Online research in philosophy

The evolutionary continuity between the prespeech functions of premotor cortex and its new linguistic functions, the main thesis of MacNeilage's target article, is confirmed by the recent discovery of “mirror” neurons in monkeys and a corresponding action-observation/action-execution matching system in humans. Physiological data (and other considerations) appear to indicate, however, that brachiomanual gestures played a greater role in language evolution than MacNeilage would like to admit.

In a New York Times article last month, entitled Cells that read minds, the neuroscience reporter, Sandra Blakeslee (January 10, 2006) provided a list of all the things that mirror neurons can explain. As we know, mirror neurons, discovered by Rizzolattis group in Parma, are neurons that are activated when we engage in action, and when we perceive intentional movement in another person. According to Blakeslee and the scientists she interviewed, mirror neurons explain not only how we are capable of understanding another persons actions, but also language, empathy, how children learn, why people respond to certain types of sports, dance, music and art, why watching media violence may be harmful and why many men like pornography. Let me set aside the controversial questions about whether mirror neurons can explain all of these things, and accept that mirror neurons are clearly smart little cells. But let me ask whether Blakeslee and her scientists are expressing things in the right way.

The neurological discovery of mirror neurons is of eminent importance for the phenomenological theory of intersubjectivity. G. Rizzolatti and V. Gallese found in experiments with primates that a set of neurons in the premotor cortex represents the visually registered movements of another animal. The activity of these mirror neurons presents exactly the same pattern of activity as appears in the movement of one's own body. These findings may be extended to other cognitive and emotive functions in humans. I show how these neurological findings might be “translated” phenomenologically into our own experienced sensations, feelings and volitions.

Single cell recordings in monkeys provide strong evidence for an important role of the motor system in action understanding. This evidence is backed up by data from studies of the (human) mirror neuron system using neuroimaging or TMS techniques, and behavioral experiments. Although the data acquired from single cell recordings are generally considered to be robust, several debates have shown that the interpretation of these data is far from straightforward. We will show that research based on single-cell recordings allows for unlimited content attribution to mirror neurons. We will argue that a theoretical analysis of the mirroring process, combined with behavioral and brain studies, can provide the necessary limitations. A complexity analysis of the type of processing attributed to the mirror neuron system can help formulate restrictions on what mirroring is and what cognitive functions could, in principle, be explained by a mirror mechanism. We argue that processing at higher levels of abstraction needs assistance of non-mirroring processes to such an extent that subsuming the processes needed to infer goals from actions under the label ?mirroring? is not warranted.

Commonsense says we are isolated. After all, our bodies are physically separate. But Seneca’s colamus humanitatem, and John Donne’s observation that “no man is an island” suggests we are neither entirely isolated nor separate. A recent discovery in neuroscience—that of mirror neurons—argues that the brain and the mind is neither built nor functions remote from what happens in other individuals. What are mirror neurons? They are brain cells that process both what happens to or is done by an individual, and, as it were, its perceived “refl ection,” when that same thing happens or is done by another individual. Thus, mirror neurons are both activated when an individual does a particular action, and when that individual perceives that same action done by another. The discovery of mirror neurons suggests we need to radically revise our notions of human nature since they offer a means by which we may not be so separated as we think. Humans unlike other apes are adapted to mirror interact nonverbally when together. Notably, our faces have been evolved to display agile and nimble movements. While this is usually explained as enabling nonverbal communication, a better description would be nonverbal commune based upon mirror neurons. I argue we cherish humanity, colamus humanitatem, because mirror neurons and our adapted mirror interpersonal interface blur the physical boundaries that separate us.

1. Properties of mirror neurons in monkeys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 1.1. Action types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 1.2. Context effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 2. Is there a human ‘mirror neuron system’? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 2.1. Monkeys versus humans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 2.2. Action understanding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 3. The development of mirroring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 3.1. Imitation in newborns? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 3.2. Effects of experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 3.3. Effects of sensorimotor experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

Mirror neurons are neurons which fire in two distinct conditions: (i) when an agent performs a specific action, like a precision grasp of an object using fingers, and (ii) when an agent observes that action performed by another. Some theorists have suggested that the existence of such neurons may lend support to the simulation approach to mindreading (e.g. Gallese and Goldman, 1998, 'Mirror neurons and the simulation theory of mind reading'). In this note I critically examine this suggestion, in both its original and a revised form (due to Iacoboni et al., 2005, 'Grasping the intentions of others with one's own mirror neuron system'), and argue that the existence of mirror neurons can in fact tell us very little about how intentional attribution actually proceeds.

The discovery of mirror neurons has been hailed as one of the most exciting developments in neuroscience in the past few decades. These neurons discharge in response to the observation of others’ actions. But how are we to understand the function of these neurons? In this paper I defend the idea that mirror neurons are best conceived as components of a sensory system that has the function to perceive action. In short, mirror neurons are part of a hitherto unrecognized “sixth sense”. In this spirit, research should move toward developing a psychophysics of mirror neurons.

Both macaque monkeys and humans have been shown to have what are called ‘mirror neurons’, a class of neurons that respond to goal-related motor-actions, both when these actions are performed by the subject and when they are performed by another individual observed by the subject. Gallese and Goldman (1998) contend that mirror neurons may be seen as ‘a part of, or a precursor to, a more general mind- reading ability’, and that of the two competing theories of mind-reading, mirror neurons lend support to simulation theory. I here offer four reasons why I think mirror neurons do not provide support for simulation theory over its contender, theory theory.

Proposition 1 is based on the received Aristotelian analysis of intentional action and a commonsense view about understanding. Proposition 2 represents a consensus view among primatologists about the absence of higher order “theory of mind” capacities in monkeys. Proposition 3 reflects a common interpretation of the functions of so-called “mirror neurons” found in the ventral premotor (F5) cortex of macaque monkeys (e.g., Gallese and Goldman 1998; Rizzolatti and Craighero 2004; Fogassi et al. 2005). Taken at face value, then, this inconsistent triad presents a paradox for understanding the contribution of F5 neurons in macaques to their cognitive capacities. This paradox does not arise for humans because the human analogue to proposition 2 is the obvious candidate for rejection. Nevertheless, the considerations relevant to resolving the paradox for monkeys are also important for a properly skeptical interpretation of the neurological evidence about the mirror neuron system in humans (see Debes, submitted). In this chapter I discuss each of the possibilities for resolving the paradox by rejecting one of the three propositions. Although my philosophical sympathies pError (27674): Unknown form typeError (27725): Unknown form typeError (27815): Unknown form typeresently lie with rejecting proposition 1, some of the arguments depend on empirical knowledge that is presently lacking. Nevertheless, I describe an approach to understanding the functions of F5 mirror..