Face processing involves, according to Sergent (1989, as cited in Simion, Valenza & Umilta, 1998), face detection, discrimination and recognition. Face detection is the process of identifying a stimulus as a face and implies capacities to detect defining characteristics of a face. Some researchers, for example Bruce and Young (1986), have argued faces are processed separately and differently to other stimuli. This suggests an innate preference for the face. Other theories, for example the sensory hypothesis (Kleiner 1990, 1993 as cited in Simion, Valenza & Umilta, 1998), argue that faces are processed similarly to other patterns, and the innate preference is for complex patterns. Both views have been supported by demonstrations of face preference in newborns, where an innate capacity is inferred.
Early experiments on infants, exposing them to various patterns and measuring length of looking at each, indicated preference for certain patterns over others, indicating an innate degree of form perception (Fantz, 1961). Fantz theorised, however, that learning also had a role in relation to innate, and maturation of, perception. This theory was overshadowed for many years by consistent findings of face preference in infants emerging at around two months of age, for example, Maurer and Barrera, (1981). These results indicated that face preference was a result of either learning or maturation of the visual system. Many researchers favoured the leaning hypothesis, as there is a bias in the perception face patterns over others. Furthermore, research suggests that at two to three months of age infants begin to pay attention to social or emotional cues (Fantz, 1961, Maurer & Barerra, 1981), which will give preference to faces over inanimate objects (Ellsworth, Muir & Hains, 1993, as cited in Bee & Boyd, 2004).
Research with findings inconsistent to the popular view of face preference emerging over time, as by Goren, Sarty and Wu (1975, as cited in Morton & Johnson, 1991), began to emerge more frequently by the demonstrations in newborns of greater following behaviour of facelike patterns than non-facelike patterns (Morton & Johnson, 1991). These findings clearly indicate an innate preference for facelike patterns.
In an experiment using blank, facelike and scrambled stimuli, Maurer and Barrera (1981) found that at 2 months preference for faces was absent. Morton and Johnson (1991) also observed the phenomenon, in 5 week old infants, though in10 week old infants face preference was again present. These results summed up the previously inconsistent research and lead to the understanding that both nature and nurture were involved in facial perception.
Morton and Johnson's (1991) consequent structural hypothesis states that there is a predisposition for salient stimuli, such as the face. The Conspec device present subcortically at birth contains structural information about facial spatial components, automatically favouring face-like patterns. Conlern, the cortical mechanism, which grows via learning from birth and takes over at about 2 months of age, mediates the subcortical preference and allows the acquisition and retention of facial information via cortical pathway development. This hypothesis therefore encapsulates both nativism and empiricism and demonstrates environmental influence on neural capacities.
Moron and Johnson's (1991) finding of non-facelike preference of nineteen week old infants in the visual tracking task is explained by the influence of experience, as Conlern will have had sufficient experience of facelike stimuli to find the stimulus uninteresting, and prefer novel stimuli.
Later research by Cassia, Turati and Simion (2004), using photographs of natural and scrambled faces, demonstrated a bias in newborns for top heavy configurations. The preference may be a result of the infant's limited visual capacity and upper field advantage in visual sensitivity, though whether or not this purposefully favours faces can again be argued. The evidence suggests, however, that preference for faces is not pre-wired, but arises from a general perceptual process. Later preference may develop as the infant becomes accustomed to seeing faces over other visual stimuli, through experience. Conlern may produce a preference for faces over top-heavy configurations once it becomes activated, though evidence for Conspec as a domain specific mechanism tuned to face geometry is overshadowed.
In this brief summary of research into face perception, I have highlighted the current research goals of explaining perception by means of innate criteria and environmental influence. It has been commonly accepted that nativism and empiricism each have a role to play in development and research findings and interpretations reflect this. Modern day research stresses the importance of innate criteria, environmental influence and interaction between the two. However, despite the amount of research into perception, no one account can fully explain this interaction.
There are research limitations for exploring nativism and empiricism in perception. Research needs to be centred on young infants, which are difficult to assess. Though successful techniques have been employed, the young infant is continually developing and as such key changes in perceptual preference, for example, may be missed. The role of experience may also have taken affect before measurements are taken, possibly exaggerating the role of innateness.
References
Bee, H., & Boyd, D. (2004). Perceptual development. In The developing Child (10th ed.), (pp. 123-145). Boston: Allyn and Bacon.
Cassia, V.M., Turati, C., & Simion, F. (2004). Can a non-specific bias toward top-heavy patterns explain newborns' face preference? Psychological Science, 15(6), 379-383.
Fantz, R.L. The origin of form perception. (1961). Scientific American, 204(5), 66-72.
Keenan, T. (2002). Perceptual development. In An introduction to child development (pp. 94-117). London: Sage Publications.
Maurer, D., & Barrera, M. E. (1981). Infants' perception of natural and distorted arrangements of a schematic face. Child Development, 52(1), 196-202.
Morton, J., & Johnson, M.J. (1991) Conspec and Conlern: A two-process theory of infant face recognition. Psychological Review, 98(2), 164-181.
Simion, F., Valenza, E., & Umiltà, C. (1998). Mechanisms underlying face preference at birth. In F. Simion & G. Butterworth (Eds.), The development of sensory, motor and cognitive capacities in early infancy (pp.87-101). Hove: The Psychology Press.
