Are impairments of time perception in schizophrenia a neglected phenomenon?

Metric error monitoring as a component of metacognitive processing

Metacognitive processing constitutes one of the contemporary target domains in consciousness research. Error monitoring (the ability to correctly report one's own errors without feedback) is considered one of the functional outcomes of metacognitive processing. Error monitoring is traditionally investigated as part of categorical decisions where choice accuracy is a binary construct (choice is either correct or incorrect). However, recent studies revealed that this ability is characterized by metric features (i.e., direction and magnitude) in temporal, spatial, and numerical domains. Here, we discuss methodological approaches to investigating metric error monitoring in both humans and non-human animals and review their findings. The potential neural substrates of metric error monitoring measures are also discussed. This new scope of metacognitive processing can help improve our current understanding of conscious processing from a new perspective. Thus, by summarizing and discussing the perspectives, findings, and common applications in the metric error monitoring literature, this paper aims to provide a guideline for future research.

The Photic Stimulation Has an Impact on the Reproduction of 10 s Intervals Only in Healthy Controls but Not in Patients with Schizophrenia: The EEG Study

Schizophrenia is a mental disorder characterized by both abnormal time perception and atypical relationships with external factors. Here we compare the influence of external photic stimulation on time production between healthy subjects (n = 24) and patients with schizophrenia (n = 22). To delve into neuropsychological mechanisms of such a relationship, the EEG was recorded during variable conditions: during production of 10 s intervals; during photic stimulation of 4, 9, 16, and 25 Hz; and during combinations of these conditions. We found that the higher frequency of photic stimulation influenced the production of time intervals in healthy volunteers, which became significantly longer and were accompanied by corresponding EEG changes. The impact of photic stimulation was absent in patients with schizophrenia. In addition, the time production was characterized by less accuracy and the absence of EEG dynamics typical for healthy controls that included an increase in alpha2 power and envelope frequency. Our findings indicated that the time perception was not adjusted by external factors in patients with schizophrenia and might have involved cognitive and mental processes different from those of healthy volunteers.

Time in schizophrenia: a link between psychopathology, psychophysics and technology

It has been widely demonstrated that time processing is altered in patients with schizophrenia. This perspective review delves into such temporal deficit and highlights its link to low-level sensory alterations, which are often overlooked in rehabilitation protocols for psychosis. However, if temporal impairment at the sensory level is inherent to the disease, new interventions should focus on this dimension. Beyond more traditional types of intervention, here we review the most recent digital technologies for rehabilitation and the most promising ones for sensory training. The overall aim is to synthesise existing literature on time in schizophrenia linking psychopathology, psychophysics, and technology to help future developments.

Deconstructing emotion regulation in schizophrenia: The nature and consequences of abnormalities in monitoring dynamics

Prior studies implicate abnormalities at the identification, selection, and implementation stages of Gross' extended process model of emotion regulation in schizophrenia. However, it is unclear whether monitoring dynamics (i.e., emotion regulation maintenance, switching, and stopping), another critical component of the model, are also abnormal or what predicts those abnormalities. The current study evaluated switching (i.e., switching to a different emotion regulation strategy because the initial strategy was not effective) and stopping dynamics (i.e., terminating the implementation of an emotion regulation strategy) and their associated mechanisms using 6 days of ecological momentary assessment in 47 outpatients with schizophrenia or schizoaffective disorder (SZ) and 52 healthy controls (CN). Results indicated that individuals with SZ exhibited excessive switching between emotion regulation strategies and delayed stopping compared to CN, self-efficacy moderated group differences in stopping abnormalities, and switching and stopping abnormalities were associated with different patterns of state-level positive and negative symptoms in SZ. Findings may inform psychosocial emotion regulation therapies for SZ that could incorporate elements for monitoring dynamics and associated mechanisms.

Incidental finding of age and time disorientation in a clinical sample of patients with schizophrenia: Findings from a short term follow up survey regarding cannabis use

Age disorientation has been described in a subtype of patients with schizophrenia. The current article reports on an incidental finding from our survey study on patterns of cannabis use pre-post legalization in patients with schizophrenia. For the purpose of the survey study, patients were asked to fill out a total of 41 survey questions. The same participants were contacted over the phone 8 weeks post-legalization. Responses to the survey questions were consistent pre- and post-legalization except for four items which required estimation of time/age. This incidental finding highlights the need for further exploration of this phenomenon by future studies.

Impaired memory for temporal context in schizophrenia patients with hallucinations and thought disorganisation

INTRODUCTION

Context processing deficiencies have been established in patients with schizophrenia and it has been proposed that these deficiencies are involved in the formation of positive symptoms.

METHOD

We administered a temporal context discrimination task to 60 schizophrenia patients and 60 healthy individuals. Pictures were presented in two sessions separated by half an hour and the participants were required to remember afterwards whether the pictures had been presented in the first or the second session.

RESULTS

The number of temporal context errors was significantly increased in the patient group. More specifically, it was highly significantly increased in a subgroup of patients presenting hallucinations, while the patients without hallucinations were equivalent to the healthy individuals. Regression analyses revealed that, independently of memory of the pictures themselves, verbal and visual hallucinations, as well as thought disorganisation, were associated with more temporal context errors. In contrast, affective flattening and anhedonia were associated with fewer of these errors.

CONCLUSION

Inability to process or remember the temporal context of production of events might be a mechanism underlying both hallucinations and thought disorganisation.

Experimental Psychosis Research and Schizophrenia-Similarities and Dissimilarities in Psychopathology

The aim of experimental psychopathology is to delineate overlapping functional disorders of psychoneurobiologically-defined systems where a set of common symptoms may correspond to a variety of nosological entities. According to the vulnerability model of psychosis, experimental research needs to go beyond categories such as "schizophrenia". Prospective studies of the effects of psychoactive substances in normal control subjects offer several methodological advantages over routine clinical reviews of schizophrenic patients, especially in terms of standardization. Carefully designed studies utilizing a model psychosis paradigm are a step toward symptom-oriented research. Combining psychological and neurobiological techniques, the experimental psychopathological approach can provide us with a valuable tool for psychiatric research.

