Central and Divided Visual Field Presentation of Emotional Images to Measure Hemispheric Differences in Motivated Attention

Summary

This study compared central versus divided visual field presentations of emotional images to assess differences in motivated attention between the two hemispheres. The late positive potential (LPP) was recorded using electroencephalography (EEG) and event-related potentials (ERPs) methodologies to assess motivated attention.

Abstract

Two dominant theories on lateralized processing of emotional information exist in the literature. One theory posits that unpleasant emotions are processed by right frontal regions, while pleasant emotions are processed by left frontal regions. The other theory posits that the right hemisphere is more specialized for the processing of emotional information overall, particularly in posterior regions.

Assessing the different roles of the cerebral hemispheres in processing emotional information can be difficult without the use of neuroimaging methodologies, which are not accessible or affordable to all scientists. Divided visual field presentation of stimuli can allow for the investigation of lateralized processing of information without the use of neuroimaging technology.

This study compared central versus divided visual field presentations of emotional images to assess differences in motivated attention between the two hemispheres. The late positive potential (LPP) was recorded using electroencephalography (EEG) and event-related potentials (ERPs) methodologies to assess motivated attention. Future work will pair this paradigm with a more active behavioral task to explore the behavioral impacts on the attentional differences found.

Introduction

Several theories on lateralized processing have been posited for the two cerebral hemispheres. Among these include theories of emotional processing. The valence model¹ proposes that the left hemisphere is specialized for pleasant emotions, while the right hemisphere is specialized for unpleasant emotions. The right hemisphere dominance hypothesis² proposes that the right hemisphere is specialized for processing all emotional information compared to the left hemisphere. Finally, the Circumplex Theory³ proposes that in addition to frontal asymmetries for valence, the posterior regions of the right h....

Protocol

All methods described here have been approved by the Internal Review Board for human subject research at the University of Kansas, Lawrence, KS.

1. Selecting Participants

1. Use right-handed participants for DVF research. In rare cases (10%), left-handed individuals are lateralized for language processing in the right hemisphere, which would result in scalp-recorded ERP components with non-typical topographical distributions.
2. Have participants complete the Edinburgh Handedness Inventory⁹ to determine strong right-handedness. Scores of eight or higher indicate strong right-handedness.

Results

To replicate previous research on the LPP, both LPP responses to unpleasant and pleasant images should be larger than LPP responses to neutral images. This is confirmed by the CVF analysis, which finds the LPP in the early epoch to be significantly larger to unpleasant (M = 1.90 μv) and pleasant (M = 1.71 μv) images compared to neutral images (M = 0.72 μv), but unpleasant and pleasant images are not found to be significantly different from each other. Interestin.......

Discussion

In this study, manipulations of stimulus valence and arousal were used with the DVF paradigm to test theories of lateralized processing of emotion as they apply to the motivated attention network. However, DVF methodologies can be used to explore any lateralized processing of visual information. What is critical when using DVF paradigms is the control of the stimuli presentation to ensure that the information is isolated to one hemisphere for initial processing. There are several key steps to the DVF paradigm that contri.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
64-channel Ag-AgCl active electrodes	Cortech Solutions	DA-AT-ESP32102064A/DA-AT-ESP32102064B	EEG electrodes for data collection
ActiveTwo Base System	Cortech Solutions	DA-AT-BCBS	Digitizes and ampliphies EEG data at 500 Hz
E-Prime Professional 2.0	Psychology Software Tools	NA	Stimulus presentation software, available at https://www.pstnet.com/eprime.cfm
CURRY 7.0	Compumedics Neuroscan	NA	EEG/ERP data processing and analysis, available at http://compumedicsneuroscan.com/products/by-name/curry/