scholarly journals Time perception deficits and its dose-dependent effect in methamphetamine dependents with short-term abstinence

2019 ◽  
Vol 5 (10) ◽  
pp. eaax6916 ◽  
Author(s):  
Mingming Zhang ◽  
Di Zhao ◽  
Zhao Zhang ◽  
Xinyu Cao ◽  
Lu Yin ◽  
...  

Intake of addictive substances acutely modifies dopaminergic transmission in the striatum and prefrontal cortex, which is the neural substrate underlying time processing. However, the persistent effects of methamphetamine (meth) abuse (e.g., during abstinence) on temporal processing have not been fully elucidated. Here, we recruited different samples in two experiments. We first compared the potential differences in motor timing between healthy controls and meth dependents with varied length of abstinence and then examined the ability of perceptual timing between the healthy subjects and the meth group at short abstinence. We found that motor timing, but not perceptual timing, was altered in meth dependents, which persisted for at least 3 months of abstinence. Dose-dependent effects on time perception were only observed when short-term abstinent meth abusers processed long time intervals. We conclude that time perception alteration in meth dependents is task specific and dose dependent.

2009 ◽  
Vol 364 (1525) ◽  
pp. 1933-1942 ◽  
Author(s):  
A.D. (Bud) Craig

A model of awareness based on interoceptive salience is described, which has an endogenous time base that might provide a basis for the human capacity to perceive and estimate time intervals in the range of seconds to subseconds. The model posits that the neural substrate for awareness across time is located in the anterior insular cortex, which fits with recent functional imaging evidence relevant to awareness and time perception. The time base in this model is adaptive and emotional, and thus it offers an explanation for some aspects of the subjective nature of time perception. This model does not describe the mechanism of the time base, but it suggests a possible relationship with interoceptive afferent activity, such as heartbeat-related inputs.


1972 ◽  
Vol 3 (3) ◽  
pp. 181-186 ◽  
Author(s):  
Charles Neuringer ◽  
Marvin Levenson

An attempt was made to further investigate the hypothesis that suicidal individuals perceive time as moving slower than do geriatric and normal patients. Behavioral type estimates of two short and two long time intervals were elicited from serious suicide attempters, geriatric patients and normal hospitalized subjects (N = 15 for each group). It was found that the suicidal Ss overestimated the length of the time intervals to a greater degree than did the other patients. The data suggested that the slowing down of time was more accelerated for the suicidal patients than for the other Ss (i.e., time estimations increased faster for the suicidal Ss as compared to the other groups as interval length increased).


2016 ◽  
Author(s):  
Eric Libby ◽  
William Ratcliff

AbstractTo survive unpredictable environmental change, many organisms adopt bet-hedging strategies that trade short-term population growth for long-term fitness benefits. Because the benefits of bet-hedging may manifest over long time intervals, bet-hedging strategies may be out-competed by strategies maximizing short-term fitness. Here, we investigate the interplay between two drivers of selection, environmental fluctuations and competition for limited resources, on different bet-hedging strategies. We consider an environment with frequent disasters that switch between which phenotypes they affect in a temporally-correlated fashion. We determine how organisms that stochastically switch between phenotypes at different rates fare in both competition and survival. When disasters are correlated in time, the best strategy for competition is among the worst for survival. Since the time scales over which the two agents of selection act are significantly different, environmental fluctuations and resource competition act in opposition and lead populations to evolve diversification strategies that ultimately drive them extinct.


Author(s):  
Yuhong Jiang

Abstract. When two dot arrays are briefly presented, separated by a short interval of time, visual short-term memory of the first array is disrupted if the interval between arrays is shorter than 1300-1500 ms ( Brockmole, Wang, & Irwin, 2002 ). Here we investigated whether such a time window was triggered by the necessity to integrate arrays. Using a probe task we removed the need for integration but retained the requirement to represent the images. We found that a long time window was needed for performance to reach asymptote even when integration across images was not required. Furthermore, such window was lengthened if subjects had to remember the locations of the second array, but not if they only conducted a visual search among it. We suggest that a temporal window is required for consolidation of the first array, which is vulnerable to disruption by subsequent images that also need to be memorized.


