Tuesday, June 20, 2006

Face Recognition Developmental Trends in 6-, 10- and 18-year-olds

Abstract

The aim of this study is to show an overall increase in face recognition developmental trends, and determine if there is a significant difference in the ways children and adults encode and recall face recognition information. It is hypothesised that 10-year-olds will correctly recognise a greater proportion of upright faces than will six- year-olds, and that 18-year-olds will correctly recognise a greater proportion of upright faces than 10-year-olds. It is also hypothesised that 10-year-olds will not correctly recognise a greater proportion of inverted faces than will six-year-olds, and that 18-year-olds will not correctly recognise a greater proportion of inverted faces than 10-year-olds. It was also predicted that 10- and 18-year-olds will recognise a greater proportion of upright compared to inverted faces, and six year olds will not correctly recognise more upright than inverted faces. All three hypotheses are supported; however, there is an unexpected over-all increase in the proportion of correctly recognised inverted faces between the ages of six and 18 which suggests that, although previous studies have found no increase in inverted face recognition across such an age-range, perhaps it does exist.
The aim of this study is to show an overall increase in face recognition developmental trends, and determine if there is a significant difference in the ways children and adults encode and recall face recognition information. The results will enhance our understanding of this seemingly specialised aspect of memory encoding and recall.

Although infantile amnesia is a common phenomenon, there is abundant proof that from the moment of birth there exists implicit memory, as well as the beginnings of explicit memory (Westen, Burton & Kowalski 2006, pp. 478). Turati, Cassia, Simion and Leo (2006) report that newborns have face recognition abilities. One’s ability to process and store memories seems to increase during the growth and development period. (Westen, et al. 2006, pp. 478).

There is little difference in the ability of children aged under 10 between recognising photographs of unfamiliar faces, whether inverted or not; unlike people aged 10 or over, who exhibit difficulty in recognising inverted faces (Carey & Diamond, 1977). Carey and Diamond (1977) offer direct evidence that 10-year-olds do not use isolated facial features in attempts to recognise faces, whereas six-year-olds rely heavily on this form of encoding. They suggest that the reason for this is because children under 10 have not developed ‘the ability to encode orientation-specific configurational aspects of a face’ yet, which forces them to focus on specific aspects of a face in remembering it, and therefore they have difficulty recalling a face if a feature they remember, such as bushy eyebrows, has been disguised (Carey & Diamond, 1977). Carey and Diamond (1977) also found that people aged 10 and over encode spatial relationships among facial features. As an effect of this learned ability, between the ages of six and 10 recognition performance of upright faces improves dramatically, as apposed to recognition performance of inverted faces, which remains constant and is comparable to adult ability.

From age six there is a decline in the ability to recognise inverted faces, while the ability to recognise upright faces increases. Indeed, it has been shown that normal adults are able to recognise the faces of 90% of their classmates 35 years after graduation. This all seems to imply a loss of encoding ability. (Carey, et al. 1980)

Blaney and Winograd (1978) suggest that in the case of face recognition “… older children encode more features than younger children and that at both ages additional features are sampled when judgments of niceness are demanded.” Investigation of facial judgement with regards to likeability indicates support for the assertion that children lack the capacity, rather than the ability, to encode upright faces as efficiently as adults (Carey et al. 1980). Carey, Diamond and Woods’ (1980) study suggests that only a five second viewing is required for an adult to encode a face, whereas it takes a 6-year-old several minutes of exposure to different facial variants, such as angle and expression.

Given these previous studies it is hypothesised for this study that 10-year-olds will correctly recognise a greater proportion of upright faces than will six-year-olds, and that 18-year-olds will correctly recognise a greater proportion of upright faces than will 10-year-olds.

It is also hypothesised that 10-year-olds will not correctly recognise a greater proportion of inverted faces than will six-year-olds, and that 18-year-olds will not correctly recognise a greater proportion of inverted faces than 10-year-olds.

It was also predicted that 10- and 18-year-olds will recognise a greater proportion of upright compared to inverted faces, and six-year-olds will not correctly recognise more upright than inverted faces.


Method


Participants
A total of 75 participants were recruited by experimenters at La Trobe University, Melbourne, of which 25 were six-year-old children, 25, 10-year-old children and 25, 18-year-old adults. The sex of the participants was uncontrolled, for this variable has been found to not influence performance in face recognition.

Apparatus
Apparatus included a set of 40 black-and-white photographs of faces, half each of either sex, cropped beneath the chin and taken against a uniform background with all distinctive cues eliminated to ensure uniformity. There were 20 target faces and 20 distracter faces, half each of either sex per grouping. These were divided equally into two sets, one upright and one inverted set. A slide projector and screen was used to present the faces.

Procedure
Two tests were administered to each participant, both the upright and inverted faces tests, with each test consisting of a familiarization phase and a recognition phase. Participants were told which orientation of the pictures they were to be presented and tested in. During the familiarization phase, 10 faces (five female; five male) were randomly presented for five seconds each. During the recognition phase, the 10 target faces were presented along with the 10 distracter faces (5 female: 5 male), all in a different, random order. There was no time limit imposed here; rather, the participants were required to note whether the face shown in each recognition phase was familiar or novel. The number of faces correctly identified from the target set for each condition (maximum 10) was recorded for each participant. The order of testing was counterbalanced across groups.


