Motor control week 2

EMG onset occurs:

After movement completion

Simultaneously with response time

Between stimulus and movement onset (premotor time)

Before stimulus presentation

Between stimulus and movement onset (premotor time)

Which lab task best demonstrated the difference between RT, MT, and response time?

Golf putting task

Mouse RT task

Simple RT keyboard task

Tracking task

Simple RT keyboard task

(^WRONG)

In-phase coordination occurs when when:

The task is performed at high speed

Arms swing in the same direction

EMG is disrupted

Arms swing in opposite directions

Arms swing in the same direction

MEG measures:

Blood oxygenation levels

Oxygen use in muscles

Muscle vibrations

Magnetic fields from brain activity

Magnetic fields from brain activity

Acceleration is most useful to identify:

Average bias in performance

Overshoot in putting

Variability in repeated tasks

Sudden changes in movement speed

Sudden changes in movement speed

An in-phase relative phase corresponds to:

0° (or 360°)

120°

90°

180°

0° (or 360°)

Performance outcome measures tell us:

What happened as a result of the performance

The variability in limb coordination

How muscles and joints functioned during performance

How much brain activity occurred during the task

What happened as a result of the performance

RMSE (root mean squared error) is most commonly used to measure:

Two-dimensional accuracy

Premotor time

Continuous skill accuracy

One-dimensional accuracy

Continuous skill accuracy

Performer A consistently overshoots the target by +6 cm, while Performer B sometimes overshoots and sometimes undershoots, averaging near zero. Which performer has higher CE?

CE does not measure overshoot/undershoot

Performer B

Performer A

They are equal

Performer A

Relative phase is most applicable to:

Continuous pursuit tracking

EMG muscle onset

Discrete putting accuracy

Cyclic movements like walking or arm swinging

Cyclic movements like walking or arm swinging

Which of the following is a performance production measure?

Time taken to run 100 m

Points scored in a basketball game

Height jumped

EMG activity of the biceps

EMG activity of the biceps

A force plate primarily measures:

Ground reaction forces

EMG activity

Blood flow

Velocity profiles

Ground reaction forces

Response time is equal to:

Displacement ÷ time

Premotor time + motor time

Reaction time + movement time

Constant error + variable error

Reaction time + movement time

In continuous tracking, RMSE is analogous to:

VE in one-dimensional tasks

Simple RT

CE

AE in one-dimensional tasks

AE in one-dimensional tasks

Discrimination RT involves:

Continuous skill tracking

One stimulus and one response

Multiple stimuli, but only one requires a response

Multiple stimuli, each requiring its own response

Multiple stimuli, but only one requires a response

Which error measure is most useful to determine the overall accuracy of skill performance?

Variable error (VE)

Absolute error (AE)

Constant error (CE)

RMSE

Absolute error (AE)

Which of the following is not a kinematic performance measure?

Velocity

Acceleration

Force

Displacement

Force

If a person improves in tracking across trials, their RMSE would:

Decrease

Increase

Fluctuate randomly

Stay constant

Decrease

If a golfer consistently overshoots the hole by 10 cm, their error is best described as:

Low AE

High VE

High AE

High positive CE

High positive CE

Angle-angle diagrams plot:

Reaction time vs movement time

Time vs joint acceleration

The angle of one joint vs another joint

Displacement vs velocity

The angle of one joint vs another joint

Comparing dominant vs non-dominant hand tracking performance, what is usually true?

Only movement time differs

Both hands perform identically

Dominant hand often has lower RMSE, especially early in practice

Non-dominant hand always has lower RMSE

Dominant hand often has lower RMSE, especially early in practice

RMSE provides:

Grouping of errors to evaluate bias

Average deviation from the target trajectory

Reaction time variance

Signed direction of error

Average deviation from the target trajectory

fMRI assesses:

Brain's electrical signals

Cortical disruptions from magnetic pulses

Blood oxygenation changes during activity

Reaction times in cognitive tasks

Blood oxygenation changes during activity

If two performers have the same AE, but one has higher VE, what does this mean?