Motor Synchronization in Patients With Schizophrenia: Preserved Time Representation With Abnormalities in Predictive Timing

Objective: Basic temporal dysfunctions have been described in patients with schizophrenia, which may impact their ability to connect and synchronize with the outer world. The present study was conducted with the aim to distinguish between interval timing and synchronization difficulties and more generally the spatial-temporal organization disturbances for voluntary actions. A new sensorimotor synchronization task was developed to test these abilities. Method: Twenty-four chronic schizophrenia patients matched with 27 controls performed a spatial-tapping task in which finger taps were to be produced in synchrony with a regular metronome to six visual targets presented around a virtual circle on a tactile screen. Isochronous (time intervals of 500 ms) and non-isochronous auditory sequences (alternated time intervals of 300/600 ms) were presented. The capacity to produce time intervals accurately versus the ability to synchronize own actions (tap) with external events (tone) were measured. Results: Patients with schizophrenia were able to produce the tapping patterns of both isochronous and non-isochronous auditory sequences as accurately as controls producing inter-response intervals close to the expected interval of 500 and 900 ms, respectively. However, the synchronization performances revealed significantly more positive asynchrony means (but similar variances) in the patient group than in the control group for both types of auditory sequences. Conclusion: The patterns of results suggest that patients with schizophrenia are able to perceive and produce both simple and complex sequences of time intervals but are impaired in the ability to synchronize their actions with external events. These findings suggest a specific deficit in predictive timing, which may be at the core of early symptoms previously described in schizophrenia.

Minimal Self and Timing Disorders in Schizophrenia: A Case Report

For years, phenomenological psychiatry has proposed that distortions of the temporal structure of consciousness contribute to the abnormal experiences described before schizophrenia emerges, and may relate to basic disturbances in consciousness of the self. However, considering that temporality refers mainly to an implicit aspect of our relationship with the world, disturbances in the temporal structure of consciousness remain difficult to access. Nonetheless, previous studies have shown a correlation between self disorders and the automatic ability to expect an event in time, suggesting timing is a key issue for the psychopathology of schizophrenia. Timing disorders may represent a target for cognitive remediation, but this requires that disorders can be demonstrated at an individual level. Since cognitive impairments in patients with schizophrenia are discrete, and there is no standardized timing exploration, we focused on timing impairments suggested to be related to self disorders. We present the case report of AF, a 22 year old man suffering from schizophrenia, with no antipsychotic intake. Although AF shows few positive and negative symptoms and has a normal neurocognitive assessment, he shows a high level of disturbance of Minimal Self Disorders (SDs) (assessed with the EASE scale). Moreover, AF has a rare ability to describe his self and time difficulties. An objective assessment of timing ability (variable foreperiod task) confirmed that AF had temporal impairments similar to those previously described in patients, i.e., a preserved ability to distinguish time intervals, but a difficulty to benefit from the passage of time to expect a visual stimulus. He presents additional difficulties in benefitting from temporal cues and adapting to changes in time delays. The impairments were ample enough to yield significant effects with analyses at the individual level. Although causal relationships between subjective and objective impairments cannot be established, the results show that exploring timing deficits at the individual level is possible in patients with schizophrenia. Besides, the results are consistent with hypotheses relating minimal self disorders (SDs) to timing difficulties. They suggest that both subjective and objective timing investigations should be developed further so that their use at an individual level can be generalized in clinical practice.

Individual differences in first- and second-order temporal judgment

The ability of subjects to identify and reproduce brief temporal intervals is influenced by many factors whether they be stimulus-based, task-based or subject-based. The current study examines the role individual differences play in subsecond and suprasecond timing judgments, using the schizoptypy personality scale as a test-case approach for quantifying a broad range of individual differences. In two experiments, 129 (Experiment 1) and 141 (Experiment 2) subjects completed the O-LIFE personality questionnaire prior to performing a modified temporal-bisection task. In the bisection task, subjects responded to two identical instantiations of a luminance grating presented in a 4deg window, 4deg above fixation for 1.5 s (Experiment 1) or 3 s (Experiment 2). Subjects initiated presentation with a button-press, and released the button when they considered the stimulus to be half-way through (750/1500 ms). Subjects were then asked to indicate their 'most accurate estimate' of the two intervals. In this way we measure both performance on the task (a first-order measure) and the subjects' knowledge of their performance (a second-order measure). In Experiment 1 the effect of grating-drift and feedback on performance was also examined. Experiment 2 focused on the static/no-feedback condition. For the group data, Experiment 1 showed a significant effect of presentation order in the baseline condition (no feedback), which disappeared when feedback was provided. Moving the stimulus had no effect on perceived duration. Experiment 2 showed no effect of stimulus presentation order. This elimination of the subsecond order-effect was at the expense of accuracy, as the mid-point of the suprasecond interval was generally underestimated. Response precision increased as a proportion of total duration, reducing the variance below that predicted by Weber's law. This result is consistent with a breakdown of the scalar properties of time perception in the early suprasecond range. All subjects showed good insight into their own performance, though that insight did not necessarily correlate with the veridical bisection point. In terms of personality, we found evidence of significant differences in performance along the Unusual Experiences subscale, of most theoretical interest here, in the subsecond condition only. There was also significant correlation with Impulsive Nonconformity and Cognitive Disorganisation in the sub- and suprasecond conditions, respectively. Overall, these data support a partial dissociation of timing mechanisms at very short and slightly longer intervals. Further, these results suggest that perception is not the only critical mitigator of confidence in temporal experience, since individuals can effectively compensate for differences in perception at the level of metacognition in early suprasecond time. Though there are individual differences in performance, these are perhaps less than expected from previous reports and indicate an effective timing mechanism dealing with brief durations independent of the influence of significant personality trait differences.

