The study involved 46 participants living with chronic, severe schizophrenia who were receiving state-mandated care in a locked facility 30 miles east of San Diego.
“For too long, it has been thought that the neural systems in schizophrenia are fixed, that they can’t be modified—and that the best one can hope for is to manage psychotic symptoms,” he says. “But now we’re learning that cognition itself is remediable and that recovery is a possibility.”
[Dr. Light & Drs. David Braff and Neal Swerdlow] had a theory that the disabling deficits in cognitive function seen in people with schizophrenia are caused, at least in part, by problems receiving or analyzing signals that enter the brain through the senses. Perhaps the brain’s auditory and frontal cortices, for instance, were not processing sounds properly.
In the most recent test, in the facility outside San Diego where he tested TCT in medicated patients with longstanding, chronic illness, not only did TCT provide a real, measurable benefit to two-thirds of these patients in the form of improved results on cognitive tests. The research also demonstrated that MMN measured after the very first hour of training accurately predicted which patients were going to benefit from the full 4-week program. This was confirmed once the training course was completed.
Dr. Light and colleagues still are not sure why some respond to TCT and others do not, but they speculate that MMN and possibly other measures of brain activity (one is called auditory steady-state response) are able to show which patients have sufficient plasticity in their neural circuitry to benefit from this particular type of training—which, in essence, is a form of learning.
Plasticity refers to the ability of neurons to adjust the strength of their connections. Neuroscientists have long understood that such adjustments are part of the mechanical basis of memory and learning.
TCT, the training method recently used by Dr. Light, is itself not revolutionary, he says. His team used a commercially available “brain-training” software program that worked perfectly well. Other programs might also work well, he says. In TCT, auditory exercises are delivered to each patient for 3 to 5 hours weekly, via computer. The patient is asked to make progressively finer discriminations of sounds, beginning with comparatively easy discriminations and steadily moving to harder choices—but only after correct answers have been delivered. “If they get it right, it gets harder; if they make a mistake they go back to where they were challenged. They are constantly being pressed up against their ability level.”