Schizophrenia
Progress in identifying the neural correlates of auditory verbal hallucinations (AVHs) experienced by patients with schizophrenia has not fulfilled its promise to lead to new methods of treatments. Given the existence of a large number of such patients who have AVHs that are refractory to traditional treatments, there is the urgent need for the development of new effective interventions. This article proposes that the technique of neurofeedback may be an appropriate method to allow the translation of pure research findings from AVH-research into a clinical intervention. Neurofeedback is a method through which individuals can self-regulate their neural activity in specific neural regions/frequencies, following operant conditioning of their intentional manipulation of visually presented real-time feedback of their neural activity. Four empirically testable hypotheses are proposed as to how neurofeedback may be employed to therapeutic effect in patients with AVHs.
Contrary to the belief that schizophrenic patients will be unable to learn self control of electrocortical activity due to attentional and motivational deficits, the two studies which have investigated this, both involving operant conditioning of slow cortical potentials, have demonstrated that self regulation can take place. This was particularly true of a study of interhemispheric control. Learning difficulties were found to be more to do with sustaining motivation towards the end of sessions or training programs, rather than in initial learning. Schizotypical features in the normal population have in the case of anhedonia been associated with slower learning, while withdrawn introversion has been associated with faster learning. In view of the affirmative evidence and advances in understanding the functional significance of electroencephalographic (EEG) rhythms, the undertaking of therepeutic regimens with electrocortical operant conditioning is warranted in the schizophrenia spectrum.
We report on the feasibility of teaching 16 (DSM-IV) schizophrenic patients, subdivided by syndrome, self-regulation of interhemispheric asymmetry having demonstrated efficient learning of interhemispheric control in normal subjects. Reversal of asymmetry may be important to treatment and recovery in schizophrenia for following improvement on neuroleptic drugs functional hemispheric asymmetries have reversed, with directions of reversal and pre-existing asymmetry dependent on syndrome. Asymmetry reversal in animals, manifested by spatial turning tendencies, has been used as a marker of neuroleptic action and involves striatal dopamine under reciprocal hemispheric control. We gave as feedback the left right asymmetry in slow potential negativity recorded from the sensory motor strip (C3,4). Feedback took the form of a rocket on a screen which rose or fell with leftward or rightward shifts in negativity. Patients were able to learn control (P < 0.01). In those patients with lesser ability this was due to inability to sustain concentration throughout the session rather than slow initial learning. Active syndrome patients were better able to shift negativity rightward and withdrawn patients leftward, directions associated with drug reversal of functional asymmetry and symptom recovery for each syndrome. Accordingly our demonstration that many symptomatic schizophrenic patients are capable of learning control opens the door to electrocortical operant conditioning training in schizophrenia with therapeutic regimens.