As an extension on a study that is currently running and has previously been approved by the METC (NL69407.091.19) the aim of this study is to identify the importance of scene context in the perception of objects by manipulating activity in object…
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Source
Brief title
Condition
- Other condition
Synonym
Health condition
Niet van toepassing - Onderzoek bij gezonde vrijwilligers
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
In the object recognition task (experiment 2a) percentage correctly categorized
objects is the main dependent variable. In the template matching task the
difference between size judgement error in distant and near object conditions
will be the main dependent variable.
Secondary outcome
none.
Background summary
The human visual cortex is able to rapidly categorize objects. In ambiguous
situations contextual information from the surrounding scene can help this
process. This implies that the early visual cortex, receiving visual
information, object-selective visual cortex and scene-selective cortex have to
interact. Indeed, neuroimaging studies have provided evidence for such
interactions. However, causal evidence as well as the specific timing of when
the visual information is processed remains elusive.
Study objective
As an extension on a study that is currently running and has previously been
approved by the METC (NL69407.091.19) the aim of this study is to identify the
importance of scene context in the perception of objects by manipulating
activity in object and scene-selective visual cortices using transcranial
magnetic stimulation (TMS).
Study design
A two-part within-subjects design. In the first experimental session
sensitivity to TMS over object- and scene-selective cortex will be determined
by using the design of Dilks et al. (2013). Based on participants* behavioural
response to TMS, they will perform one of three experiments in the second
session. Participants sensitive to TMS over the lateral occipital cortex (LOC),
an object-selective visual area, perform a study in which an object within a
scene or an object without scene has to be recognized. It will be investigated
how priming using the scene alone may speed up object recognition. To
investigate this timing, TMS will be applied ~100, ~200, ~300, and ~400 ms
after stimulus onset to the LOC. Participants sensitive to TMS over the
occipital place area (OPA) or first visual cortex (V1), perform a study in
which the size of an object has to be judged relative to a scene containing
depth. An error in size judgement is expected to depend on the scene depth, and
thus processing in OPA and V1. To investigate this timing, TMS will be applied
~100, ~200, ~300, and ~400 ms after stimulus onset.
Intervention
TMS will be applied to interfere with ongoing brain activity. In experiment 1
five pulses separated by 100 ms will be given per trial (following the
procedure of Dilks et al., 2013 and NL69407.091.19). In experiment 2 two pulses
separated by 40 ms will be given per trial.
Study burden and risks
The currently proposed TMS paradigms do not carry any significant risks. Safety
guidelines as acknowledged by the International Federation of Clinical
Neurophysiology will be followed strictly. Potential side-effects are fatigue
and headache. These are generally mild discomforts that respond promptly to
common analgesics. Volunteers can withdraw from the study at any given time and
there are no direct benefits for the participants.
Montessorilaan 3
Nijmegen 6525HR
NL
Montessorilaan 3
Nijmegen 6525HR
NL
Listed location countries
Age
Inclusion criteria
Between 18-35 years of age years; Right-handed; Non-smoking; Normal or
corrected-to-normal vision; Willingness and ability to give written informed
consent and willingness and ability to understand the nature and content, to
participate and to comply with the study requirements.
Exclusion criteria
1) Average use of more than 3 alcoholic beverages daily; 2) Use of psychotropic
medication or recreational drugs; 3) Epilepsy or history of an epileptic
insult; 4) A nuclear family member with epilepsy; 5) Pregnancy; 6) Serious head
trauma or brain surgery; 7) Neurological or psychiatric disorders; 8) Large or
ferromagnetic metal parts in the head (except for a dental wire); 9) Implanted
cardiac pacemaker or neurostimulator; 10) Participation in a NBS study in the
past 28 days; 11) Previous participation in 10 or more NBS studies.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL72752.091.20 |