Deregowski pictorial perception
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You will find that this study has been criticised for being ethnocentric. Ethnocentrism refers to the tendency to view the world from the your own particular cultural or social group. This often leads to overestimating the importance and worth of people who are in your group (e.g. Westerners in Deregowski's study) and to underestimating the importance and worth of people who are not in your group (e.g. non-Western tribal people in Deregowski's study).
Deregowski can be seen as being ethnocentric in the way that he carried out his study by, for example, making the measures unfair, and in the explanations he gives for his findings.
Perception refers to the way we analyse and make sense of the information we receive from our senses. Our senses provide us with the raw data about our environment, but it is the brain that actually helps us to make sense of this confusion of information. The brain actively interprets and organises our sensory input, going beyond the basic data to create an understanding of our surroundings. Most of the time this occurs effortlessly. This process is called perception.
This article by Deregowski is interested in how we perceive pictures and in particular how we perceive depth in pictures. In Western cultures we tend to perceive depth in pictures even though they are really two-dimensional representations of three-dimensional objects.
Linear perspective (when parallel lines are pointing away from us they seem to get closer together in the distance)
Texture gradient (when objects such as grass or pebbles are closer we perceive more detail and when they are further away they tend to have less texture)
The aim of Deregowski's study was to discover to what extent perception of pictures relies upon learning
Deregowski starts his study by reviewing a number of reports of how people in different cultures often have difficulties with the perception of pictures (pictorial perception). For example, he recalled a story told by Mrs Donald Fraser, who taught health care to Africans in the 1920s. This is her description of an African woman slowly discovering that a picture she was looking at portrayed a human head in profile: 'She discovered in turn the nose, the mouth, the eye, but where was the other eye? I tried by turning my profile to explain why she could only see one eye but she hopped round to my other side to point out that I possessed a second eye which the other lacked'. Deregowski presented other anecdotal evidence to point out that some non-Western cultures find it difficult to perceive depth in pictures.
Deregowski conducted a review article which involved bringing together research by other psychologists and him-self. The research is cross-cultural. because a comparison is being made between the perception of 3-D pictures by members of Western cultures (unspecified) and various African countries (e.g. Zambia).
The method actually used to collect the data is a kind of natural experiment in which either the independent variable is the culture of the participants or is the characteristics of being a 3-D or 2-D perceiver (based on the answers to the Hudson’s picture tests). The method is an example of a natural (or quasi) experiment because the researcher is unable to manipulate the independent variable as it is a characteristic the participant already possesses.
Hudson's test consists of a series of pictures in which there are various combinations of three pictorial depth cues; relative size, superimposition and linear perspective.
Participants were shown the top picture and asked a number of questions including ‘what is the man is doing with the spear?’ and ‘which is nearer the antelope or the elephant?’
Both children and adults from African tribes found it difficult to perceive depth in the pictorial material.
Research participants were shown a drawing of two squares, one behind the other and connected with a single rod. They were also given sticks and modelling clay and asked to build a model of what they saw.
Almost all the 3-D perceivers built a 3-D object. Participants who did not readily perceive depth in pictures tended to build a flat model.
Participants were asked to copy a 'two pronged trident’; a tantalising drawing that confuses many people. The confusion is apparently a direct result of attempting to interpret the drawing as a 3-D object. When asked to copy the ambiguous trident participants who were classified as 3-D perceivers spent more time looking at the ambiguous trident than at the control trident, whereas 2-D perceivers did not differ significantly in the time spent viewing each of the two tridents.
This experiment used an apparatus designed by Richard Gregory. The apparatus for studying perceived depth enables the participant to adjust a spot of light so that it appears to lie at the same depth as an object in the picture. The light is seen stereoscopically with both eyes, but the picture is seen with only one eye.
A Hudson-test picture that embodied both familiar-size and overlap depth cues was presented in the apparatus to the participants. 2-D perceivers set the light at the same apparent depth regardless of whether they were asked to place it above the hunter, the antelope or the elephant. In contrast, when 3-D perceivers were tested, they set the light farther away from themselves when placing it on the elephant than when setting it on the figures in the foreground.
