Editing Mirror neuron (section)

==Doubts concerning mirror neurons==
Although some in the scientific community have expressed excitement about the discovery of mirror neurons, there are scientists who have expressed doubts about both the existence and role of mirror neurons in humans. The consensus today{{as of?|date=April 2025}} seems to be that the importance of so-called mirror neurons is widely overblown. According to scientists such as Hickok, Pascolo, and Dinstein, it is not clear whether mirror neurons really form a distinct class of cells (as opposed to an occasional phenomenon seen in cells that have other functions),<ref name="Pascolo Ragogna Rossi" /> and whether mirror activity is a distinct type of response or simply an artifact of an overall facilitation of the motor system.<ref name="Hickok" />

In 2008, Ilan Dinstein et al. argued that the original analyses were unconvincing because they were based on qualitative descriptions of individual cell properties, and did not take into account the small number of strongly mirror-selective neurons in motor areas.<ref name="Dinstein" /> Other scientists have argued that the measurements of neuron fire delay seem not to be compatible with standard reaction times,<ref name="Pascolo Ragogna Rossi">{{cite journal |journal=Gait & Posture |year=2009 |volume=30 |issue=Suppl. 1 |pages=65 |title=The Mirror-Neuron System Paradigm and its consistency |vauthors =Pascolo PB, Ragogna R, Rossi R |doi=10.1016/j.gaitpost.2009.07.064}}</ref> and pointed out that nobody has reported that an interruption of the motor areas in F5 would produce a decrease in action recognition.<ref name="Hickok">{{cite journal | vauthors = Hickok G | title = Eight problems for the mirror neuron theory of action understanding in monkeys and humans | journal = Journal of Cognitive Neuroscience | volume = 21 | issue = 7 | pages = 1229–1243 | date = July 2009 | pmid = 19199415 | pmc = 2773693 | doi = 10.1162/jocn.2009.21189 }}</ref> Critics of this argument have replied that these authors have missed human neuropsychological and [[Transcranial magnetic stimulation|TMS]] studies reporting disruption of these areas do indeed cause action deficits<ref name="pmid20957578" /><ref name="pmid16527749" /> without affecting other kinds of perception.<ref name="pmid17660183" />

In 2009, Lingnau et al. carried out an experiment in which they compared motor acts that were first observed and then executed to motor acts that were first executed and then observed. They concluded that there was a significant asymmetry between the two processes that indicated that mirror neurons do not exist in humans. They stated "Crucially, we found no signs of adaptation for motor acts that were first executed and then observed. Failure to find cross-modal adaptation for executed and observed motor acts is not compatible with the core assumption
of mirror neuron theory, which holds that action recognition and understanding are based on motor simulation."<ref>{{cite journal | vauthors = Lingnau A, Gesierich B, Caramazza A | title = Asymmetric fMRI adaptation reveals no evidence for mirror neurons in humans | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 106 | issue = 24 | pages = 9925–9930 | date = June 2009 | pmid = 19497880 | pmc = 2701024 | doi = 10.1073/pnas.0902262106 | doi-access = free | bibcode = 2009PNAS..106.9925L }}</ref> However, in the same year, Kilner et al. showed that if goal directed actions are used as stimuli, both IPL and premotor regions show the repetition suppression between observation and execution that is predicted by mirror neurons.<ref>{{cite journal | vauthors = Kilner JM, Neal A, Weiskopf N, Friston KJ, Frith CD | title = Evidence of mirror neurons in human inferior frontal gyrus | journal = The Journal of Neuroscience | volume = 29 | issue = 32 | pages = 10153–10159 | date = August 2009 | pmid = 19675249 | pmc = 2788150 | doi = 10.1523/jneurosci.2668-09.2009 }}</ref>

In 2009, Greg Hickok published an extensive argument against the claim that mirror neurons are involved in action-understanding: "Eight Problems for the Mirror Neuron Theory of Action Understanding in Monkeys and Humans." He concluded that "The early hypothesis that these cells underlie action understanding is likewise an interesting and prima facie reasonable idea. However, despite its widespread acceptance, the proposal has never been adequately tested in monkeys, and in humans there is strong empirical evidence, in the form of physiological and neuropsychological (double-) dissociations, against the claim."<ref name="Hickok" />

[[File:Goal attribution and mirror neurons.JPG|thumb|The mirror neurons can be activated only after the goal of the observed action has been attributed by other brain structures.]]
Vladimir Kosonogov sees another contradiction. The proponents of mirror neuron theory of action understanding postulate that the mirror neurons code the goals of others' actions because they are activated if the observed action is goal-directed. However, the mirror neurons are activated only when the observed action is goal-directed (object-directed action or a communicative gesture, which certainly has a goal too). How do they "know" that the definite action is goal-directed? At what stage of their activation do they detect a goal of the movement or its absence? In his opinion, the mirror neuron system can be activated only after the goal of the observed action is attributed by some other brain structures.<ref name="Kosonogov2012">{{cite journal |last1=Kosonogov |first1=V. |title=Why the Mirror Neurons Cannot Support Action Understanding |journal=Neurophysiology |date=December 2012 |volume=44 |issue=6 |pages=499–502 |doi=10.1007/s11062-012-9327-4 |s2cid=254867235 }}</ref>

Neurophilosophers such as [[Patricia Churchland]] have expressed both scientific and philosophical objections to the theory that mirror neurons are responsible for understanding the intentions of others. In chapter 5 of her 2011 book, ''Braintrust'', Churchland points out that the claim that mirror neurons are involved in understanding intentions (through simulating observed actions) is based on assumptions that are clouded by unresolved philosophical issues. She makes the argument that intentions are understood (coded) at a more complex level of neural activity than that of individual neurons. Churchland states that "A neuron, though computationally complex, is just a neuron. It is not an intelligent homunculus. If a neural network represents something complex, such as an intention [to insult], it must have the right input and be in the right place in the neural circuitry to do that."<ref>Churchland, Patricia, Braintrust (2011), Chapter 6, page 142</ref>

[[Cecilia Heyes]] has advanced the theory that mirror neurons are the byproduct of associative learning as opposed to evolutionary adaptation. She argues that mirror neurons in humans are the product of social interaction and not an evolutionary adaptation for action-understanding. In particular, Heyes rejects the theory advanced by V.S. Ramachandran that mirror neurons have been "the driving force behind the great leap forward in human evolution."<ref name=Heyes2010/><ref name="Ramachandran 2000">{{cite magazine | vauthors = Ramachandran VS |title=Mirror neurons and imitation learning as the driving force behind "the great leap forward" in human evolution |magazine=Edge |year=2000 |url=http://www.edge.org/3rd_culture/ramachandran/ramachandran_index.html |access-date=13 April 2013}}</ref>