/ Child Psychol. Psychiai. Vol. 31, No. 2, pp. 203-215, 1990 Printed in Great Britain.
0021-9630/90 $3.00 + 0.00 Pergamon Press pic © 1990 Association for Child Psychology and Psychiatry
The Recognition Failure and Graphic Success of Idiot-Savant Artists Neil O'Connor and Beate Hermelin Abstract—Three groups of subjects, an idiot-savant group, a group of mentally handicapped subjects matched for IQ, and normal artistically gifted children, were compared for their recognition and graphic reproduction abilities. It was found that, independent of input modality, level of intelligence determined recognition performance, while graphic ability independent of I Q was the determining factor in reproduction accuracy. Keywords: Recognition or visual recognition, reproduction or graphic reproduction, intelligence-independent
Introduction There have been two independent trends in the study of drawing. One is the investigation of normal child development as illustrated through drawing (Freeman & Cox, 1985) and the other the consideration of the aesthetic quality of drawings of highly gifted people independent of age. A third issue, the study of the strategies involved in successful drawing has received very little attention, although van Sommers (1984) has made a beginning. The presence of such strategies as manifested in the drawings of talented artists may be shown at a very early age. Paine (1981) noted that a number of people who subsequently enjoyed reputations as artists of merit were precocious. Her list includes Millais and Toulouse-Lautrec. Gardner (1984) similarly noted Michelangelo's early development. Research by Harris (1963) into the development of drawing in children, led to the conclusion that artistic talent was associated with high intelligence. However, some of the justification for such a view rests on the results of the Goodenough-Harris "Draw a Man" test of intelligence which in itself may measure artistic talent as much as intelligence. Thus, the relationship between artistic talent and intelligence may be much weaker than Harris thought, and indeed reports of idiot-savant artists occur early in the literature (Tredgold, 1947). Selfe (1985) has more recently collected a number of cases of autistic children with considerable artistic ability but of low intelligence. In explaining Accepted manuscript received 15 March 1989
Medical Research Council, Institute of Education, University of London, London, U.K. Requests for reprints to: Dr Neil O'Connor, MRC Developmental Psychology Project, 18 Woburn Square, London WCIH ONS, U.K.
204
N. O'Connor and B. Hermelin
this phenomenon Selfe (1985) points out that Hermelin and O'Gonnor (1970) drew attention to the failure of autistic children to connect material perceptually presented with conceptual schemata. Such children showed a tendency to restrict attention to currently presented data. She speculates that this tendency on the part of autistic children may account for their representational accuracy in drawing. However, as she herself points out, only a very limited number of autistic children are talented and one could add, not all talented children of low IQare autistic. The explanation of talent in those of below average IQ, therefore, cannot reside solely in autism and in fact our previous studies give reason to see it as independent of both autism and high intelligence. If, therefore, these explanations are insufficient or inadequate, could artistic talent be a function of a tenacious memory as Gardner (1984) suggests? Michelangelo is reported by Georgio Vasari in his Lives of the Artists to have been able to remember the works of others after having once seen them, and to never repeat any of his own. While this sort of visual memory may exist in some notable artists, our own work with talented artists of low intelligence (O'Gonnor & Hermelin, 1987b) suggests that visual recognition memory is positively related to intelligence and is not found to be well developed in mentally handicapped artists. Thus, if neither intelligence, autism nor good visual memory infallibly accounts for artistic talent, it is not surprising that Selfe (1985) confessed herself baffled by the occurrence of artistic ability in the mentally handicapped. From the results of our previous study, we concluded that idiot-savant artists may be able to generate better view-sf)ecific motor programmes than their intellectual equals. Such an inference was supported by the superiority of such subjects in copying a Rey-Osterrieth (Rey, 1942) figure and in reproducing it from memory. In discussing the question of good and bad drawers, van Sommers (1984) concludes that some people draw consistently well and others less well. However, he thinks that he cannot be so definite in deciding whether good drawers select graphically more appropriate strategies. He does, nonetheless, say that although the best performers use the best strategies, they can apparently make good use of strategies which when employed by bad drawers, seem to lead to disaster. Are they, therefore, he asks "using knowledge of important internal relationships that do not show up directly in the structure of their production sequences?" Previously we had established that mentally handicapped individuals with a talent