A setup for simultaneous measurement of electrophysiological and psychometric temporal encoding in the auditory system

J Neurosci Methods. 2015 Jul 15;249:50-8. doi: 10.1016/j.jneumeth.2015.04.003. Epub 2015 Apr 8.

Abstract

Background: Simultaneous assessment of psychometric tasks and electrophysiological recordings is challenging because each requires specific technical and physiological preconditions. Electrophysiological recordings require a comparatively long test time duration to gain sufficient signal-to-noise ratios, whereas test duration of psychometric measurements should be limited to prevent challenges to the attention of the subject. In order to investigate immediate correlation between both measurements a method is described, which combines electrophysiological and psychometrical measurements in a single test procedure. The test may be applied to subjects with deficits in temporal resolution (e.g. auditory neuropathy spectrum disorder, ANSD).

New method: Auditory steady state responses (ASSR) and a pitch discrimination task were combined in a single procedure. The setup employed two short-time ASSR sub-stimuli with different fixed modulation frequencies but same carrier frequencies (signal 1 and 2). Simultaneously to the recording of ASSR, the test subject had to determine the signal interval which generated the perception of higher pitch.

Results: The developed setup was successfully tested by means of an artificial EEG signal and in one human subject. ASSR signal as well as pitch discrimination performance.

Comparison with existing methods: To our knowledge the presented method has not yet been described elsewhere.

Conclusions: The feasibility of a setup to simultaneously perform a pitch discrimination task and electrophysiological measurements was demonstrated for the first time. The method provides the facility to apply sinusoidal amplitude modulated stimuli (SAM) with jittered modulation period lengths.

Keywords: ASSR; Electrophysiology; Jitter; Psychophysic; SAM; Temporal coding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Electroencephalography / methods*
  • Humans
  • Pitch Discrimination / physiology*
  • Psychometrics / methods*
  • Psychophysics / methods*
  • Time Factors