Effects of benzodiazepine‐induced sedation on temporal processing

Abstract

Unlike processing of time intervals in the range of seconds or more, processing of brief durations ranging from approximately 50 to 100 ms appears to be beyond cognitive control and based on neural counting mechanisms. In a placebo-controlled study either 15 mg of midazolam or placebo were applied to 36 healthy male volunteers to investigate the effect of pharmacologically induced sedation on temporal processing of intervals in the range of milliseconds indicating performance on time perception and in the range of seconds indicating performance on time estimation. In addition, a test battery consisting of subtests measuring speed of information processing and cortical arousal was applied. Midazolam induced a very pronounced decrease in cortical arousal as well as a marked impairment of speed of information processing and performance on time estimation as compared to placebo. Performance on time perception, however, was not affected suggesting that temporal processing of very brief intervals is unrelated to the effective level of cortical arousal. These findings support the notion of two different timing mechanisms underlying time estimation and time perception.

Dissociations between motor timing, motor coordination, and time perception after the administration of alcohol or caffeine

“…Our results may be seen as having parallels with Rammsayer's (1992Rammsayer's ( , 1993Rammsayer's ( , 1997Rammsayer's ( , 1999Rammsayer's ( , 2006 findings that the timing of longer intervals is more susceptible to drug effects than the timing of shorter intervals. The relative insensitivity of short interval timing to the disruptive effects of drugs has been taken as evidence against a unitary account of timing based on a single timer.…”

“…Many drug effects on timing are specific to certain time intervals: for example, the minor tranquillizer midazolam, the atypical neuroleptic remoxipride, and the NMDA receptor antagonist memantine, all reduce estimation accuracy for longer time intervals (in the range of seconds) but not for shorter intervals (in the range of hundreds of milliseconds; Rammsayer 1992Rammsayer , 1993Rammsayer , 1997Rammsayer , 1999Rammsayer , 2006, and the noradrenaline reuptake inhibitor reboxetine improves accuracy only at longer intervals (Rammsayer et al 2001). These dissociations, together with recent neuroimaging evidence (for a review see Lewis and Miall 2003) suggest that intervals below and above approximately one second are represented by two distinct timing processes that may be differentially sensitive to drug effects.…”

Subjective Duration as a Signature of Coding Efficiency: Emerging Links Among Stimulus Repetition, Predictive Coding, and Cortical GABA Levels

“…Pharmacological studies complement this finding by showing that GABA agonists reduce perceptual awareness (van Loon et al, 2012) and visual discrimination (Giersch & Herzog, 2004), and attenuate the neurophysiological response to visual oddball stimuli (P3 event-related brain potential component; Watson et al, 2009). Further studies showed that GABA agonists also impair temporal discrimination of auditory intervals (Rammsayer, 1992(Rammsayer, , 1999. In addition to cortical regions, the dendritic spines of GABAergic projection neurons in the basal ganglia make contact with the corticostriatal-thalamostriatal glutamatergic and nigrostriatal dopaminergic neurons involved in interval timing (Meck, 1996).…”

Effects of aging on absolute identification of duration.

“…There is some debate in the literature regarding the extent to which timing of different duration values exploits different timing mechanisms (see Gibbon, Malapani, Dale, & Gallistel, 1997). For example, Rammsayer (1992Rammsayer ( , 1994Rammsayer ( , 1999Rammsayer & Lima, 1991) has claimed that timing of durations shorter than approximately 500 ms is mediated by different mechanisms than timing of intervals in the range of 1 to 2 s, although other authors have made parallel claims regarding different duration ranges (see Clarke, Ivry, Grinband, Roberts, & Shimizu, 1996;Poppel, 1996). Gibbon et al have argued that demonstrating that impairments in timing are not dissociable across different duration values would provide crucial evidence for common timing mechanisms across the range of durations.…”