Group 202 – Stimulate the brain

Tutors: Nina Bien Christianne Jacobs

1

Background of our research

Relevance of this study

Intention

Implementation

Expectations of the study/research practical

2

Posterior Parietal Cortex cross modal tasks

integration of information from different modalities in the brain

update of visual-spatial information of the hand essential to perform a

hand-eye coordination task

3

Repetitive TMS intermittent theta burst stimulation (iTBS)▪ stimulated every 10 seconds for 2 seconds within

190 seconds (50Hz)▪ excitatory effect

continuous theta burst stimulation (cTBS)▪ stimulation lasts 40 seconds without disruption

(50 Hz)▪ inhibitory effect

4

Evidence of disruption of motor evoked potentials in humans lasting up to one hour after use of TBS

Handedness plays an important role in finding the

responsible brain area to stimulate it in right handed people eye-hand

coordination is initiated by left hemisphere

5

Influence of iTBS and cTBS on complex cognitive tasks?

Is the Nintendo Wii game console a reliable instrument? Can we use it in other studies?

6

Find support for the idea that the dorsolateral posterior parietal cortex indeed plays a critical role in the hand-eye coordination

Use TMS in order to indicate a causal relationship

Examine effects of iTBS and cTBS on a complex cognitive task such as the coordination of the hand with the help of visual information 7

MRI get an insight into

anatomical structure of the participant’s brain

precise localization of TMS stimulation

A counterbalanced experimental design with two sessions 8

Session 1 and 2 (each 1 hour) Pre-measurements▪ Nintendo Wii baseball game▪ Motor task

iTBS/cTBS stimulation Post-measurements▪ Nintendo Wii baseball game▪ Motor task

9

Both tasks within the measurements

and the TBS protocols will be

applied in a random order

reason: TMS effect decreases over

time and therefore

necessary to reduce the risk of

order effects

Both tasks within the measurements

and the TBS protocols will be

applied in a random order

reason: TMS effect decreases over

time and therefore

necessary to reduce the risk of

order effects

Nintendo Wii game console game: Wii Sports - Baseball hit/miss ratio

10

Motor task:

participants will use a normal keyboard to react as fast as possible to a visual stimulus

stimulus is made by the program 'Presentation' → will tell them which letter/number they have to type

11

there are 3 keys for each side, 1 key for every finger▪ we cannot use the thumb and little finger

because it is to hard to type with the different conditions are (2x2x2

design):▪ eyes open vs. eyes closed▪ hands crossed vs. hands uncrossed▪ left vs. right hand

on their left side are letters and on their right side numbers

reaction time will be measured12

iTBS/cTBS stimulation intensity of TMS is dosed relative to the

motor threshold (MT)▪ determining the correct MT is important for

determining the proper TMS dose for each subject and is important with respect to safety▪ MT can be determined when muscle groups

are active (aMT) or when they are at rest (rMT)▪ Will be defined by the point at which the

muscle groups aren't active yet, but the stimulation can be felt by the participant

13

Implementation (7)

▪ MT determined separately for every participant by applying TMS on the arm▪ We'll take 80% of the Motor Threshold

Stimulation of the posterior parietal cortex leads to an alteration of the task performance cTBS should have an inhibitory effect iTBS should have an excitatory effect

15

16

17