Anatomy, Physiology, and Pathology of the Organs of Hearing, Vision, and Speech - Shvetsov A.G. 2006

Anatomy, Physiology, and Pathology of Speech
The Role of Vision in Speech Development

The visual system plays a minimal role in The Development of a child's speech Functions, as blind children and adults rely on acoustic channels of speech information, and occasionally on tactile ones (such as Braille). Difficulties arise when transitioning to forms of speech that depend on the active functioning of the visual analyzer, specifically those associated with mastering reading and writing skills.

On the other hand, it is an established fact that congenitally blind children, even those with normal Hearing, begin to speak significantly later. This is linked to the development of vocal imitation (echolalia), which begins during the second half of the child's first year. A sighted child, by focusing their gaze on the speaker's face, begins to open and close their Mouth, move their Lips, and readily mimic exaggerated articulatory movements, subsequently repeating sounds and eventually entire words. Echolalia is typically well-developed by the child's second year. Imitation and repetition Reflexes remain strong at 5–6 years of age, which is why starting foreign language acquisition is recommended during this period.

While speech acquisition in sighted individuals and those with visual impairments follows fundamentally the same principles, the absence or profound loss of Vision alters the interaction between sensory analyzers. This triggers a restructuring of Neural Pathways, integrating speech development into a different system of connections compared to sighted individuals. Blindness and severe visual impairment lead to deviations across all types of cognitive activity, reducing the volume of incoming information. Consequently, The Role of hearing, Touch (haptic exploration of objects during perception), and other sensory modalities increases in the lives and activities of blind and visually impaired individuals. Qualitative shifts occur within the sensory system, giving rise to specific characteristics in The formation of mental images, concepts, speech, spatial orientation, and other functions.

Significant changes also occur in the child's physical development: motor precision is compromised and movement intensity decreases. Meanwhile, the Development of the motor analyzer and an active physical regimen serve as powerful stimulants of speech function, as The Mechanism of speech production relies on the highly coordinated interaction between speech centers and the motor areas of the Cerebral Cortex.

Although the speech of blind and visually impaired individuals develops through interpersonal communication, its acquisition exhibits unique characteristics: the pace of development is altered, the lexical-semantic aspect of speech is disrupted, and "formalism" emerges.

Impairment of the visual analyzer leads to the formation of new inter- and intra-sensory connections, altering relationships within the sensory system. This results in a unique psychological system specific to the blind and visually impaired, characterized by its own distinct patterns of perception, cognition, memory, emotion, and other functions.

Human thought consists in establishing relationships between perceptions and concepts (inferences). It is therefore logical to assume that if perception is compromised by visual impairment, cognitive inference must also suffer. However, most researchers directly or indirectly indicate that there is no correlation between the level of cognitive and memory development and the severity of visual acuity loss, although they do acknowledge a slower rate of development.