Effect of Motion Perception on Intertemporal Choice Is Associated With the Altered Time Perception

Intertemporal choice refers to the choice between receiving a small immediate reward or a large delayed one. Previous studies have indicated that time perception plays a critical role in the intertemporal choice, and it could be affected by the features of the target stimulus in the time reproduction task, such as speed of movement and state of motion. However, there is no evidence about whether backward or forward motion perception could alter the intertemporal choice. Thus, in our current study, 29 participants were asked to perform two tasks in a random order. One was the intertemporal choice task after viewing videos containing moving elements with forward/backward directions as well as stationary ones, and another was the time perception task. We found that the discounting rate in intertemporal choice was significantly larger in backward motion condition than in both forward motion and stationary conditions, indicating that backward motion perception made participants more myopic (specifically, more likely to choose the smaller immediate reward instead of the large delayed one) during their decision-makings. Meanwhile, participants overestimated the temporal duration in a time perception task in backward motion condition compared to the other two conditions. Furthermore, the Pearson's correlation analysis showed that the changes of the intertemporal choice induced by backward motion perception could be associated with the altered time perception. As far as we know, we provide the first evidence on influence of motion perception on the intertemporal choice as well as its possible cognitive correlates, which extend previous studies on cognitive basis of the intertemporal choices.

Slower Time estimation in Post-Traumatic Stress Disorder

Cognitive deficits in Posttraumatic Stress Disorder (PTSD) and dissociative symptoms suggest there may be an underlying and persistent problem with temporal processing in PTSD, but this question has not been systematically examined. We investigated the ability of a group of PTSD participants in estimating the duration of supra-second visual stimuli relative to healthy controls. The data of 59 participants with PTSD and 62 healthy controls, collected from the BRID database, have been examined. Overall, our results indicate that PTSD patients overestimate the duration of the displayed stimuli. Moreover, we found that PTSD are more variable in the time estimation compared to the control group. Finally, we found evidence that working memory and attention impairments were associated with time overestimation in PTSD. The finding of time overestimation in PTSD accords with previous reports of time overestimation during stressful experiences associated with fear and arousal, but extends findings to suggest it remains in chronic PTSD populations processing non-emotional stimuli. The evidence of time overestimation in PTSD suggests the potential relevance of this factor as a cognitive marker in assessing the neuropsychological profile of this clinical population.

The dopaminergic system dynamic in the time perception: a review of the evidence

Dopaminergic system plays a key role in perception, which is an important executive function of the brain. Modulation in dopaminergic system forms an important biochemical underpinning of neural mechanisms of time perception in a very wide range, from milliseconds to seconds to longer daily rhythms. Distinct types of temporal experience are poorly understood, and the relationship between processing of different intervals by the brain has received little attention. A comprehensive understanding of interval timing functions should be sought within a wider context of temporal processing, involving genetic aspects, pharmacological models, cognitive aspects, motor control and the neurological diseases with impaired dopaminergic system. Particularly, an unexplored question is whether the role of dopamine in interval timing can be integrated with the role of dopamine in non-interval timing temporal components. In this review, we explore a wider perspective of dopaminergic system, involving genetic polymorphisms, pharmacological models, executive functions and neurological diseases on the time perception. We conclude that the dopaminergic system has great participation in impact on time perception and neurobiological basis of the executive functions and neurological diseases.

[Time perception and schizophrenia: Phenomenological and neuropsychological approach]

OBJECTIVES

Based on clinical, phenomenological and neurobiological observations, psychiatrists often report a deficit in time estimation in patients with schizophrenia. Cognitive models of time estimation in healthy subjects have been proposed and developed for approximately 30 years. The investigation of time perception is pertinent to the understanding of neurobiological and cognitive abnormalities in schizophrenia. Brain lesions and neuroimaging studies have shown that the critical brain structures engaged in time perception include the prefrontal and parietal lobes, thalamus, basal ganglia and cerebellum. These brain areas have been implicated in the physiopathology of schizophrenia in that there is impaired coordination of activity among these regions. Clinical and experimental date strongly suggest that patients with schizophrenia are less accurate in their ability to estimate time than healthy subjects. The specificity of these clinical and behavioral impairments is still in question. The aims of this article are to present an overview of the literature regarding time estimation and schizophrenia, to discuss specific issues related to how perceptual dysfunction in schizophrenia may lead to abnormalities in time perception, and to propose new perspectives towards an integrative approach between phenomenology and neuroscience.

METHODS

We present a review of the literature describing the current theory in the field of time perception, which is supported by a connectionist model, postulating that temporal judgment is based upon a pacemaker-counter device that depends mostly upon memory and attentional resources. The pacemaker emits pulses that are accumulated in a counter, and the number of pulses determines the perceived length of an interval. Patients with schizophrenia are known to display attentional and memory dysfunctions. Moreover, dopamine regulation mechanisms are involved in both the temporal perception and schizophrenia.

DISCUSSION

It is still unclear if temporal impairments in schizophrenia are related to a specific disturbance in central temporal processes or are due to certain cognitive problems, such as attentional and memory dysfunctions, or biological abnormalities. While psychopathological and phenomenological work strongly suggests that time perception disturbance may be the key or core symptom in schizophrenia, neuroscience studies have failed to do the same. The question of specificity of temporal perception impairments in schizophrenia remains contested. Neuroscience studies suggest that time symptoms in patients with schizophrenia are only secondary to thought disorders and primary cognitive impairments. This debate refers to the etiologic/organic versus psychogenesis/psychological dichotomy and may be over-taken.

CONCLUSION

Clinical evidence associated with psychopathological, biological and cognitive theories strongly suggests that patients with schizophrenia have a deficit in time perception. Discrimination and reproduction of durations have been found to be constantly impaired and disorganized. There is still much work to be done to identify the exact sources of variability in temporal judgments in schizophrenia, and the study of developmental course of time perception could be an interesting route. Regardless of the role of temporal deficits in the pathogenesis of schizophrenia (as a general cognitive disorder or a core role), clinical and phenomenological data encourage us to conduct further studies, especially in the field of developmental psychology.

