Scanpath variation in individuals with 22q11.2 deletion syndrome during the Benton Visual Retention Test

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Scanpath variation in individuals with 22q11.2
deletion syndrome during the Benton Visual
Retention Test

• Marie-Christine Ottet, Bronwyn Glaser, Manolo
  Fuentes, Catherine Pasca, Mélanie Chabloz, Martin
  Debbané, Stephan Eliez

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How do we look at things ?
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Why is this pertinent to VCFS ?

• Previous findings
• Deficits in attentional skills (Simon et al.,
  2002 Bish et al., 2005)
• Efficient scanpath needs attention
• Deficits of visuo-spatial memory (Bearden et al.,
  2001)
• Alteration of parietal lobe (Simon et al., 2005)
• Memory relies on visual exploration
• Parents report an incomplete visual exploration

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Population

• 78 participants
• 41 VCFS and 38 Controls
• Range of age 8 to 26 years
• 2 types of evaluation
• Cognitive with an Eyetracker
• Cerebral with MRI scans

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Benton Visual Retention (Test BVRT)Computer
version
Image 1 Image 2
Image 3 Image 4
Image 5 Image 6
Image 7 Image 8
Image 9 Image 10

• BVRT multiple choice
• 10 cards with geometric figures

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How to measure and analyze the scanpath

• Eyetracker Tobii 1750
• Measurements of the eyetracker
• Total time and spread of exploration
• Number, duration and coordinates of fixation
  points
• Analyze regions of interest (AOI)
• 3 groups of figures
• Main simple figure
• Main complex figure
• Peripheral figure

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Global Results

• Less fixations
• More spread
• Same areas oberved

Controls
VCFS
Controls
VCFS
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Results of AOI

• In red lower number of fixations made by VCFS

10.78gt8.67
8.45gt6.83
10.24gt8.63
2.68gt1.44
Image 3
Image 1
Image 2
5.50gt4.59
2.11gt1.15
2.29gt1.54
Image 4
Image 5
Image 6
3.58gt2.56
2.34gt1,51
1.45gt0.98
1.39gt0.83
1.76gt1.12
5.87gt4.22
Image 7

• Image 8

Image 9
4.82gt3.71
1.42gt0.59
Image 10
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Results Analysis of AOI

• Less fixations on
• 7 of 8 peripheral figures
• 5 of 7 main simple figures
• 2 influences
• Spatial deficits
• Lateral  negletion  of the image
• Less fixations on peripheral figures
• Alterations of the parietal lobe
• Attentional deficits
• Deficit in attentional disengagement
• Less fixations on main figures simples
• Alterations of the frontal lobe

Image 1
Image 2
Image 3
Image 5
Image 6
Image 4
Image 7

• Image 8

Image 9
Image 10
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Anatomical cerebral measurments

• Method FreeSurfer (http//surfer.nmr.mgh.harvard
  .edu/)

• Measure of the volume of gray matter of the
  cortex
• parcels of frontal lobe
• parcels of parietal lobe

Automatic subdivision of the cortex Desikan,
R.S., (2006)
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Analysis of parcel volumes related to the scanpath
Left hemisphere

• Correlations controled for age and gender
  between
• Gray matter volume
• AOIs

• Caudal middle frontal
• Precentral
• Postcentral

• Superior frontal
• Anterior cingulate

• Parahippocampal

Right hemisphere

• Caudal middle frontal

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In summary

• Same areas observed between groups but less
  precise scanpath in VCFS (number, duration and
  spread)
• Deficits attentional and spatial on global
  scanpath
• Possible alteration of the motor planification

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How do our results guide interventions ?

• Importance in treatment of attentional deficit
• Cognitive remediation
• Medical treatments
• Strategies
• Always start with the sides of images
• Salient stimulus on important items (e.g. key
  word in red for homework)

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Thank you

• for your attention

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Acknowledgment
Thanks to collegues Stephan Eliez Martin
Debbané Bronwyn Glaser AnnaLaura Lagioia Marie
Schaer Maude Schneider Catherine Pasca Mélanie
Chabloz Bertrand Auckenthaler Michal
Epstein Catherine Audrin Manolo Fuentes Ryan
Murray
Thanks to the associations Generation22 Connect22
Relais22 Financial Support SNF CIBM Eagle FHMS NA
RSAD Von Meissner
Thanks to all the families