Neuroelectric Markers of Hemispheric Differences in Ambiguity Resolution of Words in Context: A Split Visual Field ERP Study

2014 ◽  
Author(s):  
Mark Faust ◽  
Elaine Hill ◽  
Jordan Pierce
Keyword(s):  
Visual Field ◽  
Ambiguity Resolution ◽  
Hemispheric Differences

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.

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.

Right Hemisphere Memory Bias Does Not Extend to Involuntary Memories for Negative Scenes

Perception ◽  
2021 ◽  
Vol 50 (1) ◽  
pp. 27-38
Author(s):  
Ella K. Moeck ◽  
Nicole A. Thomas ◽  
Melanie K. T. Takarangi
Keyword(s):  
Visual Field ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Memory Bias ◽  
Right Visual Field ◽  
Hemispheric Differences ◽  
Involuntary Memory ◽  
Involuntary Memories ◽  
The Right

Attention is unequally distributed across the visual field. Due to greater right than left hemisphere activation for visuospatial attention, people attend slightly more to the left than the right side. As a result, people voluntarily remember visual stimuli better when it first appears in the left than the right visual field. But does this effect—termed a right hemisphere memory bias—also enhance involuntary memory? We manipulated the presentation location of 100 highly negative images (chosen to increase the likelihood that participants would experience any involuntary memories) in three conditions: predominantly leftward (right hemisphere bias), predominantly rightward (left hemisphere bias), or equally in both visual fields (bilateral). We measured subsequent involuntary memories immediately and for 3 days after encoding. Contrary to predictions, biased hemispheric processing did not affect short- or long-term involuntary memory frequency or duration. Future research should measure hemispheric differences at retrieval, rather than just encoding.

scholarly journals Exploration of the Hemispheric Differences in Number Processing of the Brain

2012 ◽  
Vol 1 (2) ◽  
pp. 55-61
Author(s):  
Aaron Wyland Walters
Keyword(s):  
Reaction Time ◽  
Visual Field ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Reaction Time Data ◽  
Right Visual Field ◽  
Hemispheric Differences ◽  
Time Data ◽  
Central Target ◽  
The Right

Abstract The current study explored how reaction time and accuracy differed in the left and right visual fields by altering various dot clusters in both number and organization. Researchers have hypothesized that the left hemisphere uses counting to judge small, disorganized clusters of objects accurately and that the right hemisphere uses estimation to judge clusters organized in geometric shape accurately. The current study tested both visual fields of participant’s with organized and unorganized clusters of dots. Dots were clustered between 3 and 12. The clusters were presented on separate sides of a computer screen to analyze visual field differences in counting and estimation. A central target was presented on the screen to maintain central focus for the visual fields. Data from 40 participants (30 men, 10 women) from a small liberal arts college indicated that when clusters reached between 7 and 8 dots, organization in the right visual field created inaccuracy in judgment. Reaction time data indicated that as number level increased, reaction time slowed. Reaction time data also showed that organization slowed reaction times in both visual fields. These data indicated that different numerical judgment abilities do exist within the hemispheres.

Attention and Hemispheric Differences in Reaction Time during Simultaneous Audio-Visual Tasks

1973 ◽  
Vol 25 (3) ◽  
pp. 404-412 ◽  
Author(s):  
Gina Geffen ◽  
J. L. Bradshaw ◽  
N. C. Nettleton
Keyword(s):  
Reaction Time ◽  
Visual Field ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Normal Subjects ◽  
Auditory Task ◽  
Right Visual Field ◽  
Hemispheric Differences ◽  
Language Functions ◽  
The Right

The effect of different types of competing auditory tasks on laterality differences in visual perception was investigated. Right-handed subjects were presented with digits which occurred randomly in the left or right visual fields. They responded vocally to previously specified digits in a go, no-go reaction time situation. In the absence of any competing auditory task, digits presented in the right visual field were processed more quickly. This visual field difference in reaction time was in the same direction while subjects performed a secondary musical task. However, when a secondary verbal task had to be performed, digits in the left visual field received faster responses. The results support the view that the right hemisphere is capable of some language functions, and that hemispheric differences in performance have at their basis a quantitative asymmetry, which can be reversed even in normal subjects by overloading their limited capacity.

Recognition of CVC Syllables from LVF, RVF, and Central Locations: Hemispheric Differences and Interhemispheric Interaction

1995 ◽  
Vol 7 (2) ◽  
pp. 258-266 ◽  
Author(s):  
Joseph B. Hellige ◽  
Elizabeth L. Cowin ◽  
Tami L. Eng
Keyword(s):  
Visual Field ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
The Other ◽  
Right Visual Field ◽  
Interhemispheric Interaction ◽  
Hemispheric Differences ◽  
Qualitative Pattern ◽  
Nonsense Syllables

In each of two experiments, subjects were required to identify consonant-vowel-consonant nonsense syllables projected to the left visual fiel/right hemisphere (LVF/RH), right visual field/left hemisphere (RVF/LH), or to the CENTER of the visual field. There were fewer errors on RVF/LH than on LVF/RH trials and the pattern of errors was qualitatively different on RVF/LH and LVF/RH trials. The pattern of errors was consistent with the hypothesis that attention is distributed across the three letters in a relatively slow serial fashion on LVF/RH trials whereas attention is distributed more rapidly and evenly across the three letters on RVF/LH trials. Despite the large RVF/LH advantage, the qualitative pattern of errors on CENTER trials (when viewing conditions do not favor one hemisphere or the other) was very similar to the pattern obtained on LW/RH trials. Implications of this counterintuitive finding are considered for the nature of interhemispheric interaction.

Sign in / Sign up

Export Citation Format

Share Document