scholarly journals Multivariate EEG analyses support high-resolution tracking of feature-based attentional selection

2016 ◽  
Author(s):  
Johannes Jacobus Fahrenfort ◽  
Anna Grubert ◽  
Christian N. L. Olivers ◽  
Martin Eimer
Keyword(s):  
Visual Field ◽  
Multivariate Analyses ◽  
Target Selection ◽  
Target Position ◽  
Attentional Selection ◽  
Forward Model ◽  
Hemispheric Differences ◽  
Neural Basis ◽  
Eeg Data ◽  
Feature Based

AbstractThe primary electrophysiological marker of feature-based selection is the N2pc, a lateralized posterior negativity emerging around 180-200 ms. As it relies on hemispheric differences, its ability to discriminate the locus of focal attention is severely limited. Here we demonstrate that multivariate analyses of raw EEG data provide a much more fine-grained spatial profile of feature-based target selection. When training a pattern classifier to determine target position from EEG, we were able to decode target positions on the vertical midline, which cannot be achieved using standard N2pc methodology. Next, we used a forward encoding model to construct a channel tuning function that describes the continuous relationship between target position and multivariate EEG in an eight-position display. This model can spatially discriminate individual target positions in these displays and is fully invertible, enabling us to construct hypothetical topographic activation maps for target positions that were never used. When tested against the real pattern of neural activity obtained from a different group of subjects, the constructed maps from the forward model turned out statistically indistinguishable, thus providing independent validation of our model. Our findings demonstrate the power of multivariate EEG analysis to track feature-based target selection with high spatial and temporal precision.Significance StatementFeature-based attentional selection enables observers to find objects in their visual field. The spatiotemporal profile of this process is difficult to assess with standard electrophysiological methods, which rely on activity differences between cerebral hemispheres. We demonstrate that multivariate analyses of EEG data can track target selection across the visual field with high temporal and spatial resolution. Using a forward model, we were able to capture the continuous relationship between target position and EEG measurements, allowing us to reconstruct the distribution of cortical activity for target locations that were never shown during the experiment. Our findings demonstrate the existence of a temporally and spatially precise EEG signal that can be used to study the neural basis of feature-based attentional selection.

scholarly journals Multivariate methods to track the spatiotemporal profile of feature-based attentional selection using EEG

2019 ◽  
Author(s):  
Johannes Jacobus Fahrenfort
Keyword(s):  
Visual Field ◽  
Time Series Data ◽  
Univariate Analysis ◽  
Attentional Selection ◽  
Series Data ◽  
Attentional Processes ◽  
Eeg Data ◽  
Feature Based ◽  
Multivariate Pattern ◽  
The Relationship

This chapter provides a tutorial-style guide to analyzing electroencephalogram (EEG) data contingent on feature-based attentional selection. It is targeted at researchers that currently investigate attentional processes using univariate methods but consider moving to multivariate analyses. The chapter starts by providing examples of classical univariate analysis, in which the EEG signal occurring ipsilateral to the target is subtracted from the signal that occurs in a contralateral electrode (i.e. the classical N2pc, an interhemispheric posterior negativity emerging around 180–200 ms). Next, it shows how the same type of information can also be identified using multivariate pattern analysis (MVPA). MVPA does not restrict one to contrast attentional selection in opposite hemifields, but also allows one to assess attentional selection on the vertical meridian, or even within a quadrant of the visual field, opening up new avenues for research. The chapter demonstrates how to visualize topographic maps of attentional selection when using MVPA, and shows how to assess timing onsets using the percent-amplitude latency method. Finally, it shows how a forward encoding model enables one to characterize the relationship between a continuous experimental variable (such as attended targets positioned on a circle) and EEG activity. This allows one to construct brain patterns for positions in the visual field that were never attended in the data that was used to generate the forward model. This chapter is intended as a practical guide, explaining the methods and providing the scripts that can be used to generate the figures in-line, thus providing a step-by-step cookbook for analyzing neural time series data in the field of feature-based attentional selection.

scholarly journals Rapid Parallel Attentional Selection Can Be Controlled by Shape and Alphanumerical Category

2016 ◽  
Vol 28 (11) ◽  
pp. 1672-1687 ◽  
Author(s):  
Michael Jenkins ◽  
Anna Grubert ◽  
Martin Eimer
Keyword(s):  
Attentional Control ◽  
Time Course ◽  
Target Selection ◽  
Attentional Selection ◽  
Visual Features ◽  
Multiple Target ◽  
Neural Basis ◽  
Selection Processes ◽  
Selection Tasks ◽  
Selection Of

