Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Cerebral mechanisms of word masking and unconscious repetition priming

Abstract

We used functional magnetic resonance imaging (fMRI) and event-related potentials (ERPs) to visualize the cerebral processing of unseen masked words. Within the areas associated with conscious reading, masked words activated left extrastriate, fusiform and precentral areas. Furthermore, masked words reduced the amount of activation evoked by a subsequent conscious presentation of the same word. In the left fusiform gyrus, this repetition suppression phenomenon was independent of whether the prime and target shared the same case, indicating that case-independent information about letter strings was extracted unconsciously. In comparison to an unmasked situation, however, the activation evoked by masked words was drastically reduced and was undetectable in prefrontal and parietal areas, correlating with participants' inability to report the masked words.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Design and behavioral results of experiment 1.
Figure 2: fMRI activations to visible and masked words in experiment 1.
Figure 3: Cartography of ERPs in reponse to visible words and to masked words.
Figure 4: Design and behavioral results of experiment 2.
Figure 5: fMRI correlates of unconscious repetition priming.

References

  1. 1

    Forster, K. I. & Davis, C. Repetition priming and frequency attenuation in lexical access. J. Exp. Psychol. Learn. Mem. Cogn. 10, 680–698 (1984).

    Article  Google Scholar 

  2. 2

    Ferrand, L. & Grainger, J. Effects of orthography are independent of phonology in masked form priming. Q. J. Exp. Psychol. A 47, 365–382 (1994).

    CAS  Article  Google Scholar 

  3. 3

    Bowers, J. S., Vigliocco, G. & Haan, R. Orthographic, phonological, and articulatory contributions to masked letter and word priming. J. Exp. Psychol. Hum. Percept. Perf. 24, 1705–1719 (1998).

    CAS  Article  Google Scholar 

  4. 4

    Cheesman, J. & Merikle, P. M. Priming with and without awareness. Percept. Psychophys. 36, 387–395 (1984).

    CAS  Article  Google Scholar 

  5. 5

    Greenwald, A. G. Three cognitive markers of unconscious semantic activation. Science 273, 1699–1702 (1996).

    CAS  Article  Google Scholar 

  6. 6

    Dehaene, S. et al. Imaging unconscious semantic priming. Nature 395, 597–600 (1998).

    CAS  Article  Google Scholar 

  7. 7

    Fiez, J. A. & Petersen, S. E. Neuroimaging studies of word reading. Proc. Natl. Acad. Sci. USA 95, 914–921 (1998).

    CAS  Article  Google Scholar 

  8. 8

    Cohen, L. et al. The visual word form area: spatial and temporal characterization of an initial stage of reading in normal subjects and posterior split-brain patients. Brain 123, 291–307 (2000).

    Article  Google Scholar 

  9. 9

    Wiggs, C. L. & Martin, A. Properties and mechanisms of perceptual priming. Curr. Opin. Neurobiol. 8, 227–233 (1998).

    CAS  Article  Google Scholar 

  10. 10

    Lueschow, A., Miller, E. K. & Desimone, R. Inferior temporal mechanisms for invariant object recognition. Cereb. Cortex 4, 523–531 (1994).

    CAS  Article  Google Scholar 

  11. 11

    Buckner, R. L. et al. Functional-anatomic correlates of object priming in humans revealed by rapid presentation event-related fMRI. Neuron 20, 285–296 (1998).

    CAS  Article  Google Scholar 

  12. 12

    Grill-Spector, K. et al. Differential processing of objects under various viewing conditions in the human lateral occipital complex. Neuron 24, 187–203 (1999).

    CAS  Article  Google Scholar 

  13. 13

    Schacter, D. L. & Buckner, R. L. Priming and the brain. Neuron 20, 185–195 (1998).

    CAS  Article  Google Scholar 

  14. 14

    Gauthier, I. et al. The fusiform “face area” is part of a network that processes faces at the individual level. J. Cogn. Neurosci. 12, 495–504 (2000).

