Selective attention enhances the auditory 40-Hz transient response in humans

Abstract

Studies of human auditory and somatosensory modalities have shown that there is an oscillatory response in the gamma-band (at about 40 Hz) frequency which is elicited by either steady state or transient stimulation. The auditory 40-Hz response is generated at least partially in the auditory cortex as a result of thalamocortical interaction and may serve perceptual integration and conscious perception. A connection to selective attention has been implied in human and animal studies, although the evidence is inconclusive. Moreover, fundamental differences between the human and animal 40-Hz responses prohibit generalization. Furthermore, most experiments have used steady-state stimulation during which the brain does not regain its resting state between stimuli as it does when transient stimulation is used. Here we study the effect of selective attention on the auditory gamma-band (40-Hz) transient response using subjects listening to tone pips presented in one ear while ignoring a concurrent sequence of tone pips in the other ear. The 40-Hz response was larger when subjects paid attention to stimuli rather than ignored them. This attention effect was most pronounced over the frontal and central scalp areas. Our results demonstrate a physiological correlate of selective attention in the 40-Hz transient response in humans.

Binding, spatial attention and perceptual awareness

“…Consistently, manipulations of spatial attention modulate γ-band activity of the EEG over occipital-parietal sites 60 . These effects have been observed with visual, auditory 61 and somatosensory 62 stimuli.…”

Gamma and beta neural activity evoked during a sensory gating paradigm: Effects of auditory, somatosensory and cross-modal stimulation

“…Further, a detectable influence of top-down attention on stimulus-evoked beta activity has not been found. In fact the demonstrable effect of this manipulation on non-invasive neurophysiological measures appears to be manifest in frequency bands below beta (<10 Hz: Clementz et al, 2002) or above beta (>30 Hz: Debener et al, 2003;Tiitinen et al, 1993). Considered within the model described above, and in agreement with Yamaguchi et al (2004), this implies that top-down attention does not necessarily modify the neural computation of stimulus-driven salience.…”

Dynamic causal modelling of induced responses

“…Induced oscillations are a hallmark of many neuronal systems (Gray et al, 1989;Tiitinen et al, 1993;Tass et al, 1998;Singer, 1999;Tallon-Baudry and Bertrand, 1999;Varela et al, 2001;Singh et al, 2002;TallonBaudry et al, 1997;Pantev, 1995). They are ubiquitous in both the sensory and motor systems and may play an important role in the functional integration of distributed brain systems.…”