Impaired Attention in Schizophrenia: Insights from Electrophysiology and Noninvasive Brain Stimulation

Abstract

Since the time of Kraepelin (1896) and Bleuler (1911) nearly every description of schizophrenia cognitive dysfunction highlights impairments in attention, yet the locus of this deficit is not well understood. One model proposes that the locus of schizophrenia attentional dysfunction is due to an abnormality in the memory representations that we activate to control our attention (i.e., selection guidance). Another model proposes that the neural mechanism important for shifting perceptual attention itself is damaged (i.e., input selection). Here, I use visual search tasks, electrophysiological methods, and noninvasive brain stimulation to develop an approach for understanding the processes underlying attention in healthy individuals. Next, I identify a set of neural and behavioral abnormalities related to impaired attention in patients with schizophrenia. Last, I use the noninvasive brain stimulation protocol I developed in healthy individuals to determine whether it is possible to improve attention in patients with schizophrenia. The results demonstrate that 20 minutes of noninvasive stimulation can enhance the transmission of information between memory systems leading to the temporary normalization of attention in schizophrenia. The results support theories of schizophrenia that cast the cognitive impairment as a selection-guidance abnormality, and suggest a new avenue for the development of intervention therapies in the treatment of neuropsychiatric disorders, such as schizophrenia.