Thursday, November 15, 2007

Evolutionary Metaphysics IV

Since I drifted away from discussing baboons and Cheney and Seyfarth’s book quite a bit, I decided to name this post (jokingly) ‘Evolutionary Metaphysics, because, according to the OED, metaphysics includes questions about
"the underlying concepts or first principles on which a particular branch of knowledge is based."
OK, there actually is already such a field, called evolutionary epistemology, or its evil twin brother, evolutionary psychology, but I’ll still go with this title.
In my last post, I considered some proposals how our – in some parts species-continuous – conceptual system had been extended. Deacon (1998) and Barsalou (2005) both observed the higher frontal cortical control which humans show compared to other animals. Whereas Deacon proposed that we had a ‘front heavy’ cognitive style, Barsalou broke our conceptual extensions down into component parts. Some of them explicitly seem to be reliant on frontal control, such as Mental Time Travel and Conceptual Blending.
Another proposal for a human specialization similar to these traits is cause-and-effect reasoning, in order to outwit defences of plants and animals, as well as competitors (Tooby and DeVore 1987). The enhancement of these capacities in humans is congruent with the fact that the prefrontal cortex synthesizes the information received from other areas into representations of concepts, rules and contingencies, and that this structure is especially elaborate in primates and especially so in humans (Miller et al. 2002, Deacon 1998, Ivry & Knight 2002). Prefrontal enlargement could have led to enhanced cognitive control over the conceptual system, and thereby to a greater cognitive control over our own actions and their goals.

However, when taking into account human ToM-abilities, there seems to be a lot more to it than just prefrontal enlargement. How wan we take different perspectives and attribute false beliefs to others? Regarding the blending of incompatible concepts, Mark Turner asks: ”How can we fire up incompatible mental patterns simultaneuously […] Evolutionary, how did our species develop this ability?” (Turner 2003: 118). What are the evolutionary steps complementing higher frontal control?
Cheney and Seyfarth amassed evidence for the existence of mental representations in baboons; neuroimaging studies showed the same for macaque monkeys (Gil-da-Cost et al. 2004). Following Barsalou (2005) in assuming a common architecture for human and animal conceptual systems, what are the foundations of social cognition in other animals, on which human ToM-abilities were built?
One part of the answer seems to lie in the discovery of ‘mirror neurons’ “a particular class of visuomotor neurons, originally discovered in area F5 of the monkey premotor cortex, that discharge both when the monkey does a particular action and when it observes another individual (monkey or human) doing a similar action” (Rizzolatti et al. 2001: 661). A similar mirror neuron system crucial to the understanding of action, imitation, and also involved in language is argued to exist in humans (Rizzolatti/Craighero 2004). Mirror neurons sometimes seem to be hyped as the answer to every open question in the cognitive studies, but at the moment no one really seems to know what to conclude from them.

So how do we understand others? Gallese and his colleagues (2004) propose that we understand others and infer mental states to them by simulating their actions in our ‘mirror system.’ These proposals are in accordance with Barsalou’s view of conceptualization as integrated simulations of experience-based concepts in our conceptual system (Barsalou in press) But as Barsalou himself stresses, mirror circuits seem to be part of a larger system which also involves inhibitory processes that keep simulated and own mental states apart from each other (Decety and Grazes 2006) and the establishment of joint attention (Sebanz et al. 2006).
This larger system is sometimes identified as a functional system called ‘social network’ which integrates contributed information from others systems into the mental representation of an animate being (Wheatley et al. 2007). Wheatley and colleagues found that the mirror system does not respond selectively to biological actions, but to actions in general. The failure of the mirror system to be modulated by the interpretation of animacy when observing or simulating an action makes it unlikely to be the origin of general social cognition. Instead, Wheatley and his colleagues argue that inferring animacy is done by the ‘social network’ and propose to see the mirror system as a general simulation machinery which is employed in tandem by the social network, imagery and other cognitive processes.They conclude that the social network’s ability to infer animacy should be seen as an important component of, as well as an evolutionary precursor to our complex social cognition and Theory of Mind-abilities.

Yet another component of the social network may be the so-called cortical midline structures (CMS), which process information about others and the self in more evaluative and abstract and ways (Uddin et al. 2007). Uddin and her colleagues see CMS and the mirror system as interactive components. They propose that the mirror system is responsible for the ability to map representations of others onto our own mental architecture, and that the CMS evaluates and underscores these mappings. It would be interesting to know if CMS exist in non-human primates and other animals, and if not, if there are possible homologues. Another question is if Wheatley et al.’s and Uddin et al’s proposals are compatible. I, for instance, have no idea. In my next post I will sum up my previous observations and see if I can draw some rough skeletal evolutionary scenario from it.


Barsalou, Lawrence W. In press. “Grounded Cognition.” In: Annual Review of Psychology 59

Barsalou, Lawrence W. 2005a. “Continuity of the conceptual system across species.” Trends. Cog. Sc. 9.7: 309-311.

Deacon, Terrence William 1998. The Symbolic Species: The Co-evolution ofLanguage and the Brain. New York / London: W.W. Norton.

Decety, Jean, & Julie Grèzes. 2006. “The power of simulation: Imagining one's own and other's behavior.” Brain Research 1079: 4-14.

Gil-da-Costa, Ricardo, Allen Braun, Marco Lopes, Marc D. Hauser, Richard E. Carson, Peter Herscovitch and Alex Martin. 2004. “Toward an evolutionary perspective on conceptual representation: Species-specific calls activate visual and affective processing systems in the macaque.” PNAS 101.50: 17516–17521.

Ivry Richard and Robert T. Knight. 2002. “Making order from chaos: the misguided frontal lobe” Nature Neuroscience 5.5: 394-396.

Miller, Earl K., David J. Freedman and Jonathan D. Wallis 2002. “The Prefrontal Cortex: Categories, Concepts and Cognition.” In: Phil. Trans. R. Soc. Lond. B 357: 1123–1136

Rizzolatti, Giacomo and Laila Craighero. “The Mirror-Neuron System.” Annual Review of Neuroscience 27 (2004): 169–192.

Rizzolatti, Giacomo, Leonardo Fogassi and Vittorio Gallese. “Neurophysiological Mechanisms Underlying the Understanding and Imitation of Action.” Nature Reviews Neuroscience 2 (2001): 661–670.

Sebanz, N., Bekkering, H., & Knoblich, G. 2006. Joint action: Bodies and minds moving together. Tr. Cog. Sc. 10: 70-76.

Tooby, John and Irven DeVore 1987. “The Reconstruction of Hominid Rvolution Through Strategic Modelling.” The Evolution of Human Behavior: Primate Models. Ed. W.G. Kinzey. Albany: SUNY.

Uddin, Lucina Q., Marco Iacoboni, Claudia Lange and Julian Paul Keenan. 2007. “The Self and Social Cognition: The Role of Cortical Midline Structures and Mirror Neurons.” Trends in Cognitive Sciences 11.4 (2007): 153-157.

Wheatley, Thalia, Shawn C. Milleville and Alex Martin. “Understanding Animate
Agents: Distinct Roles for the Social Network and Mirror System.” Psychological Science 18.6 (2007): 469-474.

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