Previous research has shown that when two color-defined target objects appear in rapid succession at different locations, attention is deployed independently and in parallel to both targets. This study investigated whether this rapid simultaneous attentional target selection mechanism can also be employed in tasks where targets are defined by a different visual feature (shape) or when alphanumerical category is the target selection attribute. Two displays that both contained a target and a nontarget object on opposite sides were presented successively, and the SOA between the two displays was 100, 50, 20, or 10 msec in different blocks. N2pc components were recorded to both targets as a temporal marker of their attentional selection. When observers searched for shape-defined targets (Experiment 1), N2pc components to the two targets were equal in size and overlapped in time when the SOA between the two displays was short, reflecting two parallel shape-guided target selection processes with their own independent time course. Essentially the same temporal pattern of N2pc components was observed when alphanumerical category was the target-defining attribute (Experiment 2), demonstrating that the rapid parallel attentional selection of multiple target objects is not restricted to situations where the deployment of attention can be guided by elementary visual features but that these processes can even be employed in category-based attentional selection tasks. These findings have important implications for our understanding of the cognitive and neural basis of top–down attentional control.

scholarly journals On the origin of event-related potentials indexing covert attentional selection during visual search: timing of selection by macaque frontal eye field and event-related potentials during pop-out search

2013 ◽  
Vol 109 (2) ◽  
pp. 557-569 ◽  
Author(s):  
Braden A. Purcell ◽  
Jeffrey D. Schall ◽  
Geoffrey F. Woodman
Keyword(s):  
Time Course ◽  
Target Selection ◽  
Event Related Potentials ◽  
Attentional Selection ◽  
Task Demands ◽  
Frontal Eye Field ◽  
Neural Basis ◽  
Set Size ◽  
Related Potentials ◽  
Eye Field

Event-related potentials (ERPs) have provided crucial data concerning the time course of psychological processes, but the neural mechanisms producing ERP components remain poorly understood. This study continues a program of research in which we investigated the neural basis of attention-related ERP components by simultaneously recording intracranially and extracranially from macaque monkeys. Here, we compare the timing of attentional selection by the macaque homologue of the human N2pc component (m-N2pc) with the timing of selection in the frontal eye field (FEF), an attentional-control structure believed to influence posterior visual areas thought to generate the N2pc. We recorded FEF single-unit spiking and local field potentials (LFPs) simultaneously with the m-N2pc in monkeys performing an efficient pop-out search task. We assessed how the timing of attentional selection depends on task demands by direct comparison with a previous study of inefficient search in the same monkeys (e.g., finding a T among Ls). Target selection by FEF spikes, LFPs, and the m-N2pc was earlier during efficient pop-out search rather than during inefficient search. The timing and magnitude of selection in all three signals varied with set size during inefficient but not efficient search. During pop-out search, attentional selection was evident in FEF spiking and LFP before the m-N2pc, following the same sequence observed during inefficient search. These observations are consistent with the hypothesis that feedback from FEF modulates neural activity in posterior regions that appear to generate the m-N2pc even when competition for attention among items in a visual scene is minimal.

scholarly journals Mind-wandering Is Accompanied by Both Local Sleep and Enhanced Processes of Spatial Attention Allocation

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Christian Wienke ◽  
Mandy V Bartsch ◽  
Lena Vogelgesang ◽  
Christoph Reichert ◽  
Hermann Hinrichs ◽  
...  
Keyword(s):  
Search Task ◽  
Brain Activity ◽  
Target Selection ◽  
Mind Wandering ◽  
Attentional Selection ◽  
Self Report ◽  
Cortical Processing ◽  
High Frequency Activity ◽  
External Stimuli ◽  
Local Sleep

Abstract Mind-wandering (MW) is a subjective, cognitive phenomenon, in which thoughts move away from the task toward an internal train of thoughts, possibly during phases of neuronal sleep-like activity (local sleep, LS). MW decreases cortical processing of external stimuli and is assumed to decouple attention from the external world. Here, we directly tested how indicators of LS, cortical processing, and attentional selection change in a pop-out visual search task during phases of MW. Participants’ brain activity was recorded using magnetoencephalography, MW was assessed via self-report using randomly interspersed probes. As expected, the performance decreased under MW. Consistent with the occurrence of LS, MW was accompanied by a decrease in high-frequency activity (HFA, 80–150 Hz) and an increase in slow wave activity (SWA, 1–6 Hz). In contrast, visual attentional selection as indexed by the N2pc component was enhanced during MW with the N2pc amplitude being directly linked to participants’ performance. This observation clearly contradicts accounts of attentional decoupling that would predict a decrease in attention-related responses to external stimuli during MW. Together, our results suggest that MW occurs during phases of LS with processes of attentional target selection being upregulated, potentially to compensate for the mental distraction during MW.

