Candidate models for how neurons or networks operate must be validated against experimental data. For this, it is necessary to have a good model for the measurement itself. For example, to compare model predictions from cortical networks with electrical signals recorded by electrodes placed on the cortical surface or the head scalp, the so-called volume conductor theory is required to make a proper quantitative link between the network activity and the measured signals. Here we describe the physics and modelling of electric, magnetic and other measurements of brain activity. The physical principles behind electric and magnetic stimulation of brain tissue are the same as those covering electric and magnetic measurements, and are also outlined.

This chapter describes pseudoscience and questionable ideas related to obsessive-compulsive disorder and other related disorders. The chapter opens by discussing controversies such as the assumptions of pseudoscientific medical interventions. Dubious treatments include energy therapies, neurofeedback, thought stopping, psychodynamic therapy, ketamine, magnetic stimulation, and new age wellness remedies. The chapter closes by reviewing research-supported approaches.