Periodic Reporting for period 4 - SENSOCOM (The tiny and the fast: the role of subcortical sensory structures in human communication)
Periodo di rendicontazione: 2020-07-01 al 2022-06-30
(i) We found that subcortical sensory nuclei (i.e. the sensory thalami) are involved not only when humans recognise auditory speech, but also when they recognise visual speech (i.e. when they understand what is said based on articulatory movements of the face). The amount of responses in the sensory thalami in both the auditory and the visual modality is related to speech recognition abilities. These findings imply that a full understanding of human speech recognition abilities needs to take dynamic corticothalamic interactions into account.
(ii) We found that developmental dyslexia is characterised by a reduction of white matter tracts that connect visual motion areas (V5/MT) to the visual sensory thalamus (lateral geniculate nucleus, LGN), but that white matter tracts between primary visual areas (V1) and LGN are intact. The specificity of the reduction to white matter tracts involved in visual motion processing is an important finding for two reasons: First it is a clear indication that developmental dyslexia is characterised not only by cerebral cortex dysfunction as proposed in most current developmental dyslexia models. Second, it gives first insight into the potential underlying mechanisms of the cortico-subcortical deficit.