Delayed Speech Development and Functional Speech Disorders – What You Should Know About Primitive Reflexes

Who would think that the primitive reflexes present at birth could be related to speech development or even the emergence of speech disorders? Yet early nervous system maturation, motor development, and speech are closely interconnected. If a deviation occurs in any of these areas, it can affect both speech comprehension and speech production.

What are primitive reflexes?

Primitive reflexes are innate, automatic movement responses. Some appear during the fetal stage of life, while others emerge in the period following birth. What they have in common is that they support the newborn’s adaptation to the environment. These reflexes—such as the Moro reflex, the sucking reflex, or the grasp reflex—are active for a specific period, then gradually integrate or come under cortical inhibition as the nervous system matures. They give way to various voluntary, conscious movements.

Why is appropriate muscle tone at birth important?

Appropriate muscle tone at birth is crucial, because only then can the movement patterns of primitive reflexes be fully expressed. If muscle tone is too “loose” (hypotonic) or too tense, the triggering of reflexes may become distorted or incomplete. This can make later integration and cortical inhibition of the primitive reflex more difficult. In the long term, this may influence motor coordination, sensory processing, and the muscle functions required for speech.

What is the primary role of primitive reflexes?

The primary roles of primitive reflexes include:

• Protection (e.g., Moro reflex, paralysis reflex)

• Support of sensory functions (e.g., tonic labyrinthine reactions, grasp reflex)

• Regulation of muscle tone (e.g., asymmetric tonic neck reflex, parachute reflex)

• Ensuring feeding (e.g., sucking reflex, rooting reflex)

If these reflexes are elicited in adequate quantity, quality, and duration during infancy, they promote the maturation of a higher-level brain structure, the cerebral cortex. Parallel to this process, the production of GABA (gamma-aminobutyric acid) increases in cortical cells, enabling inhibition of the given primitive reflex and signaling to the nervous system that it is no longer needed. At this point, voluntary movement replaces the primitive reflex—for example, voluntary grasping or later, speech.

Which primitive reflexes influence speech?

For a child to speak, vision and hearing must function accurately, since its native language is acquired through imitation. This requires:

• Appropriate muscle tone in the muscles involved in speech production

• Coordinated, precise functioning of the muscles necessary for vision and hearing (e.g., eye muscles, tensor tympani muscle)

It is also important to mention that high-quality breast feeding for an adequate duration plays an essential role in early development. The ideal time for weaning is between 9 and 18 months of age. Additionally, it is crucial that in infancy and early childhood, the child’s palms and soles receive sufficient sensory stimulation.

The palmar grasp plays a particularly significant role. Through the Babkin reaction—which describes the connection between the grasp and sucking reflexes—stimulation of the palm affects the functioning of the tongue and lips. This connection can also be observed in neurological conditions. For example, in dementia, especially in Alzheimer’s disease, the re-emergence of the grasp reflex often occurs together with involuntary mouth movements and speech difficulties.

The plantar grasp reflex is also connected to this system, as there is a neural connection between the palmar and plantar grasp reflexes in early life.

Balance, head position, and emotional factors

The accuracy of balance perception is also fundamental. Based on the spatial position of the head, the nervous system regulates and sets muscle tone—that is, it “decides” which muscles should tense and which should relax. Certain early infant reflexes trigger head turning, lifting, and tilting, which are essential for stimulating the balance organ and promoting its maturation. This process is indispensable for later motor and speech development.

In addition, a child’s emotional balance is important. Beyond environmental factors, certain infant reflexes also influence the nervous system’s stress-management capacity and emotional regulation. Balanced nervous system functioning is a prerequisite for optimal development.

Reflexes frequently involved in delayed speech development

The following primitive or infant reflexes often persist in children with delayed speech development, speech comprehension difficulties, or speech production disorders:

• ATNR (Asymmetric Tonic Neck Reflex)

• TLR flexor (Tonic Labyrinthine Reflex forward)

• TLR extension (Tonic Labyrinthine Reflex backward)

• Parachute reflex

• Grasp reflex (palmar, plantar)

• Sucking reflex

• Moro reflex

• FPR (Fear Paralysis Reflex)

When and how should reflex integration exercises begin?

At 2.5–3 years of age, it is already advisable—and necessary—to begin exercises if the child does not speak or if vocabulary does not reach an age-appropriate level. This is also recommended if speech is unclear. The primary goal of the exercises is to bring retained infant reflexes under cortical inhibition. As mentioned above, cortical inhibition occurs through the maturation processes of the cerebral cortex, and targeted exercises support this process.

The exercises can be performed safely at home with parental support by following the tasks described in the book Rewiring the Brain - The Stephens-Sarlós Program, using the video materials available at drsarlos.com/videos, or based on guidance received during individual consultation with a qualified mentor.

Regular, guided home practice can effectively support the integration and inhibition of retained infant reflexes and, through the maturation of appropriate cortical areas, promote speech development. If the child has any medical, internal, neurological, or orthopedic condition that would contraindicate the exercises, consultation first with the child’s treating physician is essential.

The exercises are very simple. Twenty to thirty years ago, they were part of everyday activities with children. One might think of simple finger-play games (“This little pig went to market…”), rocking movements, “cycling” while lying on the back, or rhythmic clapping games. There is no need for complicated exercises.

If the child is younger than 2.5 years, the goal is not inhibition of primitive reflexes but strengthening the natural movement patterns associated with primitive reflexes. This is best done in consultation with a mentor.

Closing thoughts – responsibility and opportunity

Communication and speech are of fundamental importance, as they are among the most defining elements of socialization. It is the shared responsibility of parents and professionals to do everything possible to help a child speak clearly and confidently.

In most cases—if there is no organic obstacle—a few months of regular targeted exercises will bring visible results. It requires around only 8–12 minutes, or at most 15 minutes, of specific movement each day.

✨ It is never too early to take action, and never too late to help.

✨ Movement is the language of the nervous system—through it, speech can also be developed.

The exercises can be found in the book Rewiring the Brain - The Stephens-Sarlós Program and in the speech development video package.