They are equally consistent

One was faster in reaction time

One overshot while the other undershot

One is less consistent in performance

One is less consistent in performance

Who is considered the better putter?

The one with lower AE (with consideration of CE and VE)

The one with lower VE only

The one with the highest RMSE

The one with higher CE

The one with lower AE (with consideration of CE and VE)

Near-infrared spectroscopy (NIRS) measures:

Consistency of movements

Oxygenation levels in muscles

Force production

Joint displacement

Oxygenation levels in muscles

Which term best describes "bias" in repeated performance?

CE

VE

AE

RMSE

CE

If a golfer's 10 putts consistently overshoot the line by ~5 cm, their performance indicates:

High negative CE

Low CE, high VE

High positive CE

Low AE

High positive CE

A choice RT task generally produces:

Faster times than simple RT

The same times as simple RT

Slower times due to increased decision processing

No measurable difference in time

Slower times due to increased decision processing

Premotor time is defined as:

Total RT + MT

Interval between initial muscle activation and observable movement

Movement onset to completion

Interval between stimulus onset and initial muscle activation

Interval between stimulus onset and initial muscle activation

Variable error (VE) represents:

Overshoot vs undershoot bias

Accuracy of performance

Average signed error

Consistency of performance across trials

Consistency of performance across trials

Which statement best describes the relationship between reaction time (RT) and movement time (MT)?

They are independent measures—RT reflects preparation, MT reflects execution

MT is always longer than RT

RT always increases when MT decreases

They are the same measure and always change together

They are independent measures—RT reflects preparation, MT reflects execution

In a putting task, Performer A has an AE of 5 cm, and Performer B has an AE of 10 cm. Who was more accurate overall?

Performer B

Performer A

Cannot be determined from AE

Both are equally accurate

Performer A

Choice RT involves:

Multiple stimuli but only one requiring a response

Multiple stimuli with each requiring its own response

Only one stimulus and one response

Continuous tracking

Multiple stimuli with each requiring its own response

Response time is the sum of:

Absolute error + constant error

Reaction time + movement time

Displacement + acceleration

Premotor time + motor time

Reaction time + movement time

The main tool to record external forces in motor performance is:

EEG

EMG

Stopwatch

Force plate

Force plate

Which brain measure uses magnetic pulses to temporarily disrupt cortical activity?

MEG

EEG

fMRI

TMS

TMS

A "Go/No-Go" task is an example of:

Discrimination RT

Choice RT

Simple RT

Absolute error

Discrimination RT

Which lab task was designed to measure continuous skill accuracy?

Tracking task

Golf putting

Go/No-Go

Simple RT

Tracking task

EEG measures:

Electrical activity at the scalp from cortical neurons

Magnetic fields of neural activity

Blood oxygenation changes in the brain

Muscle activation during a task

Electrical activity at the scalp from cortical neurons

Movement time (MT) is:

The time from the stimulus to the start of the response

The variability in how consistent the movement is

The time from signal onset to completion of response

The time from movement initiation to completion

The time from movement initiation to completion

In the keyboard-based Simple RT task we did in lab, what was measured?

The time between stimulus onset and the onset of pressing a key

The variability in repeated key presses

The total time from stimulus onset to movement completion

The displacement of finger joints

The time between stimulus onset and the onset of pressing a key

In a dart-throwing task, Performer A has AE = 8 cm, CE = +8 cm, VE = 2 cm. Performer B has AE = 8 cm, CE = 0 cm, VE = 8 cm. Who is more biased?

