The Disordered Mind: What Unusual Brains Tell Us About Ourselves

by Eric R. Kandel

Several disorders of movement and of memory, such as Parkinson’s disease and Alzheimer’s disease, result from misfolded proteins. The symptoms of these disorders vary widely because the particular proteins affected and the functions for which they are responsible differ. Similarly, both autism and schizophrenia involve synaptic pruning, the removal of excess dendrites on neurons. In autism, not enough dendrites are pruned, whereas in schizophrenia too many are. In another example, three different disorders—autism, schizophrenia, and bipolar disorder—share genetic variants. That is, some of the same genes that create a risk for schizophrenia also create a risk for bipolar disorder, and some of the same genes that create a risk for schizophrenia also create a risk for autism spectrum disorders. The interplay of unconscious and conscious mental processes is critical to how we function in the world. We see this particularly clearly in creativity and decision making. Our innate creativity—in any field—hinges on loosening the bonds of consciousness and gaining access to our unconscious. This is easier for some people than for others.