    CAS  Article  Google Scholar 

  15. 15

    Schnyer, D. M., Allen, J. J. & Forster, K. I. Event-related brain potential examination of implicit memory processes: masked and unmasked repetition priming. Neuropsychology 11, 243–260 (1997).

    CAS  Article  Google Scholar 

  16. 16

    Deacon, D., Hewitt, S., Yang, C. & Nagata, M. Event-related potential indices of semantic priming using masked and unmasked words: evidence that the N400 does not reflect a post-lexical process. Brain. Res. Cogn. Brain. Res. 9, 137–146 (2000).

    CAS  Article  Google Scholar 

  17. 17

    Naccache, L. & Dehaene, S. The priming method: imaging unconscious repetition priming reveals an abstract representation of number in the parietal lobes. Cereb. Cortex (in press).

  18. 18

    Kiefer, M. & Spitzer, M. Time course of conscious and unconscious semantic brain activation. Neuroreport 11, 2401–2407 (2000).

    CAS  Article  Google Scholar 

  19. 19

    Rolls, E. T. & Tovee, M. J. Processing speed in the cerebral cortex and the neurophysiology of visual masking. Proc. R. Soc. Lond. B Biol. Sci. 257, 9–15 (1994).

    CAS  Article  Google Scholar 

  20. 20

    Rolls, E. T., Tovee, M. J. & Panzeri, S. The neurophysiology of backward visual masking: information analysis. J. Cogn. Neurosci. 11, 300–311 (1999).

    CAS  Article  Google Scholar 

  21. 21

    Marsolek, C. J., Kosslyn, S. M. & Squire, L. R. Form-specific visual priming in the right cerebral hemisphere. J. Exp. Psychol. Learn. Mem. Cogn. 18, 492–508 (1992).

    CAS  Article  Google Scholar 

  22. 22

    Compton, P. E., Grossenbacher, P., Posner, M. I. & Tucker, D. M. A cognitive-anatomical approach to attention in lexical access. J. Cogn. Neurosci. 3, 304–312 (1991).

    CAS  Article  Google Scholar 

  23. 23

    Posner, M. I. & McCandliss, B. D. Converging methods for investigating lexical access. Psychol. Sci. 4, 305–309 (1993).

    Article  Google Scholar 

  24. 24

    Marsolek, C. J. Abstract visual-form representations in the left cerebral hemisphere. J. Exp. Psychol. Hum. Percept. Perf. 21, 375–386 (1995).

    CAS  Article  Google Scholar 

  25. 25

    Fiez, J. A., Balota, D. A., Raichle, M. E. & Petersen, S. E. Effects of lexicality, frequency, and spelling-to-sound consistency on the functional anatomy of reading. Neuron 24, 205–218 (1999).

    CAS  Article  Google Scholar 

  26. 26

    Tong, F., Nakayama, K., Vaughan, J. T. & Kanwisher, N. Binocular rivalry and visual awareness in human extrastriate cortex. Neuron 21, 753–759 (1998).

    CAS  Article  Google Scholar 

  27. 27

    Grill-Spector, K., Kushnir, T., Hendler, T. & Malach, R. The dynamics of object-selective activation correlate with recognition performance in humans. Nat. Neurosci. 3, 837–843 (2000).

    CAS  Article  Google Scholar 

  28. 28

    Leopold, D. A. & Logothetis, N. K. Multistable phenomena: changing views in perception. Trends Cogn. Sci. 3, 254–264 (1999).

    CAS  Article  Google Scholar 

  29. 29

    Bar, M. & Biederman, I. Localizing the cortical region mediating visual awareness of object identity. Proc. Natl. Acad. Sci. USA 96, 1790–1793 (1999).

    CAS  Article  Google Scholar 

  30. 30

    Bar, M. et al. Cortical mechanisms specific to explicit visual object recognition. Neuron 29, 529–535 (2001).

