• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. Jun 15, 1992; 89(12): 5670–5674.

Coherent 25- to 35-Hz oscillations in the sensorimotor cortex of awake behaving monkeys.


Synchronous 25- to 35-Hz oscillations were observed in local field potentials and unit activity in sensorimotor cortex of awake rhesus monkeys. The oscillatory episodes occurred often when the monkeys retrieved raisins from a Klüver board or from unseen locations using somatosensory feedback; they occurred less often during performance of repetitive wrist flexion and extension movements. The amplitude, duration, and frequency of oscillations were not directly related to movement parameters in behaviors studied so far. The occurrence of the oscillations was not consistently related to bursts of activity in forearm muscles, but cycle-triggered averages of electromyograms revealed synchronous modulation in flexor and extensor muscles. The phase of the oscillations changed continuously from the surface to the deeper layers of the cortex, reversing their polarity completely at depths exceeding 800 microns. The oscillations could become synchronized over a distance of 14 mm mediolaterally in precentral cortex. Coherent oscillations could also occur at pre- and postcentral sites separated by an estimated tangential intracortical distance of 20 mm. Activity of single units was commonly seen to burst in synchrony with field potential oscillations. These findings suggest that such oscillations may facilitate interactions between cells during exploratory and manipulative movements, requiring attention to sensorimotor integration.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.1M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Freeman WJ. Spatial properties of an EEG event in the olfactory bulb and cortex. Electroencephalogr Clin Neurophysiol. 1978 May;44(5):586–605. [PubMed]
  • Bouyer JJ, Montaron MF, Vahnée JM, Albert MP, Rougeul A. Anatomical localization of cortical beta rhythms in cat. Neuroscience. 1987 Sep;22(3):863–869. [PubMed]
  • Gray CM, König P, Engel AK, Singer W. Oscillatory responses in cat visual cortex exhibit inter-columnar synchronization which reflects global stimulus properties. Nature. 1989 Mar 23;338(6213):334–337. [PubMed]
  • Galambos R, Makeig S, Talmachoff PJ. A 40-Hz auditory potential recorded from the human scalp. Proc Natl Acad Sci U S A. 1981 Apr;78(4):2643–2647. [PMC free article] [PubMed]
  • Eckhorn R, Bauer R, Jordan W, Brosch M, Kruse W, Munk M, Reitboeck HJ. Coherent oscillations: a mechanism of feature linking in the visual cortex? Multiple electrode and correlation analyses in the cat. Biol Cybern. 1988;60(2):121–130. [PubMed]
  • Freeman WJ, van Dijk BW. Spatial patterns of visual cortical fast EEG during conditioned reflex in a rhesus monkey. Brain Res. 1987 Oct 6;422(2):267–276. [PubMed]
  • Engel AK, Kreiter AK, König P, Singer W. Synchronization of oscillatory neuronal responses between striate and extrastriate visual cortical areas of the cat. Proc Natl Acad Sci U S A. 1991 Jul 15;88(14):6048–6052. [PMC free article] [PubMed]
  • Rougeul A, Bouyer JJ, Dedet L, Debray O. Fast somato-parietal rhythms during combined focal attention and immobility in baboon and squirrel monkey. Electroencephalogr Clin Neurophysiol. 1979 Mar;46(3):310–319. [PubMed]
  • Llinás RR, Paré D. Of dreaming and wakefulness. Neuroscience. 1991;44(3):521–535. [PubMed]
  • von der Malsburg C, Schneider W. A neural cocktail-party processor. Biol Cybern. 1986;54(1):29–40. [PubMed]
  • Ahissar E, Vaadia E. Oscillatory activity of single units in a somatosensory cortex of an awake monkey and their possible role in texture analysis. Proc Natl Acad Sci U S A. 1990 Nov;87(22):8935–8939. [PMC free article] [PubMed]
  • Fetz EE, Cheney PD. Postspike facilitation of forelimb muscle activity by primate corticomotoneuronal cells. J Neurophysiol. 1980 Oct;44(4):751–772. [PubMed]
  • Bernander O, Douglas RJ, Martin KA, Koch C. Synaptic background activity influences spatiotemporal integration in single pyramidal cells. Proc Natl Acad Sci U S A. 1991 Dec 15;88(24):11569–11573. [PMC free article] [PubMed]
  • Chagnac-Amitai Y, Connors BW. Synchronized excitation and inhibition driven by intrinsically bursting neurons in neocortex. J Neurophysiol. 1989 Nov;62(5):1149–1162. [PubMed]
  • Llinás RR, Grace AA, Yarom Y. In vitro neurons in mammalian cortical layer 4 exhibit intrinsic oscillatory activity in the 10- to 50-Hz frequency range. Proc Natl Acad Sci U S A. 1991 Feb 1;88(3):897–901. [PMC free article] [PubMed]
  • Steriade M, Dossi RC, Paré D, Oakson G. Fast oscillations (20-40 Hz) in thalamocortical systems and their potentiation by mesopontine cholinergic nuclei in the cat. Proc Natl Acad Sci U S A. 1991 May 15;88(10):4396–4400. [PMC free article] [PubMed]
  • Sporns O, Gally JA, Reeke GN, Jr, Edelman GM. Reentrant signaling among simulated neuronal groups leads to coherency in their oscillatory activity. Proc Natl Acad Sci U S A. 1989 Sep;86(18):7265–7269. [PMC free article] [PubMed]
  • Sompolinsky H, Golomb D, Kleinfeld D. Global processing of visual stimuli in a neural network of coupled oscillators. Proc Natl Acad Sci U S A. 1990 Sep;87(18):7200–7204. [PMC free article] [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • Cited in Books
    Cited in Books
    PubMed Central articles cited in books
  • MedGen
    Related information in MedGen
  • PubMed
    PubMed citations for these articles

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...