Post on 16-Nov-2020
An Update on Blinding Practices in tDCS and tACS Research
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Jessica D. Richardson, Ph.D., CCC-SLP--------
University of New Mexico--------
Center for Brain Recovery and RepairDepartment of Speech and Hearing Sciences
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Neuroscience of Rehabilitation Lab--------
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Importance of Blinding in Research
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Benjamin Franklin
Blindfolded participants during “mesmerism”/sixth sense experiments
Performance worse when blind(fold)ed
Revealed bias and importance of blinding
Claude Bernard
Wrote first seminal essays about blinding participants in order to promote objectivity
Importance of Blinding in Research
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Benjamin Franklin
Blindfolded participants durinse experiments
Performance worse when blind(fold)ed
Revealed bias and importance of blinding
Clever Hans
Smartest horse in the world ?
or
“Reading” the investigator ? (tension, facial expression, other unintentional cues)
Recommendations for Blinding in Research
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Recommendations for Blinding in Research
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Recommendations for Blinding in Research
DEPARTMENT OF SPEECHAND HEARING SCIENCES
~ behavioral task - online, offline, both
~ voltage - <1 to 2.5 mA (most common 2, 1, 1.5)
~ duration – 1 to 60 min (most common 20, 15, 10)
~ montage – highly variable, study-specific
Blinding in tDCS Research - 2016
DEPARTMENT OF SPEECHAND HEARING SCIENCES
N=206
85%
15%
Didthestudyuseasham/placebocondition?
Blinding in tDCS Research - 2016
DEPARTMENT OF SPEECHAND HEARING SCIENCES
N=173
84%
7%4%
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Blinding in tDCS Research - 2016
N=173
25%
75%
Didthestudyassesseffectivenessofshamcondition?
How?
-sensation/AE questionnaire
-interview/briefing
-3-choice questionnaire(+/- confidence rating)
-method not specified
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Blinding in tDCS Research - 2016
Didthestudyreportadministratorblinding?
39%
61%
N=173
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Blinding in tDCS Research - 2016
98.8%
1.2%
N=173
Didthestudyassessadministratorblinding?
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Blinding in tDCS Research - 2016
92%
8%
N=204*
Didthestudyreportassessorblinding?*
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Blinding in tDCS Research - 2016
N=204*
96.6%
3.4%
Didthestudyreportraterblinding?
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Blinding in tDCS Research - 2016
Didthestudycollectandreportsensation/AEdata?
N=206
33%
67%
Blinding in tACS
DEPARTMENT OF SPEECHAND HEARING SCIENCES
no sham
Recommendation – Checklist
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Adapted from Richardson et al., in press and Gearing et al., 2011
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Recommendation – Checklist/Questionnaire
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Brunoni et al., 2011
Fertonani et al., 2011
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Brunoni et al., 2011
Fertonani et al., 2011
___Phosphenes
___Dizziness
___Pressure
___Skinsensations(other)
(Raco etal.,2014)
Recommendation – Checklist/Questionnaire
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Recommendation – Questionnaire
Adapted from Bang et al., 2010, Brinjikji et al., 2010, O’Connell et al., 2012, Zhang et al., 2013
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Recommendation – Questionnaire
Recommendation – Devices, HD
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Dmochowski et al., 2013Richardson et al., 2015
Gbadeyan et al., 2016Garnett & den Ouden, 2015
Recommendation – Design and Analysis
DEPARTMENT OF SPEECHAND HEARING SCIENCES
• Recruitment/ParticipantCharacteristics• Consent
– DeFactoMasking?• participants,administrators,assessors
• Betweengroupsinsteadofcrossover– (doesnotfreeyoufromshamconcerns)
• Ifcrossover,analyzefirst-perioddataonly• Complementaryactivecontrolandshamconditions
Recommendation – Sham Development
DEPARTMENT OF SPEECHAND HEARING SCIENCES
• Ashamconditionshouldbe“indistinguishable”– equivalencetestinginsteadofnull-hypothesistesting?
• Shamdevelopmentwithinvestigators– Ifitworksforaseasonedinvestigator,itshouldworkforeveryone
Thank You
DEPARTMENT OF SPEECHAND HEARING SCIENCES
Lab Members
Sarah Grace Dalton
Holly Stewart
Michaella Maddry
Departmental Collaborators
Rick Arenas
Mentors and Collaborators
Center for Brain Recovery and Repair
NIH
DEPARTMENT OF SPEECHAND HEARING SCIENCES