Viljami Sairanen

Kanta-Häme Central Hospital, Finland

Infants are well known to seek eye contact, and they prefer to fixate on developmentally meaningful objects, such as the human face. It is also known, that visual abilities are important for the developmental cascades of cognition from later infancy to childhood. It is less understood, however, whether newborn visual abilities relate to later cogni...

Learning and speaking a second language (L2) may result in profound changes in the human brain. Here, we investigated local structural differences along two language-related white matter trajectories, the arcuate fasciculus and the inferior fronto-occipital fasciculus (IFOF), between early simultaneous bilinguals and late sequential bilinguals. We...

In healthy subjects, motor cortex activity and electromyographic (EMG) signals from contracting contralateral muscle show coherence in the beta (15-30 Hz) range. Corticomuscular coherence (CMC) is considered a sign of functional coupling between muscle and brain. Based on prior studies, CMC is altered in stroke, but functional significance of this...

The white matter structures of the human brain can be represented using diffusion-weighted MRI tractography. Unfortunately, tractography is prone to find false-positive streamlines causing a severe decline in its specificity and limiting its feasibility in accurate structural brain connectivity analyses. Filtering algorithms have been proposed to r...

The segmentation of brain structures is a key component of many neuroimaging studies. Consistent anatomical definitions are crucial to ensure consensus on the position and shape of brain structures, but segmentations are prone to variation in their interpretation and execution. White‐matter (WM) pathways are global structures of the brain defined b...

The white matter structures of the human brain can be represented using diffusion-weighted MRI tractography. Unfortunately, tractography is prone to find false-positive streamlines causing a severe decline in its specificity and limiting its feasibility in accurate structural brain connectivity analyses. Filtering algorithms have been proposed to r...

The white matter structures of the human brain can be represented via diffusion tractography. Unfortunately, tractography is prone to find false-positive streamlines causing a severe decline in its specificity and limiting its clinical feasibility. Filtering algorithms have been proposed to reduce these invalid streamlines. We augmented the COMMIT...

Diffusion MRI measurements are affected by noise which propagates into the model estimation. Residual bootstrapping has been proposed to assess the uncertainty of parameter estimates, but do not consider the confounding effect of measurement outliers (e.g. due to subject motion), limiting their usage on clinical data. We present a robust bootstrapp...

Diffusion-weighted magnetic resonance imaging tractography is used to represent brain structures but it has limited specificity. Tractogram filtering is proposed to fix this by utilizing e.g. microstructural information to find which streamlines are essential in respect to the original measurements. However, filtered results can be biased if the me...

Aspartylglucosaminuria (AGU) is a rare lysosomal storage disorder causing developmental delay, intellectual disability, and eventual death. A distinct feature in AGU is iron accumulation within the thalamus. Our aim is to demonstrate that susceptibility-weighted images (SWI) could be used as an MRI biomarker to evaluate the response within the AGU...

We report an original finding of a strong linear correlation (F=26, p=1.5e-4, R =0.65) between iron accumulation within specific thalamic structures and the age of children with aspartylglucosaminuria (AGU). AGU is a rare lysosomal storage disorder which has no cure, causes a negative effect on the development of a child, and leads to a premature d...

Diffusion-and kurtosis tensor estimators generally assume independent and a Gaussian distributed noise. While with adequate signal-to-noise ratios (SNR) this assumption can be made without significant bias in the estimated models, this is not true when utilizing high diffusion weighting thus low SNR. In such case, the Rician noise should be conside...

Characterizing uncertainty distributions in diffusion MRI derived metrics such as fractional anisotropy or kurtosis anisotropy requires non-parametric approaches, since the correct form of the distribution is rarely known a priori. Previously suggested wild bootstrapping methods, however, have not considered the impact of outliers in the data. In t...

The accurate characterization of diffusion process with MRI is compromised by various artefacts including intensity related errors. If not appropriately accounted for, model estimates can become significantly biased resulting in erroneous metrics. Slicewise intensity errors, in particular, are often handled by excluding the entire image or slice in...

Despite numerous functional neuroimaging and intraoperative electrical cortical mapping studies aimed at investigating the cortical organisation of native (L1) and second (L2) language processing, the neural underpinnings of bilingualism remain elusive. We investigated whether the neural network engaged in speech production over the bilateral poste...

electronic poster

paper poster

Objective To compare methods of estimating spike strength as a potential index in the assessment of continuous spikes and waves during sleep (CSWS). Methods Spikes were searched and averaged automatically from pre- and postoperative EEGs of ten patients with CSWS who underwent corpus callosotomy (eight) or resective epilepsy surgery (two). From th...