Journal of Neural Transmission

, Volume 113, Issue 10, pp 1477–1486

Frontal theta event-related synchronization: comparison of directed attention and working memory load effects

  • P. Missonnier
  • M.-P. Deiber
  • G. Gold
  • P. Millet
  • M. Gex-Fabry Pun
  • L. Fazio-Costa
  • P. Giannakopoulos
  • V. Ibáñez
Article

DOI: 10.1007/s00702-005-0443-9

Cite this article as:
Missonnier, P., Deiber, M., Gold, G. et al. J Neural Transm (2006) 113: 1477. doi:10.1007/s00702-005-0443-9

Summary.

Early studies showed that long-term encoding and retrieval of new information is associated with modulation of the theta rhythm. More recently, changes in theta power amplitude over frontal electrode sites were reported during working memory, yet their relative significance in regard to attentional and memory processes remains unclear. Event-related synchronisation responses in the 4–7.5 Hz theta EEG frequency band was studied in 12 normal subjects performing four different tasks: two working memory tasks in which load varied from one (1-back task) to two (2-back task) items, an oddball detection (attention) task and a passive fixation task. A phasic theta increase was observed following stimulus apparition on all electrode sites within each task, with longer culmination peak and maximal amplitude over frontal electrodes. Frontal theta event-related synchronization (ERS) was of higher amplitude in the 1-back, 2-back and detection tasks as compared to the passive fixation task. Additionally, the detection task elicited a larger frontal and central theta ERS than the 2-back task. By analyzing theta ERS characteristics in various experimental conditions, the present study reveals that early phasic theta response over frontal regions primarily reflects the activation of neural networks involved in allocation of attention related to target stimuli rather than working memory processes.

Keywords: Working memory, EEG, event-related synchronisation, theta oscillations, attention.

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • P. Missonnier
    • 1
    • 2
  • M.-P. Deiber
    • 2
  • G. Gold
    • 4
  • P. Millet
    • 1
  • M. Gex-Fabry Pun
    • 3
  • L. Fazio-Costa
    • 4
  • P. Giannakopoulos
    • 2
    • 5
  • V. Ibáñez
    • 1
  1. 1.Neuroimaging UnitUniversity Hospitals of GenevaGenevaSwitzerland
  2. 2.Service of Geriatric PsychiatryUniversity Hospitals of GenevaGenevaSwitzerland
  3. 3.Unit of Clinical Research, Department of PsychiatryUniversity Hospitals of GenevaGenevaSwitzerland
  4. 4.Department of GeriatricsUniversity Hospitals of GenevaGenevaSwitzerland
  5. 5.Service of Old Age PsychiatryUniversity Hospitals of LausannePrillySwitzerland