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brevia: R. Shayna Rosenbaum, Donald T. Stuss, Brian Levine, and Endel Tulving Theory of Mind Is Independent of Episodic Memory Science 2007; 318: 1257 [Abstract] [Full text] [PDF]

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Response to N. Reinhold and H. J. Markowitsch's E-Letter

R. Shayna Rosenbaum   (24 April 2008)

Theory of Mind and the Sense of Self

Nadine Reinhold, Hans J. Markowitsch   (10 April 2008)

Response to N. Reinhold and H. J. Markowitsch's E-Letter 24 April 2008
R. Shayna Rosenbaum Department of Psychology, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada Respond to this E-Letter: Re: Response to N. Reinhold and H. J. Markowitsch's E-Letter	My colleagues and I showed that episodic memory (1) is not necessary for theory of mind (ToM) by demonstrating intact ToM in individuals with episodic memory loss following medial temporal lobe damage or disconnection [i.e., organic amnesia (2)]. Reinhold and Markowitsch propose that this issue may be better addressed by studying individuals with functional retrograde amnesia (RA). I agree that both types of amnesic patients do not offer the same sort of insight into understanding the relationship between episodic memory and ToM, though not for the reasons cited by Reinhold and Markowitsch. Functional RA refers to memory disturbance of psychological origin characterized by focal loss of episodic and/or semantic information acquired prior to amnesia onset (3, 4). Importantly, it often occurs in individuals with an extensive psychiatric history that predates or accompanies their amnesic episode (5). Thus, it is difficult to decipher if the reported inability of these individuals to infer other people’s thoughts and feelings (6, 7) is due to faulty episodic memory processes, or to some other aspect of personality or cognitive function, semantic memory or otherwise, that is simultaneously altered. Nevertheless, it is important to clarify that the claim in our paper is that episodic memory is not needed for ToM as measured by a range of widely accepted ToM tests (8). Our demonstration of intact ToM in individuals with complete impairment to episodic memory (9) is sufficient to support this claim, irrespective of etiology and time of testing since RA onset. Like Reinhold and Markowitsch, we commented in our paper that the individuals that we tested are likely using a cognitive system in place of episodic memory to sustain ToM. We further suggested semantic memory as a candidate system, and this was intended to include self-identity and other personal knowledge, though additional investigation is needed. R. Shayna Rosenbaum Department of Psychology, York University, Rotman Research Institute, Baycrest, 4700 Keele Street, Toronto, ON M3J 1P3, Canada. References 1. E. Tulving, Annu. Rev. Psychol. 53, 1 (2002). 2. R. S. Rosenbaum, D. T. Stuss, B. Levine, E. Tulving, Science 318, 1257 (2007). 3. D. L. Schacter, P. L. Wang, E. Tulving, M. Freedman, Neuropsychologia 20, 523 (1982). 4. M. D. Kopelman, Cogn. Neuropsychol. 17, 585 (2000). 5. H. J. Markowitsch, Neuroimage 20, S132 (2003). 6. E. Fujiwara et al., Cortex (in press). 7. N. Reinhold, H. J. Markowitsch, J. Neuropsychol. 1, 53 (2007). 8. R. S. Rosenbaum, D. T. Stuss, B. Levine, E. Tulving, Science 318, 1257 (2007). 9. R. S. Rosenbaum et al., Neuropsychologia 43, 989 (2005).
Theory of Mind and the Sense of Self 10 April 2008
Nadine Reinhold Department of Physiological Psychology, University of Bielefeld, Bielefeld, 33615, Germany, Hans J. Markowitsch Respond to this E-Letter: Re: Theory of Mind and the Sense of Self	R. S. Rosenbaum et al. argue that the ability to infer other people's current mental states is independent of a well-functioning episodic memory system (Brevia, "Theory of mind is independent of episodic memory," 23 November 2007, p. 1257). The authors also extend their findings to an independency of autonoetic consciousness and Theory of Mind (ToM) abilities. They rest this extension on Tulving's definition of (1) episodic memory as the conjunction of three different concepts: self, autonoetic awareness, and subjective time. ToM, on the other hand, is strongly connected with the concepts of self and autonoetic awareness (2, 3). Although the presented results appear convincing, they have some limitations. Both patients presented by Rosenbaum et al. were tested long after the onset of their retrograde amnesia. Patients with psychogenic or functional retrograde amnesia investigated only 2 to 8 months after their amnesia onset are clearly impaired in ToM-tasks (4, 5). In ontogenetic development ToM abilities emerge at roughly the same time, but in close interaction with the development of episodic memory. We therefore propose that although both abilities overlap in their functions as well as in their neural correlates, they might be impaired independently. We suggest that the self as a core feature of episodic (autobiographical) memory and ToM abilities is essential for both processes—the emergence of autobiographical memories as well as for building up and strengthening the capability to infer other people's mental states (6). After disruption of the episodic memory system, other memory systems may, over time, replace the need to rely on the episodic memory system for ToM abilities, leading to restitution or substitution processes of ToM functions, similarly, as observed for other mental functions following brain damage. Nadine Reinhold and Hans J. Markowitsch Department of Physiological Psychology, University of Bielefeld, Universitaetsstr. 25, Bielefeld, 33615, GERMANY. References 1. E. Tulving, Annu. Rev. Psychol. 53, 1 (2002). 2. L. Q. Uddin, M. Iacoboni, C. Lange, J. P. Keenan, Trends Cogn. Sci. 11, 153 (2007). 3. Y. Moriguchi et al., Neuroimage 32, 1472 (2006). 4. E. Fujiwara et al., Cortex (in press). 5. N. Reinhold, H. J. Markowitsch, J. Neuropsychol. 1, 53 (2007). 6. D. Hassabis, E. A. Maguire, Trends Cogn. Sci. 11, 299 (2007).