Numerous studies have reported that time perception and temporal processing are impaired in schizophrenia. In a meta-analytical review, we differentiate between time perception (judgments of time ...intervals) and basic temporal processing (e.g., judgments of temporal order) as well as between effects on accuracy (deviation of estimates from the veridical value) and precision (variability of judgments). In a meta-regression approach, we also included the specific tasks and the different time interval ranges as covariates. We considered 68 publications of the past 65years, and meta-analyzed data from 957 patients with schizophrenia and 1060 healthy control participants. Independent of tasks and interval durations, our results demonstrate that time perception and basic temporal processing are less precise (more variable) in patients (Hedges' g>1.00), whereas effects of schizophrenia on accuracy of time perception are rather small and task-dependent. Our review also shows that several aspects, e.g., potential influences of medication, have not yet been investigated in sufficient detail. In conclusion, the results are in accordance with theoretical assumptions and the notion of a more variable internal clock in patients with schizophrenia, but not with a strong effect of schizophrenia on clock speed. The impairment of temporal precision, however, may also be clock-unspecific as part of a general cognitive deficiency in schizophrenia.
•Schizophrenia strongly impairs precision of time perception and temporal processing.•Effects on the accuracy of time perception are weaker and task-dependent.•Schizophrenic patients tend to overestimate duration in time estimation/production.•Effects do not differ significantly between interval duration ranges.
Abstract Background Depressive patients frequently report to perceive time as going by very slowly. Potential effects of depression on duration judgments have been investigated mostly by means of ...four different time perception tasks: verbal time estimation , time production, time reproduction, and duration discrimination . Ratings of the subjective flow of time have also been obtained. Methods By means of a classical random-effects meta-regression model and a robust variance estimation model, this meta-analysis aims at evaluating the inconsistent results from 16 previous studies on time perception in depression, representing data of 433 depressive patients and 485 healthy control subjects. Results Depressive patients perceive time as going by less quickly relative to control subjects ( g =0.66, p =0.033). However, the analyses showed no significant effects of depression in the four time perception tasks. There was a trend towards inferior time discrimination performance in depression ( g= 0.38, p =0.079). The meta-regression also showed no significant effects of interval duration. Thus, the lack of effects of depression on timing does not depend on interval duration. However, for time production, there was a tendency towards overproduction of short and underproduction of long durations in depressive patients compared to healthy controls. Limitations Several aspects, such as influences of medication and the dopaminergic neurotransmitter system on time perception in depression, have not been investigated in sufficient detail yet and were therefore not addressed by this meta-analysis. Conclusions Depression has medium effects on the subjective flow of time whereas duration judgments basically remain unaffected.
Research on the mental representation of time (‘subjective time’) has provided broad insights into the nature of time perception and temporal processing. As the field comprises different scientific ...disciplines, such as psychology, philosophy, and neuroscience, studies differ with regard to the basic terms and concepts used. For this reason, research on subjective time lacks a coherent conceptual system. We argue that research in the field of subjective time should aim at establishing such a system, i.e., a more standardized terminology, in order to strengthen its theoretical basis and to support an efficient communication of results. Based on key empirical findings and concepts that are commonly (but inconsistently) used in the literature, we argue for a conceptual framework for the study of subjective time that differentiates between three types of mental representations of time: basic temporal processing, time perception in terms of passage, and time perception in terms of duration.
Susceptibility to interference increases with age but there is large inter-individual variability in interference control in older adults due to a number of biological and environmental factors. The ...present study aims at analyzing behavior and ERPs in a Stroop interference task with increasing difficulty in a sample of 246 young, middle-aged and healthy old participants. The old age group was divided into three subgroups based on performance scores. The results show a gradual performance reduction with increasing age and task difficulty. However, old high performers reached a performance level comparable to middle-aged subjects. The contingent negative variation (CNV) reflecting preparation and proactive task control and the target-locked P2/N2 complex associated with retrieval and implementation of S-R mappings during reactive task control were larger in the old high than low performers and similar to middle-aged or even young participants. High performance was limited to executive control tasks, while other cognitive functions were less affected. In addition, high performance was associated with higher level of education, usage of foreign languages and higher IQ. Thus, the performance differences in old age were discussed in the framework of cognitive reserve that constitutes individual differences in neural networks underlying task performance.
