Depression is vastly heterogeneous in its symptoms, neuroimaging data, and treatment responses. As such, describing how it develops at the network level has been notoriously difficult. In an attempt to overcome this issue, a theoretical “negative prediction mechanism” is proposed. Here, eight key brain regions are connected in a transient, state-dependent, core network of pathological communication that could facilitate the development of depressive cognition. In the context of predictive processing, it is suggested that this mechanism is activated as a response (...) to negative/adverse stimuli in the external and/or internal environment that exceed a vulnerable individual’s capacity for cognitive appraisal. Specifically, repeated activation across this network is proposed to update an individual’s brain so that it increasingly predicts and reinforces negative experiences over time—pushing an individual at-risk for or suffering from depression deeper into mental illness. Within this, the negative prediction mechanism is poised to explain various aspects of prognostic outcome, describing how depression might ebb and flow over multiple timescales in a dynamically changing, complex environment. (shrink)

Enhancing brain activity and function is a very ancient practice which is usually accomplished by taking illegal drugs. Prescription medication is becoming more commonly used as a means of enhancing mood, and recently, it has become possible to modulate mood by applying magnetic or electrical current to the brain or by training the brain to work at predetermined oscillations. A summary of the available neuromodulation techniques will be presented associated with data from human subjects implanted with cortical and/or subcutaneous electrodes (...) that demonstrate the potential for electrical neuro-enhancement. (shrink)