Humans Brains are Less Simple Than We Think
Connections between attention and emotion circuits hint at complex neural-network interactions
We like to think that the brain has simple, discrete circuits for any number of complex functions, like attention, short term memory, fear responses or addiction. Indeed, in the 1990’s, the advent of technologies like functional MRI (fMRI) and PET scans allowed neuroscientists to map out many such neural pathways. Researchers identified where the neurons critical for these pathways were located in the brain, where they sent projections to other neurons within the circuit, and what neurotransmitters were involved in these connections.
Each function of the brain tended to be studied in isolation. It was as if, because an artist could draw a pretty diagram of a series of neural connections, these circuits were independently functioning machines. Add input X to the fear circuit, and output Y would always result.
Psychologists extended this framework for looking at healthy brains to include mental health conditions as well. They categorized conditions based on the important functions and networks thought to be impaired. Depression and anxiety were designated emotional conditions. Schizophrenia and ADHD were classified as problems with the organization of thoughts and…
