All talk? Left temporal alpha oscillations are not specific to verbal-analytical processing during conscious motor control

AbstractThe present study tested the validity of inferring verbal-analytic motor processing from EEG left-temporal alpha activity. Participants (n = 20) reached for and transport a jar under three conditions: one control condition and two self-talk conditions aimed at eliciting either task-unrelated verbal processing or task-related conscious control, while 32-channel EEG and kinematics were recorded. Compared to the control condition, both self-talk conditions elicited greater self-reported levels of verbal processing, but only the task-related self-talk condition was accompanied by greater left temporal activity (i.e., EEG alpha power decreased) during movement production. However, this increase was not localised to the left temporal region but was rather evident over all scalp regions examined, suggesting an interpretation more consistent with diminished neural efficiency. No effects for left temporal-frontal (T7-Fz) connectivity were detected across conditions. Our results failed to endorse left-temporal EEG alpha activity as valid index of verbal-analytic processing during motor tasks.

Download Full-text

Neurophysiological indicators of internal attention: An EEG-eye-tracking co-registration study [preprint]

10.31234/osf.io/25hzb ◽

2020 ◽

Author(s):

Simon Ceh ◽

Sonja Annerer-Walcher ◽

Christof Körner ◽

Christian Rominger ◽

Silivia E. Kober ◽

...

Keyword(s):

Eye Tracking ◽

Sensory Information ◽

Alpha Activity ◽

Alpha Power ◽

Gating Mechanism ◽

Eeg Alpha ◽

Eeg Alpha Activity ◽

Task Irrelevant ◽

Attention Demands ◽

Internal Attention

Many goal-directed, as well as spontaneous everyday activities (e.g., planning, mind wandering) rely on an internal focus of attention. In this EEG-eye-tracking co-registration study, we investigated effects of attention direction on EEG alpha activity and various relevant eye parameters. We used an established paradigm to manipulate internal attention demands within tasks by means of conditional stimulus masking. Consistent with previous research, IDC involved relatively higher EEG alpha activity (lower alpha desynchronization) at posterior cortical sites. Moreover, IDC was characterized by greater pupil diameter (PD) and PD variance, more and longer blinks, and fewer microsaccades, fixations and saccades. These findings show that internal versus external cognition is associated with robust differences in several neurophysiological indicators that contribute to suppress task-irrelevant information processing at the neural and perceptual level. In a second line of analysis, we explored the intrinsic temporal covariation between EEG alpha activity and eye parameters during rest. This analysis revealed a positive correlation of EEG alpha power with PD especially in bilateral parieto-occipital regions. Together, these findings suggest that EEG alpha activity and PD represent time-sensitive indicators of internal attention demands and are part of a neurophysiological gating mechanism to shield internal cognition from irrelevant sensory information.

Download Full-text

Functional but not obligatory link between microsaccades and neural modulation by covert spatial attention

10.1101/2021.11.10.468033 ◽

2021 ◽

Author(s):

Baiwei Liu ◽

Anna C Nobre ◽

Freek van Ede

Keyword(s):

Spatial Attention ◽

Neural Activity ◽

Alpha Activity ◽

Spatial Modulation ◽

Fixational Eye Movements ◽

Neural Modulation ◽

Gaze Behaviour ◽

Eeg Alpha ◽

Eeg Alpha Activity ◽

Spatial Modulations

Covert spatial attention is associated with spatially specific modulation of neural activity as well as with directional biases in fixational eye-movements known as microsaccades. Recently, this link has been suggested to be obligatory, such that modulation of neural activity by covert spatial attention occurs only when paired with microsaccades toward the attended location. Here we revisited this link between microsaccades and neural modulation by covert spatial attention in humans. We investigated spatial modulation of 8-12 Hz EEG alpha activity and microsaccades in a context with no incentive for overt gaze behaviour: when attention is directed internally within the spatial layout of visual working memory. In line with a common attentional origin, we show that spatial modulations of alpha activity and microsaccades co-vary: alpha lateralisation is stronger in trials with microsaccades toward compared to away from the memorised location of the to-be-attended item and occurs earlier in trials with earlier microsaccades toward this item. Critically, however, trials without attention-driven microsaccades nevertheless showed clear spatial modulation of alpha activity - comparable to the neural modulation observed in trials with attention-driven microsaccades. Thus, directional biases in microsaccades are correlated with neural signatures of covert spatial attention, but they are not a prerequisite for neural modulation by covert spatial attention to be manifest.

Download Full-text