Cognitive Aging and Time Perception: Roles of Bayesian Optimization and Degeneracy

This review outlines the basic psychological and neurobiological processes associated with age-related distortions in timing and time perception in the hundredths of milliseconds-to-minutes range. The difficulty in separating indirect effects of impairments in attention and memory from direct effects on timing mechanisms is addressed. The main premise is that normal aging is commonly associated with increased noise and temporal uncertainty as a result of impairments in attention and memory as well as the possible reduction in the accuracy and precision of a central timing mechanism supported by dopamine-glutamate interactions in cortico-striatal circuits. Pertinent to these findings, potential interventions that may reduce the likelihood of observing age-related declines in timing are discussed. Bayesian optimization models are able to account for the adaptive changes observed in time perception by assuming that older adults are more likely to base their temporal judgments on statistical inferences derived from multiple trials than on a single trial's clock reading, which is more susceptible to distortion. We propose that the timing functions assigned to the age-sensitive fronto-striatal network can be subserved by other neural networks typically associated with finely-tuned perceptuo-motor adjustments, through degeneracy principles (different structures serving a common function).

Time Perception Mechanisms at Central Nervous System

The five senses have specific ways to receive environmental information and lead to central nervous system. The perception of time is the sum of stimuli associated with cognitive processes and environmental changes. Thus, the perception of time requires a complex neural mechanism and may be changed by emotional state, level of attention, memory and diseases. Despite this knowledge, the neural mechanisms of time perception are not yet fully understood. The objective is to relate the mechanisms involved the neurofunctional aspects, theories, executive functions and pathologies that contribute the understanding of temporal perception. Articles form 1980 to 2015 were searched by using the key themes: neuroanatomy, neurophysiology, theories, time cells, memory, schizophrenia, depression, attention-deficit hyperactivity disorder and Parkinson’s disease combined with the term perception of time. We evaluated 158 articles within the inclusion criteria for the purpose of the study. We conclude that research about the holdings of the frontal cortex, parietal, basal ganglia, cerebellum and hippocampus have provided advances in the understanding of the regions related to the perception of time. In neurological and psychiatric disorders, the understanding of time depends on the severity of the diseases and the type of tasks.

Beyond Neglect: Preliminary Evidence of Retrospective Time Estimation Abnormalities in Non-Neglect Stroke and Transient Ischemic Attack Patients

Perception of the passage of time is essential for safe planning and navigation of everyday activities. Findings from the literature have demonstrated a gross underestimation of time interval in right-hemisphere damaged neglect patients, but not in non-neglect unilaterally-damaged patients, compared to controls. This study aimed to investigate retrospective estimation of the duration of a target detection task over two occasions, in 30 stroke patients (12 left-side stroke 15 right-side stroke, and 3 right-side stroke with neglect) and 10 transient ischemic attack patients, relative to 31 age-matched controls. Performances on visual short-term and working memory tasks were also examined to investigate the associations between timing abilities with residual cognitive functioning. Initial results revealed evidence of perceptual time underestimation, not just in neglect patients, but also in non-neglect unilaterally-damaged stroke patients and transient ischemic attack patients. Three months later, underestimation of time persisted only in left-side stroke and right-side stroke with neglect patients, who also demonstrated reduced short-term and working memory abilities. Findings from this study suggest a predictive role of residual cognitive impairments in determining the prognosis of perceptual timing abnormalities.

Explicit Time Deficit in Schizophrenia: Systematic Review and Meta-Analysis Indicate It Is Primary and Not Domain Specific

Although timing deficits are a robust finding in schizophrenia (SZ), the notion of a genuine time perception disorder in SZ is still being debated because distortions in timing might depend on neuropsychological deficits that are characteristics of the illness. Here we used meta-analytic methods to summarize the evidence of timing deficits in SZ and moderator analyses to determine whether defective timing in SZ arises from nontemporal sources or from defective time perception. PubMed Services, PsycNET, and Scopus were searched through March 2015, and all references in articles were investigated to find other relevant studies. Studies were selected if they included subjects with a primary diagnosis of SZ compared to a healthy control (HC) group and if they reported behavioral measures of duration estimation (perceptual and motor explicit timing). Data from 24 studies published from 1956 to 2015, which comprised 747 SZ individuals and 808 HC, were included. Results indicate that SZ individuals are less accurate than HC in estimating time duration across a wide range of tasks. Subgroup analyses showed that the fundamental timing deficit in SZ is independent from the length of the to-be-timed duration (automatic and cognitively controlled timing) and from methods of stimuli estimation (perceptual and motor timing). Thus, time perception per se is disturbed in SZ (not just task-specific timing processes) and this perturbation is independent from more generalized cognitive impairments. Behavioral evidence of disturbed automatic timing should be more thoroughly investigated with the aim of defining it as a cognitive phenotype for more homogeneous diagnostic subgrouping.

Meta-Analysis of Functional Neuroimaging and Cognitive Control Studies in Schizophrenia: Preliminary Elucidation of a Core Dysfunctional Timing Network

Timing and other cognitive processes demanding cognitive control become interlinked when there is an increase in the level of difficulty or effort required. Both functions are interrelated and share neuroanatomical bases. A previous meta-analysis of neuroimaging studies found that people with schizophrenia had significantly lower activation, relative to normal controls, of most right hemisphere regions of the time circuit. This finding suggests that a pattern of disconnectivity of this circuit, particularly in the supplementary motor area, is a trait of this mental disease. We hypothesize that a dysfunctional temporal/cognitive control network underlies both cognitive and psychiatric symptoms of schizophrenia and that timing dysfunction is at the root of the cognitive deficits observed. The goal of our study was to look, in schizophrenia patients, for brain structures activated both by execution of cognitive tasks requiring increased effort and by performance of time perception tasks. We conducted a signed differential mapping (SDM) meta-analysis of functional neuroimaging studies in schizophrenia patients assessing the brain response to increasing levels of cognitive difficulty. Then, we performed a multimodal meta-analysis to identify common brain regions in the findings of that SDM meta-analysis and our previously-published activation likelihood estimate (ALE) meta-analysis of neuroimaging of time perception in schizophrenia patients. The current study supports the hypothesis that there exists an overlap between neural structures engaged by both timing tasks and non-temporal cognitive tasks of escalating difficulty in schizophrenia. The implication is that a deficit in timing can be considered as a trait marker of the schizophrenia cognitive profile.

Psychopathology of Lived Time: Abnormal Time Experience in Persons With Schizophrenia

Abnormal time experience (ATE) in schizophrenia is a long-standing theme of phenomenological psychopathology. This is because temporality constitutes the bedrock of any experience and its integrity is fundamental for the sense of coherence and continuity of selfhood and personal identity. To characterize ATE in schizophrenia patients as compared to major depressives we interviewed, in a clinical setting over a period of 15 years, 550 consecutive patients affected by schizophrenic and affective disorders. Clinical files were analyzed by means of Consensual Qualitative Research (CQR), an inductive method suited to research that requires rich descriptions of inner experiences. Of the whole sample, 109 persons affected by schizophrenic (n = 95 acute, n = 14 chronic) and 37 by major depression reported at least 1 ATE. ATE are more represented in acute (N = 109 out of 198; 55%) than in chronic schizophrenic patients (N = 14 out of 103; 13%). The main feature of ATE in people with schizophrenia is the fragmentation of time experience (71 out of 109 patients), an impairment of the automatic and prereflexive synthesis of primal impression-retention-protention. This includes 4 subcategories: disruption of time flowing, déjà vu/vecu, premonitions about oneself and the external world. We contrasted ATE in schizophrenia and in major depression, finding relevant differences: in major depressives there is no disarticulation of time experience, rather timelessness because time lacks duration, not articulation. These core features of the schizophrenic pheno-phenotype may be related to self-disorders and to the manifold of characteristic schizophrenic symptoms, including so called bizarre delusions and verbal-acoustic hallucinations.

Perceptual confidence demonstrates trial-by-trial insight into the precision of audio-visual timing encoding

Peoples' subjective feelings of confidence typically correlate positively with objective measures of task performance, even when no performance feedback is provided. This relationship has seldom been investigated in the field of human time perception. Here we find a positive relationship between the precision of human timing perception and decisional confidence. We first demonstrate that subjective audio-visual timing judgements are more precise when people report a high, as opposed to a low, level of confidence. We then find that this relationship is more likely to result from variance in sensory timing estimates than the application of variable decision criteria, as the relationship held when we adopted a measure of timing sensitivity designed to limit the influence of subjective criteria. Our results suggest analyses of timing perception and associated decisional confidence reflect the trial-by-trial variability with which timing has been encoded.

Analysis of Genetic and Non-Genetic Factors Influencing Timing and Time Perception

Performance on different psychophysical tasks measuring the sense of time indicates a large amount of individual variation in the accuracy and precision of timing in the hundredths of milliseconds-to-minutes range. Quantifying factors with an influence on timing is essential to isolating a biological (genetic) contribution to the perception and estimation of time. In the largest timing study to date, 647 participants completed a duration-discrimination task in the sub-second range and a time-production task in the supra-second range. We confirm the stability of a participant's time sense across multiple sessions and substantiate a modest sex difference on time production. Moreover, we demonstrate a strong correlation between performance on a standardized cognitive battery and performance in both duration-discrimination and time-production tasks; we further show that performance is uncorrelated with age after controlling for general intelligence. Additionally, we find an effect of ethnicity on time sense, with African Americans and possibly Hispanics in our cohort differing in accuracy and precision from other ethnic groups. Finally, a preliminary genome-wide association and exome chip study was performed on 148 of the participants, ruling out the possibility for a single common variant or groups of low-frequency coding variants within a single gene to explain more than ~18% of the variation in the sense of time.

Understanding schizophrenia as a disorder of consciousness: biological correlates and translational implications from quantum theory perspectives

From neurophenomenological perspectives, schizophrenia has been conceptualized as "a disorder with heterogeneous manifestations that can be integrally understood to involve fundamental perturbations in consciousness". While these theoretical constructs based on consciousness facilitate understanding the 'gestalt' of schizophrenia, systematic research to unravel translational implications of these models is warranted. To address this, one needs to begin with exploration of plausible biological underpinnings of "perturbed consciousness" in schizophrenia. In this context, an attractive proposition to understand the biology of consciousness is "the orchestrated object reduction (Orch-OR) theory" which invokes quantum processes in the microtubules of neurons. The Orch-OR model is particularly important for understanding schizophrenia especially due to the shared 'scaffold' of microtubules. The initial sections of this review focus on the compelling evidence to support the view that "schizophrenia is a disorder of consciousness" through critical summary of the studies that have demonstrated self-abnormalities, aberrant time perception as well as dysfunctional intentional binding in this disorder. Subsequently, these findings are linked with 'Orch-OR theory' through the research evidence for aberrant neural oscillations as well as microtubule abnormalities observed in schizophrenia. Further sections emphasize the applicability and translational implications of Orch-OR theory in the context of schizophrenia and elucidate the relevance of quantum biology to understand the origins of this puzzling disorder as "fundamental disturbances in consciousness".

Myopic decisions under negative emotions correlate with altered time perception

Previous studies have obtained inconsistent findings about emotional influence on inter-temporal choice (IC). In the present study, we first examined the effect of temporary emotional priming induced by affective pictures in a trial-to-trial paradigm on IC. The results showed that negative priming resulted in much higher percentages of trials during which smaller-but-sooner reward (SS%) were chosen compared with positive and neutral priming. Next, we attempted to explore the possible mechanisms underlying such emotional effects. When participants performed a time reproduction task, mean reaction times in negative priming condition were significantly shorter than those in the other two emotional contexts, which indicated that negative emotional priming led to overestimation of time. Moreover, such overestimation was negatively correlated with performance in the IC task. In contrast, temporary changes of emotional contexts did not alter performances in a Go/NoGo task (including commission errors and omission errors). In sum, our present findings suggested that myopic decisions under negative emotions were associated with altered time perception but not response inhibition.

Timing Tasks Synchronize Cerebellar and Frontal Ramping Activity and Theta Oscillations: Implications for Cerebellar Stimulation in Diseases of Impaired Cognition

Timing is a fundamental and highly conserved mammalian capability, yet the underlying neural mechanisms are widely debated. Ramping activity of single neurons that gradually increase or decrease activity to encode the passage of time has been speculated to predict a behaviorally relevant temporal event. Cue-evoked low-frequency activity has also been implicated in temporal processing. Ramping activity and low-frequency oscillations occur throughout the brain and could indicate a network-based approach to timing. Temporal processing requires cognitive mechanisms of working memory, attention, and reasoning, which are dysfunctional in neuropsychiatric disease. Therefore, timing tasks could be used to probe cognition in animals with disease phenotypes. The medial frontal cortex and cerebellum are involved in cognition. Cerebellar stimulation has been shown to influence medial frontal activity and improve cognition in schizophrenia. However, the mechanism underlying the efficacy of cerebellar stimulation is unknown. Here, we discuss how timing tasks can be used to probe cerebellar interactions with the frontal cortex and the therapeutic potential of cerebellar stimulation. The goal of this theory and hypothesis manuscript is threefold. First, we will summarize evidence indicating that in addition to motor learning, timing tasks involve cognitive processes that are present within both the cerebellum and medial frontal cortex. Second, we propose methodologies to investigate the connections between these areas in patients with Parkinson's disease, autism, and schizophrenia. Lastly, we hypothesize that cerebellar transcranial stimulation may rescue medial frontal ramping activity, theta oscillations, and timing abnormalities, thereby restoring executive function in diseases of impaired cognition. This hypothesis could inspire the use of timing tasks as biomarkers for neuronal and cognitive abnormalities in neuropsychiatric disease and promote the therapeutic potential of the cerebellum in diseases of impaired cognition.

Time perception networks and cognition in schizophrenia: a review and a proposal

Timing is an essential function for the survival of many living organisms. Despite its significance, it is relatively under-researched, particularly in schizophrenia. We examined neurophysiological, neuropathological, imaging and genetic studies of both healthy subjects and subjects suffering from schizophrenia in relation to time perception as measured by interval timing. We found that the data from studies in healthy populations indicate that time perception may be inter-linked with numerous other cognitive functions and share common brain networks. The same networks are implicated in the pathophysiology of schizophrenia. There is also evidence that several neurotransmitter systems, particularly the dopaminergic D2 system, are involved in interval timing. Patients with schizophrenia have been shown to suffer from a distorted sense of time, which has an impact on their cognitive function and results in both positive and negative symptoms. Therefore, genes involved in interval timing can be considered candidate genes for distorted cognition in schizophrenia. We discuss the hypothesis that time perception dysfunction is a primary cognitive dysfunction in schizophrenia.

The Dawning of Computational Psychoanalysis

In this paper, the author wishes first to highlight, within the general cultural context, some possible elementary computational psychoanalysis formalizations concerning Matte Blanco's bi-logic components through certain very elementary mathematical tools and notions drawn from theoretical physics and algebra. Afterwards, on the basis of recent work of Giampaolo Sasso (1999; 2005; 2011), relying on the crucial crossroad between neurosciences and psychoanalysis, it will be possible to identify some hints for further formalization attempts turned toward a computational psychoanalysis outlook. Lastly, possible interesting relationships with cognitive informatics are also outlined.

The therapeutic potential of the cerebellum in schizophrenia

The cognitive role of the cerebellum is critically tied to its distributed connections throughout the brain. Accumulating evidence from anatomical, structural and functional imaging, and lesion studies advocate a cognitive network involving indirect connections between the cerebellum and non-motor areas in the prefrontal cortex. Cerebellar stimulation dynamically influences activity in several regions of the frontal cortex and effectively improves cognition in schizophrenia. In this manuscript, we summarize current literature on the cingulocerebellar circuit and we introduce a method to interrogate this circuit combining opotogenetics, neuropharmacology, and electrophysiology in awake-behaving animals while minimizing incidental stimulation of neighboring cerebellar nuclei. We propose the novel hypothesis that optogenetic cerebellar stimulation can restore aberrant frontal activity and rescue impaired cognition in schizophrenia. We focus on how a known cognitive region in the frontal cortex, the anterior cingulate, is influenced by the cerebellum. This circuit is of particular interest because it has been confirmed using tracing studies, neuroimaging reveals its role in cognitive tasks, it is conserved from rodents to humans, and diseases such as schizophrenia and autism appear in its aberrancy. Novel tract tracing results presented here provide support for how these two areas communicate. The primary pathway involves a disynaptic connection between the cerebellar dentate nuclei (DN) and the anterior cingulate cortex. Secondarily, the pathway from cerebellar fastigial nuclei (FN) to the ventral tegmental area, which supplies dopamine to the prefrontal cortex, may play a role as schizophrenia characteristically involves dopamine deficiencies. We hope that the hypothesis described here will inspire new therapeutic strategies targeting currently untreatable cognitive impairments in schizophrenia.

The influence of hallucination proneness and social threat on time perception

INTRODUCTION

Individuals with schizophrenia frequently report disturbances in time perception, but the precise nature of such deficits and their relation to specific symptoms of the disorder is unclear. We sought to determine the relationship between hallucination proneness and time perception in healthy individuals, and whether this relationship is moderated by hypervigilance to threat-related stimuli.

METHODS

206 participants completed the Revised Launay-Slade Hallucination Scale (LSHS-R) and a time reproduction task in which, on each trial, participants viewed a face (happy, angry, neutral, or fearful) for between 1 and 5 s and then reproduced the time period with a spacebar press.

RESULTS

High LSHS-R scores were associated with longer time estimates, but only during exposure to angry faces. A factor analysis of LSHS-R scores identified a factor comprising items related to reality monitoring, and this factor was most associated with the longer time estimates.

CONCLUSIONS

During exposure to potential threat in the environment, duration estimates increase with hallucination proneness. The experience of feeling exposed to threat for longer may serve to maintain a state of hypervigilance which has been shown previously to be associated with positive symptoms of schizophrenia.

Isolating the delay component of impulsive choice in adolescent rats

Impulsive choice—the preference for small immediate rewards over larger delayed rewards—has been linked to various psychological conditions ranging from behavioral disorders to addiction. These links highlight the critical need to dissect the various components of this multifaceted behavioral trait. Delay discounting tasks allow researchers to study an important factor of this behavior: how the subjective value of a rewards changes over a delay period. However, existing methods of delay discounting include a confound of different reward sizes within the procedure. Here we present a new approach of using a single constant reward size to assess delay discounting. A complementary approach could hold delay constant and assess the utility of changing quantities of a reward. Isolating these behavioral components can advance our ability to explore the behavioral complexity of impulsive choice. We present in detail the methods for isolating delay, and further capitalize on this method by pairing it with a standard peak interval task to test whether individual variation in delay discounting can be explained by differences in perception of time in male and female adolescent rats. We find that rats that were more precise in discriminating time intervals were also less impulsive in their choice. Our data suggest that differences in timing and delay discounting are not causally related, but instead are more likely influenced by a common factor. Further, the mean-level change in our measure between post-natal day 28 and 42 suggests this test may be capturing a developmental change in this factor. In summary, this new method of isolating individual components of impulsive choice (delay or quantity) can be efficiently applied in either adolescent or adult animal models and may help elucidate the mechanisms underlying impulsivity and its links to psychological disorders.

Serotonergic hallucinogens as translational models relevant to schizophrenia

One of the oldest models of schizophrenia is based on the effects of serotonergic hallucinogens such as mescaline, psilocybin, and (+)-lysergic acid diethylamide (LSD), which act through the serotonin 5-HT(2A) receptor. These compounds produce a 'model psychosis' in normal individuals that resembles at least some of the positive symptoms of schizophrenia. Based on these similarities, and because evidence has emerged that the serotonergic system plays a role in the pathogenesis of schizophrenia in some patients, animal models relevant to schizophrenia have been developed based on hallucinogen effects. Here we review the behavioural effects of hallucinogens in four of those models, the receptor and neurochemical mechanisms for the effects and their translational relevance. Despite the difficulty of modelling hallucinogen effects in nonverbal species, animal models of schizophrenia based on hallucinogens have yielded important insights into the linkage between 5-HT and schizophrenia and have helped to identify receptor targets and interactions that could be exploited in the development of new therapeutic agents.

Experiences of activity and causality in schizophrenia: when predictive deficits lead to a retrospective over-binding

In this paper I discuss an intriguing and relatively little studied symptomatic expression of schizophrenia known as experiences of activity in which patients form the delusion that they can control some external events by the sole means of their mind. I argue that experiences of activity result from patients being prone to aberrantly infer causal relations between unrelated events in a retrospective way owing to widespread predictive deficits. Moreover, I suggest that such deficits may, in addition, lead to an aberrant intentional binding effect i.e., the subjective compression of the temporal interval between an intentional action and its external effects (Haggard, Clark, & Kalogeras, 2002). In particular, it might be that patient's thoughts are bound to the external events they aimed to control producing, arguably, a temporal contiguity between these two components. Such temporal contiguity would reinforce or sustain the (causal) feeling that the patient mind is directly causally efficient.

Impaired Representation of Time in Schizophrenia Is Linked to Positive Symptoms and Cognitive Demand

Time processing critically relies on the mesencephalic dopamine system and striato-prefrontal projections and has thus been suggested to play a key role in schizophrenia. Previous studies have provided evidence for an acceleration of the internal clock in schizophrenia that may be linked to dopaminergic pathology. The present study aimed to assess the relationship between altered time processing in schizophrenia and symptom manifestation in 22 patients and 22 controls. Subjects were required to estimate the time needed for a visual stimulus to complete a horizontal movement towards a target position on trials of varying cognitive demand. It was hypothesized that patients – compared to controls – would be less accurate at estimating the movement time, and that this effect would be modulated by symptom manifestation and task difficulty. In line with the notion of an accelerated internal clock due to dopaminergic dysregulation, particularly patients with severe positive symptoms were expected to underestimate movement time. However, if altered time perception in schizophrenia was better explained in terms of cognitive deficits, patients with severe negative symptoms should be specifically impaired, while generally, task performance should correlate with measures of processing speed and cognitive flexibility. Patients underestimated movement time on more demanding trials, although there was no link to disease-related cognitive dysfunction. Task performance was modulated by symptom manifestation. Impaired estimation of movement time was significantly correlated with PANSS positive symptom scores, with higher positive symptom scores associated with stronger underestimation of movement time. The present data thus support the notion of a deficit in anticipatory and predictive mechanisms in schizophrenia that is modulated both by symptom manifestation and by cognitive demand.

Illness perception, time perception and phenomenology - an extended response to Borrett

Borrett joins other phenomenologists in using phenomenological ideas on temporality to explain how illness affects the individual's experience of time. Unlike others, he attempts to synthesize this use of phenomenology with a biomedical understanding of the relation between time and illness. My paper expands on Borrett's ideas by reviewing current medical scholarship on time and illness perception, including Heidegger's ideas on temporality. The first section considers questions and suggestions emerging from contemporary medicine. After a short review of theories of time perception, I describe and critique how Borrett and others use phenomenological temporality in a medical context. My conclusion suggests how Heideggerian temporality might help with the questions and recommendations emerging within diverse medical fields.

A neuropsychological approach to time estimation

Time estimation, within a range of seconds, involves cognitive functions which depend on multiple brain regions. Here we report on studies investigating the reproduction and production of three durations (5, 14, and 38 seconds) in four groups of patients. The amnesic patient underproduced the length of the long durations because of episodic memory deficit following bilateral medial temporal lesions. Epileptic patients (n = 9) with right medial temporal lobe resections underproduced the three durations because of a distorted representation of time in long-term memory. Traumatic brain injury patients (n = 15) made more variable duration productions and reproductions because of working memory deficits following frontal-lobe dysfunction. Patients with Parkinson's disease (n = 18) overproduced the short duration and underproduced the long duration because of a possible increase in internal clock speed following levodopa treatment, as well as working memory deficits associated with frontal-lobe damage. Further research, in neurological and psychiatric patients, is required to better understand the underlying mechanisms of time estimation.

Temporal processing dysfunction in schizophrenia as measured by time interval discrimination and tempo reproduction tasks

OBJECTIVE

Time perception deficiency has been implicated in schizophrenia; however the exact nature of this remains unclear. The present study was designed with the aim to delineate timing deficits in schizophrenia by examining performance of patients with schizophrenia and healthy volunteers in an interval discrimination test and their accuracy and precision in a pacing reproduction–replication test.

METHODS

The first task involved temporal discrimination of intervals, in which participants (60 patients with schizophrenia and 35 healthy controls) had to judge whether intervals were longer, shorter or equal than a standard interval. The second task required repetitive self-paced tapping to test accuracy and precision in the reproduction and replication of tempos.

RESULTS

Patients were found to differ significantly from the controls in the psychoticism scale of EPQ, the proportion of correct responses in the interval discrimination test and the overall accuracy and precision in the reproduction and replication of sound sequences (p < 0.01). Within the patient group bad responders concerning the ability to discriminate time intervals were associated with increased scores in the Positive and Negative Syndrome Scale (PANSS) and in the Brief Psychiatric Rating Scale (BPRS) in comparison to good responders (p < 0.01). There were no gender effects and there were no differences between subgroups of patients taking different kinds or combinations of drugs.

CONCLUSIONS

Analysis has shown that performance on timing tasks decreased with increasing psychopathology and therefore that timing dysfunctions are directly linked to the severity of the illness. Different temporal dysfunctions can be traced to different psychophysiological origins that can be explained using the Scalar Expectancy Theory (SET).

Accuracy of estimation of time-intervals in psychogeriatric outpatients

BACKGROUND

Accuracy of estimation of time-intervals has received marginal attention in psychogeriatrics. We examined presumed differences in this time measure in participants with dementia (PWD) versus participants without dementia (PWoutD), further subdivided into specific diagnoses and performance subgroups. We also studied its demographic, clinical, and cognitive correlates and predictors. A diagnostic role was hypothesized.

METHODS

Forty-three individuals (27 PWD: 16 dementia of the Alzheimer's type (DAT), 11 vascular dementia (VaD); 16 PWoutD: 10 major depressive disorder (MDD), 6 normal) were interviewed with the Cambridge Examination for Mental Disorders of the Elderly - Revised (CAMDEX-R) that permits the registration of this time measure. Demographic, clinical, and cognitive data were obtained.

RESULTS

Neither absolute accuracy of estimation of duration of interview nor its transformed logarithm were significantly different between PWD and PWoutD, or between DAT and VaD participants. MDD participants performed significantly poorer than normal and did not differ from PWD, and the PWD relatively better performing subgroup. The logarithm of absolute accuracy of estimation correlated with some clinical and cognitive variables. Only a measure of depression and of impaired judgment could significantly predict it.

CONCLUSIONS

The absolute accuracy of estimation of time-intervals did not differ between the major groups and the main diagnoses subgroups. It was associated with a variety of clinical and cognitive measures, and was predicted by the composite constructs of depression and impaired judgment. The diagnostic value of this measure in the psychogeriatric clinic is questionable, and limited to "worried" well individuals.

Time and its representations: at the crossroads between psychoanalysis and neuroscience

Representations of time and time measurements depend on subjective constructs that vary according to changes in our concepts, beliefs and technological advances. Similarly, the past, the future and also the present are subjective representations that depend on each individual's psychic time and biological time. Nonetheless, the construction of these representations is influenced by objective factors (cognitive, physiological and physical) related to neuroscience. Thus, studying representation of time lies at the crossroads between neuroscience and psychoanalysis. Furthermore, these objective factors are supposed to meet criteria of scientific validity, such as reproducibility. However, reproducibility depends on the individual's state that will not be exactly the same later, due precisely to the passage of time. The criteria of scientific validity are therefore only applicable if we place ourselves at time "t". This does not take into account lifespan biological changes. In fact, it is not neuroscience that is opposed to psychoanalysis based on this notion of subjectivity, illustrated by the concept of temporality, but rather the use and interpretation of neuroscience centered on taking snapshots. We can assume that focusing on present time, in particular instantaneity rather than infinity, prevents us from facing our own finitude. Individuals with autism provide us a good illustration of this idea. Through their autistic behaviors, they are totally focused on the present moment and create repeated discontinuity out of continuity. The hypothesis stated here is that children with autism need to create stereotyped discontinuity because discontinuity repeated at regular intervals might have been fundamentally lacking in their physiological development, due to circadian rhythm alterations. In conclusion, the question is raised that both the current use of neuroscience and the current representation of time might be a means of managing our fear of death, giving us the illusion of controlling the uncontrollable, in particular the passage of time.