Tactile perception by mouth: Perceiving properties of objects when vision is impaired

The lips and tongue demonstrate similar or greater spatial acuity than the fingertips. Indeed, infants use the mouth to perceive properties of objects such as hardness, texture, and shape. In normal development, it is assumed that mouthing decreases in favour of increasingly advanced hand exploration patterns. However, anecdotal reports suggest that mouthing continues to serve a perceptual function when a person’s vision is abnormal. This study explored blind or visually impaired (BVI) adults’ self-reported use of mouthing to perceive properties of objects. We conducted semi-structured interviews with 20 BVI adults with visual acuities ranging from no light perception to 20/40. Data were analysed using content analysis to identify specific properties perceived by the mouth. Despite social norms that discourage mouthing, some BVI adults use oral tactile perception of texture, shape, temperature, and taste to better characterize objects. These findings suggest that compensatory behaviours using the mouth can support the rehabilitation of individuals with abnormal vision.

A Test of Tactile Concentration and Short-term Memory

This article reports the initial findings of a two-part test of tactile concentration and short-term memory involving the reproduction of the order of finger stimulation—a forward series and a backward series. A newly devised instrument, the Finger Knocking Box, was used for the mechanical stimulation of fingers and the recording of responses by 65 totally blind or partially sighted subjects of average intelligence.

Adaptive capacity of 2- to 5-month-old infants to the flow, shape, and flexibility of different teats during bottle feeding: a cross-sectional study

Background

Nutritive sucking is a complex activity, the biomechanical components of which may vary in relation to respiratory phase, swallow-rate per minute, suck-swallow ratio, and swallow non-inspiratory flow (SNIF). Quantitative measurement of these components during nutritive sucking in healthy infants could help us to understand the complex development of sucking, swallowing, and breathing. This is important because the coordination between these components is often disturbed in infants with feeding difficulties. The aims of this study were to describe the biomechanical components of sucking and swallowing in healthy 2- to 5-month-old infants during bottle feeding, to assess whether infants adapt to the characteristics of two different teats, and to determine which independent variables influence the occurrence of SNIF.

Methods

Submental muscle activity, nasal airflow, and cervical auscultation were evaluated during bottle-feeding with two different teats.

Results

Sixteen term-born infants (6 boys) aged 2–5 months were included. All infants showed variable inhalation and exhalation after swallowing. The swallow rate per minute was significantly higher when infants fed with a higher flow teat (Philips Avent Natural 2.0™). Infants had suck:swallow ratios ranging from 1:1 to 4:1. A suck:swallow ratio of 1:1 occurred significantly more often when infants fed with a higher flow teat, whereas a suck:swallow ratio of 2:1 occurred significantly more often when infants fed with a low-flow teat (Philips Avent Classic+™). A suck:swallow ratio of 1:1 was negatively correlated with SNIF, whereas a suck:swallow ratio of 2:1 was positively correlated with SNIF.

Conclusion

Healthy infants aged 2–5 months can adapt to the flow, shape, and flexibility of different teats, showing a wide range of biomechanical and motor adaptations.

Telling Apart Motor Noise and Exploratory Behavior, in Early Development

Infants' minutes long babbling bouts or repetitive reaching for or mouthing of whatever they can get their hands on gives very much the impression of active exploration, a building block for early learning. But how can we tell apart active exploration from the activity of an immature motor system, attempting but failing to achieve goal directed behavior? I will focus here on evidence that infants increase motor activity and variability when faced with opportunities to gather new information (about their own bodies or the world) and propose this as a guiding principle for separating variability generated for exploration from noise. I will discuss mechanisms generating movement variability, and suggests that, in the various forms it takes, from deliberate hypothesis testing to increasing environmental variability, it could be exploited for learning. However, understanding how variability in motor acts contributes to early learning will require more in-depth investigations of both the nature of and the contextual modulation of this variability.

Early influence of auditory stimuli on upper-limb movements in young human infants: an overview

Given that the auditory system is rather well developed at the end of the third trimester of pregnancy, it is likely that couplings between acoustics and motor activity can be integrated as early as at the beginning of postnatal life. The aim of the present mini-review was to summarize and discuss studies on early auditory-motor integration, focusing particularly on upper-limb movements (one of the most crucial means to interact with the environment) in association with auditory stimuli, to develop further understanding of their significance with regard to early infant development. Many studies have investigated the relationship between various infant behaviors (e.g., sucking, visual fixation, head turning) and auditory stimuli, and established that human infants can be observed displaying couplings between action and environmental sensory stimulation already from just after birth, clearly indicating a propensity for intentional behavior. Surprisingly few studies, however, have investigated the associations between upper-limb movements and different auditory stimuli in newborns and young infants, infants born at risk for developmental disorders/delays in particular. Findings from studies of early auditory-motor interaction support that the developing integration of sensory and motor systems is a fundamental part of the process guiding the development of goal-directed action in infancy, of great importance for continued motor, perceptual, and cognitive development. At-risk infants (e.g., those born preterm) may display increasing central auditory processing disorders, negatively affecting early sensory-motor integration, and resulting in long-term consequences on gesturing, language development, and social communication. Consequently, there is a need for more studies on such implications.

