Brain Correlates of Visual Processing of Emotional Scenes in ACTion and EMOtional Judgments During Normal VIeillissement
Condition: Aging
Study type: Interventional

Summary: 
      It is accepted that emotional events engage more attention and are detected and identified
      faster than neutral events. The same is true of negative events with regard to positive
      events. At the cerebral level, this facilitation results in greater activation of brain
      regions involved in visual and emotional processing. In normal aging, the preference for the
      negative stimuli (named negativity bias) tends to disappear and, sometimes, to shifts towards
      a preference for positive stimuli compared to both the negative and neutral stimuli
      (positivity bias). Most studies have assessed the age effect on emotional processing using
      tasks which require the identification of a personal emotional experience or the emotions of
      others.

      Although many studies suggest a strong link between emotion and action, relatively little is
      known about the age effect on emotional processing when the task requires the identification
      of a tendency to action (i.e. preparation of the individual to react and direction of action
      - example: fear prepares to avoid danger).

      ACTEMOVI project aims to identify the brain bases and neural networks involved in the
      processing of emotional visual information in normal aging when performing emotional
      appraisal and action-oriented tasks, through a functional MRI study.
    

Detailed description: 
      It is accepted that emotional events engage more attention and are detected and identified
      faster than neutral. The same is true for negative events compared to positive events. On the
      cerebral level, this facilitation results in greater activation of brain regions involved in
      visual and emotional processing. In normal aging, the preference for the negative stimuli
      (named negativity bias) tends to disappear and, sometimes, to shifts towards a preference for
      positive stimuli compared to both the negative and neutral stimuli (positivity bias), which
      could be mainly related to a decrease with age in processing of negative stimuli and in
      attention to this type of information. Only a few studies rather suggest an improvement in
      processing of positive stimuli with age. On the cerebral level, various fMRI studies mainly
      highlight an age effect on processing of negative stimuli in several brain regions involved
      in emotional processing such as amygdalae and prefrontal cortex (respectively a lower and
      higher activity in older adults compared to young adults). This age effect also induces a
      higher level of well-being and less frequent negative emotional feelings in the elderly than
      in younger people. Most studies have assessed the age effect on emotional processing using
      tasks which require the identification of a personal emotional experience or the emotions of
      others. Although many studies suggest a strong link between emotion and action, relatively
      little is known about the age effect on emotional processing when the task requires the
      identification of a tendency-to-action (i.e. preparation of the individual to react and
      direction of action - example: fear prepares to avoid danger). Team's works on this research
      question show the negativity bias with age is preserved in a tendency-to-action appraisal
      task while it disappears with age in an emotional appraisal task, suggesting a dissociation
      between emotion and tendency to action. In addition, a pilot fMRI study by our team in young
      people show the tendency-to-action appraisal task compared to emotional appraisal task
      induces higher activation in brain regions involved in visual and emotional processing. To
      our knowledge, no study has yet investigated the evolution with aging of neural circuitry
      involved in emotional processing during a tendency-to-action appraisal task compared to an
      emotional apparaisal task. Studying this evolution could allow to better understand the
      observed dissociation with increasing age between emotional and tendency-to-action tasks and
      more generally to better understand the evolution of the interactions between emotional and
      action processes with aging.

      ACTEMOVI project aims to identify the brain bases and neural networks involved in the
      processing of emotional visual information in normal aging when performing emotional
      appraisal and action-oriented tasks, through a functional MRI study and using an original
      mathematical modeling of functional connectivity based on the Graph theroy developed in the
      team. Findings will be used to develop a first neural network mapping model involved in
      visual perception of emotional scenes during emotional and tendency-to-action appraisals
      during normal aging.

      The experiment will be conducted in two age groups (20-35 and 60-85 years old) of 50 healthy
      participants each (number based on currently requirements in terms of size of effects for the
      envisaged connectivity analyzes), and carried out using a whole-body 3-T Philips scanner
      (Philips Medical Systems, Best, NL).

      Participants will perform two appraisal tasks during viewing a succession of emotional
      scenes, one emotional based on the appraisal of personal emotional experience (pleasant,
      unpleasant or neutral), and the other based on the appraisal of the tendency-to-action
      (approach, avoidance or no action). Two characteristics of stimuli will be manipulated in the
      study : valence and arousal.The age effect is modulated by these two characteristics.

      For each task, stimuli will be organized into two blocks: "High" block containing pleasant
      and unpleasant stimuli of high activation and neutral stimuli, and "Low" block including
      unpleasant and pleasant stimuli of low activation and neutral stimuli. The tendency-to-action
      induced by stimuli will be congruent with the valence of stimuli (i.e. pleasant/approach,
      unpleasant/avoidance and neutral/no action). The emotional stimuli in each block will be
      displayed according to a block fMRI paradigm.

      In total, each participant will successively perform four experimental blocks. Two blocks
      will involve an emotional task (for the high and low blocks) and the other two will involve a
      tendency-to-action task (for the high and low blocks).The order of tasks and images within a
      task will be counterbalanced between the participants

      For fMRI analyses, the protocol will aso include an anatomical MRI, a Diffusion Tension
      Imaging (DTI) and a resting-state measure in order to take into account the anatomical and
      functional differences between age groups. fMRI data (MRI signal of the BOLD type - Blood
      Oxygen Level Dependent) will be analyzed using standard neuroimaging analysis software (e.g.
      SPM, FSL). Analysis will perform on whole-body and in regions of interest (ROIs, e.g.
      amygdala). Regions of interest (ROIs) associated with emotional processing will be
      functionally identified and delimited for each participant using a separate functional
      localizer experiment adapted from Vuilleumier et al. (2003). These regions will also be used
      for Resting-State network analysis.
    

Intervention name(s): MRI
Intervention type(s): Other
Intervention description(s): The MRI examination will consist of a series of acquisition scans:
Scanning Scan: for positioning the functional volume of interest.
Task Scans: for exploring cerebral activation in emotional and action appraisal tasks during viewing high and low arousal stimuli and a localizer task ".
Anatomical MRI: for analyzing the functional images, and measuring volumes of gray and white substances.
Resting state functional scan: for exploring cerebral activation during a rest activity.
Diffusion Tension Imaging: for measuring structural connectivity.
Perfusion imaging: scan for ensuring good perfusion conditions
All functional acquisitions will be performed in multi-slices in echoplanar mode using gradient echo sequences allowing the exploitation of the BOLD contrast.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science