for drawing which would have allowed them entry into art school, drew abstract shapes from memory as well as artistically gifted controls of above average intelligence (O'Gonnor & Hermelin, 1987b). Yet when a drawing of a shape had, after prior presentation, to be recognised from amongst five alternatives, these same subjects only performed at the level of an IQ-matched control group. Thus, while reproduction ability was dependent on artistic talent, the level of recognition skill was associated with the level of general intelligence. Several questions arose out of these results. The first was whether they would also apply if the stimuli were not meaningless shapes but pictures of named objects. The second question was whether the required response mode, i.e. selecting a previously seen stimulus from amongst a number of others which were simultaneously shown, represented a particularly difficult task for people of low intelligence, as a great deal
Recognition and graphic ability of idiot-savant artists
205
of information had to be processed and sifted with such a procedure. Finally, we considered the possibility that the idiot-savant graphic artists might have converted visual input directly into a motor output programme, without storing the visual information. Thus in the following study the stimuli we used, in addition to abstract designs, were representations of common objects, and a recognition paradigm was employed where a single stimulus was presented and had to be judged as the same as/or different from one experienced immediately before. Matching, recognition and reproduction were required, and the stimuli were either visually presented or were explored by touch. Three groups of subjects were used. The experimental group consisted of mentally retarded individuals with an exceptional graphic talent. Although of low IQ, they matched a group of normal children who were gifted for drawing on the Goodenough "Draw a Man" test. A second control group, not graphically talented but matched for IQwith the idiot-savants, was also included. Thus it was hoped to elucidate which of the variables tested might be a function of artistic talent, and which depended on the level of generail cognitive functioning. Subjects
There were three groups of subjects with eight members in each group. The first group consisted of idiot-savant artists who were chosen for their outstanding drawing ability. They were judged by a group of artists teaching art at the University of London as being at a standard to enter art school. Examples of their drawings are given in Fig. 1. Of these eight subjects, four of whom were autistic, and four mentally handicapped, seven were males and one female. They had an average age of 25.7 yrs, and their performance I Q on the Columbia Scale was 72.2. Their average verbal IQ on the Peabody was 67.0. The second group was a group matched for age and diagnosis with the idiot-savant group. Their mean age was 24.1 years and their performance and verbal IQs were 71.3 and 63.5 respectively. The third group of subjects of normal intelligence and notable artistic ability were chosen from a group of 13- to 14-year-old pupils of a high school near London. These subjects (average age 13.8 years) were believed by their art teacher to fall into the top 2% of children in terms of their artistic ability. In addition to the IQs already mentioned, the idiots-savants and the normal gifted children were given the Goodenough "Draw a Man" test. The I Q equivalents for the idiot-savants were 114.4 and for the normal gifted artist group 119.6. The two scores did not differ significantly. We thus had three groups of subjects, two matched for talent, the normal and idiot-savant artist group, and two matched for intelligence, i.e. the idiot-savant group and the mentally handicapped control group. The same subjects were used in all studies described here.
Visual-visual recognition memory We had previously found that idiot-savant artists were inferior to artistically gifted normal children and no better than IQ-matched controls in recognising a previously presented complex visual shape from amongst five alternatives. The question in regard to this finding was whether this mzinner of testing recognition, which made it necessary to process a great deal of information, had provided some special and additional difficulty for those subjects with low IQs. In the present task, therefore, the method was to present one shape, followed by a second one, and to require a "same-different" judgement.
206
N. O'Connor and B. Hermelin
Fig. 1. Examples of drawings by idiot-savant artists. Materials and procedure
The material consisted of six pairs of designs, members of which were either identical or differed in prominent detail. Two examples, one of a pair which was the same and one of a different pair are given in Fig. 2. Subjects were visually presented with the first member of a pair of these complex abstract shapes and then after a brief exposure of five seconds the first member of the pair was removed and the second member shown. A judgement of "same" or "different" was requested. Six such stimulus pairs were thus successively presented. The comparison required recognition memory and was unimodal as both stimuli were visual.
