are prevalent in individuals with PWS and are often triggered by unexpected changes to routines or plans. However, such outbursts are also common in individuals with several other neurodevelopmental disorders, including those with a diagnosis of autism spectrum disorder (ASD). We compared the profile of temper outbursts in children with PWS to that in children with ASD. We examined whether differences in the temper outburst profile predicted differences in the outcomes of two caregiver led intervention strategies aiming to reduce change triggered outbursts.
Methods and results
Thirteen 7-15 year olds with PWS – taking part in a larger study involving 60 children evidencing temper outbursts following changes – were individually matched for age to children with ASD (mean ages: 10.70; 10.76 yrs). Caregivers participated in a structured/semi-structured interview on children's outbursts; completed a web-based outburst diary over a 6 month baseline; and are currently using either a change signalling intervention to reliably warn children of forthcoming changes; or a planning ahead intervention to reduce children's exposure to unexpected changes.
As reported at interview, on average, children with PWS showed more frequent temper outbursts than those with ASD (closer to daily vs. weekly). For seven children with PWS and six with ASD, 60% or more of their temper outbursts were reported to be triggered by changes. Whilst outbursts had similar durations when triggered by changes or by other events in children with PWS; change triggered outbursts in children with ASD were generally shorter. The most commonly reported outburst components in children with PWS included indicators of heightened emotional arousal but this was not the case for children with ASD. Data on behavioural change associated with each of the intervention strategies will be discussed.
Conclusions
Change triggered temper outbursts can be a problem for children PWS and ASD, however subtle differences appear to exist in the profile of these outbursts. Some of these differences may be relevant for the expected efficacy of different behavioural intervention strategies that target outbursts.
Summary
Temper outbursts (tantrums) were compared in children with PWS or autism spectrum disorder before and during use of one of two helping strategies. Helping strategies were led by caregivers and aimed to reduce outbursts that follow changes to routines or plans by making such changes more predictable, or by reducing the quantity of changes. Characteristics of outbursts may be important to help us predict which helping strategies may be most effective.