Taking Sides: Asymmetries in the Evolution of Human Brain Development in Better Understanding Autism Spectrum Disorder

Abstract

Confirmation from structural, functional, and behavioral studies agree and suggest a configuration of atypical lateralization in individuals with autistic spectrum disorders (ASD). It is suggested that patterns of cortical and behavioral atypicality are evident in individuals with ASDs with atypical lateralization being common in individuals with ASDs. The paper endeavors to better understand the relationship between alterations in typical cortical asymmetries and functional lateralization in ASD in evolutionary terms. We have proposed that both early genetic and/or environmental influences can alter the developmental process of cortical lateralization. There invariably is a “chicken or egg” issue that arises whether atypical cortical anatomy associated with abnormal function, or alternatively whether functional atypicality generates abnormal structure.

Identification and reduction of retained primitive reflexes by sensory stimulation in autism spectrum disorder: effects on qEEG networks and cognitive functions

“…The persistence of primitive reflexes is significantly associated with an infant’s performance in both interaction with objects (ie, actions) and with people (ie, communicative gestures) implying that a high persistence of RPRs inversely correlate with low scores in motor repertoire (General Movement Assessment) independent of the infants’ age 11 25 26. Motor proficiency testing comprises 18 tasks divided into four areas that include: locomotion, stability, object control and fine movement skills.…”

“…Reflexes were graded on a scale of 0–4 based on clinical judgement (0=0 fully integrated; 1=25%; retained; 2=50% retained; 3=75%; 4=100% completely retained when tested by three examiners. The testing procedures are described more fully in table 1 and in online supplemental appendix 1 2 3 10–12…”

“…It has also been demonstrated that this functional disconnection can relate to a cortical maturational imbalance between networks 10. It has been hypothesised that a delay in cortical maturation in certain networks may result in an increased cortical maturation and development in other networks, leading to developmental asynchrony and unevenness of functional skills 10 11. Some authors12 13 consider RPRs as predictive of diffuse cerebral dysfunction since these signs are significantly correlated with cognitive deficits in a wide age range of individuals as determined by the Halstead-Reitan neuropsychological test battery 12.…”

Hemispheric lateralization of white matter microstructure in children and its potential role in sensory processing dysfunction

“…Altered hemispheric lateralization on DTI has been seen in neurodevelopmental disorders like autistic spectrum disorder (ASD), schizophrenia and dyslexia ( Fletcher et al, 2010 ; Lange et al, 2010 ; Lo et al, 2011 ; Ocklenburg et al, 2016 ; Postema et al, 2019 ; Andica et al, 2021 ; Floris et al, 2021 ). While a number of studies have shown loss of normal left lateralization in large association tracts and temporal lobes in autistic children and adolescents ( Lo et al, 2011 ) some studies have shown increased left lateralization ( Leisman et al, 2022 ). The variation in results is likely due to heterogeneity in the autism group with different subjects showing differing symptoms and having different underlying etiologies.…”

The Effectiveness of Mnemonic Device Techniques in Improving Long-Term Memory in Learning in Elementary Schools: A Literature Review

“…The optimal functioning of the human brain is contingent upon achieving a balance between the left and right hemispheres (e.g. Leisman et al, 2022;Sollmann et al, 2017). This represents the fundamental element of our exceptional memory capacity.…”