Results
Each subject could obtain a maximum score of six correct responses, i.e. a total of 48 for each group. For the eight subjects of each group, total correct recognition
Recognition and graphic ability of idiot-savant artists
207
(b)
Fig. l(b).
responses were, for the normal children 45, for the idiot savant artists 36, and for the handicapped control group 33. A one-way analysis of variance resulted in a significant F of 8.02; /?< 0.01. In testing for simple effects a ^ o f 2 . 8 7 ; / ? < 0 . 0 1 was obtained in comparing the normal with the idiot-savant artists. There was no significant difference between the idiot-savant group and the mentally handicapped controls but the latter differed significantly from the normal artists. These results indicate that where visual recognition memory is involved, the performance of the idiot-savant group closely approximates that of the handicapped controls of the same intelligence level and differs significantly from that pf children of higher intelligence but similar graphic ability.
208
N. O'Connor and B. Hermelin
Fig. l(c). Discussion
Recognition and graphic ability of idiot-savant artists
209
Fig. 2. Same and different stimulus pairs for visual recognition.
Visual-kinaesthetic matching The basic result obtained in previous studies was that idiot-savant artists appeared to have a good reproductive recall as expressed in their drawings from memory but poor visual recognition capacity. The question therefore arises whether graphic reproductive ability depends on a conversion of visual into motor memory, or whether the motor reproduction is a generated motor programme which is independent of visual memory. In the two following tasks cross-modal visual-kinaesthetic comparisons have to be made, which require either matching or recognition. The first of these tasks deals with cross-modal matching ability. Moving the finger around a stimulus may, in its motor aspects, be akin to drawing it. It was therefore asked whether mentally handicapped subjects with superior graphic ability would behave like normal artistically gifted subjects or like IQ-matched controls when asked to decide whether two stimuli, which were presented simultaneously to vision and touch, were either the same or different. Material
The material used in this, as well as in the following tasks, consisted of cut-out representational shapes mounted on white painted hardboard measuring 7" xl". There were four sets of eight pairs of outline representations of common objects. In any set four pairs contained stimuli which, though representing the same kind of object, differed from each other in regard to detailed features. The stimuli represented for instance two different trees, or two faces, vases, vehicles, or leaves. There were also four identical pairs in each set. Examples of same and different stimulus pairs are given in Fig. 3. The four different sets of eight stimulus pairs were varied over tasks, as was the order in which the tasks were presented.
210
N. O'Connor and B. Hermelin
Fig. 3. Examples of same and different pairs. Procedure
A visual stimulus was presented to the subject, at the same time as he was asked to trace around another, presented behind a screen so that it could not be seen. The subject had to make eight judgements, for four "same" and four "different" pairs. Subjects were always told what the stimulus represented, for instance, "Here are two trees, look at one while you move your finger around the other. Are they the same or do they differ in some way?"
Results
Each subject was asked to make eight judgements and was thus able to achieve a maximum score of eight. Therefore, for the eight subjects in each group there were 64 possible correct responses. The total scores for the three groups are 60 for the normal artists, 59 for the idiot-savant artists, and 45 for the mentally handicapped controls. The results of a simple smalysis of variance yielded an F of 5.17; df = 2/21; /> < 0.05. A significant ^ of 2.68; />< 0.05 was obtained between the idiot-savant artist group and the subnormal controls, while the difference between the normal talented group and the idiot-savant artists was not significant. Discussion
The results from this visual-kinaesthetic task are reminiscent of those from a previous experiment (O'Gonnor & Hermelin, 1987b) on visual-visual matching. In both
Recognition and graphic ability of idiot-savant artists
211
instances the idiot-savant artists perform at a similar level to normal artistically gifted children and significantly better than IQ-matched controls. Thus deciding whether two simultaneously presented stimuli are the same or not appears to be correlated with graphic ability and to be independent of level of IQ. This applies whether these stimuli represent abstract shapes or common objects, and regardless of the modality of input. Visual-kinaesthetic recognition memory While we found that idiot-savant artists were no better in visual-visual recognition memory than IQ-matched controls, they were equal to artistically gifted normal children in their ability to judge simultaneously presented visual and tactile stimuli as being either the same or different. Thus while visual-visual recognition clearly seemed to be dependent on IQ, visual-kinaesthetic matching ability appeared to be related to artistic talent. The next question to be asked therefore was which of these two factors, i.e. intelligence level or graphic ability, would determine visual-kinaesthetic recognition memory. Material and procedure
The material used was similar to that already described (see Fig. 3). The procedure was the same as in the matching task, except that the visual and kinaesthetic stimuli were presented successively. A delay of 10 seconds was introduced between the first, visual, presentation and the second, kinaesthetic, presentation. The visual presentation usually occupied five seconds and the tracing was of approximately the same duration. Subjects were always asked whether the two stimuli, one seen and one subsequently traced unseen, were the same or different.
