Fronto-central theta oscillations are related to oscillations in saccadic response times (SRT): an EEG and behavioral data analysis

PLoS One. 2014 Nov 18;9(11):e112974. doi: 10.1371/journal.pone.0112974. eCollection 2014.

Abstract

The phase reset hypothesis states that the phase of an ongoing neural oscillation, reflecting periodic fluctuations in neural activity between states of high and low excitability, can be shifted by the occurrence of a sensory stimulus so that the phase value become highly constant across trials (Schroeder et al., 2008). From EEG/MEG studies it has been hypothesized that coupled oscillatory activity in primary sensory cortices regulates multi sensory processing (Senkowski et al. 2008). We follow up on a study in which evidence of phase reset was found using a purely behavioral paradigm by including also EEG measures. In this paradigm, presentation of an auditory accessory stimulus was followed by a visual target with a stimulus-onset asynchrony (SOA) across a range from 0 to 404 ms in steps of 4 ms. This fine-grained stimulus presentation allowed us to do a spectral analysis on the mean SRT as a function of the SOA, which revealed distinct peak spectral components within a frequency range of 6 to 11 Hz with a modus of 7 Hz. The EEG analysis showed that the auditory stimulus caused a phase reset in 7-Hz brain oscillations in a widespread set of channels. Moreover, there was a significant difference in the average phase at which the visual target stimulus appeared between slow and fast SRT trials. This effect was evident in three different analyses, and occurred primarily in frontal and central electrodes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Adult
  • Electroencephalography
  • Female
  • Humans
  • Photic Stimulation
  • Reaction Time / physiology*
  • Saccades / physiology*
  • Theta Rhythm / physiology*

Grants and funding

The work was supported by Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) grant DI506/12-1 to AD. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.