Letters
The nature of visual self-recognition revisited Gordon G. Gallup Jr1, *, Steven M. Platek2, and Kristina N. Spaulding1 1 2
Department of Psychology, University at Albany, State University of New York, Albany, NY 12222, USA Department of Psychology, Georgia Gwinnett College, Lawrenceville, GA 30043, USA
It is not true that mirror self-recognition has nothing to do with self-awareness and, contrary to Suddendorf and Butler’s claim [1], that self-recognition is ‘universally acquired in toddlers’, there are failures to find mirror selfrecognition in mentally retarded children, adolescents, and adults, as well as in autistic children, schizophrenics, patients with damage to the frontal cortex, and those with dementia [2]. Also consistent with predictions based on self-awareness, chimpanzees show an ensemble of intricate reactions to the death of companions that parallel responses humans make [3]. The emergence of self-recognition corresponds with other behaviors linked to the development of self-awareness (e.g., prosocial behavior, use of personal pronouns, visual perspective taking, and autobiographical memory). Bischof-Kohler [4] found that only children who passed the mark test showed clear evidence of prosocial behavior and empathy. People lacking self-recognition exhibit deficits in similar aspects of self-awareness (mental state attribution, empathy, visual perspective taking). Deficits and delays in self-recognition (e.g., autism) covary with mental state attribution deficits, and this holds for braindamaged patients deficient in self-recognition and those who lose the capacity to recognize themselves due to mental illness [2]. Schizophrenia is a self-processing disorder [2]. Although schizophrenics have no trouble adjusting distorting mirrors to achieve undistorted images of other objects, they are incapable of adjusting mirrors to achieve undistorted images of themselves. Most people show a right hemisphere (left hand) advantage for identifying their face, but those with premorbid schizophrenic traits show right-hemisphere deficits in both self-face identification and picking self-descriptive adjectives [5]. Righthemisphere damage not only impairs mental state attribution and autobiographical memory [2], but produces deficits in awareness of ownership and agency of body parts [6]. Just as schizophrenics have difficulty distinguishing images of their hand from another person’s hand, normal people mistake their hand for a stranger’s hand when the right hemisphere is inactivated by sodium amobarbital. Corresponding author: Gallup, G.G. Jr ([email protected]). 1364-6613/$ – see front matter ß 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.tics.2013.10.012
Claims that mirror self-recognition has nothing to do with self-awareness ignore the fact that self-recognition extends beyond the visual domain. A study of selfprocessing in different modalities found that selfprimes in different sensory domains (e.g., briefly being shown their name or hearing their name) facilitated self-recognition [7]. If self-recognition was a byproduct of collating representations, seeing or hearing your name should leave your ability to identify your face unaffected because people rarely see or hear their names in contexts where they also see their faces. Your name is special because it is an embedded feature of your sense of self. Because the way people process information about themselves in one modality is affected by the presentation of independent information about the self in other modalities and, because other aspects of self-awareness coexist with self-recognition in common brain regions, this implicates self-recognition as an expression of a larger, underlying, well-integrated, multimodal self-processing system. Recent findings showing human-like electroencephalography (EEG) activation in a chimpanzee on hearing its own name [8] illustrate these multimodal features of self-awareness. The hypothesis that self-conception is an adaptation to the risk of falling in large arboreal primates [9] also fits the multimodal nature of self-awareness and accounts for the emergence of selfrecognition in great apes but not gibbons. Posing questions about the adaptive value of mirror selfrecognition misses the point. Mirrors were rare in the evolutionary environment, providing no advantage to recognizing your reflection. The significance of self-recognition is what it implies about the existence of a self-processing system [10]. People that can become the object of their own attention can use their experience to infer experiences and mental states in others. As predicted, the development of self-recognition in children coincides with the appearance of mental state attribution. Although more sophisticated instances (e.g., false belief) emerge later, there are no bona fide instances of being able to take into account what others know, want, or intend to do in the absence of being able to recognize yourself. References 1 Suddendorf, T. and Butler, D.L. (2013) The nature of visual selfrecognition. Trends Cogn. Sci. 17, 121–127 2 Gallup, G.G., Jr et al. (2003) Self-awareness, social intelligence, and schizophrenia. In The Self in Neuroscience and Psychiatry (Kircher, T. and David, A.S., eds), pp. 147–165, Cambridge University Press 3 Anderson, J.R. et al. (2010) Pan thanatology. Curr. Biol. 20, 349–351 4 Bischof-Ko¨hler, D. (1994) Self-object and interpersonal emotions. Identification of own mirror-image, empathy and prosocial behavior. Z. Psychol. 202, 349–377 Trends in Cognitive Sciences, February 2014, Vol. 18, No. 2
57