Results
Out of 64 possible correct recognition responses, the score of the normal artists was 57, of the idiot-savant artists 42, and of the mentally handicapped controls 43. A simple analysis of variance of these visual-kinaesthetic recognition scores resulted in an F of 4.58; df = 2/21; p < 0.05. Subsequent Mests between the normal group and the two groups of below normal IQwere significant at the 0.05 level. These were for the idiot-savant artists 2.71; p < 0.05, and for the subnormal controls 2.52; p < 0.05. Discussion
In contrast to visual-kinaesthetic matching, visual-kinaesthetic recognition is clearly a function of I Q and not of artistic talent. Both groups, idiot-savant artists as well as controls, were inferior in their recognition performance to the normal children. This conclusion is independent of whether recognition is tested with material representing abstract shapes or common objects, and applies regardless of whether uni-modal or cross-modal presentation is involved. Thus while matching depends on graphic ability, recognition memory is related to intelligence. Memory reproduction after visual presentation Thus far we had established that while in a visual-kinaesthetic matching task idiotsavant artists performed at a level equal to that of graphically able normal children,
212
N. O'Connor and B. Hermelin
they were only equal to an IQ-matched control group, and significantly worse than the normals, when the task involved visual-kinaesthetic recognition memory. However, in a previous experiment (O'Gonnor & Hermelin, 1987b) results had shown that while I Q had determined performance levels of visual recognition memory, reproduction of shapes after visual presentation was dependent on artistic ability, and was independent of level of intelligence. Two separate processes would appear to be operating in these two tasks. For recognition, two kinds of input are successively submitted for comparison, while for reproduction one input is recoded for graphic reproduction. Idiot-savant artists appear to be efficient in such recoding of input into motor programmes. In order to test this hypothesis further in this study a stimulus was presented for visual inspection and the subject was then asked to draw it from memory. The same three groups of subjects, i.e. idiot-savant artists, normal artists and mentally handicapped controls took part. Procedure
Each subject was shown a stimulus and was always told what it represented, i.e. a tree, a face, etc. After a short time interval he was asked to draw as precisely as possible what he had just seen.
Results
In this task each stimulus when reproduced was scored according to the number of departures from the original, which for each of the eight drawings was judged to a maximum of seven errors. The total possible number of errors for a group of eight subjects was, therefore, 8 x 56 or 448 errors. The error scores for the drawings after visuad presentation of stimuli were for the normal artists 138, for the idiot-savant artists 211, and for the mentally handicapped controls 328. A simple analysis of variance yielded an i^ of 21.03; df= 2/21; />< 0.001. A subsequent ^test, between the idiot-savant group and the subnormal controls showed that these two groups differed at the 0.01 level. However, the idiot-savant artist group did not differ significantly from the normal gifted artists. To clarify the nature of the error data, errors for each subject were sub-divided into "Additions", "Omissions" and "Distortions" of features in the originally presented outline. Table 1 gives the error data for each group. Table 1. Reproduction error scores: visual presentation Groups Normal artists Idiot-savant artists Mentally handicapped
Additions 10 42 51
Omissions Distortions 49 58 171
79 111 106
Additions were counted if, for example, a vehicle which had no tyres was given tyres, or a figure was given features not in the original. Omissions were recorded when features such as waists or legs on figures were not represented, branches left off trees, or petals omitted from flowers. Distortions were recorded when a feature
Recognition and graphic ability of idiot-savant artists
213
of a model was correctly included but represented in a distorted fashion. For example, pointed petals on a flower might be drawn as smoothly rounded, or a markedly long branch on a tree reduced considerably in extent so as to distort the gestalt of the model. An analysis of variance showed a significant interaction of groups by error types (F= 3.96; df = 4/63; p
0021-9630/90 $3.00 + 0.00 Pergamon Press pic © 1990 Association for Child Psychology and Psychiatry
The Recognition Failure and Graphic Success of Idiot-Savant Artists Neil O'Connor and Beate Hermelin Abstract—Three groups of subjects, an idiot-savant group, a group of mentally handicapped subjects matched for IQ, and normal artistically gifted children, were compared for their recognition and graphic reproduction abilities. It was found that, independent of input modality, level of intelligence determined recognition performance, while graphic ability independent of I Q was the determining factor in reproduction accuracy. Keywords: Recognition or visual recognition, reproduction or graphic reproduction, intelligence-independent
