The Timing Perception Measure



Timing perception is derived from your duration discrimination task. This is the test that asks “Which stimulus lasted longer?” The first trial of the task (during training) delivers a 650 msec duration stimulus to one finger and subsequently a 500 msec duration stimulus to the other (a 150 msec difference). Each time the person taking the test identifies the finger that received the longer stimulus correctly, the difference between the two durations on the next trial is reduced. Most people track down to a difference limen of 35-60 msec, and


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The Accuracy Measure



Lateral inhibition: using amplitude discrimination to probe the balance between excitation and inhibition
Lateral inhibition is the brain's way of improving contrast between adjacent or near-adjacent cortical areas. In the 1960s, Nobel prize winner Georg Von Bekesy postulated the idea of lateral inhibition. The basic idea was that when you deliver a stimulus, brain activity will be correlated with the stimulus site, and the surrounding areas will be inhibited or turned off. Long story short, Von Bekesy’s predictions, which were based on sensory testing, turned out to be true.


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The TOJ Measure



Discussing the Temporal Order Judgement task
One of the cortical metrics that you get is called “TOJ” which stands for Temporal Order Judgement. This test delivers two taps, one to each of the two fingers positioned on the Brain Gauge, and queries “which came first?”. The test starts out easy (taps are initially 150 msec apart) and gets harder each time you get the question right (sort of like reading an eye chart – it gets more difficult the farther you progress). If you look at your TOJ raw score (on


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The Connectivity Measure



In a previous report, we discussed how an illusory conditioning stimulus could be context dependent and that frequently delivering repetitive stimuli has the effect of suppressing the percept of a stimulus. Repeat a stimulus many times (the conditioning stimuli that are delivered by the Brain Gauge are typically sinusoidal at a frequency that delivers many repeats to the same place on the finger tip) and the effect is that stimuli feel much smaller. Are there other illusions? The obvious answer is yes, since we’re writing this report. The illusion


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The Plasticity Measure



Measuring tactile illusions with Brain Gauge .
Most people are familiar with optical illusions. For example, the one shown here is a context dependent illusion. Glancing at the two sets of circles, it appears that the center circle of the cluster on the left is smaller than the center circle of the cluster on the right. But in fact, the two center circles are of equal size. Why does the brain trick you into thinking this? Part of the answer is that your brain quickly evaluates the center circle in the


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The Speed Measure



Reaction time has been used since the mid-1800s to assess cognitive function, and it is still useful for that today.
The reaction time test has been used for a really long time to investigate nervous system function. Papers written as early as the mid 1800’s describe the reaction time test and since that time, most papers focused on differences in reaction time and other populations. In other words, most of these papers demonstrated comparisons that were made between healthy control populations and populations of individuals that had some condition


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