Experimental Brain Research

, Volume 170, Issue 1, pp 116–121 | Cite as

Hemispheric sensitivity to body stimuli in simple reaction time

  • Lisa Aziz-Zadeh
  • Marco Iacoboni
  • Eran Zaidel
Research Article


Previous research indicates that people respond fastest when the motor response is (spatially, functionally, anatomically, or otherwise) congruent to the visual stimulus. This effect, called ideomotor compatibility, is thought to be expressed in motor areas. Congruence occurs when the stimulus and response share some dimensions in their internal representations. If the ideomotor compatibility hypothesis were true, we would expect facilitation when right hand stimuli are presented to the left hemisphere, or left hand stimuli are presented to the right hemisphere. To address this issue, we conducted a simple reaction time experiment with lateralized targets. Participants were instructed to press a button as soon as a target was observed. The target stimulus was a left hand, a right hand, or a neutral control. Each hemisphere showed faster responses to contralateral hand stimuli as compared with ipsilateral hand stimuli, consistent with the ideomotor compatibility hypothesis. The results support an automatic and implicit processing of visual stimuli within motor representations even when no recognition of, or decision about, the stimulus is necessary.


Body observation Sensory-motor integration Hemispheres Laterality Motor representation Ideomotor compatibility Perception-action 



Left visual field


Right visual field


Visual field



We thank Ian Gizer and Eric Mooshagian for their assistance with this study. We also thank two anonymous reviewers for their useful comments on this manuscript. This work was supported by NIH grant NS20187.


  1. Allison JD, Meador KJ, Loring DW, Figueroa RE, Wright JC (2000) Functional MRI cerebral activation and deactivation during finger movement. Neurology 54:135–142PubMedGoogle Scholar
  2. Brass M, Bekkering H, Prinz W (2001) Movement observation affects movement execution in a simple response task. Acta Psychol (Amst) 106:3–22CrossRefGoogle Scholar
  3. Craighero L, Bello A, Fadiga L, Rizzolatti G (2002) Hand action preparation influences the responses to hand pictures. Neuropsychologia 40:492–502CrossRefPubMedGoogle Scholar
  4. Desmurget M, Epstein CM, Turner RS, Prablanc C, Alexander GE, Grafton ST (1999) Role of the posterior parietal cortex in updating reaching movements to a visual target. Nat Neurosci 2:563–567CrossRefPubMedGoogle Scholar
  5. Downing PE, Jiang Y, Shuman M, Kanwisher N (2001) A cortical area selective for visual processing of the human body. Science 293:2470–2473CrossRefPubMedGoogle Scholar
  6. Gallese V, Fadiga L, Fogassi L, Rizzolatti G (1996) Action recognition in the premotor cortex. Brain 119:593–609PubMedCrossRefGoogle Scholar
  7. Greenwald AG (1970) Sensory feedback mechanism in performance control: with special reference to the ideomotor mechanism. Psychol Rev 77:73–99PubMedCrossRefGoogle Scholar
  8. Iacoboni M, Zaidel E (2000) Crossed–uncrossed difference in simple reaction times to lateralized flashes: between- and within-subjects variability. Neuropsychologia 38:535–541CrossRefPubMedGoogle Scholar
  9. Iacoboni M, Rayman J, Zaidel E (1997) Does the previous trial affect lateralized lexical decision? Neuropsychologia 35:81–88CrossRefPubMedGoogle Scholar
  10. Iacoboni M, Koski L, Brass M, Bekkering H, Woods RP, Dubeau M-C, Mazziotta JC, Rizzolatti G (2001) Reafferent copies of imitated actions in the right superior temporal cortex. Proc Natl Acad Sci U S A 98:13995–13999CrossRefPubMedGoogle Scholar
  11. James W (1890) The principles of psychology. MacMillan, New YorkGoogle Scholar
  12. Kohler E, Keysers C, Umilta MA, Fogassi L, Gallese V, Rizzolatti G (2002) Hearing sounds, understanding actions: action representation in mirror neurons. Science 297:846–848CrossRefPubMedGoogle Scholar
  13. Koski L, Wohlschlager A, Bekkering H, Woods RP, Dubeau MC, Mazziotta JC, Iacoboni M (2002) Modulation of motor and premotor activity during imitation of target-directed actions. Cereb Cortex 12:847–855CrossRefPubMedGoogle Scholar
  14. Knuf L, Aschersleben G, Prinz W (2001) An analysis of ideomotor action. J Exp Psychol Gen 130:779–798CrossRefPubMedGoogle Scholar
  15. Oldfield RC (1971) The assessment and analysis of handedness: the Edinburgh Inventory. Neuropsychologia 9:97–113CrossRefPubMedGoogle Scholar
  16. Parsons LM, Fox PT (1998) The neural basis of implicit movements used in recognising hand shape. Cogn Neuropsychol 16:583–615Google Scholar
  17. Prinz W (1997) Perception and action planning. Eur J Cogn Psychol 9:129–154CrossRefGoogle Scholar
  18. Vogt S, Taylor P, Hopkins B (2003) Visuomotor priming by pictures of hand postures: perspective matters. Neuropsychologia 41:941–951CrossRefPubMedGoogle Scholar
  19. Weekes NY, Capetillo-Cunliffe L, Rayman J, Iacoboni M, Zaidel E (1999) Individual differences in the hemispheric specialization of dual route variables. Brain Lang 67:110–133CrossRefPubMedGoogle Scholar
  20. Weems SA, Zaidel E (2005) Repetition priming within and between the two cerebral hemispheres. Brain Lang 93:298–307CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Lisa Aziz-Zadeh
    • 1
    • 2
  • Marco Iacoboni
    • 2
    • 3
    • 4
  • Eran Zaidel
    • 1
    • 4
  1. 1.Department of PsychologyUniversity of CaliforniaLos AngelesUSA
  2. 2.Ahmanson Lovelace Brain Mapping CenterUniversity of CaliforniaLos AngelesUSA
  3. 3.Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLAUniversity of CaliforniaLos AngelesUSA
  4. 4.Brain Research InstituteUniversity of CaliforniaLos AngelesUSA

Personalised recommendations