The Sensitive Period for Tactile Remapping Does Not Include Early Infancy

Abstract

Visual input during development seems crucial in tactile spatial perception, given that late, but not congenitally, blind people are impaired when skin-based and tactile external representations are in conflict (when crossing the limbs). To test whether there is a sensitive period during which visual input is necessary, 14 children (age = 7.95) and a teenager (LM; age = 17.38) deprived of early vision by cataracts, and whose sight was restored during the first 5 months and at age 7, respectively, were tested. Tactile localization with arms crossed and uncrossed was measured. Children showed a crossing effect indistinguishable from a control group (Ns = 28, age = 8.24), whereas LM showed no crossing effect (Ns controls = 14, age = 20.78). This demonstrates a sensitive period which, critically, does not include early infancy.

Multisensory Development: Calibrating a Coherent Sensory Milieu in Early Life

“…Because their sight was restored at around 4.5 months, they were only deprived of visual-tactile experience in a period in which infants do not spend much time considering such multisensory content in any case. This would seem to chime with a recent study [10] which indicates that visual deprivation in the first five months of life does not impair the typical development of tactile spatial perception as it does when such deprivation continues into later infancy [11] and childhood. …”

“…Their result (few inhibitory receptors on foveal ganglion cells) agrees with their physiology but conflicts with earlier studies using electron microscopy [8][9][10]. Because their technique strains the limits of light microscopy, more information will be needed to get to the bottom of this.…”

“…In the domain of multisensory space, studies indicate the importance of visual experience in early development. The most recent case studies of congenitally blind individuals who have had their sight restored through the removal of cataracts seems to indicate that deprivation of vision in a sensitive period between 5 months [10] and two years [11] leads to atypical development of an ability to map touches into visual space.…”

A Conceptual Model of Tactile Processing across Body Features of Size, Shape, Side, and Spatial Location

“…This suggests that extensive visual experience during the first years of life leads to a default encoding of touch in terms of external space, even in cases where taking posture into account is detrimental. In support to this idea, the deprivation of visual input during the first years of life, by congenital dense bilateral cataracts in humans, hinders the normal development of a default remapping of touch in external space (Ley et al., 2013; Azañón et al., 2018).…”

Sensitivity to Visual‐Tactile Colocation on the Body Prior to Skilled Reaching in Early Infancy

“…It has been established for some time that congenitally blind adults show less interference of external spatial coordinates when locating touches on the body (Röder, Rösler, & Spence, 2004). However, one particular study with congenitally blind children who had had cataracts removed in the first months of life, indicates that visual experience plays a particular role only after 4 months of age: If cataracts were removed before 5 months of age, tactile localization developed typically (Azañón, Camacho, Morales, & Longo, 2018; see also Ley, Bottari, Shenoy, Kekunnaya, & Röder, 2013). On the basis of these findings, we predicted that 4‐month‐olds would not have gained experience of visual‐tactile spatial colocation, and would therefore not be able to differentiate colocated and noncolocated visual‐tactile stimuli.…”