Researchers have been able to examine sensorimotor behaviour in very early infancy. Von Hofsten (1982) investigated eye hand coordination behaviours in sixteen newborns (aged between 4 and 9 days old) and found that when newborns fixated on a moving object that was dangled in front of them, they extended their arm outwards in an attempt to grasp the moving object. However, the infants were unsuccessful in touching or grasping the dangled object. This lack of success may be due to immature visual-motor integration abilities – after all, considering the age of infants tested in this study, producing an accurate grasp towards a moving target may be a particularly difficult task. Nonetheless, Von Hofsten argued that infants’ attempts at reaching for the toy demonstrated newborns’
rudimentary ability to integrate visual and motor information to some extent.
Von Hofsten and Fazel-Zandy (1984) have further investigated visually guided hand movements in infancy. This particular study involved a longitudinal design in which a group of 15 infants were assessed at monthly intervals between the ages of 18 and 34 weeks.
Infants in this study were presented with horizontal or vertical rods and the infant’s hand orientation was measured as it approached the object.
The researchers found that even at 18 weeks, there appeared to be some adjustment of hand orientation in order to successfully grasp the object. It appears that infants within the first four months of life are able to
co-ordinate, to some extent, visual information about objects and their own body in order to successfully take hold of the object.
The research described above has been conducted with infants having visual information of their limbs and/or the objects to be grasped, however there is a body of research that has examined reaching ability in infants when vision of their hand was not available (e.g., in the dark, but with the target object luminesced) and has found that at approximately 4 months of age, infants were able to successfully guide their hands to an object to grasp. This was comparable to when the first successful reaches in conditions where visual information of the limbs were available (Clifton, Muir, Ashmead & Clarkson, 1993). Research from this lab has also shown that infants are able to contact luminescent objects that are moving in the dark, although the occurrence of grasping the moving object was much more pronounced in infants that were 7.5 months of age (Robin, Berthier & Clifton, 1996).
Further to this, regardless of the visual information concerning the arm and/or object (a vertically or horizontally placed rod) that were available, 8-month-old infants’ positioning of their hands differed to the same extent when producing a reach to contact an object that was positioned either vertically or horizontally (McCarty, Clifton, Ashmead, Lee & Goubet, 2001). Therefore, it appears that infants within the first year of life are able to make use of proprioceptive cues to their limb position to produce an accurate reach, and this can be in combination with visual information of the hand and/or toy, but visual information of either
the hand or the toy is not a necessity for this. Although, it has been suggested that rather than relying on current proprioceptive information of the limb alone, perhaps the infant is also making use of a multisensory representation of the arm regarding the usual position and location of this arm (Bremner, Holmes & Spence, 2008a).
Of the research discussed above, infant’s co-ordination of vision and proprioception for action has been addressed, demonstrating that infants as young as 4 months of age possess some rudimentary skills concerning multisensory representations of the body in which to guide reaching.
Specifically, these studies illustrate that proprioceptive guidance of movement is related to a representation of external space.
Further to this, the above research has shown differing levels of ability (of sensorimotor representations at differing complexities) emerge at different ages; from the newborn stage (Von Hofsten, 1982; Von Hoften
& Fazel-Zandy, 1984) to the second half-year of life (Robin et al., 1996;
McCarty et al., 2001). Therefore, it is possible that whilst sensorimotor representations may emerge within the first few weeks life, they continue to develop and become more precise and mature throughout the first year of life.
1.3.3 Imitation
Imitation describes the act of copying an observed gesture. In terms of this thesis and the questions to be asked, imitation is particularly related to
the ability of infants to perceive and act upon their bodies. By imitating an observed gesture, this could suggest that the infant is able to understand the spatial relations of others bodies and then map these onto their own.
Piaget (1952) believed that imitation was a result of learning (either conditioning or learning associations between the observed action and producing it) through everyday interactions with caregivers. However, this account of imitation fails to explain observations that very young infants are able to imitate actions they have never seen before.
In a particularly influential study, Meltzoff and Moore (1983) investigated imitation of facial gestures in typical newborn infants who were less than 72 hours old (ranging from 42 minutes to 71 hours in age).
The infant observed a researcher producing a facial gesture (mouth opening or tongue protrusion) and was then seen producing the gesture themselves. Due to the age of the participants in this study, it is difficult to attribute these results to a learnt association between gesture observation and production. The most interesting aspect of this study, in terms of body representations, is that the newborn infant was able to translate knowledge of an other’s body to then produce an action using their corresponding body part, specifically different actions using the same region of the body (i.e. using the mouth to produce an opening and a tongue protrusion gesture). The results of the described study would suggest that we have an innate ability to map observed actions by others to corresponding co-ordinates on our own bodies to mimic the action. From these assertions, researchers have argued that this ability may well be
explained by the mirror neuron system (Marshall & Meltzoff, 2011). This could mean that, from birth and possibly even prenatally, the human infant has some way of representing different features of their bodies and how these features (e.g. limbs) can be used to produce an action.
However, other researchers (e.g., Anisfeld, Turkewitz, Rose, Rosenberg, Sheiber, Counterier-Fagan & Ger, 2001) have been more sceptical of the conclusions drawn from newborn imitation research. For example, rather than attributing infant’s facial responses to imitation, tongue protrusion has been attributed to general arousal (Anisfeld, 1991, 1996, see Anisfeld, 2005 for a review of infant imitation) or general oral exploration behaviours in response to interesting distal stimuli (Jones, 1996, 2006); with the aforementioned researchers arguing that if tongue protrusion is the only behaviour to be mimicked by infants, this behaviour is too specific to constitute imitation (Heyes, 2001; also see Jones, 2009 for critique of other ‘imitated’ behaviours by newborn infants such as mouth opening and finger tapping). In addition, other researchers using the same experimental procedures as Meltzoff & Moore (1983) have failed to replicate the finding that newborns are able to imitate a range of facial gestures (e.g., McKenzie & Over, 1983; Hayes & Watson, 1981; Koepke, Hamm, Legerstee & Russell, 1983a, 1983b).
Furthermore, studies have found that imitation of actions seems to develop much later in infancy than first proposed by Meltzoff and Moore (1983). For example, Jones (2007) did not find evidence of imitation before 8 months of age, with ‘traditional’ acts of imitation (such as tongue
protrusion) not mimicked until well into the second year of life, at 20 months. This sits uneasily in relation to other research which has shown that tongue protrusion can be produced by infants as young as 6 months of age during imitative behaviour (Fontaine, 1984). Ultimately, due to the later onset of these imitative behaviours in recent studies many have argued that imitation is a behaviour learnt through sensorimotor learning (Ray & Heyes, 2011 provide a detailed review of this account of imitation).
Considering the large number of studies, from across different labs, that contradict prior observations of newborn imitation and the fact that the earlier body of research on newborn and infant imitation has been criticised (e.g., Anisfeld, 1996, 2005; Jones, 1996; Abravanel & DeYong, 1997), it is difficult to conclude that very young infants possess the capability to map a seen action from another and produce the felt action themselves. So what does this mean in terms of infants' body representations? If we accept that action imitation has been demonstrated in infants no younger than 8 months, this would give rise to the view that, rather than infants possessing an innate understanding of the map of the body, body representation develop (perhaps through sensorimotor experience; Heyes, 2001) in the first few years of life.