A cursory review of the literature reveals that the techniques used to assess psychomotor functions are diverse, often complex, frequently insensitive to drug induced changes and sometimes inconvenient to enact or replicate. Adams (1974) used proof reading ability; Croucher & Hindmarch (1974), the duration of the spiral after effect ; Betts, Clayton & Mackay (1972), low speed car handling tasks; Malpas, Rowan, Joyce & Scott (1970), card sorting ability; Fargus & Hindmarch (1974), a cardriving simulator; Ashton, Hall, Savage, Telford & Thompson (1972), a pursuit rotor; File & Bond (1979), symbol copying; Van Houten & Zenhausern (1967), the absolute auditory threshold; Davis, Hollister, Overall, Johnson & Train (1976), short and long term memory; Ghoneim & Mewaldt (1977), verbal learning; Gendreau, Sherlock, Parsons, McLean, Scott & Suboske (1972), discrimination conditioning of the eyelid response; Gupta (1974), the kinaesthetic figural after effect.

https://bpspubs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2125.1980.tb01745.x

Psychomotor Function and Psychoactive Drugs

The amnesic action of benzodiazepines in man

Tranquillising memories: a review of the effects of benzodiazepines on human memory.

The Neuropsychology of Autobiographical Memory

The effects of intramuscular injections of diazepam (0.3 mg/kg) and scopolamine (8 Μg/kg) on memory processes and subjective moods were studied in 36 volunteers. Subjects (Ss) were tested in groups of four in a double blind procedure with treatments distributed according to a Latin square design. Lists of words were presented to Ss who were then tested with an immediate free recall test prior to drug administration. Following injection delayed free recall and recognition tests were given. Subsequently two sets of lists were presented separately and tested in the same fashion. Two of the lists in the last set were composed of words falling into distinct categories. Memory was additionally analyzed by testing immediate recall of digit sequences and employing a visual recognition test. Subjective moods were evaluated with a rating questionnaire. Both diazepam and scopolamine impaired memory functions although the action of the latter drug was more pronounced and prolonged. The deficit appeared to be in the storage process leaving retrieval processes unaffected. Scopolamine in addition interfered with organizational processes. Subjectively, scopolamine also produced a larger sedative effect than diazepam.

Effects of diazepam and scopolamine on storage, retrieval and organizational processes in memory.

SUMMARY A double-blind trial of intravenous diazepam (0.24 mg/kg) versus saline was carried out on twelve young intelligent male volunteers to examine the amnesic effect of the drug. Complex psychological testing extended over a 2-hour period. Dense anterograde amnesia was found for approximately 10 minutes with a less severe impairment of memory persisting at least half an hour after injection. It is considered that the memory difficulties were not due to serious reduction of level of consciousness but do focus on the input or “consolidation” processes rather than on retrieval. Further studies are needed to define more clearly the nature of the deficit.

P.R.F. Clarke

Papers

The amnesic effect of diazepam (valium)