Results


Figure 1 shows that there is an increased ability to recognise upright faces across age groups, as there was found to be an overlap of less than half the margin of error between the age groups of 10 and 18, and no overlap in the margin of error between the age groups of six and 10.

Figure 1. Percentage of correctly recognised upright faces for each age group (with bars showing standard error of means)

Figure 2 shows an overlap of more than half the margin of error between the age groups of six and 10, and of 10 and 18, which indicates that there are no significant differences in the ability to recognise inverted faces between these age groups. However, there is slight overlap in the margin of error between the age group of six and 18, thus indicating an overall increased ability to recognise inverted faces between these two ages.

Figure 2. Percentage of correctly recognised inverted faces for each age group (with bars showing standard error of means)

Figure 3 shows that there was no difference in six-year-olds’ ability to correctly recognise upright and inverted faces, for the margin of error crossed 0. Conversely, the graph shows a significant difference in ability between the 10- and 18-year-olds.

Figure 3. Difference in the percentage of correctly recognised upright and inverted faces for each age group (with bars showing standard error of means)


Discussion


All three hypotheses are supported, although an unexpected over-all increase in the proportion of correctly recognised inverted faces between the ages of six and 18 is indicated. Previous studies found no increase in inverted face recognition across such an age-range; however, this study suggests that it may, in fact, exist, developing at an initially rapid rate in early childhood and then continuing development throughout life, only at a slower rate, thereby assuming a secondary role to the more reliable method of encoding that is spatial relationship encoding.

One limitation of this study is that a photograph can only represent a single view of a subject, which, as discussed earlier in relation to Carey, Diamond and Woods’ (1980) conclusions, may limit a child’s ability to encode a face. Another limitation is that imposed by the shifts in perception as people mature. To an 18-year-old, distinct facial features like a ‘stoned’ look provide a sense of familiarity, but a six-year-old’s interpretation of a purely superficial feature, like a big nose, provides little. Diamond and Carey (1977) found that “young children were not fooled by simple disguises if the photographs showed persons already highly familiar to them;” if the distinct features recognisable to an 18-year-old were absent would they do any better than a six-year-old, or would they, too, revert to encoding piecemeal, causing inverted faces to have little bearing on their recall accuracy? This absence of distinguishing features is, I believe, a contributing factor in the phenomenon of own-race face recognition bias.

So, there seems to be at least two factors involved in face recognition – the encoding of specific features, and the encoding of spatial relationships. This does not, however, explain the own-race face recognition bias, which, as Anderson (1999) points out, “… has been reliably demonstrated by innumerable experiments” and seems to indicate that there is more involved in the encoding of faces than the two aforementioned factors. It is my opinion that own-face recognition bias occurs because most people find the interpretation of emotion and character difficult in, what is to them, an unusual facial configuration, thus causing categorisation conflict in the encoding of the face. This encoding conflict probably has something to do with six-year-old children’s inability to recognise new faces from a photograph, where they do not possess enough information to categorise it except in a very superficial, piecemeal fashion. This is in accordance with Blaney and Winograd’s (1978) study, where they showed that the accuracy of memory recall increased across all age groups when faces were judged in terms of ‘niceness’.

It would be interesting to undertake a study on face recognition of upright and inverted faces using photographs of different race faces, to ascertain how the encoding would then work.


References


Anderson, Justin Lee. (1999). Determinants of accuracy in cross-racial identification [Electronic version]. Ann Arbor, MI: UMI Company.

Blaney, R.L., & Winograd, E. (1978). Developmental differences in children’s recognition memory for faces [Electronic version]. Developmental Psychology, 14, 441-442.

Carey, S., & Diamond, R. (1977). From piecemeal to configurational representation of faces [Electronic version]. Science, 195, 312-314.

Carey, S., Diamond, R., & Woods, B. (1980). Development of face recognition – A maturational component [Electronic version]? Developmental Psychology, 16, 257- 269.

Chiara Turati, Viola Macchi Cassia, Francesca Simion, & Irene Leo. (2006). Newborns' Face Recognition: Role of Inner and Outer Facial Features [Electronic version]. Child Development, 77 (2), 297.

Graham, Reiko & Cabeza, Robert. (2001). Dissociating the Neural Correlates of Item and Context Memory: An ERP Study of Face Recognition [Electronic version]. Canadian Journal of Experimental Psychology, 55 (2), 154-161.

Westen, D., Burton, L., and Kowalski, R. (2006). Psychology: Australian and New Zealand Edition. Milton, Qld: Wiley

1 Comments:

Blogger Assignment Nerd said...

University: La Trobe
Subject: PSYCHOLOGY A
Semester: 1, 2006
Mark: don't know yet
Comments: Can you think of anything more boring? I assume not, if you read this essay you are most likely asleep by now.

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