Healthy Volunteers
Conditions
Keywords
Memory, naturalistic, context, fMRI, Attention
Brief summary
The project is dedicated to development of new paradigms to investigate memory and attention in the rich and realistic environments. The investigator will use modern interactive digital technologies for encoding complex episodes either using mobile phone technology in everyday life or using a virtual reality life-like simulation. He aims to characterize the role of the medial temporal lobe and prefrontal cortex during recall of naturalistic episodic experiences, using functional neuroimaging (fMRI) in healthy participants. The secondary aim is assess how the allocation of attention during memory encoding contribute to mechanisms of the subsequent recall. He will achieve this by monitoring gaze direction during encoding and by analyzing the retrieval data as a function of the elements that participants attended / fixated during encoding. The protocol will involve, first, behavioral testing of memory performance with encoding in the real-life or in virtual reality, followed by the main hypothesis testing phase when fMRI will be used to measure brain activity during retrieval.
Interventions
During the fMRI protocol, the subject will perform the retrieval tasks while whole-brain activity will be recorded using Echo Planar Imaging (EPI) that measures the Blood Oxygen Level Dependent (BOLD) signal (2x2x2 isotropic voxels, Echo Time (TE) = 30 ms, Repetition Time (TR) = 2.5 sec). The functional session will be subdivided into several parts (Runs, duration: 10-15 min). Together with the functional data, the protocol will include a structural scan (T1 weighted, 1x1x1 mm voxels; duration 5-7 min) and a field mapping sequence (duration: 1 min).
Sponsors
Hospices Civils de Lyon
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* Possession a Smartphone compatible with GPS 3-rd generation and exploitation system Android 4.2 with user-activated geolocation (for mobile phone studies). * Able to navigate in virtual reality with a help of the keyboard (for virtual reality studies). * Not using glasses. * All subjects will give their written consent for participation in the study. * They will be right-handed * They will have French social coverage.
Exclusion criteria
* Previous neurologic or psychiatric disease. * Cognitive deficits restricting understanding of the tasks. * Pregnant or breath-feeding women. * Persons under guardianship, curatorship or any other administrative or judicial measure of deprivation of rights or liberty. * Subjects currently participating in other study. Additional
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| BOLD cerebral response to contextual recall in medial temporal lobe | up to 1 week after the end of the encoding session | After spatial preprocessing of individual series of EPI fMRI images, normalization and smoothing as suggested for SPM analysis, the successful and failed contextual recall will be modeled and convolved with canonical HRF function. The GLM will be estimated according to the algorithm of SPM, the significance threshold will be p\<0.05 FWE within the regions of interest. Our hypothesis will be confirmed by activation of medial temporal lobe and prefrontal cortex in contextual recall, congruent contextual cueing and recall of episodes when targets were semantically congruent with the context at encoding. |
| BOLD cerebral response to contextual recall in prefrontal cortex | up to 1 week after the end of the encoding session | After spatial preprocessing of individual series of EPI fMRI images, normalization and smoothing as suggested for Statistical Parametric Mapping (SPM) analysis, the successful and failed contextual recall will be modeled and convolved with canonical HRF function. The GLM will be estimated according to the algorithm of SPM, the significance threshold will be p\<0.05 Family-wise error (FWE) within the regions of interest. Our hypothesis will be confirmed by activation of medial temporal lobe and prefrontal cortex in contextual recall, congruent contextual cueing and recall of episodes when targets were semantically congruent with the context at encoding. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pattern of gaze fixation during episodic encoding and cerebral activity during recall | up to 1 week after the end of the encoding session | The gaze direction during both during episodic encoding and recall. We will estimate a correlation between the activation of medial temporal lobe/ prefrontal cortex and the similarity of the gaze fixations during encoding and retrieval. A positive correlation will support our hypothesis about the link between attention and contextual encoding. |
Countries
France
Outcome results
None listed