Introduction There have been two independent trends in the study of drawing. One is the investigation of normal child development as illustrated through drawing (Freeman & Cox, 1985) and the other the consideration of the aesthetic quality of drawings of highly gifted people independent of age. A third issue, the study of the strategies involved in successful drawing has received very little attention, although van Sommers (1984) has made a beginning. The presence of such strategies as manifested in the drawings of talented artists may be shown at a very early age. Paine (1981) noted that a number of people who subsequently enjoyed reputations as artists of merit were precocious. Her list includes Millais and Toulouse-Lautrec. Gardner (1984) similarly noted Michelangelo's early development. Research by Harris (1963) into the development of drawing in children, led to the conclusion that artistic talent was associated with high intelligence. However, some of the justification for such a view rests on the results of the Goodenough-Harris "Draw a Man" test of intelligence which in itself may measure artistic talent as much as intelligence. Thus, the relationship between artistic talent and intelligence may be much weaker than Harris thought, and indeed reports of idiot-savant artists occur early in the literature (Tredgold, 1947). Selfe (1985) has more recently collected a number of cases of autistic children with considerable artistic ability but of low intelligence. In explaining Accepted manuscript received 15 March 1989
Medical Research Council, Institute of Education, University of London, London, U.K. Requests for reprints to: Dr Neil O'Connor, MRC Developmental Psychology Project, 18 Woburn Square, London WCIH ONS, U.K.
204
N. O'Connor and B. Hermelin
this phenomenon Selfe (1985) points out that Hermelin and O'Gonnor (1970) drew attention to the failure of autistic children to connect material perceptually presented with conceptual schemata. Such children showed a tendency to restrict attention to currently presented data. She speculates that this tendency on the part of autistic children may account for their representational accuracy in drawing. However, as she herself points out, only a very limited number of autistic children are talented and one could add, not all talented children of low IQare autistic. The explanation of talent in those of below average IQ, therefore, cannot reside solely in autism and in fact our previous studies give reason to see it as independent of both autism and high intelligence. If, therefore, these explanations are insufficient or inadequate, could artistic talent be a function of a tenacious memory as Gardner (1984) suggests? Michelangelo is reported by Georgio Vasari in his Lives of the Artists to have been able to remember the works of others after having once seen them, and to never repeat any of his own. While this sort of visual memory may exist in some notable artists, our own work with talented artists of low intelligence (O'Gonnor & Hermelin, 1987b) suggests that visual recognition memory is positively related to intelligence and is not found to be well developed in mentally handicapped artists. Thus, if neither intelligence, autism nor good visual memory infallibly accounts for artistic talent, it is not surprising that Selfe (1985) confessed herself baffled by the occurrence of artistic ability in the mentally handicapped. From the results of our previous study, we concluded that idiot-savant artists may be able to generate better view-sf)ecific motor programmes than their intellectual equals. Such an inference was supported by the superiority of such subjects in copying a Rey-Osterrieth (Rey, 1942) figure and in reproducing it from memory. In discussing the question of good and bad drawers, van Sommers (1984) concludes that some people draw consistently well and others less well. However, he thinks that he cannot be so definite in deciding whether good drawers select graphically more appropriate strategies. He does, nonetheless, say that although the best performers use the best strategies, they can apparently make good use of strategies which when employed by bad drawers, seem to lead to disaster. Are they, therefore, he asks "using knowledge of important internal relationships that do not show up directly in the structure of their production sequences?" Previously we had established that mentally handicapped individuals with a talent for drawing which would have allowed them entry into art school, drew abstract shapes from memory as well as artistically gifted controls of above average intelligence (O'Gonnor & Hermelin, 1987b). Yet when a drawing of a shape had, after prior presentation, to be recognised from amongst five alternatives, these same subjects only performed at the level of an IQ-matched control group. Thus, while reproduction ability was dependent on artistic talent, the level of recognition skill was associated with the level of general intelligence. Several questions arose out of these results. The first was whether they would also apply if the stimuli were not meaningless shapes but pictures of named objects. The second question was whether the required response mode, i.e. selecting a previously seen stimulus from amongst a number of others which were simultaneously shown, represented a particularly difficult task for people of low intelligence, as a great deal
