Effects of Visual Scene Complexity on Neural Signatures of Spatial Attention

Abstract

Spatial selective attention greatly affects our processing of complex visual scenes, yet the way in which the brain selects relevant objects while suppressing irrelevant objects is still unclear. Evidence of these processes has been found using non-invasive electroencephalography (EEG). However, few studies have characterized these measures during attention to dynamic stimuli, and little is known regarding how these measures change with increased scene complexity. Here, we compared attentional modulation of the EEG N1 and alpha power (oscillations between 8-14 Hz) across three visual selective attention tasks. The tasks differed in the number of irrelevant stimuli presented, but all required sustained attention to the orientation trajectory of a lateralized stimulus. In scenes with few irrelevant stimuli, top-down control of spatial attention is associated with strong modulation of both the N1 and alpha power across parietal-occipital channels. In scenes with many irrelevant stimuli in both hemifields, however, top-down control is no longer represented by strong modulation of alpha power, and N1 amplitudes are overall weaker. These results suggest that as a scene becomes more complex, requiring suppression in both hemifields, the neural signatures of top-down control degrade, likely reflecting some limitation in EEG to represent this suppression.

Operator State in a Workplace Simulation Modulates Eye-Blink Related EEG Activity

“…The P1 possibly indicated the increased involvement of filter functions of visual inputs during active conditions [68], [69], whereas the decreased P2 was related to higher-level perceptual processes [70], facilitating targeted information processing and identification relating to the manipulation of steam engine pressure. The frontal N2 and SFN also significantly decreased during active system manipulation, which may be attributed to attentional narrowing during processing complex information, leading to reduced information processing demands [71].…”

Visual Demands of Walking Are Reflected in Eye-Blink-Evoked EEG-Activity

“…Looking into effects of walk load, the decrease in amplitude of the fronto-central N2, the occipital P2, and the P3 may indicate the reduced availability of mental resources when walking conditions become more demanding [13]. However, the effects in the N2 and the P3 may also be interpreted in terms of attentional narrowing when processing complex input [42]. The same interpretations can be applied to the decrease in Theta perturbations.…”

“…The same set of predictions may hold true for ERSPs, in particular, Theta and Alpha activity. A purely function-based view would predict that more demanding tasks reduce levels of Alpha power, since more task engagement is involved [40,41], However, Alpha activity could also increase with more complex scenes [42]. Additionally, this effect can be interpreted in terms of increased inhibitory processing for irrelevant information in favor of relevant signals.…”

Spatiotemporal characteristics of cortical activities of REM sleep behavior disorder revealed by explainable machine learning using 3D convolutional neural network

“…During the 300–350 ms period, the LO and right SPL regions were found to be critical and are known to reflect higher-order visual processing, which is modulated by top-down control of spatial attention 58 , 59 . This is also consistent with previous results that showed right hemisphere dominance in visuospatial processing 60 .…”