WHAT TYPES of neurocognitive deficits do patients with schizophrenia have? The list of seemingly unrelated neurocognitive deficits is rather long and leaves one yearning for parsimony. After hearing about problems with vigilance, secondary memory, sensory gating, problem solving, psychomotor abilities, and verbal fluency, one wonders about a simpler way to view the problem. Surely, when a complex system such as cognitive processing breaks down in schizophrenia, it must do so in a small number of basic ways that generate a variety of cognitive performance deficits. But how do we conceptualize these basic deficits?