Public defence in Neuroscience and Biomedical Engineering, Lic.Sc. Eero Ahtola

Title of the thesis: Neurophysiological methods for evaluation of infants’ sensory processing

Doctoral student: Eero Ahtola
Opponent: Professor Petro Julkunen, University of Eastern Finland
Custos: Professor Matias Palva, Aalto University School of Science, Department of Neuroscience and Biomedical Engineering

Birth and early infancy are crucial phases for the later brain development. During the first months of life, infants rely on their developing senses to acquire cognitive and motor skills. Several neurological developmental disorders are linked to early sensory impairments that emerge already during infancy. However, early neurological assessments are challenging because tests designed for older children do not always capture the unique characteristics of younger babies’ brain function.

In this doctoral research, new neurophysiological methods were developed to provide objective information about the visual and sensorimotor systems in infants under one year of age. The methods incorporate electroencephalography (EEG) and eye tracking measurements, employing complex visual stimuli and repetitive hand movements. Sensory information processing was investigated by analyzing functional brain networks through advanced computational methods.
The key findings of the research are: i) infants show age-dependent gaze patterns when viewing different emotional facial expressions, ii) eye tracking can improve the analytic gain of the EEG-based studies of the visual system, and iii) newborn brain networks are activated by repetitive hand movements. The findings demonstrate widespread processing of visual and somatosensory information in the infant brain. Additionally, the characteristics of these brain networks are linked to a child's later cognitive development and the severity of potential brain injury at birth.

The dissertation provides new insights into the use of EEG and eye tracking in pediatric neurophysiological studies. Some of the developed methods hold potential for future clinical studies and practical applications. Specific use cases could be found in pediatric neurology, neonatology, and developmental psychology. The computational frameworks developed in this research are also broadly applicable to other sensory assessments and across different ages.
The research contributes to ongoing efforts to integrate cutting-edge computational and technical solutions into neurophysiological diagnostics, while also addressing the need for reliable novel biomarkers for evaluating brain development. Although further studies with larger cohorts are necessary, the dissertation represents a significant step toward the clinical implementation of the new methods.

Keywords: Electroencephalography, eye tracking, evoked responses, functional brain networks, sensory systems, brain development

Thesis available for public display 10 days prior to the defence at: https://aaltodoc.aalto.fi/doc_public/eonly/riiputus/ 

Yhteystiedot: eero.ahtola@aalto.fi 

Doctoral theses at the School of Science: https://aaltodoc.aalto.fi/handle/123456789/52