•Cognitive aging is associated with compromised interference control and reduced ERP.•Interference control was evaluated in 246 young, middle-aged and old subjects.•Old participants were subdivided in three performance groups.•High old performers showed larger CNV and P2/N2 than other groups.•High proactive and reactive control in older age is associated with higher IQ.
It is common to use counting strategies to produce time intervals accurately. Does counting improve the accuracy (deviation of produced duration from veridical duration) and precision (variability of ...produced duration) of time productions in the range of seconds to minutes? In a series of experiments, we compared chronometric counting to intuitive timing (no counting) and to attentional control (simultaneously performing mental arithmetic). In a field experiment, participants had to produce time intervals of 60-s duration in a classroom setting. Relative to intuitive timing, counting did not improve the accuracy (absolute error) of time productions but led to overproduction of duration (larger constant error). In four laboratory experiments, we tested the effects of counting on time production of 10-, 30-, 45-, 60-, and 90-s intervals. Consistently, counting did not improve the accuracy of time production. The relative overproduction due to counting was replicated for long intervals (60 and 90 s) but disappeared at shorter intervals. However, across all intervals tested, counting had positive effects on the precision of time production. As expected, mental arithmetic impaired accuracy and precision and led to overproduction of duration, indicating that participants followed instructions. Based on the experimental data, the overproduction of longer intervals due to counting can neither be explained in terms of attentional processes nor by means of a word-length effect when counting multisyllabic numbers or when participants switch their pace of counting from mono- to multisyllables.
Working memory (WM) declines with increasing age. The WM capacity is often measured by means of the computerized version of the
-back task. Although the
-back task is widely used in aging research, ...little is known about its construct validity and specific cognitive functions involved in this task. Moreover, to date, no studies analyzed the construct validity as a function of age. To this end, we conducted a study in a sample of
= 533 individuals aged between 20 and 80 years. The sample was divided into three age groups: young (20-40), middle-aged (41-60), and old (61-80 years). A number of psychometric tests was selected that measure attention, memory, and executive control to elucidate the impact of these constructs on
-back performance. A series of correlation analyses was conducted to assess the relationship between
-back performance and specific cognitive functions in each age group separately. The results show a progressive increase in reaction times and a decrease in the proportion of detected targets from young to old subjects. Age-related impairments were also found in all psychometric tests except for the vocabulary choice test measuring crystallized intelligence. Most importantly, correlations yielded different age-related patterns of functions contributing to performance in the
-back task: whereas performance was most related to executive functions in young age, a combination of attentional and executive processes was associated with performance in middle-aged subjects. In contrast, in older age, mainly attentional, verbal memory, and updating and to a lesser extent executive processes seem to play a crucial role in the
-back task, suggesting a shift of processing strategies across the lifespan.
Quantifying the Wollaston Illusion Hecht, Heiko; Siebrand, Stefanie; Thönes, Sven
Perception (London),
05/2020, Letnik:
49, Številka:
5
Journal Article
Recenzirano
In the early 19th century, William H. Wollaston impressed the Royal Society of London with engravings of portraits. He manipulated facial features, such as the nose, and thereby dramatically changed ...the perceived gaze direction, although the eye region with iris and eye socket had remained unaltered. This Wollaston illusion has been replicated numerous times but never with the original stimuli. We took the eyes (pupil and iris) from Wollaston’s most prominent engraving and measured their perceived gaze direction in an analog fashion. We then systematically added facial features (eye socket, eyebrows, nose, skull, and hair). These features had the power to divert perceived gaze direction by up to 20°, which confirms Wollaston’s phenomenal observation. The effect can be thought of as an attractor effect, that is, cues that indicate a slight change in head orientation have the power to divert perceived gaze direction.