Letters 5 Platek, S.M. et al. (2003) A left-hand advantage for self-description: the impact of schizotypal personality traits. Schizophr. Res. 65, 147–151 6 Feinberg, T.E. and Keenan, J.P. (2005) The Lost Self: Pathologies of the Brain and Identity, Oxford University Press 7 Platek, S.M. et al. (2004) Cross-modal self-recognition: the role of visual, auditory, and olfactory primes. Conscious. Cogn. 13, 197–210
Trends in Cognitive Sciences February 2014, Vol. 18, No. 2
8 Ueno, A. et al. (2010) Brain activity in an awake chimpanzee in response to the sound of her own name. Biol. Lett. 6, 311–313 9 Povinell, D.J. and Cant, J.G.H. (1995) Arboreal clambering and the evolution of self-conception. Q. Rev. Biol. 70, 393–421 10 Gallup, G.G., Jr et al. (2011) Self-recognition. In The Oxford Handbook of the Self (Gallagher, S., ed.), pp. 80–110, Oxford University Press
Response to Gallup et al.: are rich interpretations of visual self-recognition a bit too rich? Thomas Suddendorf and David L. Butler School of Psychology, University of Queensland, St Lucia, Qld 4072, Australia
In our article we distinguish between rich and lean interpretations of what it means to pass the mirror mark task [1]. In their response Gallup, Platek, and Spaulding reiterate their rich interpretation [2] and give us occasion to explain why we advocate a cautious, moderate perspective. We did not claim that ‘mirror self-recognition has nothing to do with self-awareness’. When self-awareness is defined as the capacity to become the object of one’s own attention, then it seems relevant to passing the mark test. Indeed, we presented evidence that children rapidly update their expectation about their appearance and concluded that ‘those who pass may be said to be self-aware about what they currently look like’. However, we also cautioned that ‘this need not mean that they are self-aware in other respects’. Gallup et al., by contrast, assert that visual self-recognition entails self-awareness in a much broader sense, including awareness about one’s own mental states and even about one’s eventual death. Both the rationale and the evidence for such a rich interpretation are problematic. What precisely is this ‘larger self-processing system’ the task purportedly entails? On the one hand, are not animals that fail the task capable of becoming the object of their own attention, as they groom themselves, recognize their own scent, or assess whether they can beat a rival? On the other hand, are there not aspects of self-awareness that those who pass the task may lack? We noted that even adults are often aware about only some aspects of self (they may even deceive themselves [3]). The broader sense of self-awareness the rich interpretation appeals to remains ill defined. The evidence for rich interpretations, as noted in the original article, primarily rests on correlations. However, after 40 years of research there is little empirical support for the proposed links to mindreading and death awareness. On the face of it, there is a considerable lag between the onset of mirror self-recognition and developing conceptions of death [4] and of minds [5]. Stating that there Corresponding author: Suddendorf, T. ([email protected]). 1364-6613/$ – see front matter ß 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.tics.2013.11.004
58
are no instances of mindreading in the absence of selfrecognition does not add much weight to the argument given that many other traits (even breathing) fulfil the same criterion. Furthermore, claims that deficits in self-recognition co-vary with deficits in mental state attribution are debatable. Children with autism, for instance, tend to pass the mark test and even performance on a delayed version was not associated with theory of mind [6]. (Incidentally, we dealt with disorders of self-recognition in some detail (Box 2) and claimed universality in development only in the context of minor cultural differences.) The current comparative data do little to bolster the case of Gallup et al. There is no clear evidence that those apes that pass the mark test reason about minds. Indeed (although we acknowledge the possibility), no animal has as yet unequivocally demonstrated mindreading by passing false-belief tasks [7]. Similarly, even if one were to accept at face value their claim that ‘chimpanzees show an ensemble of intricate reactions to the death of companions that parallel responses humans make’, this does not show that (i) individuals who pass the mark test demonstrate these reactions, nor that (ii) chimpanzees showing these reactions to another’s death are aware of their own impending death. Finally, neuroscientific evidence for rich interpretations is limited. While there are grounds to conclude that selfrelated processing predominantly involves the right hemisphere, there is disagreement about what specific areas of the brain are implicated. We argued that a systematic comparison of animal data within an evolutionary perspective can help to narrow down the search space for neurological and genetic underpinnings [8]. Note also that contrary to the claim by Gallup et al., we did not miss the point by examining the potential adaptive value of mirror-self-recognition because we actually argued that it probably evolved as a side-effect of a more general ability to compare multiple models of the same thing (even across modalities). We wrote our article because we saw a need to move beyond the rhetoric of rich or lean assertions. Perhaps a relatively rich interpretation will turn out to be correct, but more work is required before we have established what
