Delayed match-to-sample task. Repeated-measures ANOVA results of the delayed match-to-sample task (colors indicate P values of significant voxels, cluster-based P ? .05; K ? 10) superimposed to a standard brain template. A, Probability map overlays show positive drug X time interactions in favor of a methylene blue effect in the bilateral inferior frontal gyri during the encoding phase, B, in the right superior frontal gyrus, left middle frontal gyrus, and posterior cerebellum during the maintenance phase, and, C, in the right inferior frontal gyrus and cuneus during the retrieval phase (n = 26, with 24 degrees of freedom). D, Representative blocks from the delayed match-to-sample task show the encoding, maintenance, retrieval, feedback, and rest phases as demarcated by set times. (Credit: Radiological Society of North America)

Methylene blue, an orally administered drug currently used to treat a certain blood disorder, has shown promise for improving short-term memory.  A new study using MRI’s showed an increased response in areas of patients brains linked to memory and attention after taking a single low oral dose.

Previous studies in rodents have shown methylene blue has memory enhancing effects, but the underlying neural changes had not been investigated until now.

“This work certainly provides a foundation for future trials of methylene blue in healthy aging, cognitive impairment, dementia, and other conditions that might benefit from drug-induced memory enhancement,” study author Timothy Duong, Ph.D. from the University of Texas Health Science Center, said in a prepared statement.

For the study, 26 healthy participants were randomly assigned to a group receiving methylene blue or a placebo.  The team performed functional MRI’s on participants, who were between the ages of 22 and 62, both before and one hour after receiving the drug or placebo.  They administered tests to evaluate the effects on the brain during working memory and sustained-attention tasks.

The results, published online in Radiology, found that methylene blue affected several areas of the brain.  There were increased responses in the prefrontal cortex, which is involved in processing memories, the visual processing center, and the parietal lobe which is associated with sensory information processing.  On memory retrieval tests, subjects that received the methylene blue saw an increased correct response rate of 7 percent.

Contributing Editor/Science Writer