Impaired time perception and motor timing in stimulant-dependent subjects

Abstract

Stimulant-dependent individuals (SDI) have abnormal brain metabolism and structural changes involving dopaminergic target areas important for the processing of time. These individuals are also more impulsive and impaired in working memory and attention. The current study tested whether SDI show altered temporal processing in relation to impulsivity or impaired prefrontal cortex functioning. We employed a series of timing tasks aimed to examine time processing from the milliseconds to multiple seconds range and assessed cognitive function in 15 male SDI and 15 stimulant-naïve individuals. A mediation analysis determined the degree to which impulsivity or executive dysfunctions contributed to group differences in time processing. SDI showed several abnormal time processing characteristics. SDI needed larger time differences for effective duration discrimination, particularly for intervals of around 1 sec. SDI also accelerated finger tapping during a continuation period after a 1 Hz pacing stimulus was removed. In addition, SDI overestimated the duration of a relatively long time interval, an effect which was attributable to higher impulsivity. Taken together, these data show for the first time that SDI exhibit altered time processing in several domains, one which can be explained by increased impulsivity. Altered time processing in SDI could explain why SDI have difficulty delaying gratification.

Relation Between Time Perspective and Delay Discounting: A Literature Review

“…However, if an internal clock plays a role, it will complicate the putative relation between future time perspective and delay discounting. Wittmann, Leland, Churan, & Paulus (2007) reported that stimulant-dependent individuals, who in other studies exhibit steeper discounting functions and would have shorter predicted time horizons, estimated time intervals of 53 s as substantially longer than control participants, implying a faster running internal clock. In summary, although the association between delinquency and delay discounting is unclear, delinquency does appear to be associated with a shorter future time perspective.…”

Insights into features of anxiety through multiple aspects of psychological time

“…First, many studies in this area (mental distress and time estimation and specifically anxiety and time estimation) have used between-group designs, either based on existing groups or on cut-off scores. A between-group design thus facilitates comparisons with these studies [3,7,21,[26][27][28]. Second, the groups were divided on the basis of clinical levels versus non-clinical levels of anxiety, which further motivates the use of a between-group analysis.…”

“…Mean ratios were calculated for all the time estimation tasks by dividing the estimated duration in every condition by the actual duration of the same condition. In this procedure, a value <1 indicates underestimation and a value >1 indicates overestimation of the time interval [28]. There was one missing value in the S-ZTPI data and it was replaced using the multiple imputation function in SPSS.…”

Clock Speed as a Window into Dopaminergic Control of Emotion and Time Perception

“…Furthermore, many commonly prescribed drugs powerfully modulate dopaminergic signaling. Thus, understanding the precise mechanism of dopaminergic control of emotion and clock speed is of great clinical relevance, as it may help provide insight into symptoms of Parkinson's disease, schizophrenia, and ADHD, as well as help develop and tune current and novel therapies and genetic tests for these and other human diseases including drug abuse, anxiety, and depression (e.g., Bartholomew et al, 2015;Howland, 2012;Lake, 2016;Lake et al, in press;Meck, 2005;Schapira et al, 2006;Thönes & Oberfeld, 2015;Tomasi et al, 2015;Wittmann et al, 2007).…”