Author(s):  
K.S. Pavlova ◽  
D.S. Mdinaradze

По данным ВОЗ, рекомендации врача выполняют не более 50 пациентов. В конечном итоге это приводит к снижению или отсутствию эффекта от назначаемого лечения. В связи с этим во всех последних международных и национальных руководствах говорится о необходимости учета предпочтений пациента при выборе терапии. Аллерген-специфическая иммунотерапия (АСИТ) является одним из основных методов лечения аллергических заболеваний, таких как аллергический ринит, конъюнктивит и атопическая бронхиальная астма, обладает болезнь-модифицирующими свойствами и долгосрочным эффектом после окончания лечения. АСИТ относится к профилактическому и продолжительному методу (рекомендовано на протяжении не менее 3 лет), что часто является причиной снижения приверженности к терапии. В различных исследованиях подтвержден зависимый от дозы аллергена эффект АСИТ, а следовательно, изменение режимов или сокращение сроков терапии могут влиять на конечный результат. При недостаточной эффективности АСИТ необходимо в первую очередь рассматривать вероятность низкого комплаенса. Сублингвальная АСИТ (СЛИТ) требует от пациента высокой вовлеченности в процесс лечения. Задачей врача в данном случае становится повышение терапевтического сотрудничества как одного из важнейших факторов обеспечения эффективности СЛИТ. Основными способами в данном случае являются улучшение понимания пациентом цели терапии и регулярный контроль со стороны врача.According to WHO at last 50 of the patient dont follow doctors recommendations. Ultimately, this leads to a decrease or absence of the treatment effect. In this regard, all the latest international and national guidelines mention the need to take into account the patients preferences in the choice of therapy. Allergen-specific immunotherapy (AIT) is one of the main methods of treatment of allergic diseases such as allergic rhinitis, allergic conjunctivitis and atopic asthma, and has disease modifying properties and the long-term efficacy after stop treatment. AIT refers to a preventive and long-term method (recommended for at least 3 years), that is often the cause of reduced adherence to therapy. Various studies have confirmed the dose-dependent effect of AIT, and, consequently, changes in regimens or shortening of therapy may affect the end result. In case of insufficient effectiveness of AIT, the probability of low compliance should be considered first of all. Sublingual AIT (SLIT) requires the patient to be highly involved in the treatment process. The task of the doctor in this case is increasing therapeutic cooperation, as one of the most important factors to ensure the effectiveness of SLIT. The main methods in this case are to improve the patients understanding of the purpose of the therapy and regular monitoring by the doctor.


Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 660
Author(s):  
Zhongshuo Hu ◽  
Jianwei Yang ◽  
Dechen Yao ◽  
Jinhai Wang ◽  
Yongliang Bai

In the signal processing of real subway vehicles, impacts between wheelsets and rail joint gaps have significant negative effects on the spectrum. This introduces great difficulties for the fault diagnosis of gearboxes. To solve this problem, this paper proposes an adaptive time-domain signal segmentation method that envelopes the original signal using a cubic spline interpolation. The peak values of the rail joint gap impacts are extracted to realize the adaptive segmentation of gearbox fault signals when the vehicle was moving at a uniform speed. A long-time and unsteady signal affected by wheel–rail impacts is segmented into multiple short-term, steady-state signals, which can suppress the high amplitude of the shock response signal. Finally, on this basis, multiple short-term sample signals are analyzed by time- and frequency-domain analyses and compared with the nonfaulty results. The results showed that the method can efficiently suppress the high-amplitude components of subway gearbox vibration signals and effectively extract the characteristics of weak faults due to uniform wear of the gearbox in the time and frequency domains. This provides reference value for the gearbox fault diagnosis in engineering practice.


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