The nature of visual self-recognition revisited Gordon G. Gallup Jr1, *, Steven M. Platek2, and Kristina N. Spaulding1 1 2
Department of Psychology, University at Albany, State University of New York, Albany, NY 12222, USA Department of Psychology, Georgia Gwinnett College, Lawrenceville, GA 30043, USA
It is not true that mirror self-recognition has nothing to do with self-awareness and, contrary to Suddendorf and Butler’s claim [1], that self-recognition is ‘universally acquired in toddlers’, there are failures to find mirror selfrecognition in mentally retarded children, adolescents, and adults, as well as in autistic children, schizophrenics, patients with damage to the frontal cortex, and those with dementia [2]. Also consistent with predictions based on self-awareness, chimpanzees show an ensemble of intricate reactions to the death of companions that parallel responses humans make [3]. The emergence of self-recognition corresponds with other behaviors linked to the development of self-awareness (e.g., prosocial behavior, use of personal pronouns, visual perspective taking, and autobiographical memory). Bischof-Kohler [4] found that only children who passed the mark test showed clear evidence of prosocial behavior and empathy. People lacking self-recognition exhibit deficits in similar aspects of self-awareness (mental state attribution, empathy, visual perspective taking). Deficits and delays in self-recognition (e.g., autism) covary with mental state attribution deficits, and this holds for braindamaged patients deficient in self-recognition and those who lose the capacity to recognize themselves due to mental illness [2]. Schizophrenia is a self-processing disorder [2]. Although schizophrenics have no trouble adjusting distorting mirrors to achieve undistorted images of other objects, they are incapable of adjusting mirrors to achieve undistorted images of themselves. Most people show a right hemisphere (left hand) advantage for identifying their face, but those with premorbid schizophrenic traits show right-hemisphere deficits in both self-face identification and picking self-descriptive adjectives [5]. Righthemisphere damage not only impairs mental state attribution and autobiographical memory [2], but produces deficits in awareness of ownership and agency of body parts [6]. Just as schizophrenics have difficulty distinguishing images of their hand from another person’s hand, normal people mistake their hand for a stranger’s hand when the right hemisphere is inactivated by sodium amobarbital. Corresponding author: Gallup, G.G. Jr ([email protected]). 1364-6613/$ – see front matter ß 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.tics.2013.10.012
Claims that mirror self-recognition has nothing to do with self-awareness ignore the fact that self-recognition extends beyond the visual domain. A study of selfprocessing in different modalities found that selfprimes in different sensory domains (e.g., briefly being shown their name or hearing their name) facilitated self-recognition [7]. If self-recognition was a byproduct of collating representations, seeing or hearing your name should leave your ability to identify your face unaffected because people rarely see or hear their names in contexts where they also see their faces. Your name is special because it is an embedded feature of your sense of self. Because the way people process information about themselves in one modality is affected by the presentation of independent information about the self in other modalities and, because other aspects of self-awareness coexist with self-recognition in common brain regions, this implicates self-recognition as an expression of a larger, underlying, well-integrated, multimodal self-processing system. Recent findings showing human-like electroencephalography (EEG) activation in a chimpanzee on hearing its own name [8] illustrate these multimodal features of self-awareness. The hypothesis that self-conception is an adaptation to the risk of falling in large arboreal primates [9] also fits the multimodal nature of self-awareness and accounts for the emergence of selfrecognition in great apes but not gibbons. Posing questions about the adaptive value of mirror selfrecognition misses the point. Mirrors were rare in the evolutionary environment, providing no advantage to recognizing your reflection. The significance of self-recognition is what it implies about the existence of a self-processing system [10]. People that can become the object of their own attention can use their experience to infer experiences and mental states in others. As predicted, the development of self-recognition in children coincides with the appearance of mental state attribution. Although more sophisticated instances (e.g., false belief) emerge later, there are no bona fide instances of being able to take into account what others know, want, or intend to do in the absence of being able to recognize yourself. References 1 Suddendorf, T. and Butler, D.L. (2013) The nature of visual selfrecognition. Trends Cogn. Sci. 17, 121–127 2 Gallup, G.G., Jr et al. (2003) Self-awareness, social intelligence, and schizophrenia. In The Self in Neuroscience and Psychiatry (Kircher, T. and David, A.S., eds), pp. 147–165, Cambridge University Press 3 Anderson, J.R. et al. (2010) Pan thanatology. Curr. Biol. 20, 349–351 4 Bischof-Ko¨hler, D. (1994) Self-object and interpersonal emotions. Identification of own mirror-image, empathy and prosocial behavior. Z. Psychol. 202, 349–377 Trends in Cognitive Sciences, February 2014, Vol. 18, No. 2
57
