Decoding the contents and strength of imagery before volitional engagement

Roger Koenig-Robert,Joel Pearson

doi:10.1038/s41598-019-39813-y

Abstract

Is it possible to predict the freely chosen content of voluntary imagery from prior neural signals? Here we show that the content and strength of future voluntary imagery can be decoded from activity patterns in visual and frontal areas well before participants engage in voluntary imagery. Participants freely chose which of two images to imagine. Using functional magnetic resonance (fMRI) and multi-voxel pattern analysis, we decoded imagery content as far as 11 seconds before the voluntary decision, in visual, frontal and subcortical areas. Decoding in visual areas in addition to perception-imagery generalization suggested that predictive patterns correspond to visual representations. Importantly, activity patterns in the primary visual cortex (V1) from before the decision, predicted future imagery vividness. Our results suggest that the contents and strength of mental imagery are influenced by sensory-like neural representations that emerge spontaneously before volition.

Highlights

A large amount of psychology and, more recently, neuroscience has been dedicated to examining the origins, dynamics and categories of thoughts[1,2,3]
We found that activity patterns were predictive of mental imagery content as far back as 11 seconds before the voluntary decision of what to imagine –in visual, frontal and subcortical areas
We show that the subjective strength of future mental imagery can be predicted from activation patterns contained in the primary visual cortex (V1) before a decision is made

Summary

Introduction

A large amount of psychology and, more recently, neuroscience has been dedicated to examining the origins, dynamics and categories of thoughts[1,2,3]. Functional brain images from the perceptual blocks were used to train classifiers, which were subsequently tested on imagery blocks both before and after the decision This so called perception-imagery generalization cross decoding was used to show common informational content between visual perceptual representations and predictive signals. Such an involvement of visual areas in the future strength of visual imagery would provide further evidence that sensory areas play an important role in the phenomenology of future thoughts Using this paradigm, we found that activity patterns were predictive of mental imagery content as far back as 11 seconds before the voluntary decision of what to imagine –in visual, frontal and subcortical areas. These results are important as they point to a role of visual areas in the pre-volitional processes leading to visual thought production, shedding light on the mechanisms of intrusive mental imagery in conditions such as PTSD, as well as the origins of normal mental imagery

Objectives

Methods

Results

Discussion

Conclusion