Recognition and graphic ability of idiot-savant artists
205
of information had to be processed and sifted with such a procedure. Finally, we considered the possibility that the idiot-savant graphic artists might have converted visual input directly into a motor output programme, without storing the visual information. Thus in the following study the stimuli we used, in addition to abstract designs, were representations of common objects, and a recognition paradigm was employed where a single stimulus was presented and had to be judged as the same as/or different from one experienced immediately before. Matching, recognition and reproduction were required, and the stimuli were either visually presented or were explored by touch. Three groups of subjects were used. The experimental group consisted of mentally retarded individuals with an exceptional graphic talent. Although of low IQ, they matched a group of normal children who were gifted for drawing on the Goodenough "Draw a Man" test. A second control group, not graphically talented but matched for IQwith the idiot-savants, was also included. Thus it was hoped to elucidate which of the variables tested might be a function of artistic talent, and which depended on the level of generail cognitive functioning. Subjects
There were three groups of subjects with eight members in each group. The first group consisted of idiot-savant artists who were chosen for their outstanding drawing ability. They were judged by a group of artists teaching art at the University of London as being at a standard to enter art school. Examples of their drawings are given in Fig. 1. Of these eight subjects, four of whom were autistic, and four mentally handicapped, seven were males and one female. They had an average age of 25.7 yrs, and their performance I Q on the Columbia Scale was 72.2. Their average verbal IQ on the Peabody was 67.0. The second group was a group matched for age and diagnosis with the idiot-savant group. Their mean age was 24.1 years and their performance and verbal IQs were 71.3 and 63.5 respectively. The third group of subjects of normal intelligence and notable artistic ability were chosen from a group of 13- to 14-year-old pupils of a high school near London. These subjects (average age 13.8 years) were believed by their art teacher to fall into the top 2% of children in terms of their artistic ability. In addition to the IQs already mentioned, the idiots-savants and the normal gifted children were given the Goodenough "Draw a Man" test. The I Q equivalents for the idiot-savants were 114.4 and for the normal gifted artist group 119.6. The two scores did not differ significantly. We thus had three groups of subjects, two matched for talent, the normal and idiot-savant artist group, and two matched for intelligence, i.e. the idiot-savant group and the mentally handicapped control group. The same subjects were used in all studies described here.
Visual-visual recognition memory We had previously found that idiot-savant artists were inferior to artistically gifted normal children and no better than IQ-matched controls in recognising a previously presented complex visual shape from amongst five alternatives. The question in regard to this finding was whether this mzinner of testing recognition, which made it necessary to process a great deal of information, had provided some special and additional difficulty for those subjects with low IQs. In the present task, therefore, the method was to present one shape, followed by a second one, and to require a "same-different" judgement.
206
N. O'Connor and B. Hermelin
Fig. 1. Examples of drawings by idiot-savant artists. Materials and procedure
The material consisted of six pairs of designs, members of which were either identical or differed in prominent detail. Two examples, one of a pair which was the same and one of a different pair are given in Fig. 2. Subjects were visually presented with the first member of a pair of these complex abstract shapes and then after a brief exposure of five seconds the first member of the pair was removed and the second member shown. A judgement of "same" or "different" was requested. Six such stimulus pairs were thus successively presented. The comparison required recognition memory and was unimodal as both stimuli were visual.
