... and memory lapses.

Schizophrenia is often marked by poor performance on memory tests, accompanied by diminished activity in frontal brain areas involved in reasoning. It's unclear, however, whether these mental lapses tap into a neural disturbance specific to the disorder or reflect the unwillingness of frequently apathetic schizophrenia sufferers to make the mental effort to remember. A study directed by neuroscientist Paul C. Fletcher of the Institute of Neurology in London lends support to the latter view.

Twelve people with schizophrenia and seven adults with no psychiatric ailments underwent positron emission tomography (PET) scanning as they learned and recalled lists of 1 to 12 words. PET scans yield measures of blood-flow changes in the brain, an indirect sign of mental activity.

In schizophrenia, frontal brain activity and memory performance dropped as tasks became more demanding, consistent with a lack of mental effort, Fletcher's group reports in the November Archives Of General Psychiatry. In contrast, the researchers found, frontal activity rose in the mentally healthy adults as they successfully recalled more information on progressively more challenging tasks.