Dissecting perception and memory-driven imagery by boosting GABA-ergic neurotransmission

Flanking lateral masks enhance or weaken the detection of a low-contrast visual target. This effect depends on the target-to-mask distance. An improvement of stimulus detection can also be observed when participants imagine (i.e., retrieve from memory) the previously presented masks. In this double-blind, placebo-controlled study, we show that the gamma-aminobutyric acid-A (GABA(A)) receptor agonist alprazolam disrupts perceptual but not imagery enhancement of contrast detection in individuals with generalized anxiety and adjustment disorder. The weakened target detection at short target-to-mask distances became more pronounced after the administration of the GABA-agonist in both perception and imagery conditions. Healthy control participants did not differ from individuals with generalized anxiety and adjustment disorder receiving placebo. These results indicate that perception and imagery can be dissociated by boosting GABA-ergic neurotransmission. Further studies are warranted to investigate this effect in healthy individuals. (C) 2014 Elsevier Ltd. All rights reserved.