Results
Each subject could obtain a maximum score of six correct responses, i.e. a total of 48 for each group. For the eight subjects of each group, total correct recognition
Recognition and graphic ability of idiot-savant artists
207
(b)
Fig. l(b).
responses were, for the normal children 45, for the idiot savant artists 36, and for the handicapped control group 33. A one-way analysis of variance resulted in a significant F of 8.02; /?< 0.01. In testing for simple effects a ^ o f 2 . 8 7 ; / ? < 0 . 0 1 was obtained in comparing the normal with the idiot-savant artists. There was no significant difference between the idiot-savant group and the mentally handicapped controls but the latter differed significantly from the normal artists. These results indicate that where visual recognition memory is involved, the performance of the idiot-savant group closely approximates that of the handicapped controls of the same intelligence level and differs significantly from that pf children of higher intelligence but similar graphic ability.
208
N. O'Connor and B. Hermelin
Fig. l(c). Discussion
Recognition and graphic ability of idiot-savant artists
209
Fig. 2. Same and different stimulus pairs for visual recognition.
Visual-kinaesthetic matching The basic result obtained in previous studies was that idiot-savant artists appeared to have a good reproductive recall as expressed in their drawings from memory but poor visual recognition capacity. The question therefore arises whether graphic reproductive ability depends on a conversion of visual into motor memory, or whether the motor reproduction is a generated motor programme which is independent of visual memory. In the two following tasks cross-modal visual-kinaesthetic comparisons have to be made, which require either matching or recognition. The first of these tasks deals with cross-modal matching ability. Moving the finger around a stimulus may, in its motor aspects, be akin to drawing it. It was therefore asked whether mentally handicapped subjects with superior graphic ability would behave like normal artistically gifted subjects or like IQ-matched controls when asked to decide whether two stimuli, which were presented simultaneously to vision and touch, were either the same or different. Material
The material used in this, as well as in the following tasks, consisted of cut-out representational shapes mounted on white painted hardboard measuring 7" xl". There were four sets of eight pairs of outline representations of common objects. In any set four pairs contained stimuli which, though representing the same kind of object, differed from each other in regard to detailed features. The stimuli represented for instance two different trees, or two faces, vases, vehicles, or leaves. There were also four identical pairs in each set. Examples of same and different stimulus pairs are given in Fig. 3. The four different sets of eight stimulus pairs were varied over tasks, as was the order in which the tasks were presented.
210
N. O'Connor and B. Hermelin
Fig. 3. Examples of same and different pairs. Procedure
A visual stimulus was presented to the subject, at the same time as he was asked to trace around another, presented behind a screen so that it could not be seen. The subject had to make eight judgements, for four "same" and four "different" pairs. Subjects were always told what the stimulus represented, for instance, "Here are two trees, look at one while you move your finger around the other. Are they the same or do they differ in some way?"
Results
Each subject was asked to make eight judgements and was thus able to achieve a maximum score of eight. Therefore, for the eight subjects in each group there were 64 possible correct responses. The total scores for the three groups are 60 for the normal artists, 59 for the idiot-savant artists, and 45 for the mentally handicapped controls. The results of a simple smalysis of variance yielded an F of 5.17; df = 2/21; /> < 0.05. A significant ^ of 2.68; />< 0.05 was obtained between the idiot-savant artist group and the subnormal controls, while the difference between the normal talented group and the idiot-savant artists was not significant. Discussion
The results from this visual-kinaesthetic task are reminiscent of those from a previous experiment (O'Gonnor & Hermelin, 1987b) on visual-visual matching. In both
Recognition and graphic ability of idiot-savant artists
211
instances the idiot-savant artists perform at a similar level to normal artistically gifted children and significantly better than IQ-matched controls. Thus deciding whether two simultaneously presented stimuli are the same or not appears to be correlated with graphic ability and to be independent of level of IQ. This applies whether these stimuli represent abstract shapes or common objects, and regardless of the modality of input. Visual-kinaesthetic recognition memory While we found that idiot-savant artists were no better in visual-visual recognition memory than IQ-matched controls, they were equal to artistically gifted normal children in their ability to judge simultaneously presented visual and tactile stimuli as being either the same or different. Thus while visual-visual recognition clearly seemed to be dependent on IQ, visual-kinaesthetic matching ability appeared to be related to artistic talent. The next question to be asked therefore was which of these two factors, i.e. intelligence level or graphic ability, would determine visual-kinaesthetic recognition memory. Material and procedure
The material used was similar to that already described (see Fig. 3). The procedure was the same as in the matching task, except that the visual and kinaesthetic stimuli were presented successively. A delay of 10 seconds was introduced between the first, visual, presentation and the second, kinaesthetic, presentation. The visual presentation usually occupied five seconds and the tracing was of approximately the same duration. Subjects were always asked whether the two stimuli, one seen and one subsequently traced unseen, were the same or different.
