Visual perception skills: a comparison between patients with Noonan syndrome and 22q11.2 deletion syndrome

Abstract

Ventral and dorsal streams are visual pathways deputed to transmit information from the photoreceptors of the retina to the lateral geniculate nucleus and then to the primary visual cortex (V1). Several studies investigated whether one pathway is more vulnerable than the other during development, and whether these streams develop at different rates. The results are still discordant. The aim of the present study was to understand the functionality of the dorsal and the ventral streams in two populations affected by different genetic disorders, Noonan syndrome (NS) and 22q11.2 deletion syndrome (22q11.2DS), and explore the possible genotype-phenotype relationships. 'Form coherence' abilities for the ventral stream and 'motion coherence' abilities for the dorsal stream were evaluated in 19 participants with NS and 20 participants with 22q11.2DS. Collected data were compared with 55 age-matched controls. Participants with NS and 22q11.2DS did not differ in the form coherence task, and their performance was significantly lower than that of controls. However, in the motion coherence task, the group with NS and controls did not differ, and both obtained significantly higher scores than the group with 22q11.2DS. Our findings indicate that deficits in the dorsal stream are related to the specific genotype, and that in our syndromic groups the ventral stream is more vulnerable than the dorsal stream.

Recognition Memory in Noonan Syndrome

“…Conversely, the reduced availability of attentional resources affects estimates of recollection much more than estimates of familiarity [75,76]. Given that perceptual alterations [77,78] and attention problems [79,80] have been reported in individuals with NS/NSML, such variables are potentially relevant for interpreting the qualitative aspects of performance in the recognition memory task of our cohort of children and adolescents with NS and NSML, although the presence of ADHD was considered an exclusion criterion in our study. It could be hypothesized that in individuals with NS/NSML, the reduced efficiency of some control mechanisms (e.g., those related to attentional or executive abilities) might interfere with the deep encoding and/or strategic retrieval of target stimuli in a way that impairs recollection more than familiarity.…”

Mindfulness meditation styles differently modulate source-level MEG microstate dynamics and complexity

“…Mounting evidence, in fact, shows that human brain activity is highly dynamic and non-stationary, transiting between different brain states coding for a wide range of cognitive functions (Brodbeck et al, 2012;Britz et al, 2014;Milz et al, 2016;Seitzman et al, 2017;Liégeois et al, 2019;Zappasodi et al, 2019;Zhou et al, 2019). Additionally, the temporal dynamic of these brain-states has been identified as a possible neurophysiological signature of abnormal self experience in clinical populations (Vellante et al, 2020), suggesting that the study of the brain-states activity could allow the investigation of early endophenotypes in genetic condition (i.e., 22q11.2) influencing the onset of schizophrenia (Tomescu et al, 2015;Piccini et al, 2017).…”