Developmental Cognitive Neuroscience - Antonia ?· A.F.d.C. Hamilton / Developmental Cognitive Neuroscience…

Download Developmental Cognitive Neuroscience - Antonia ?· A.F.d.C. Hamilton / Developmental Cognitive Neuroscience…

Post on 19-Aug-2018

212 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • R

    Ro

    AS

    a

    ARR2A

    KAMIS

    C

    1h

    Developmental Cognitive Neuroscience 3 (2013) 91 105

    Contents lists available at SciVerse ScienceDirect

    Developmental Cognitive Neuroscience

    j ourna l ho me pag e: ht t p: / /www.e lsev ier .com/ locate /dcn

    eview

    eflecting on the mirror neuron system in autism: A systematic reviewf current theories

    ntonia F. de C. Hamiltonchool of Psychology, University of Nottingham, United Kingdom

    r t i c l e i n f o

    rticle history:eceived 20 July 2012eceived in revised form7 September 2012ccepted 28 September 2012

    eywords:utism

    a b s t r a c t

    There is much interest in the claim that dysfunction of the mirror neuron system inindividuals with autism spectrum condition causes difficulties in social interaction andcommunication. This paper systematically reviews all published studies using neurosciencemethods (EEG/MEG/TMS/eyetracking/EMG/fMRI) to examine the integrity of the mirrorsystem in autism. 25 suitable papers are reviewed. The review shows that current data arevery mixed and that studies using weakly localised measures of the integrity of the mirrorsystem are hard to interpret. The only well localised measure of mirror system function is

    irror neuron systemmitationocial cognition

    fMRI. In fMRI studies, those using emotional stimuli have reported group differences, butstudies using non-emotional hand action stimuli do not. Overall, there is little evidence fora global dysfunction of the mirror system in autism. Current data can be better understoodunder an alternative model in which social top-down response modulation is abnormal in

    autism. The implications of this model and future research directions are discussed.

    2012 Elsevier Ltd. All rights reserved.

    ontents

    1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 912. The mirror system and autism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 923. Methodology of the review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 934. Studies which indirectly measure MNS function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

    4.1. EEG studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 934.2. MEG studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 964.3. TMS studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 964.4. Eyetracking studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 964.5. EMG studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

    5. fMRI studies of the MNS in autism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 975.1. Structural MRI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

    6. Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 996.1. Evaluating the broken mirror theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1006.2. Social response modulation: an alternative explanation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

    7. Conclusions and future directions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

    Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

    E-mail address: antonia.hamilton@nottingham.ac.uk

    878-9293/$ see front matter 2012 Elsevier Ltd. All rights reserved.ttp://dx.doi.org/10.1016/j.dcn.2012.09.008

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

    1. Introduction

    Individuals with autism spectrum condition (ASC)struggle with social interaction and communication, both

    dx.doi.org/10.1016/j.dcn.2012.09.008http://www.sciencedirect.com/science/journal/18789293http://www.elsevier.com/locate/dcnmailto:antonia.hamilton@nottingham.ac.ukdx.doi.org/10.1016/j.dcn.2012.09.008

  • l Cognit

    92 A.F.d.C. Hamilton / Developmenta

    in formal testing and in their everyday lives. Many differ-ent cognitive and brain-based theories have been proposedto account for these difficulties. Current proposals includedifficulties in theory of mind (Frith, 2001), in social motiva-tion (Chevallier et al., 2012) and in mirror neuron function(Dapretto and Iacoboni, 2006; Gallese et al., 2009; Rizzolattiet al., 2009). The latter is the focus of the present paper,where I examine the human mirror neuron system (MNS)and whether damage to this system might have relevancefor autism.

    The manuscript proceeds in three parts. First, I brieflydescribe the functions of the human mirror system andthe different models of MNS dysfunction which have beenproposed. Second, I systematically review the scientific lit-erature on the MNS in ASC, focusing on studies which haveused neuroscientific methods to assess the function of theMNS. Third, I provide an overall assessment of the field,and make suggestions for future directions in terms of boththeory and experiment.

    2. The mirror system and autism

    The human mirror neuron system (MNS) can be definedas the set of brain regions which are active both whenparticipants perform an action and when they observeanother person performing the same action (Rizzolatti andCraighero, 2004). The core components of the human MNSare inferior frontal gyrus (IFG) and inferior parietal lobule(IPL). In the macaque monkey equivalents of these regions,single neurons have been recorded with mirror properties(Fogassi et al., 2005; Gallese et al., 1996). Though singleunits have not been recorded in the human MNS, detailedpatterns of activation in fMRI studies leave little doubtthat these areas contain mirror neuron populations (Kilneret al., 2009; Oosterhof et al., 2010). The human MNS iswidely assumed to play a key role in action understand-ing and imitation, though this remains debated (Dinsteinet al., 2008; Hickok, 2009). There are also a number offMRI studies, some using emotional stimuli, which suggestthe existence of a broader mirror neuron network (Casperset al., 2010) that incorporates somatosensory and premo-tor cortex (Keysers et al., 2010), and possibly anterior insula(Wicker et al., 2003). The present paper will not considerthis extended mirror network in detail.

    The dominant theory of MNS function is based ona direct-matching model in which observed actions aredirectly mapped onto the observers own motor system(Rizzolatti and Sinigaglia, 2010). This framewor

Recommended

View more >