Delusion of control has long been a fascinating yet unnerving symptom of schizophrenia and other psychoses, as well as derealization and depersonalization disorders. While some antipsychotics do show promise in treating this symptom, treatment resistance is common and can be stymying, and no therapy specific to it exists. The inventive paradigm described here will be a game–changer for people with this condition. The inspiration for our intervention comes from the famous, decades–old experiments by Benjamin Libet, who observed using electrophysiological techniques that the neural impulse that generates motor actions occurs several hundred milliseconds prior to the action, and more importantly, a few hundred milliseconds prior to one’s own awareness of the intention to move. This occurs in stark contrast to the commonsense and foundational notions of individual agency and free will. The explanation proposed at the time and largely accepted since is that efference copies generated by the motor cortex lead to a retrodicted sense of ownership, known henceforth as antedating. In a small subset of psychiatric patients, this efference copy appears to be absent (confirmed using EEG data, see figure 1) leading to a lack of felt ownership of one’s actions. This explanatory gap then often sadly leads to fabricated explanations and delusions, such as that one’s actions are being controlled by a third party, be it a demon, machine, alien entity or mad scientist. Fortunately due to the simplicity of the mechanism at work, rectifying the feeling which serves as the initial trigger for such thoughts becomes fairly straightforward. While Libet himself did not anticipate such an application of his work, or even make the connection between his observed data and psychotic experience, in more recent decades, researchers and clinicians have pioneered the use of non–invasive ways to use electromagnetic waves not only to measure but also to induce or suppress human neural activity. One such method, gaining in popularity as a treatment for medication–resistant depression, is transcranial direct current stimulation (tDCS). This technique uses electrodes attached to the scalp to administer magnetic pulses to various brain regions, most commonly the left frontal cortex. Its effectiveness has had a huge impact within the field and on patients’ lives, financial cost of the treatments notwithstanding. The mechanism behind this treatment, that of activating or suppressing any superficial brain area, gives it enormous and broad potential, potential which has largely gone under-utilized. In addition to its use in research studies focusing on decision-making, it has also been applied to the treatment of depression and other disorders. This study marks the first of its kind using tDCS to treat delusion of control, by simulating the missing efference copy. As a pilot study we used only one patient, with the intention of following up with a larger study using a sample test group. Our reasons for this are technical but also include some difficulty in recruitment for a therapy this novel and ambitious, despite its total safety. Persons with severe psychiatric disorders are a category for which many legal and logistical protections exist within experimental research, even when the research concerns topics of interest to that group specifically. Furthermore, psychotic patients who are not wards of the state or under the care of other legal guardians who act as medical representatives for them (and most of them are not) may be apprehensive to engage in an experimental study this different from existing approved treatments. This hesitancy, far from paranoia, can be understood empathically as a reaction to systematic marginalization and dismissiveness in a world that is perhaps already seen as confusing and hostile through the lens of disorganized perception and cognition. However, it is lamentable that the potential benefits of our treatment are difficult for this population to realize even when explained clearly, as our attempt to help mitigate the differences in processing and ease the fluency with which they interact with the world and with others is most definitely an admirable goal. Our hope is that with the positive data from this pilot study we will gain traction in recruiting volunteers, and that any further studies will cement the benefits of this therapy as well as the complete lack of ill effects.
The participant, a 28–year–old Asian male diagnosed with schizophrenia four years previously and on antipsychotic medication, had recurrent, near–constant delusions of control. He acted as his own control by completing some routine physical tasks both with and without applied magnetic stimulation, and completing a semi structured interview before and after the tDCS. The physical tasks were given by instructions: bend your arm at the elbow, open and close your hand five times, pick up a ball and throw it at a target. The interview contained standard assessment criteria for positive and negative symptoms of schizophrenia, although the particular focus of our lab centered on the questions concerning the symptom of interest. “Do you ever feel as though someone else, or something else, is controlling your actions for you?” In the first interview, the patient answered “Yes, most of the time.” and then went on to give an elaborate description of aliens from Venus beaming electric rays into his arms and legs. We asked him if he felt this way during the tasks he’d just completed, and he answered in the affirmative. We then applied the electrodes to target the motor cortex and re–issued the same set of instructions. The patient complied, his face still blank and affectless, but beneath that mask, mild surprise. We removed the electrodes and sat him down in a different room, where we’d done the first interview, and asked him the same set of questions. His answers were the same, uncannily so, the same wording, as though he had it memorized. But the shifting tone in his voice, which parts lilted and how, made it different enough from the first time so as not to be strange. Then we got back to “Do you ever feel as though someone else, or something else, is controlling your actions for you?” The patient paused, almost furrowed his brow a little. “Did you feel like this during the last set of tasks?” I prodded. “No,” he said. “I guess I didn’t.” The exit interview he gave subsequently provided ample assurance of the safety and comfort of the procedure.
While repeat administration over multiple sessions would likely be necessary in order to have a lasting effect, observing whether this can occur is one of our future directions for this research. With adequate insurance coverage, these sessions could be made accessible and affordable for anyone who can be convinced of the benefits.
The success of this therapy is no trivial accomplishment applying merely to the treatment of a miscellaneous fringe symptom, as ultimately the core of our very humanity stems from our subjective experience of acting as free agents in the world, capable of making deliberate choices when interacting with our surroundings. When we are cruelly robbed of this liberty by the malfunctioning of our brains, we are reduced to the status of mere automatons living a flattened and colorless existence. In restoring the sense of agency to these lost souls, physicians are doing no less than reigniting the spark of purpose, and reinvigorating the animus that has dulled. The current that flows from the electrodes placed in the wearable cap can thus fundamentally restore the ghost in the machine.