Perception, Sensation, Cognition and Action in Humans

Objective:

The experiments covered by this protocol aim to uncover basic knowledge about the normal
brain mechanisms that give rise to perception and cognition. The protocol encompasses
sub-studies in healthy volunteers ( participants ) to uncover behaviors and their
physiological basis. The protocol includes only non-invasive techniques with minimal risk,
including psychophysics, functional magnetic resonance imaging (fMRI), magnetoencephalography
(MEG), and on-line tests using Amazon s Mechanical Turk (MTurk). We will conduct:

1. Pilot-phase sub-studies: The goal of these hypothesis-generating sub-studies is to
obtain enough information to generate specific testable hypotheses. This list will be
updated at the time of Continuing Review (CR) to inform the IRB which sub-studies have
been conducted to date. The hypothesis-generating sub-studies will:

1. be exploratory in nature using only non-invasive methods such as: MRI, MEG and
behavioral tasks

2. attempt to obtain sufficient information to generate a power analysis; In general,
it is anticipated that two to five subjects will be initially tested. Following
this initial phase, an additional 10-25 subjects will be recruited. It is
anticipated that 12-25 subjects will be recruited for each sub-study.

2. Hypothesis-testing sub-studies conducted in-lab. Prior to transitioning to a
hypothesis-testing sub-study, the protocol will be amended to obtain prospective IRB
approval. In these sub-studies, we will test a specific hypothesis that can be completed
with a defined number of healthy participants. The number of participants required for
each sub-study will be determined by power analysis. A statistical plan will be
submitted for prospective IRB approval for each hypothesis-testing sub-study.
Hypothesis-testing sub-studies will undergo regular statistical review. Data quality
assessment will be done after each testing session. In the event of subject dropout or
unsuccessful recording, a replacement participant will be recruited.

3. Sub-studies conducted on-line. We will conduct tests using MTurk. Subjects will be
recruited anonymously and compensated through payments we make to Amazon. For pilot
MTurk sub-studies, statistical tests will be conducted when 50 or fewer participants
have been tested, and a power analysis will be performed to determine if the sub-study
should be continued, and if so, the number of subjects required.

4. Training for new investigators.

5. Technical development: These experimental sessions will allow us to refine scan
parameters and experimental paradigms to improve data quality and increase our ability
to obtain accurate information.

Study Population:

Normal volunteer participants aged 18-65, who are in good general health and have normal or
corrected-to-normal vision will be recruited from the local community and studied under this
minimal risk protocol. We plan to recruit up to 200 in-person participants and up to 10,000
on-line volunteers.

Design:

We will design small hypothesis-generating sub-studies that are pertinent to the theme of the
brain mechanisms for perception and cognition. In some sub-studies, the same subject will be
asked to participate in tasks involving fMRI, MEG and psychophysics, and possibly multiple
sessions of each, so that we can control for individual differences in relating the outcomes
of each experimental technique. In other sub-studies, participation in multiple tasks will
not be required. The extent of the participant involvement, and what they will be asked to
do, will be clearly disclosed during consent, as indicated in the consent documents. Brain
activity of healthy human volunteers will be monitored by fMRI and/or MEG. Anatomical MRI
will be collected in some subjects to allow better localization of brain dynamics. Behavioral
tests will be conducted using standard psychophysical approaches, involving presentation of
visual and/or auditory stimuli while eye-movements are monitored using non-invasive eye
tracking (such as with an infra-red camera directed at the participant s eyes). Subjects will
be shown simple visual stimuli such as blobs, stripes and spirals in assorted colors, moving
dots, checkerboards, and every-day images and video clips, such as of fruit rolling on a
table cloth, faces, and scenery recorded in a car. Auditory stimuli will include every-day
sounds such as birds singing, conversation, whispering, footsteps, car engines, and animal
vocalizations, presented within normal sound limits (60- 90 dB). We will not use provocative
or sexually explicit images, clips or sounds.

During fMRI and MEG sessions, subjects will be asked to free view, passively fixate, or
engage in an attentional task during fixation, such as reporting with an eye movement or
button press occasions when two images of the same category are presented sequentially.