    CAS  Article  Google Scholar 

  31. 31

    Friston, K. J., Josephs, O., Rees, G. & Turner, R. Nonlinear event-related responses in fMRI. Magn. Reson. Med. 39, 41–52 (1998).

    CAS  Article  Google Scholar 

  32. 32

    Macknik, S. L. & Livingstone, M. S. Neuronal correlates of visibility and invisibility in the primate visual system. Nat. Neurosci. 1, 144–149 (1998).

    CAS  Article  Google Scholar 

  33. 33

    Breitmeyer, B. G. Visual Masking: An Integrative Approach (Oxford Univ. Press, 1984).

    Google Scholar 

  34. 34

    Enns, J. T. & Di Lollo, V. What's new in visual masking. Trends Cogn. Sci. 4, 345–352 (2000).

    CAS  Article  Google Scholar 

  35. 35

    Dehaene, S. & Naccache, L. Towards a cognitive neuroscience of consciousness: basic evidence and a workspace framework. Cognition 79, 1–37 (2001).

    CAS  Article  Google Scholar 

  36. 36

    Donchin, E. & Coles, M. G. H. Is the P300 component a manifestation of context updating? Behav. Brain Sci. 11, 357–427 (1988).

    Article  Google Scholar 

  37. 37

    Picton, T. W. The P300 wave of the human event-related potential. J. Clin. Neurophysiol. 9, 456–479 (1992).

    CAS  Article  Google Scholar 

  38. 38

    Portas, C. M. et al. Auditory processing across the sleep-wake cycle: simultaneous EEG and fMRI monitoring in humans. Neuron 28, 991–999 (2000).

    CAS  Article  Google Scholar 

  39. 39

    Rees, G., Russell, C., Frith, C. D. & Driver, J. Inattentional blindness versus inattentional amnesia for fixated but ignored words. Science 286, 2504–2507 (1999).

    CAS  Article  Google Scholar 

  40. 40

    Lumer, E. D. & Rees, G. Covariation of activity in visual and prefrontal cortex associated with subjective visual perception. Proc. Natl. Acad. Sci. USA 96, 1669–1673 (1999).

    CAS  Article  Google Scholar 

  41. 41

    McIntosh, A. R., Rajah, M. N. & Lobaugh, N. J. Interactions of prefrontal cortex in relation to awareness in sensory learning. Science 284, 1531–1533 (1999).

    CAS  Article  Google Scholar 

  42. 42

    Driver, J. & Vuilleumier, P. Unilateral neglect and perceptual awareness. Cognition 79, 39–88 (2001).

    CAS  Article  Google Scholar 

  43. 43

    Rees, G. et al. Unconscious activation of visual cortex in the damaged right hemisphere of a parietal patient with extinction. Brain 123, 1624–1633 (2000).

    Article  Google Scholar 

  44. 44

    Posner, M. I. Attention: the mechanisms of consciousness. Proc. Natl. Acad. Sci. USA 91, 7398–7403 (1994).

    CAS  Article  Google Scholar 

  45. 45

    Dehaene, S., Kerszberg, M. & Changeux, J. P. A neuronal model of a global workspace in effortful cognitive tasks. Proc. Natl. Acad. Sci. USA 95, 14529–14534 (1998).

    CAS  Article  Google Scholar 

  46. 46

    Burock, M. A., Buckner, R. L., Woldorff, M. G., Rosen, B. R. & Dale, A. M. Randomized event-related experimental designs allow for extremely rapid presentation rates using functional MRI. Neuroreport 9, 3735–3739 (1998).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

We thank J.-P. Changeux, C. Pallier and L. Spelke for useful comments. This project was supported by the McDonnell Foundation.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Stanislas Dehaene.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Dehaene, S., Naccache, L., Cohen, L. et al. Cerebral mechanisms of word masking and unconscious repetition priming. Nat Neurosci 4, 752–758 (2001). https://doi.org/10.1038/89551

Download citation

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing