Time dilation and acceleration in depression

Time processing in neurological and psychiatric conditions

A central question in understanding cognition and pathology-related cognitive changes is how we process time. However, time processing difficulties across several neurological and psychiatric conditions remain seldom investigated. The aim of this review is to develop a unifying taxonomy of time processing, and a neuropsychological perspective on temporal difficulties. Four main temporal judgments are discussed: duration processing, simultaneity and synchrony, passage of time, and mental time travel. We present an integrated theoretical framework of timing difficulties across psychiatric and neurological conditions based on selected patient populations. This framework provides new mechanistic insights on both (a) the processes involved in each temporal judgement, and (b) temporal difficulties across pathologies. By identifying underlying transdiagnostic time-processing mechanisms, this framework opens fruitful avenues for future research.

Cognitive and balance functions of astronauts after spaceflight are comparable to those of individuals with bilateral vestibulopathy

Introduction

This study compares the balance control and cognitive responses of subjects with bilateral vestibulopathy (BVP) to those of astronauts immediately after they return from long-duration spaceflight on board the International Space Station.

Methods

Twenty-eight astronauts and thirty subjects with BVP performed five tests using the same procedures: sit-to-stand, walk-and-turn, tandem walk, duration judgment, and reaction time.

Results

Compared to the astronauts' preflight responses, the BVP subjects' responses were impaired in all five tests. However, the BVP subjects' performance during the walk-and-turn and the tandem walk tests were comparable to the astronauts' performance on the day they returned from space. Moreover, the BVP subjects' time perception and reaction time were comparable to those of the astronauts during spaceflight. The BVP subjects performed the sit-to-stand test at a level that fell between the astronauts' performance on the day of landing and 1 day later.

Discussion

These results indicate that the alterations in dynamic balance control, time perception, and reaction time that astronauts experience after spaceflight are likely driven by central vestibular adaptations. Vestibular and somatosensory training in orbit and vestibular rehabilitation after spaceflight could be effective countermeasures for mitigating these post-flight performance decrements.

Supra-second interval timing in bipolar disorder: examining the role of disorder sub-type, mood, and medication status

BACKGROUND

Widely reported by bipolar disorder (BD) patients, cognitive symptoms, including deficits in executive function, memory, attention, and timing are under-studied. Work suggests that individuals with BD show impairments in interval timing tasks, including supra-second, sub-second, and implicit motor timing compared to the neuronormative population. However, how time perception differs within individuals with BD based on disorder sub-type (BDI vs II), depressed mood, or antipsychotic medication-use has not been thoroughly investigated. The present work administered a supra-second interval timing task concurrent with electroencephalography (EEG) to patients with BD and a neuronormative comparison group. As this task is known to elicit frontal theta oscillations, signal from the frontal (Fz) lead was analyzed at rest and during the task.

RESULTS

Results suggest that individuals with BD show impairments in supra-second interval timing and reduced frontal theta power during the task compared to neuronormative controls. However, within BD sub-groups, neither time perception nor frontal theta differed in accordance with BD sub-type, depressed mood, or antipsychotic medication use.

CONCLUSIONS

This work suggests that BD sub-type, depressed mood status or antipsychotic medication use does not alter timing profile or frontal theta activity. Together with previous work, these findings point to timing impairments in BD patients across a wide range of modalities and durations indicating that an altered ability to assess the passage of time may be a fundamental cognitive abnormality in BD.

Mental Gravity: Depression as Spacetime Curvature of the Self, Mind, and Brain

The principle of mental gravity contends that the mind uses physical gravity as a mental model or simulacrum to express the relation between the inner self and the outer world in terms of "UP"-ness and "DOWN"-ness. The simulation of increased gravity characterises a continuum of mental gravity which states includes depression as the paradigmatic example of being down, low, heavy, and slow. The physics of gravity can also be used to model spacetime curvature in depression, particularly gravitational time dilation as a property of MG analogous to subjective time dilation (i.e., the slowing of temporal flow in conscious experience). The principle has profound implications for the Temporo-spatial Theory of Consciousness (TTC) with regard to temporo-spatial alignment that establishes a "world-brain relation" that is centred on embodiment and the socialisation of conscious states. The principle of mental gravity provides the TTC with a way to incorporate the structure of the world into the structure of the brain, conscious experience, and thought. In concert with other theories of cognitive and neurobiological spacetime, the TTC can also work towards the "common currency" approach that also potentially connects the TTC to predictive processing frameworks such as free energy, neuronal gauge theories, and active inference accounts of depression. It gives the up/down dimension of space, as defined by the gravitational field, a unique status that is connected to both our embodied interaction with the physical world, and also the inverse, reflective, emotional but still embodied experience of ourselves.

The role of depressive symptoms in the interplay between aging and temporal processing

Temporal processing, the ability to mentally represent and process the dynamical unfolding of events over time, is a fundamental feature of cognition that evolves with advancing age. Aging has indeed been associated with slower and more variable performance in timing tasks. However, the role of depressive symptoms in age-related changes in temporal processing remains to be investigated. Therefore, the present work aims to shed light on the link between temporal processing and depressive symptoms, which are frequent with advancing age. We relied on the multicentric "Blursday Project" database, providing measures of temporal processing together with questionnaires investigating psychological wellbeing. Results reveal that aging influences several timing abilities, from the reproduction of short time intervals to verbal estimations of longer temporal distances. Furthermore, the slowing down of felt passage of time regarding the last few days with age was fully mediated by the intensity of depressive symptoms. Overall, these findings suggest that depressive symptoms may play a pivotal role in age-related temporal processing changes.

Can disorders of subjective time inform the differential diagnosis of psychiatric disorders? A transdiagnostic taxonomy of time

AIM

Time is a core aspect of psychopathology with potential for clinical use and early intervention. Temporal experience, perception, judgement and processing are distorted in various psychiatric disorders such as mood (depression and mania), anxiety, autistic, impulse-control, dissociative and attention-deficit/hyperactivity disorders. Can these disorders of time be used as early diagnostic or predictive markers? To answer this question, we develop a Transdiagnostic Taxonomy of (disordered) Time (TTT) that maps on to the symptomatological, phenomenal, perceptual and functional descriptions of each underlying disorder in a 2 × 2 × 2 state space. Temporal distortions may precede functional decline, and so assist efforts at early detection and intervention in at-risk groups.

METHOD

Firstly, this article integrates a psychological model of how time is processed with a subjective or phenomenological model of how time is experienced or perceived. Secondly, the integrated combined model of time is then used to heuristically map major psychiatric disorders on to the basic elements of temporal flow and integration.

RESULTS

The TTT systematically describes the basic temporal nature of eight diagnostic categories of psychiatric illness. It differentiates between diagnoses primarily associated with distorted "macro-level" phenomenal temporal experiences (i.e. anxiety, dissociation/PTSD, depression, and mania) from those primarily related to distorted 'micro-level' temporal processing (i.e. psychotic, impulse-control, autistic and attention-deficit/hyperactivity disorders).

CONCLUSIONS

The TTT allows differential diagnostic classification of various psychiatric disorders in terms of a possible underlying time disorder, making it useful for future diagnostic and predictive purposes using novel techniques of temporal processing, time perception, passage of time, and time perspective.

How physical activity and passion color the passage of time: A response with ultra-trail runners

The aim of this study was to replicate the results of a lengthening effect caused by physical activity already observed in duration length judgment, using the time passage judgment measure, while exploring the effects of passion types (obsessive vs. harmonious) on time perception. A total of 378 ultra-trail runners responded to an online questionnaire in which the type of passion and the passage of time (PoT) judgments associated with both an ultra-trail context and a non-trail daily context were collected. The results showed that participants systematically judged the time as being dilated in a situation of sports practice, thus extending the results obtained in interval duration judgment studies. This study also showed an influence of the type of passion: higher levels of harmonious passion were related to greater feelings of time dilation, while higher levels of obsessive passion were related to greater feelings of both time contraction and time dilation. Results are discussed in light of the two major factors that influence the PoT referenced in the literature, namely, attention and happiness level.

Identifying the difference in time perception between major depressive disorder and bipolar depression through a temporal bisection task

BACKGROUND

It is difficult to make a precise diagnosis to distinguish patients with Major Depressive Disorder (MDD) from patients with Bipolar Depressive Disorder (current depressive episode, BD). This study will explore the difference in time perception between MDD and BD using a temporal bisection task.

METHODS

In this temporal bisection task, 30 MDD patients, 30 BD patients, and 30 healthy controls (HC) had to categorize a signal duration, between 400 and 1600 milliseconds (ms), as either short or long. A repeated measurement analysis of variance with 3 (subject type) × 7 (time interval) was performed on the long response ratio with Bonferroni correction for multiple comparisons. Origin software was used to calculate the subjective bisection point (BP), difference limen (DL), and Weber ratio (WR). The Hamilton Depression Rating Scale for depression-17 was used to assess depressive symptoms in the patients.

RESULTS

The data showed that the interaction effect between subject type and duration was significant (F (6,498) = 4.656, p <0.001, η2p = 0.101). At 400 ms, and the long response of the MDD group was greater than HC group (p<0.017, Bonferroni-corrected). At 1200, 1400 and 1600 ms, the long response of BD group is smaller than HC group, (p<0.017, Bonferroni-corrected). The one-way ANOVA revealed significant difference among the HC, MDD and BD groups in the BP values WR values, F(2, 81) = 3.462, p = 0.036 vs. F(2, 81) = 3.311, p = 0.042. Post-hoc tests showed that the value of BP in the MDD group was less than BD group (p = 0.027) and the value of BP in the MDD group was less than HC group (p = 0.027), while there was not significant difference of BP values between BD group and HC group. The WR values in MDD group larger than the HC group (p = 0.022).

LIMITATIONS

Severity of depression not divided and analyzed according to the Hamilton Depression Rating Scale score.

CONCLUSION

The time perception of the MDD and BD groups was different from that of the HC group, they overestimated short time periods. Compared with the BD group, the MDD group had a smaller time bisector, and these patients felt that time passed more slowly. The time sensitivity of MDD group and BD group were less than the HC group. However, there was no statistical difference in time sensitivity between the MDD and BD groups.

Time perception at resting state and during active motion: The role of anxiety and depression

BACKGROUND

Time perception and motion intensity are interrelated factors that may influence symptom expression and severity in case of various psychiatric conditions, including anxiety and depression.

AIMS

The present study aimed to 1) explore the associations between the intensity of physical activity, time perception, impulsivity, anxiety and depressive symptoms, and to 2) investigate the extent to which resting state motion intensity can be used to identify the assessed psychiatric conditions.

METHODS

20 healthy controls and 20 psychiatric patients (with either anxiety or depression-related diagnoses) were included in the study and filled out a questionnaire consisting of validated anxiety, depression and impulsivity measures. Time perception was measured by a computerized time production task, whereas motion intensity was analyzed by a motion capture and analysis software. Respondents were randomly assigned to an experimental (with active motion task) and non-experimental group (resting state conditions). Both subgroups were repeatedly assessed, in order to explore changes in motion intensity, time perception and psychiatric symptom levels.

RESULTS

Random forest regression analysis identified the level of impulsivity, depression and anxiety as the strongest predictors of resting state motion intensity, while a path analysis model indicated that controls and psychiatric patients show different pathways regarding the connection between motion intensity changes, time production ratio alterations and symptom reduction.

CONCLUSIONS

Our study implies the importance of distinguishing between clinical and subclinical severity of psychiatric symptoms when considering the association between motion intensity, time perception, anxiety and depression. Potential transdiagnostic relevance of resting state motion intensity is also addressed.

The stigma of patients with chronic insomnia: a clinical study

BACKGROUND

The objective of this study was to explore the stigma and related influencing factors in individuals with chronic insomnia disorder (CID).

METHODS

A total of 70 CID patients and 70 healthy controls (CON) were enrolled in the study. All subjects completed the assessments of sleep, emotion, and cognition. Their stigma and life quality were measured using the Chronic Stigma Scale and the 36-Item Short-Form Health Survey (SF-36).

RESULTS

The ratio of individuals with stigma was significantly different between CID and CON groups (C² = 35.6, p < 0.001). Compared with the CON group, the CID group had higher scores for total stigma (U = 662.0, p < 0.001), internalized stigma (U = 593.0, p < 0.001), enacted stigma (U = 1568.0, p < 0.001), PSQI (U = 2485.0, p < 0.001) and HAMD-17 (U = 69.5, p < 0.001) as well as lower scores for MoCA-C (U = 3997.5, p < 0.001) and most items of SF-36. Partial correlation analysis showed that different items of the Chronic Stigma Scale were positively correlated with illness duration, PSQI and HAMD-17 scores, while negatively correlated with one or more items of the SF-36. Multivariate regression analysis showed that illness duration and the Mental Health domain of the SF-36 were independent risk factors for one or more items of stigma in CID patients.

CONCLUSION

Patients with CID have an increased risk of stigma. Moreover, illness duration and Mental Health may be primary factors related to stigma.

How Does Emotion Influence Time Perception? A Review of Evidence Linking Emotional Motivation and Time Processing

Emotions have a strong influence on how we experience time passing. The body of research investigating the role of emotion on time perception has steadily increased in the past twenty years. Several affective mechanisms have been proposed to influence the passing of time. The current review focuses on how three dimensions of affect-valence, arousal, and motivation-are related to time perception. The valence-based model of time perception predicts that all positive affects hasten the perception of time and all negative affects slow the perception of time. Arousal is thought to intensify the effects of the influence of valence on time perception. In much of this past work, motivational direction has been confounded with valence, whereas motivational intensity has been confounded with arousal. Research investigating the role of motivation in time perception has found that approach-motivated positive and negative affects hasten the perception of time, but withdrawal-motivated affects slow the perception of time. Perceiving time passing quickly while experiencing approach-motivated states may provide significant advantages related to goal pursuit. In contrast, perceiving time passing slowly while experiencing withdrawal-motivated states may increase avoidance actions. Below, we review evidence supporting that approach motivation hastens the passing of time, whereas withdrawal motivation slows the passing of time. These results suggest that motivational direction, rather than affective valence and arousal, drive emotional changes in time perception.

Mood and Proneness to Boredom Are Associated with Poorer Continuous Performance Test Results, Which May Improve with Methylphenidate Treatment, in Attention-Deficit/Hyperactivity Disorder

Objectives: This study aimed to evaluate the relationship between baseline test of variables of attention (TOVA) performance, attention-deficit/hyperactivity disorder (ADHD) symptom severity, mood symptoms, proneness to boredom in children with ADHD, and to assess the responses of the various scales to methylphenidate treatment. Methods: Thirty-three children and adolescents with ADHD, aged 7-18 years, were assessed at baseline with TOVA and treated for 3 months thereafter with methylphenidate. The ADHD Rating Scale (ADHD-RS), Short Boredom Proneness Scale (SBPS), Children's Depression Inventory (CDI) scale, and CDI-academic and social subscale (CDI-AS) were administered to all participants at baseline and after 3 months of methylphenidate (MPH) treatment. Results: The baseline TOVA reaction time (RT) and RT variability parameters correlated with baseline SBPS and CDI-AS scores as well as with baseline total CDI scores. Significant improvements were found in ADHD-RS, SBPS, and CDI-AS scores after MPH treatment. The alteration in ADHD-RS correlated with parallel changes in SBPS and CDI-AS scores. Conclusions: Mood and proneness to boredom correlate with poor attention-span in children with ADHD. Improvement in ADHD levels after MPH treatment correlates with a parallel decrease in mood symptoms related to academic achievement and social functioning.

Time perception and alcohol use: A systematic review

Attentional, executive, and memory processes play a pivotal role in time perception. As acute or chronic alcohol consumption influences these processes, it should also modify time perception. We systematically reviewed and critically assessed all existing studies on time perception among alcohol drinkers, following the PICOS procedure and PRISMA guidelines. We selected 31 articles, distributed across four populations (i.e., alcohol intoxication, binge/heavy drinking, severe alcohol use disorder [SAUD], and Korsakoff syndrome). Several studies suggested the overestimation or underestimation of time during alcohol intoxication. No direct effect of binge/heavy drinking was observed on time perception, while studies on SAUD reported conflicting results. Participants with Korsakoff syndrome exhibited globally impaired time perception and marked deficits in associated cognitive abilities. This systematic review suggests that alcohol consumption affects time perception only when specific cognitive processes are depleted. However, due to the methodological limitations related to existing studies, no firm conclusion can be drawn. Guidelines and perspectives to advance the field are proposed.

Venlafaxine Inhibits the Apoptosis of SHSY-5Y Cells Through Active Wnt/β-Catenin Signaling Pathway

OBJECTIVE

This study aimed to explore the mechanism of venlafaxine in regulating the apoptosis of SHSY-5Y cells induced by hypoxia.

METHODS

The CoCl2-induced neuronal hypoxia model was established based on SHSY-5Y cells. The morphology and related protein expression of SHSY-5Y cells were detected by qPCR, ELISA and Western blot.

RESULTS

Under the condition of hypoxia-induced by CoCl2, the expression of HIF-1α in SHSY-5Y cells was up-regulated and the expression of β-catenin was down-regulated. After adding siRNA targeting HIF-1 α to the culture cell system, down-regulation of β -catenin expression in SHSY-5Y cells was restored. This confirmed the existence of the "hypoxia-HIF-1α-Wnt/β-catenin-depression" axis. Further studies have shown that venlafaxine can alleviate neuronal apoptosis induced by hypoxia by upregulating the Wnt/β-catenin signaling pathway.

CONCLUSION

Venlafaxine regulates apoptosis induced by hypoxia through the Wnt/β-catenin signaling pathway, which provides a new theoretical basis for the treatment of depression.

Effect of Exercise-Related Factors on the Perception of Time

The concept of time whether considered through the lenses of physics or physiology is a relative measure. Alterations in time perception can have serious implications in sport, fitness and work. Accurate perception of time is an important skill with many time constrained sports (i.e., basketball, North American football, tennis, gymnastics, figure skating, ice hockey, and others), and work environments (i.e., workers who need to synchronize their actions such as police and military). In addition, time distortions may play a role in exercise adherence. Individuals may be disinclined to continue with healthy, exercise activities that seem protracted (time dilation). Two predominant theories (scalar expectancy theory and striatal beat frequency model) emphasize the perception of the number of events in a period and the role of neurotransmitters in activating and coordinating cortical structures, respectively. A number of factors including age, sex, body temperature, state of health and fitness, mental concentration and exercise intensity level have been examined for their effect on time perception. However, with the importance of time perception for work, sport and exercise, there is limited research on this area. Since work, sports, and exercise can involve an integration of many of these aforementioned factors, they are interventions that need further investigations. The multiplicity of variables involved with work, sport, and exercise offer an underdeveloped but fruitful field for future research. Thus, the objective of this review was to examine physiological and psychological factors affecting human perception of time and the mechanisms underlying time perception and distortion with activity.

Trajectories and mental health-related predictors of perceived discrimination and stigma among homeless adults with mental illness

Stigma and discrimination toward individuals experiencing homelessness and mental disorders remain pervasive across societies. However, there are few longitudinal studies of stigma and discrimination among homeless adults with mental illness. This study aimed to identify the two-year group trajectories of stigma and discrimination and examine the predictive role of mental health characteristics among 414 homeless adults with mental illness participating in the extended follow-up phase of the Toronto At Home/Chez Soi (AH/CS) randomized trial site. Mental health-related perceived stigma and discrimination were measured at baseline, one, and two years using validated scales. Group-based-trajectory modelling was used to identify stigma and discrimination group trajectory memberships and the effect of the Housing First treatment (rent supplements and mental health support services) vs treatment as usual on these trajectories. The associations between mental health-related characteristics and trajectory group memberships were also assessed using multinomial logistic regression. Over two-years, three group trajectories of stigma and discrimination were identified. For discrimination, participants followed a low, moderate, or increasingly high discrimination group trajectory, while for stigma, participants followed a low, moderate or high stigma group trajectory. The Housing First treatment had no significant effect on discrimination or stigma trajectories groups. For the discrimination trajectories, major depressive episode, mood disorder with psychotic features, alcohol abuse, suicidality, severity of mental health symptoms, and substance use severity in the previous year were predictors of moderate and increasingly high discrimination trajectories. History of discrimination within healthcare setting was also positively associated with following a moderate or high discrimination trajectory. For the stigma trajectories, substance dependence, high mental health symptoms severity, substance use severity, and discrimination experiences within healthcare settings were the main predictors for the moderate trajectory group; while substance dependence, suicidality, mental health symptom severity, substance use severity and discrimination experiences within health care setting were also positive predictors for the high stigma trajectory group. Ethno-racial status modified the association between having a major depression episode, alcohol dependence, and the likelihood of being a member of the high stigma trajectory group. This study showed that adults experiencing mental illness and homelessness followed distinct stigma and discrimination group trajectories based on their mental health-problems. There is an urgent need to increase focus on strategies and policies to reduce stigma and discrimination in this population.

Systema Temporis: A time-based dimensional framework for consciousness and cognition

This study uses a combined categorical-dimensional approach to depict a hierarchical framework for consciousness similar to, and contiguous with, factorial models of cognition (cf., intelligence). On the basis of the longstanding definition of time consciousness, the analysis employs a dimension of temporal extension, in the same manner that psychology has temporally organised memory (i.e., short-term, long-term, and long-lasting memories). By defining temporal extension in terms of the structure of time perception at short timescales (<100 s), memory and time consciousness are proposed to fit along the same logarithmic dimension. This suggests that different forms of time consciousness (e.g., experience, wakefulness, and self-consciousness) are embedded within, or supported by, the ascending timescales of different modes of memory (i.e., short-term, long-term, etc.). A secondary dimension is also proposed to integrate higher-order forms of consciousness/emotion and memory/cognition. The resulting two-dimensional structure accords with existing theories of cognitive and emotional intelligence.