scholarly journals Dissociating Reward- and Attention-driven Biasing of Global Feature-based Selection in Human Visual Cortex

2019 ◽  
Vol 31 (4) ◽  
pp. 469-481 ◽  
Author(s):  
Haydee G. Garcia-Lazaro ◽  
Mandy V. Bartsch ◽  
Carsten N. Boehler ◽  
Ruth M. Krebs ◽  
Sarah E. Donohue ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Target Selection ◽  
Target Color ◽  
Selective Area ◽  
Early Visual Cortex ◽  
Feature Based ◽  
Irrelevant Color ◽  
Task Irrelevant ◽  
Open Question ◽  
Attention Demands

Objects that promise rewards are prioritized for visual selection. The way this prioritization shapes sensory processing in visual cortex, however, is debated. It has been suggested that rewards motivate stronger attentional focusing, resulting in a modulation of sensory selection in early visual cortex. An open question is whether those reward-driven modulations would be independent of similar modulations indexing the selection of attended features that are not associated with reward. Here, we use magnetoencephalography in human observers to investigate whether the modulations indexing global color-based selection in visual cortex are separable for target- and (monetary) reward-defining colors. To assess the underlying global color-based activity modulation, we compare the event-related magnetic field response elicited by a color probe in the unattended hemifield drawn either in the target color, the reward color, both colors, or a neutral task-irrelevant color. To test whether target and reward relevance trigger separable modulations, we manipulate attention demands on target selection while keeping reward-defining experimental parameters constant. Replicating previous observations, we find that reward and target relevance produce almost indistinguishable gain modulations in ventral extratriate cortex contralateral to the unattended color probe. Importantly, increasing attention demands on target discrimination increases the response to the target-defining color, whereas the response to the rewarded color remains largely unchanged. These observations indicate that, although task relevance and reward influence the very same feature-selective area in extrastriate visual cortex, the associated modulations are largely independent.

scholarly journals Constant spread of feature-based attention across the visual field

2011 ◽  
Vol 51 (1) ◽  
pp. 26-33 ◽  
Author(s):  
Taosheng Liu ◽  
Irida Mance
Keyword(s):  
Visual Field ◽  
Feature Based

An EEG study of the combined effects of top-down and bottom-up attentional selection under varying task difficulty

2021 ◽  
Author(s):  
Einat Rashal ◽  
Mehdi Senoussi ◽  
Elisa Santandrea ◽  
Suliann Ben Hamed ◽  
Emiliano Macaluso ◽  
...  
Keyword(s):  
Visual Search ◽  
Attentional Control ◽  
Task Difficulty ◽  
Target Selection ◽  
Attentional Selection ◽  
Combined Effects ◽  
Top Down ◽  
Bottom Up ◽  
Search Tasks

This work reports an investigation of the effect of combined top-down and bottom-up attentional control sources, using known attention-related EEG components that are thought to reflect target selection (N2pc) and distractor suppression (PD), in easy and difficult visual search tasks.

Perception of Simple and Complex Visual Stimuli: Decision Strategies and Hemispheric Differences in Same—Different Judgments

Perception ◽  
1995 ◽  
Vol 24 (7) ◽  
pp. 787-809 ◽  
Author(s):  
R John Irwin ◽  
Margaret A Francis
Keyword(s):  
Visual Field ◽  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Visual Stimuli ◽  
Optimal Decision ◽  
Hemispheric Differences ◽  
Decision Strategy ◽  
Decision Strategies ◽  
Visual Patterns ◽  
Rating Method

The accuracy with which observers could judge whether two visual stimuli were the same or different was measured with the rating method of detection theory. For judgments of whether two pictures referred to natural or manufactured things, the shape of the obtained receiver operating characteristic (ROC) was consistent with the observers adopting an optimal decision strategy. A similar result was found for judgments of complex but meaningless visual patterns. For judgments of whether two colours that differed along a simple sensory dimension were the same or different, however, the resulting ROC was consistent with the observers adopting a suboptimal differencing strategy. The accuracy of the judgments did not depend on the visual field to which the stimuli were presented.

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