Outcome Measures:

Performance on behavioral tasks and brain activity (fMRI and MEG) will be combined to yield
information about the neural correlates and processes underlying different aspects of the
human neural visual processing stream including color perception, attention, visual
discrimination and object/face/place recognition.

i. MRI: to analyze measures such as the anatomical structures of the brain (using structural
MRI); amplitude of the blood-oxygenation-level-dependent (BOLD) signal & using fMRI).

ii. MEG: to quantify measures such as power spectrum, event- or task-related potentials,
synchronization/desynchronization, and coherence between sensors or sources located close to
the brain areas of interest.

iii. Behavioral measures: to quantify measures such as hit rate, reaction times, thresholds,
similarity judgments, associations, naming (such as names for color stimuli and sounds) and
eye movements.

We may measure autonomic data during the course of the experiment (such as heart rate,
respiration, end-tidal CO2, skin conductance), which will be correlated with the outcome
measures.

- INCLUSION CRITERIA FOR ALL PARTICIPANTS:

A subject can be included in this study if he/she:

- is in good general health;

- is between 18 and 65 years old;

- is capable of understanding the procedures and requirements of this study;

- is willing and able to provide his/her own informed consent;

ADDITIONAL INCLUSION CRITERIA FOR IN-LAB PARTICIPANTS:

- has visual acuity of 20/40 in at least one eye (corrected with contact lenses is
okay);

- has no hearing impairment requiring a hearing aid.

EXCLUSION CRITIERA FOR IN-LAB PARTICIPANTS:

A participant is not eligible for participation in the in-lab portion of this study if any
of the following exclusion criteria are present, as self-reported by the prospective
participant or determined during clinical testing following consent:

- Participant has serious vision or hearing problems; for some sub-studies focused on
color vision, subjects who are colorblind will also be excluded;

- Participants without consent capacity will not be enrolled.

- Participant has a neurological disorder (examples include, but are not limited to:
epilepsy, schizophrenia, Alzheimer s Disease, Parkinson s Disease, multiple sclerosis)

- Participant has had a serious head injury or has a history of brain surgery. Head
injury is defined as an injury to the brain from some external force resulting in loss
of consciousness of 30 minutes or more;

- Participant has psychoactive drug or alcohol abuse or dependence in the past three
months, as determined by DSM V, except nicotine and caffeine. A score of 6 or greater
on the DAST will be considered exclusionary. The effects of nicotine and caffeine in
neuroimaging are attenuated if participants do not smoke or consume caffeine 2-3 hours
before the scan session (Duncan and Northoff, 2013); Over-thecounter
medication/herbals will not be a criterion for exclusion.

- Participant is an NEI employee within the Sensation, Cognition and Action section.

ADDITIONAL EXCLUSION CRITERIA FOR MRI SUB-STUDIES:

Contraindication to MR scanning include the following: pregnancy; metallic tattoos or
metallic eyeliner; claustrophobia; inability to lie still on their back for ~2 hours;
implanted cardiac pacemaker or auto-defibrillator; surgical aneurysm clips; implanted
neural stimulator; artificial heart valves or pumps; metal fragments in cranial cavity,
body or eyes (e.g., history as a metal worker); nitroglycerin patch (foil backer); cochlear
implants (tubes are okay); weight > 450 lbs; metal rods, plates, screws in body; shrapnel
or bullet wound; intrauterine device (IUD) not approved on mrisafety.com (most IUDs are
okay); vestibular or inner ear abnormality such as Meniere s disease; metallic braces; hair
extensions attached with metallic wires; transdermal patches; movement disorders; dental
implants; consumed of nicotine or caffeine in the two hours prior to the experimental
session. Subjects may participate in this study, but will not be allowed to have a 7.0 T
MRI scan if they have metallic dental crowns or a bridge.

EXCLUSION CRITERIA FOR ON-LINE PARTICIPANTS:

Subjects may not participate in the on-line portion of the study if they:

- Do not have access to compatible equipment. For example, smartphone screens are too
small to be used. Amazon MTurk will outline which devices may be used.

- Are unwilling to allow permission for Javascript to run on the site and disable any
script blockers.

- Are unwilling to agree to Amazon MTurk's terms and conditions.