Poster E11, Thursday, August 22, 2019, 3:45 – 5:30 pm, Restaurant Hall
Networks of attention and general processing speed as potential predictors of late talker outcomes
Anna Kautto1, Elina Mainela-Arnold1,2;1University of Turku, 2University of Toronto
The term “late talker” is used to refer to toddlers with late onset spoken words and small early vocabulary size in absence of other developmental or hearing impairments that would otherwise explain the delay. While some of these children appear to catch up by 5 years of age, some continue to develop long-term restrictions in language comprehension and production. It is commonly agreed that in late talkers under 4 years of age, it is difficult to predict which children continue to present long-term restrictions, requiring the use of label developmental language disorder (DLD, formerly specific language impairment) (Bishop et al. 2016; 2017). While the cause(s) of DLD are unknown, it has been suggested that capacity limitations, perhaps in the form of limitations in aspects of attention constrain language development (Leonard, 2014). Attention deficits are common in children with DLD which has been suggested to possibly arise from these areas of development sharing common neurobiological basis (Tomblin & Mueller, 2012). However, we know very little about capacity limitations in children with a history of late talking. In this study, we hypothesized that differences in attentional skills would modulate late talker outcomes so that small expressive vocabulary at 24 months combined with attentional difficulties would increase the risk for DLD. We used a visual Attention Network Test (ANT; Fan, McCandliss, Sommer, Raz & Posner, 2002) to compare subcomponents of attention in school-aged children with and without history of late talking. The ANT combines tasks of cued reaction time and the flanker task to evaluate alerting, orienting, and executive attention within a task. These three subcomponents of attention have been linked with neurobiological processes (Posner & Rothbart, 2007). Alerting is linked with thalamic, frontal, and parietal cortices as well as the neurotransmitter norepinephrine. Orienting is involved with posterior brain regions (superior parietal and temporal parietal junction), frontal eye fields, and the neurotransmitter acetylcholine. Executive attention is associated with the anterior cingulate, lateral prefrontal cortex, basal ganglia, and the neurotransmitter dopamine. 68 children (7;5–10;5) participated in this study, of which half had had expressive vocabulary below age expectations at 24 months of age. Performance on the ANT was examined as a function of vocabulary size at 24 months and performance on linguistic tests at school age. Counter to our hypothesis, Generalized Linear Mixed Models analyses suggested that effects of alerting, orienting and executive attention were not meaningfully associated with late talking and school-age language impairment status. However, general processing speed across all trials was significantly associated with school-age language impairment status, but not late talker status. These results indicate that poor school age language outcomes in late talkers are not associated with limitations in attention, but slow general processing speed instead. Following these behavioural results, we are currently examining the extent to which global white matter volumes are associated with persistence of language difficulties to better understand the neural processes in DLD.
Themes: Disorders: Developmental, Development
Method: Behavioral