Arranjos cognitivos: abrangências e limitações representacionais

Este artigo avalia as características quantitativas (dimensões dos campos sensoriais) e qualitativas (padrões configuracionais, qualias e tempo/espaciais) das modalidades sensoriais faltantes e remanescentes e como elas afetam o arranjo cognitivo e a fluência representacional de indivíduos sensorialmente privados (cegos e surdos). Sugere-se que a utilização precoce e maciça do caráter predominantemente configuracional da modalidade sensorial visual, principal modalidade remanescente nos surdos congênitos, iniba a produção representacional nesses indivíduos, enquanto que o uso intensivo e precoce do caráter predominantemente insinuador da modalidade sensorial auditiva, principal modalidade nos cegos congênitos, incentive a produção representacional nesses últimos.

Intentional action arises from early reciprocal exchanges

Intentionality is defined as the cognitive ability to represent goals beyond the here and now of perception. First signs of intentionality appear by the second month after birth. A major mechanism responsible for such development might be the unique reciprocal and intentional ways humans communicate with each other, particularly their young progenies. I argue that starting in the second month, reciprocal exchanges, affective mirroring, and mutual imitations with others provide infants with the unique opportunity to differentiate as well as to compare and conjugate first (self) and third (others') person perspectives. This ability is a prerequisite not only for referential communication but also of intentionality. It corresponds to the emergence of a new contemplative and "meta" stance toward the world. An argument is made that the developmental origins of this stance are primarily social, not to be found in the individual infant interacting solely with physical objects.

WEIGHT PERCEPTION IN NEONATE INFANTS

A recent research revealed the capacity of the newborn to haptically detect, the weight of an object [12]. In this research, we tried to determine the means by which newborn infants, not having yet exploratory procedures, are able to treat this object property. We support the assumption that tactile perceptive capacities of the newborn infants derive from a fundamental property of the sensorimotor system: its primary variability. After a period of habituation with a heavy or light object, an object of new weight is presented (period test). Three parameters of the sensorimotor activity were analyzed during these two periods: holding times, amplitude of the pressure exerted on the object and frequency of the pressure. Analyses of these parameters demonstrate the neonate's capacity to discriminate objects weight.

Exploration or imitation? The effect of music on 4-week-old infants' tongue protrusions

In a newborn imitation paradigm, an auditory stimulus--music--replaced the standard adult behavioral model. Alternating intervals of music and silence affected 4-week-old infants' rates of tongue protruding--evidence that tongue protruding is a general response to interesting distal stimuli.

Towards a developmental cognitive science. The implications of cross-modal matching and imitation for the development of representation and memory in infancy

This chapter began with a query about whether there was any content to an enterprise called "developmental cognitive science," and if so, whether the findings could inform work in adult cognition and neuropsychology. Both questions can now be answered in the affirmative. Evidence has been marshaled from infant studies concerning five topics of enduring interest in the cognitive and neuro-sciences: cross-modal integration, imitation, the coordination of perception and action, memory, and representation. The data show that young human infants can detect equivalences between information picked up by different sensory modalities. This was demonstrated both in tactual-visual perception of objects and auditory-visual perception of speech. Results also show that perception and production are intertwined literally from the earliest phases of infancy, with 4-month-olds demonstrating vocal imitation and newborns reproducing elementary gestures they saw an adult perform. There seems to be a transparency between the perceptual and motor systems, and it is conceivable that they may draw on the same internal code. Infants' proclivity to imitate was used to investigate early memory. It was found that young infants were not constrained to immediate mimicry, but could imitate after significant delays. The findings support the inference that infants, perhaps as early as birth, have a functioning memory system that cannot be reduced to "habit formation" or an exclusively "procedural memory." It was proposed instead that there is a kernel of some higher level memory system right from the earliest phases of human infancy. This does not imply that there is no development in the representational world of infants. Data were reviewed suggesting that there is a watershed transformation in childhood cognition at about 18 months of age. However, this is not a change from a stage in which there was a purely sensorimotor or habit-based system. Rather the development was characterized as a shift from using empirical or experience-based representations to using hypothetical representations, which concern possible realities. This developmental shift allows children to project into the future "what must be" and deduce from the past "what must have been," in advance of, and sometimes in the absence of, strictly perceptual evidence. This capacity provides the underpinnings for the conduct of science itself. Its origins are to be found in infancy.