Performer A

Neither shows bias

Both equally biased

Performer B

Performer A

When a driver wants to start driving from a traffic light as soon as the green light comes on, the time between the light turning green and the driver's foot leaving the brake pedal is:

Reaction time

Constant error

Response time

Movement time

Reaction time

Mechanomyography (wMMG) measures:

Muscular vibrations from fused twitches

Relative phase differences in limbs

Torque at joints

Neural activity in cortex

Muscular vibrations from fused twitches

Constant error (CE) indicates:

The total error score

The RMSE of performance

The signed deviation from the target (bias)

The average absolute deviation from the target

The signed deviation from the target (bias)

Motor time is defined as:

Interval before the stimulus

Total time including RT and MT

Error score across trials

Interval between initial muscle activation and observable movement

Interval between initial muscle activation and observable movement

Reaction time (RT) is best defined as:

Total time including reaction and movement phases

Time between stimulus onset and movement initiation

The variability in repeated movements

Time between movement initiation and completion

Time between stimulus onset and movement initiation

In a Go/No-Go discrimination task, slower RT compared to simple RT is typically due to:

Kinematic constraints

Poor muscle activation

Force plate inaccuracies

Added cognitive processing to inhibit responses

Added cognitive processing to inhibit responses

Absolute error (AE) represents:

The average reaction time

The direction and amount of error

The magnitude of error regardless of direction

The variability across trials

The magnitude of error regardless of direction

Radial error is used when:

Only one spatial dimension matters

Accuracy in two spatial dimensions must be measured

The movement is continuous

The skill requires only temporal accuracy

Accuracy in two spatial dimensions must be measured

A driver sees a green light, reacts, and presses the accelerator. The time from the light turning green until the foot starts moving is ____; the time from foot movement to pressing the accelerator pedal is ____.

RT; MT

RT; response time

Response time; RT

MT; RT

RT; MT

Which of the following is a performance outcome measure?

Distance a ball was thrown

Joint angle velocity

EEG activity during skill performance

Muscle activation pattern

Distance a ball was thrown

Angle-angle diagrams are useful for:

RMSE in continuous tracking

Measuring muscle oxygenation

Accuracy of putting tasks

Studying inter-joint coordination

Studying inter-joint coordination

PET measures:

Blood flow/metabolism via radioactive tracers

Electrical activity at the scalp

Oxygenation in muscle

Muscle vibrations

Blood flow/metabolism via radioactive tracers

A golfer who hits some long and some short but averages close to the target has:

Low VE

Low AE

High VE but low CE

High CE

High VE but low CE

An antiphase relative phase corresponds to:

90°

180°

0°

45°

180°

TMS involves:

Detecting scalp-level electrical activity

Disrupting activity in specific cortical regions with magnetic pulses

Measuring brain metabolism with tracers

Recording muscle vibrations

Disrupting activity in specific cortical regions with magnetic pulses

Which is NOT a common kinetic measure?

Ground reaction force

Muscle force

Joint torque

Displacement

Displacement

Relative phase is used to measure:

Accuracy in continuous tasks

Coordination between two limb segments

Variability in repeated trials

Error in one-dimensional skills

Coordination between two limb segments

Two students perform a timing task. Performer A: AE = 5 ms, CE = -5 ms, VE = 1 ms. Performer B: AE = 5 ms, CE = 0 ms, VE = 5 ms. Who is more accurate overall?

Cannot be determined

Both, since AE is the same

Performer B

Neither; they are equally accurate

Neither; they are equally accurate

(^WRONG)

Simple RT involves:

One signal and one response

Multiple signals, each requiring a different response

Continuous adjustments of movement

Multiple signals but only one requires a response

One signal and one response

In the Mouse RT task in lab, the time from leaving the center circle to reaching the target was used to measure:

Movement time

Reaction time

Response time

Variable error

Movement time

Performance production measures provide information about:

The score or outcome accuracy

Only the final result of a task

The environment the task was performed in

The processes that produced the movement

The processes that produced the movement

Which kinematic measure was demonstrated using OpenCap in the lab?

Brain electrical activity

Radial error

Joint displacement and velocity

EMG activation

Joint displacement and velocity

EMG measures:

Blood flow in the brain

Consistency of errors

Electrical activity of muscles

Kinematic motion data

Electrical activity of muscles