Persistence of Primitive Reflexes in Developmental Disorders

Retained Primitive Reflexes and Potential for Intervention in Autistic Spectrum Disorders

“…We think that this is the basis of both the maturational cortical delay identified in almost all neurobehavioral disorders, including ASD, and their associated RPRs ( 272 – 276 ). After the first few months of life, the feedback created by primitive reflex-generated movement can lead ultimately to the inhibition of these reflexes and the activation of more complex subsequent postural reflexes ( 64 , 211 , 277 ) resulting in a more complex interaction with the environment, that in turn leads to greater sensory feedback thereby activating genes that allow for the creation of integration and coordination between various cortical networks [for a more detailed analysis cf. ( 44 )].…”

“…The absence or reduction of environmental influences that would generally promote growth and development, and neuroplasticity within higher brain regions, would typically lead to the inhibition of primitive reflexes and the expression of postural reflexes ( 3 , 64 ) according to the timeline represented in Figure 1 and in Table 1 . The persistence of these primitive reflexes can reflect a maturational lag.…”

“…The persistence of these primitive reflexes can reflect a maturational lag. The RPRs, especially with asymmetric persistence, will reflect not only a maturational delay of the brain but may also indicate, depending on the timing, abnormal asymmetrical development of the hemispheres ( 64 , 65 ). In children with cerebral palsy, an injury on one side of the brain can lead to asymmetric retention or lack of development of PRs ( 28 , 66 , 67 ).…”

“…Some authors have stated that RPRs are evidenced in neurotypical populations. The palomental reflex, for example, was found in 6–27% of individuals aged between 20 and 50 years, and 28–60% of those above 60 years ( 64 ), snouting in 13% of individuals between 40 and 57 years ( 64 ); 22–33% of those above 60 years of age ( 64 ), and the sucking reflex, which some authors associate with “frontal lobe disease” ( 79 ), and Tarawneh and Galvin ( 80 ) had noted that in neurotypical individuals between 73 and 93 years of age, the palmomental reflex was evidenced in six percent them.…”

Front and center: Maturational dysregulation of frontal lobe functional neuroanatomic connections in attention deficit hyperactivity disorder

“…Frontal lobe lesions in adults allows us to observe hyperactivity control mechanisms more readily ( Clay et al, 2019 ; Hagiescu, 2021 ). Hyperactivity, both in childhood and in adulthood, can be viewed as a disturbance of higher levels of cortical inhibition manifested as an absence of orienting responses inhibition ( Posner et al, 1998 ; Brown et al, 2021 ; Williams and Das, 2021 ), an inhibitory deficit of inappropriate responses ( Posner et al, 1998 ) and/or a disinhibition of inhibitory cortical reflexes ( Neely et al, 2017 ), or retained primitive reflexes ( Melillo and Leisman, 2010 ; Melillo et al, 2020 ; Bob et al, 2021 ; Sigafoos et al, 2021 ). Given the apparent similarity in the behavioral manifestations of ADHD and adults with dysfunction of or damage to the frontal lobe, we can hypothesize a common origin for ADHD and frontal lobe dysfunction, even though it has long been argued ( Fletcher and Taylor, 1984 , p. 46; cf.…”