Results
Out of 64 possible correct recognition responses, the score of the normal artists was 57, of the idiot-savant artists 42, and of the mentally handicapped controls 43. A simple analysis of variance of these visual-kinaesthetic recognition scores resulted in an F of 4.58; df = 2/21; p < 0.05. Subsequent Mests between the normal group and the two groups of below normal IQwere significant at the 0.05 level. These were for the idiot-savant artists 2.71; p < 0.05, and for the subnormal controls 2.52; p < 0.05. Discussion
In contrast to visual-kinaesthetic matching, visual-kinaesthetic recognition is clearly a function of I Q and not of artistic talent. Both groups, idiot-savant artists as well as controls, were inferior in their recognition performance to the normal children. This conclusion is independent of whether recognition is tested with material representing abstract shapes or common objects, and applies regardless of whether uni-modal or cross-modal presentation is involved. Thus while matching depends on graphic ability, recognition memory is related to intelligence. Memory reproduction after visual presentation Thus far we had established that while in a visual-kinaesthetic matching task idiotsavant artists performed at a level equal to that of graphically able normal children,
212
N. O'Connor and B. Hermelin
they were only equal to an IQ-matched control group, and significantly worse than the normals, when the task involved visual-kinaesthetic recognition memory. However, in a previous experiment (O'Gonnor & Hermelin, 1987b) results had shown that while I Q had determined performance levels of visual recognition memory, reproduction of shapes after visual presentation was dependent on artistic ability, and was independent of level of intelligence. Two separate processes would appear to be operating in these two tasks. For recognition, two kinds of input are successively submitted for comparison, while for reproduction one input is recoded for graphic reproduction. Idiot-savant artists appear to be efficient in such recoding of input into motor programmes. In order to test this hypothesis further in this study a stimulus was presented for visual inspection and the subject was then asked to draw it from memory. The same three groups of subjects, i.e. idiot-savant artists, normal artists and mentally handicapped controls took part. Procedure
Each subject was shown a stimulus and was always told what it represented, i.e. a tree, a face, etc. After a short time interval he was asked to draw as precisely as possible what he had just seen.
Results
In this task each stimulus when reproduced was scored according to the number of departures from the original, which for each of the eight drawings was judged to a maximum of seven errors. The total possible number of errors for a group of eight subjects was, therefore, 8 x 56 or 448 errors. The error scores for the drawings after visuad presentation of stimuli were for the normal artists 138, for the idiot-savant artists 211, and for the mentally handicapped controls 328. A simple analysis of variance yielded an i^ of 21.03; df= 2/21; />< 0.001. A subsequent ^test, between the idiot-savant group and the subnormal controls showed that these two groups differed at the 0.01 level. However, the idiot-savant artist group did not differ significantly from the normal gifted artists. To clarify the nature of the error data, errors for each subject were sub-divided into "Additions", "Omissions" and "Distortions" of features in the originally presented outline. Table 1 gives the error data for each group. Table 1. Reproduction error scores: visual presentation Groups Normal artists Idiot-savant artists Mentally handicapped
Additions 10 42 51
Omissions Distortions 49 58 171
79 111 106
Additions were counted if, for example, a vehicle which had no tyres was given tyres, or a figure was given features not in the original. Omissions were recorded when features such as waists or legs on figures were not represented, branches left off trees, or petals omitted from flowers. Distortions were recorded when a feature
Recognition and graphic ability of idiot-savant artists
213
of a model was correctly included but represented in a distorted fashion. For example, pointed petals on a flower might be drawn as smoothly rounded, or a markedly long branch on a tree reduced considerably in extent so as to distort the gestalt of the model. An analysis of variance showed a significant interaction of groups by error types (F= 3.96; df = 4/63; p
