Lorazepam induces multiple disturbances in selective attention: attentional overload, decrement in target processing efficiency, and shifts in perceptual discrimination and response bias

• Published in: Journal of psychopharmacology (Oxford) 2007-09, Vol.21 (7), p.691-699
• Main Authors: Michael, George Andrew, Bacon, Elisabeth, Offerlin-Meyer, Isabelle
• Format: Article
• Language: English
• Subjects: Adult; Anti-Anxiety Agents - pharmacology; Attention; Attention - drug effects; Benzodiazepines; Biological and medical sciences; Complications and side effects; Data Interpretation, Statistical; Discrimination; Discrimination (Psychology) - drug effects; Double-Blind Method; Female; Human performance; Humans; Lorazepam; Lorazepam - pharmacology; Male; Medical sciences; Neuropharmacology; Observations; Pharmacology. Drug treatments; Placebo effect; Psycholeptics: tranquillizer, neuroleptic; Psychology. Psychoanalysis. Psychiatry; Psychopharmacology; Response bias; Signal detection; Signal detection (Psychology); Signal Detection, Psychological - drug effects; Task Performance and Analysis; Time Factors; Visual perception; Visual Perception - drug effects; Visual task performance
• ISSN: 0269-8811; 1461-7285
• DOI: 10.1177/0269881106074011

There is a general consensus that benzodiazepines affect attentional processes, yet only few studies have tried to investigate these impairments in detail. The purpose of the present study was to investigate the effects of a single dose of Lorazepam on performance in a target cancellation task with important time constraints. We measured correct target detections and correct distractor rejections, misses and false positives. The results show that Lorazepam produces multiple kinds of shifts in performance, which suggests that it impairs multipLe processes: (a) the evolution of performance over time was not the same between the placebo and the Lorazepam groups, with the Lorazepam affecting performance quite early after the beginning of the test. This is suggestive of a depletion of attentional resources during sequential attentional processing; (b) Lorazepam affected differently target and distractor processing, with target detection being the most impaired; (c) misses were more frequent under Lorazepam than under placebo, but no such difference was observed as far as false positives were concerned. Signal detection analyses showed that Lorazepam (d) decreased perceptual discrimination, and (e) reliably increased response bias. Our results bring new insights on the multiple effects of Lorazepam on selective attention which, when combined, may have deleterious effects on human performance.