Letters 5 Platek, S.M. et al. (2003) A left-hand advantage for self-description: the impact of schizotypal personality traits. Schizophr. Res. 65, 147–151 6 Feinberg, T.E. and Keenan, J.P. (2005) The Lost Self: Pathologies of the Brain and Identity, Oxford University Press 7 Platek, S.M. et al. (2004) Cross-modal self-recognition: the role of visual, auditory, and olfactory primes. Conscious. Cogn. 13, 197–210
Trends in Cognitive Sciences February 2014, Vol. 18, No. 2
8 Ueno, A. et al. (2010) Brain activity in an awake chimpanzee in response to the sound of her own name. Biol. Lett. 6, 311–313 9 Povinell, D.J. and Cant, J.G.H. (1995) Arboreal clambering and the evolution of self-conception. Q. Rev. Biol. 70, 393–421 10 Gallup, G.G., Jr et al. (2011) Self-recognition. In The Oxford Handbook of the Self (Gallagher, S., ed.), pp. 80–110, Oxford University Press
Response to Gallup et al.: are rich interpretations of visual self-recognition a bit too rich? Thomas Suddendorf and David L. Butler School of Psychology, University of Queensland, St Lucia, Qld 4072, Australia
In our article we distinguish between rich and lean interpretations of what it means to pass the mirror mark task [1]. In their response Gallup, Platek, and Spaulding reiterate their rich interpretation [2] and give us occasion to explain why we advocate a cautious, moderate perspective. We did not claim that ‘mirror self-recognition has nothing to do with self-awareness’. When self-awareness is defined as the capacity to become the object of one’s own attention, then it seems relevant to passing the mark test. Indeed, we presented evidence that children rapidly update their expectation about their appearance and concluded that ‘those who pass may be said to be self-aware about what they currently look like’. However, we also cautioned that ‘this need not mean that they are self-aware in other respects’. Gallup et al., by contrast, assert that visual self-recognition entails self-awareness in a much broader sense, including awareness about one’s own mental states and even about one’s eventual death. Both the rationale and the evidence for such a rich interpretation are problematic. What precisely is this ‘larger self-processing system’ the task purportedly entails? On the one hand, are not animals that fail the task capable of becoming the object of their own attention, as they groom themselves, recognize their own scent, or assess whether they can beat a rival? On the other hand, are there not aspects of self-awareness that those who pass the task may lack? We noted that even adults are often aware about only some aspects of self (they may even deceive themselves [3]). The broader sense of self-awareness the rich interpretation appeals to remains ill defined. The evidence for rich interpretations, as noted in the original article, primarily rests on correlations. However, after 40 years of research there is little empirical support for the proposed links to mindreading and death awareness. On the face of it, there is a considerable lag between the onset of mirror self-recognition and developing conceptions of death [4] and of minds [5]. Stating that there Corresponding author: Suddendorf, T. ([email protected]). 1364-6613/$ – see front matter ß 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.tics.2013.11.004
58
are no instances of mindreading in the absence of selfrecognition does not add much weight to the argument given that many other traits (even breathing) fulfil the same criterion. Furthermore, claims that deficits in self-recognition co-vary with deficits in mental state attribution are debatable. Children with autism, for instance, tend to pass the mark test and even performance on a delayed version was not associated with theory of mind [6]. (Incidentally, we dealt with disorders of self-recognition in some detail (Box 2) and claimed universality in development only in the context of minor cultural differences.) The current comparative data do little to bolster the case of Gallup et al. There is no clear evidence that those apes that pass the mark test reason about minds. Indeed (although we acknowledge the possibility), no animal has as yet unequivocally demonstrated mindreading by passing false-belief tasks [7]. Similarly, even if one were to accept at face value their claim that ‘chimpanzees show an ensemble of intricate reactions to the death of companions that parallel responses humans make’, this does not show that (i) individuals who pass the mark test demonstrate these reactions, nor that (ii) chimpanzees showing these reactions to another’s death are aware of their own impending death. Finally, neuroscientific evidence for rich interpretations is limited. While there are grounds to conclude that selfrelated processing predominantly involves the right hemisphere, there is disagreement about what specific areas of the brain are implicated. We argued that a systematic comparison of animal data within an evolutionary perspective can help to narrow down the search space for neurological and genetic underpinnings [8]. Note also that contrary to the claim by Gallup et al., we did not miss the point by examining the potential adaptive value of mirror-self-recognition because we actually argued that it probably evolved as a side-effect of a more general ability to compare multiple models of the same thing (even across modalities). We wrote our article because we saw a need to move beyond the rhetoric of rich or lean assertions. Perhaps a relatively rich interpretation will turn out to be correct, but more work is required before we have established what
