Conducting head-mounted eye-tracking research with young children with autism and children with increased likelihood of later autism diagnosis.

BACKGROUND: Over the past years, researchers have been using head-mounted eye-tracking systems to study young children's gaze behaviors in everyday activities through which children learn about the world. This method has great potential to further our understanding of how millisecond-level gaze behaviors create multisensory experiences and fluctuate around social environments. While this line of work can yield insight into early perceptual experiences and potential learning mechanisms, the majority of the work is exclusively conducted with typically-developing children. Sensory sensitivities, social-communication difficulties, and challenging behaviors (e.g., disruption, elopement) are common among children with developmental disorders, and they may represent potential methodological challenges for collecting high-quality data. RESULTS: In this paper, we describe our research practices of using head-mounted eye trackers with 41 autistic children and 17 children with increased likelihood of later autism diagnosis without auditory or visual impairments, including those who are minimally or nonspeaking and/or have intellectual disabilities. The success rate in gathering data among children with autism was 92.68%. 3 of 41 children failed to complete the play-session, resulting in an 86.36% success rate among 1-4-year-olds and a 100.00% success rate among 5-8-year-olds. 1 of 17 children with increased likelihood of later autism diagnosis failed to complete the play-session, resulting in a success rate of 94.11%. There were numerous "challenging" behaviors relevant to the method. The most common challenging behaviors included taking the eye-tracking device off, elopement, and becoming distressed. Overall, among children with autism, 88.8% of 1-4-year-olds and 29.4% of 5-8-year-olds exhibited at least one challenging behavior. CONCLUSIONS: Research capitalizing on this methodology has the potential to reveal early, socially-mediated gaze behaviors that are relevant for autism screening, diagnosis, and intervention purposes. We hope that our efforts in documenting our study methodology will help researchers and clinicians effectively study early naturally-occuring gaze behaviors of children during non-experimental contexts across the spectrum and other developmental disabilities using head-mounted eye-tracking. Ultimately, such applications may increase the generalizability of results, better reflect the diversity of individual characteristics, and offer new ways in which this method can contribute to the field.

Evaluation of the polyethylene glycol precipitation method for the estimation of chicken high density lipoprotein cholesterol.

A neutral polymer precipitation procedure using polyethylene glycol 6000 (PEG) for fractionation of chicken plasma lipoproteins was optimized. Lipoprotein precipitation was dependent on PEG concentration and pH but was independent of PEG exposure time. A PEG concentration of 100 g/l (pH 8) precipitated chicken plasma very low density (VLDL) and low density (LDL) lipoproteins. Disc electrophoresis of supernates demonstrated that high density lipoprotein (HDL) was retained and LDL eliminated by PEG treatment of plasma. Gel filtration chromatography of whole plasma and PEG-treated supernatants on Bio-Gel A-5m demonstrated that HDL-cholesterol content of supernates was unchanged by PEG exposure, while VLDL-cholesterol was selectively removed.