TY - JOUR
T1 - Stimulus-driven brain rhythms within the alpha band
T2 - The attentional-modulation conundrum
AU - Keitel, Christian
AU - Keitel, Anne
AU - Benwell, Christopher
AU - Daube, Christoph
AU - Thut, Gregor
AU - Gross, Joachim
N1 - Funded by a Wellcome Trust Joint Investigator Grant awarded to GT and JG (#098433/#098434)
PY - 2019/4/17
Y1 - 2019/4/17
N2 - Two largely independent research lines use rhythmic sensory stimulation to study visual processing. Despite the use of strikingly similar experimental paradigms, they differ crucially in their notion of the stimulus-driven periodic brain responses: one regards them mostly as synchronized (entrained) intrinsic brain rhythms; the other assumes they are predominantly evoked responses [classically termed steady-state responses (SSRs)] that add to the ongoing brain activity. This conceptual difference can produce contradictory predictions about, and interpretations of, experimental outcomes. The effect of spatial attention on brain rhythms in the alpha band (8 -13 Hz) is one such instance: alpha-range SSRs have typically been found to increase in power when participants focus their spatial attention on laterally presented stimuli, in line with a gain control of the visual evoked response. In nearly identical experiments, retinotopic decreases in entrained alpha-band power have been reported, in line with the inhibitory function of intrinsic alpha. Here we reconcile these contradictory findings by showing that they result from a small but far-reaching difference between two common approaches to EEG spectral decomposition. In a new analysis of previously published human EEG data, recorded during bilateral rhythmic visual stimulation,wefind the typical SSR gain effect when emphasizing stimulus-locked neural activity and the typical retinotopic alpha suppression when focusing on ongoing rhythms. These opposite but parallel effects suggest that spatial attention may bias the neural processing of dynamic visual stimulation via two complementary neural mechanisms.
AB - Two largely independent research lines use rhythmic sensory stimulation to study visual processing. Despite the use of strikingly similar experimental paradigms, they differ crucially in their notion of the stimulus-driven periodic brain responses: one regards them mostly as synchronized (entrained) intrinsic brain rhythms; the other assumes they are predominantly evoked responses [classically termed steady-state responses (SSRs)] that add to the ongoing brain activity. This conceptual difference can produce contradictory predictions about, and interpretations of, experimental outcomes. The effect of spatial attention on brain rhythms in the alpha band (8 -13 Hz) is one such instance: alpha-range SSRs have typically been found to increase in power when participants focus their spatial attention on laterally presented stimuli, in line with a gain control of the visual evoked response. In nearly identical experiments, retinotopic decreases in entrained alpha-band power have been reported, in line with the inhibitory function of intrinsic alpha. Here we reconcile these contradictory findings by showing that they result from a small but far-reaching difference between two common approaches to EEG spectral decomposition. In a new analysis of previously published human EEG data, recorded during bilateral rhythmic visual stimulation,wefind the typical SSR gain effect when emphasizing stimulus-locked neural activity and the typical retinotopic alpha suppression when focusing on ongoing rhythms. These opposite but parallel effects suggest that spatial attention may bias the neural processing of dynamic visual stimulation via two complementary neural mechanisms.
KW - Alpha rhythm
KW - Entrainment
KW - Frequency tagging
KW - Phase synchronization
KW - Spatial attention
KW - Steady-state response (SSR)
UR - http://www.scopus.com/inward/record.url?scp=85062714933&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.1633-18.2019
DO - 10.1523/JNEUROSCI.1633-18.2019
M3 - Article
C2 - 30770401
SN - 0270-6474
VL - 39
SP - 3119
EP - 3129
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 16
ER -