Nelson Butters Award Recipients

Mild cognitive impairment (MCI) in non-clinic samples often have high prevalence and unclear predictive validity for dementia risk. We used longitudinal data from a communitybased cohort to evaluate whether MCI stability over two years reliably identified people who would develop dementia.

Ample empirical evidence exists for executive deficits in schoolchildren with developmental language disorder (DLD). Little is known though about EF in preschoolers with DLD. Since early childhood is the primary period for both language and EF to develop, the early development of language and EF plausibly interact in an empowering or inhibitive way (see Vissers et al., 2015). Therefore, to come to insight into the aetiology of DLD, research on early EF and language development is necessary.

Impaired fear learning and memory are core features of post traumatic stress disorder (PTSD) that are subserved by the hippocampus. Some, but not all, studies report smaller hippocampal volumes in PTSD patients compared to controls, and this inconsistency may reflect underlying differences in hippocampal subregions across cohorts. We tested this in an international sample of patients and controls in the PGC-ENIGMA PTSD Working Group.

Seven participants (32%) were carriers of the APOE4, while 15 (68%) were not. Bootstrapped between-group tests indicated that APOE4 carriers evidenced accelerated decline in processing speed (p=.016) and global cognition (p=.007) compared with non-carriers. Furthermore, trends were found for working memory (p=.065) and verbal fluency (p=.062). A trend towards increased inflammatory response was observed in carriers of APOE4 (p=.054).

In prior studies (Nair et al., 2013; Nair et al., 2015), we demonstrated that children with autism showed mostly reduced connectivity especially for prefrontal-thalamic networks, accompanied by overconnectivity within temporal-thalamic networks. Given the importance of early identification of biomarkers and endophenotypes of autism, it is crucial to understand how early in the developmental process these differences in thalamocortical networks emerge.

Best Submission By A Postdoctoral Fellow

Previous research has demonstrated heterogeneity in neuropsychological performance and biomarker profiles within MCI samples. We previously identified four empirically-derived MCI subtypes within the Alzheimer’s Disease Neuroimaging Initiative (ADNI) MCI cohort: amnestic MCI, dysnomic MCI, dysexecutive/mixed MCI, and a large cluster-derived normal group (34%) that was characterized by intact neuropsychological performance (despite their MCI diagnosis). The current study investigated cortical thickness profiles in these four cognitive subtypes.

Traumatic brain injury (TBI) is believed to result in alterations in functional connectivity in intrinsically connected networks. One such network is the default mode network (DMN), which displays increased activation in absence of an externally-imposed task and decreased activation during cognitively demanding tasks. Studying factors associated with post-TBI functional connectivity in the DMN may help further elucidate the role of this network, as well as the effects of TBI on functional connectivity in general.

The goal of this presentation is to provide a critical overview of the current approaches used to examine functional brain connectivity in neurologically impaired samples. There is now a growing literature using functional imaging methods to examine brain network changes and it is a goal in this presentation to offer a critique of the current methods used to examine brain pathology and aging including possible pitfalls and advantages of each approach.

Presented for the Best Submission by a Postdoctoral Fellow

Transcranial Direct Current Stimulation Changes Frontoparietal Control Network Connectivity Associated with Working Memory Performance in High-Functioning Autism

Presented for the Best Submission by a Postdoctoral Fellow

Cognitive Abilities of Children Prenatally Exposed to Opiates and Polysubstances: A Longitudinal Study