Why this test cannot be faked

Symptom validity tests exist because people lie, exaggerate, and also fail tests they should pass when they are legitimately impaired. Pencil-and-paper effort tests are useful. They are also gameable once the strategies leak into the plaintiff bar and the defense bar.

Oculomotor behavior is different. Saccadic latency, velocity main sequence, pursuit gain, and fixation stability are not under the kind of voluntary control that lets a witness “try to look injured.” Attempting to fake a TBI pattern typically produces a recording that is itself evidence of poor effort — a crystal-clear, quantifiable indication of malingering rather than a subtle clinical maybe.

What “cannot be faked” means in an expert report

It does not mean the expert is omniscient. It means that, on this battery, there is no reliable strategy for a neurologically intact person to produce the oculomotor signature of TBI, and no reliable strategy for an injured person to produce a fully normal recording on demand. That asymmetry is what makes the method useful at deposition.

When the recording is normal in a case with dramatic subjective complaints, the conversation changes. When the recording is abnormal in a case with a “normal MRI,” the conversation also changes.