Hélène (QUESTE) DEVILLEZ
PhD, Cognitive Sciences
Research

Load my thesis      View my defend




Thus far, my research has focused on high-level and low-level information influences on attention during the exploration of natural scenes. I collected behavioral data as well as recorded either eye-movement data or co-recorded eye-movement and EEG data. During these experiments, participants viewed natural scenes under different task instructions. I independently used statistical modeling and interpreted the results in order to further develop an understanding of gaze control when exploring natural scenes. The co-registration of eye movements and EEG activity offers a unique opportunity for insight into visual processing. On the one hand, EEG allows for the study of brain activity linked to specific visual events (referred to as visual evoked potentials), which can reflect visual processing with an extremely high temporal resolution. On the other hand, eye tracking allows us to know exactly where observers are looking and for how long.

Currently, I work as a postdoc on an ONR-funded grant focusing on top-down influences on visual object recognition in Curran’s lab (University of Boulder Colorado), in collaboration with Randy O’Reilly (UC Boulder, computational modeling), David Sheinberg (Brown, primate electrophysiology), and Tor Wager (UC Boulder, fMRI). The primary objective of the research is to further understand, and capture in a computational model, the powerful bidirectional constraint satisfaction processing, both within the object recognition system (i.e., the ventral What visual pathway) and between this system and spatial attention supported by the dorsal Where pathway in order to answer three major overarching questions:
1) What is the nature of bidirectional processing in the neocortex?
2) How does bidirectional processing support figure-ground organization in cluttered scenes?
3) How do the What and Where pathways interact to enable effective search, figure-ground processing, and object recognition in cluttered visual scenes?


During my thesis, I focused on the effect of task on scene exploration using simultaneous recording of eye- movements and EEG experimental design. This study aimed to better understand the neural components underlying the effects of various cognitive tasks (free-viewing, scene categorization, single-target visual search and a dual-target visual search) on the processing of natural scenes. In a follow-up analysis, I compared the patterns of results from different tasks on the processing linked to the identification of a target object. The results show a specific EFRPs, called P300, which was elicited when observers fixated the search target.

Expertize

Experimentation:

- designing experimental protocols in eye-tracking and conjoint recordings of eye-tracking and EEG

- submitting a proposal to the ethic committee

- running experimentations: recruitment and recordings with EyeLink1000 and Gtec devices

Data analysis:

- processing data of the eye-tracker with Matlab (raw data, fixation and saccade characteristics)

- statistical analysis (ANOVA) and statistical modeling (Expectation-Maximization)

- evoked potentials analysis with EEGlab (evoked-related potentials and eye-fixation related potentials)

- EEG time frequency analysis (EEGlab) and EEG source localization (sLoreta)

Computer literacy:

- object-oriented language: Java, C/C++

- Matlab (included EEGlab)

- Statistics: Statistica, R

- Prolog

- Office software: Microsoft Office, Open Office, LateX, image editing software (The Gimp)


Peer-Reviewed Publications

Devillez, H. , Campagne, A., Guérin-Dugué, A. and Guyader, N. (2016), Cognitive tasks differently impact the visual exploration of natural scenes: an ERP and EFRP study (2015). Brain Topography (under revision)

Devillez, H. , Guyader, N. and Guérin-Dugué, A. (2015), P3 during visual search task when exploring natural scenes: an EFRP study. Journal of Vision 15(13), 20-20

Devillez, H. , Guérin-Dugué, A., & Guyader, N. (2015). How task difficulty influences eye movements when exploring natural scene images. Signal Processing Conference (EUSIPCO), 2015 23rd European (pp. 1536-1540). IEEE.



Presentations at Conferences and Meetings

Devillez, H. , O’Reilly, R.C. and Curran, T. (2016), Co-registration of eye movements and EEG to study semantic congruency during scene perception. Poster presented at the Temporal Dynamics of Learning Center (TCLD) All Hands meeting, San Diego, CA, January 21-23

Devillez, H. and Curran, T. (2015), Co-registration of eye movements and EEG to study semantic congruency during scene perception. Oral presentation at the XXXIth meeting of the Perceptual Expertise Network (PEN), New Orleans, LA, November 12-13

Devillez, H. , Kristensen, E., Guyader, N., Rivet, B. and Guérin-Dugué, A. (2015), Time course of the P300 Eye-Fixation Related Potential during the visual search for a target embedded in natural scenes. Poster presented at the 15th Annual Meeting Vision Sciences Society, St. Pete Beach, FL, May 15-20

Devillez, H. , Kristensen, E., Guyader, N., Rivet, B. and Guérin-Dugué, A. (2015), The P300 potential for fixations onto target object when exploring natural scenes during a visual task after denoising overlapped EFRP. Poster presented at the 7th Int. IEEE/EMBS Conf. on Neural Engineering, Montpellier, France, April 22-24

Devillez, H. , Guyader, N. and Guérin-Dugué, A. (2014), Evoked potentials elicited by ocular fixations during the exploration of natural scenes: Analysis of the P300 potential during a visual search task. Oral presentation at the 8th Annual Forum of the GDR-vision, Lyon, France, December 1-2

Queste, H. , Guyader, N. and Guérin-Dugué, A. (2013), Eye-Fixation Related Potentials on Regions of Interest when viewing natural scene. Poster presented at the 36th European Conf. on Visual Perception, Bremen, Germany, August 25-29

Queste, H. , Guyader, N. and Guérin-Dugué, A. (2013), Statistical modeling of the influence of a visual distractor on the following eye-fixations. Oral presentation at the 17th European Conf. on Eye Movements, Lund, Sweden, August 11-16

Queste, H. , Guyader, N. and Guérin-Dugué, A. (2013), Modélisation statistique de l’influence d’un distracteur sur les fixations oculaires. Oral presentation et the 4th Meeting of the Grenoble Cognition Pole, Grenoble, France, June

Queste, H. , Guyader, N. and Guérin-Dugué, A. (2013), Etude des mouvements oculaires lors de l’exploration libre de scènes naturelles. Poster presented at the EDISCE Doctoral School PhD Students’ Day, Grenoble, France, March