Deregowski found that the 2-D perceivers prefer split type drawings to the perspective type. Split drawings are drawings that depict the essential characteristics of an object even if all those characteristics cannot be seen from a single view point - if you like, unfolded
The split drawing (left) was generally preferred by African children and adults to the perspective drawing (right). One person, however, did not like the split drawing because he thought the elephant was jumping around in a dangerous manner.
Deregowski's major findings are that many non-Western tribal lack pictorial depth perception (studies 1-4) and that many non-Western tribal people prefer split drawings to perspective drawings (study 5).
Deregowski in attempting to account for cultural differences in perception of pictorial depth (studies 1-4), believes that non-Western tribal people lack the ability to perceive and integrate depth cues in pictures. Deregowski believes this inability is due to some form of learning or lack of learning.
Deregowski in accounting for the findings that some non-Western tribal people prefer split type drawings (study 5) believes that in all societies children have an aesthetic preference for drawings of the split type. In Western societies this preference is suppressed because the drawings do not convey information about the depicted objects as accurately as perspective drawings do. Therefore, according to Deregowski, we learn perspective drawings. (perspective drawings are sometimes called orthogonal drawings)
A major advantage of cross-cultural studies is if we find differences between different cultural groups then, unless we have good reasons for believing that these differences are biologically caused, we are able to argue that these differences are due to environmental factors.
The major problem with cross-cultural studies is making sure that the measures are fair and appropriate for both cultures. (Cross-cultural studies are also, of course, expensive)
The studies Deregowski described make it difficult for the African participants to give ‘correct’ responses?
Further studies by Deregowski have shown that when unfamiliar paper was replaced by pictures painted on familiar cloth, members of a tribe were more likely to make ‘correct’ responses.
It could be that the drawings used by Hudson emphasise certain depth cues while ignoring others, thus putting non-Western perceivers at a double disadvantage?
Hudson’s pictures include the depth cues of relative size, superimposition (overlap) and linear perspective. However missing is texture gradient which seems to be the most important pictorial depth cue for Western and non-Western participants. Serpell (1976) reported a study in which the experimenter got an artist to redraw one of Hudson’s pictures using texture gradient (pebbles on the road and grass on the terrain). 12 year-old Zambian children gave 64% 3-D answers compared with 54% on Hudson’s original. When relative brightness (colour and haze around distant hills) was added, the figure rose to 76%.
The main problem with Deregowski's explanations are that they can be interpreted as being ethnocentric and perhaps, better, alternative explanations can be found.
As already stated, Deregowski in attempting to account for cultural differences in perception of pictorial depth (studies 1-4), believes that non Western people lack the ability to perceive and integrate depth cues in pictures. Deregowski believes this inability is due to some form of learning or lack of learning.
Perhaps a better explanation for why some non Western people can't perceive depth in pictures is not that they failed to learn to use pictorial depth cues but rather that they have learned their own ways for representing the 3-D world in pictures e.g. in the form of split drawings.
There is also a better, less ethnocentric explanation for why some non Western tribal people prefer split type drawings. For example it can be argued that split drawings can convey just as much information as perspective drawings. Different cultures have different ways of representing the world in pictorial form. Some cultures simply have a stylistic preference for split drawings and have pictorial conventions which are shared by members of that culture.
Thus it is possible that what is taken as a difference in perception is really a matter of stylistic preference.
Deregowski’s explanation is ethnocentric because he seems to imply a belief that the Western style of pictorial art represents the real world in an objectively correct fashion; by implication, the person who does not understand it is ‘deficient’ in some way.
Despite this we should acknowledge that Deregowski’s work was studying cultural diversity which is something which in the past has been largely ignored in mainstream psychology. At the beginning of his article Deregowski asked the question ‘do pictures offer us a lingua franca for inter-cultural communication? Or in other words, do all cultures perceive pictures in the same way and therefore offer a universal means of communicating. The study obviously demonstrated that this is not so. However the study does demonstrate that to communicate well we do need to appreciate the differences between different cultures.
An example of a split drawing developed to a high artistic level. The bear was drawn by the Tsimshian Indians from the pacific coast of British Columbia.