Timing Flashcards
Braitenberg’s Original Theory regarding Cerebellar Timing
Parallel fibers, or axons of granule cells, act as delay lines converting structure into temporal information.
Cerebellar Disorders and Timing.
Dysdiadochokinesia - what is it and what’s wrong?
Inability to perform rapid alternating movements. Temporal pattern to rapidly alternate is impaired or missing.
Ivry and Keele Time Tapping Experiment.
What was the task?
What were the results for cerebellar patients?
Listen to tone and start tapping once you have internal rhythm established.
Greatest tapping variability in cerebellar patients.
Ivry and Keele: Clock and Motor Delay Breakdown. Explain.
Results
Clock is the central signal. Peripheral Response is the motor delay.
Peripherals show variance in motor control but none in clock, which makes sense!
Cerebellar patients show greatest increase in clock variance
Rao et al Behavioral tapping fMRI study.
Methods
Results
Match tapping. Listen to tapping. Differentiate pitch. Continue tapping.
Cerebellar activation for the internally generated and synchronized timed movements.
No CBM activity for sensory tasks, so Bower would be sad.
Mayville syncopation vs synchronization experiments.
What does it say about timing?
Cerebellum is more involved in syncopation, but so are a lot of other areas that may be involved with attention and motor planning.
Bengtsson and effector-independent timing tasks rhythmic vs isochronous.
What does it mean to be effector-independent?
What were the results?
Right hand, left hand, or even your voice.
Rhythmic or sequential task have greater timing demand and it showed greater fMRI activation in CBM, temporal gyri, supplementary motor.
Bijsterbosch fMRI and TMS: Supraliminal shift activations.
What were the methods?
What were the results?
What was their follow up experiment and associated results?
Match the tone and try to correct for the tone shift.
In supraliminal condition they saw increased activation in the CBM and also some other areas. Consistent with timing.
TMS’ed the cerebellar area and saw no ability for error correction in the tone shift.
Review: does cTBS increase or decrease excitability?
Decrease.
Ivry and Keele: Time perception vs intensity perception tasks.
Results for cerebellar patients.
Cerebellars impaired on timing and perception of timing, but NOT on perception of loudness.
Grube: timing in cerebellar degeneration SCA6.
Results and conclusions for absolute timing.
Which area is important for absolute timing?
Patients impaired in absolute timing tasks.
Superior midline cerebellum important for absolute timing.
Perception of relative timing were unimpaired.
Ackermann: word discrimination
How did cerebellar patients perform the task?
They couldn’t use temporal information to distinguish the two different words.
Belin study: Auditory Duration Discrimination Task
Is test sound longer than 300 ms?
Results
Cerebellar activation, frontal lobe, midline for duration discrimination. Passive listening none.
Jueptner: Duration Tones
Cerebellar activation, basal ganglia, thalamus, cingulate cortex.
Fierro: TMS and perception of temporal intervals.
Follow up study with intensity. What did they find?
More perception errors when TMS is ipsilateral to the stimulated arm.
TMS did not affect intensity discrimination.