With the Covid-19 pandemic, many governments introduced nationwide lockdowns that disrupted people's daily routines and promoted social isolation. We applied a longitudinal online survey to ...investigate the mid-term effects of the mandated restrictions on the perceived passage of time (PPT) and boredom during and after a strict lockdown in Germany. One week after the beginning of the lockdown in March 2020, respondents reported a slower PPT and increased boredom compared to the pre-pandemic level. However, in the course of the lockdown, PPT accelerated and boredom decreased again until August 2020. Then, in October 2020, when incidence rates sharply rose and new restrictions were introduced, we again observed a slight trend toward a slowing of PPT and an increase of boredom. Our data also show that as the pandemic progressed, respondents adjusted their predictions about the pandemic's duration substantially upward. In sum, our findings suggest that respondents adapted to the pandemic situation and anticipated it as the new "normal". Furthermore, we determined perceived boredom and the general emotional state to be predictive of PPT, while depressive symptoms played a minor role.
Our perception of time varies with the degree of cognitive engagement in tasks. The perceived passage of time accelerates while working on demanding tasks, whereas time appears to drag during boring ...situations. Our experiment aimed at investigating whether this relationship is mutual: Can manipulated announcements of elapsed time systematically affect the attentional resources applied to a cognitive task? We measured behavioral performance and the EEG in a whole report working memory paradigm with six items of different colors that each had to be reported after a short delay period. The 32 participants were informed about the current time after each 20 trials, while the clock was running at either 100% (normal), 120% (fast), or 80% (slow) of normal clock speed depending on the experimental block. The mean number of correctly reported colors per trial was significantly increased in the fast as compared to the slow and normal clock conditions. In the EEG, we focused on neural oscillations during working memory encoding and storage. As an electrophysiological correlate of task engagement, frontal theta power during the storage interval was increased in the fast clock condition. Also, the power of frontal theta oscillations predicted the number of correctly reported colors on a single-trial basis. This shows that a covert manipulation of clock speed can lead to an improvement in cognitive performance, presumably mediated by a higher allocation of attentional resources resulting from an adaptation of the subjective passage of time during an experiment.
Substance use disorders (SUDs) are highly prevalent and associated with a substantial public health burden. Although evidence-based interventions exist for treating SUDs, many individuals remain ...symptomatic despite treatment, and relapse is common.Mindfulness-based interventions (MBIs) have been examined for the treatment of SUDs, but available evidence is mixed.
To determine the effects of MBIs for SUDs in terms of substance use outcomes, craving and adverse events compared to standard care, further psychotherapeutic, psychosocial or pharmacological interventions, or instructions, waiting list and no treatment.
We searched the following databases up to April 2021: Cochrane Drugs and Alcohol Specialised Register, CENTRAL, PubMed, Embase, Web of Science, CINAHL and PsycINFO. We searched two trial registries and checked the reference lists of included studies for relevant randomized controlled trials (RCTs).
RCTs testing a MBI versus no treatment or another treatment in individuals with SUDs. SUDs included alcohol and/or drug use disorders but excluded tobacco use disorders. MBIs were defined as interventions including training in mindfulness meditation with repeated meditation practice. Studies in which SUDs were formally diagnosed as well as those merely demonstrating elevated SUD risk were eligible.
We used standard methodological procedures expected by Cochrane.
Forty RCTs met our inclusion criteria, with 35 RCTs involving 2825 participants eligible for meta-analysis. All studies were at high risk of performance bias and most were at high risk of detection bias. Mindfulness-based interventions (MBIs) versus no treatment Twenty-four RCTs included a comparison between MBI and no treatment. The evidence was uncertain about the effects of MBIs relative to no treatment on all primary outcomes: continuous abstinence rate (post: risk ratio (RR) = 0.96, 95% CI 0.44 to 2.14, 1 RCT, 112 participants; follow-up: RR = 1.04, 95% CI 0.54 to 2.01, 1 RCT, 112 participants); percentage of days with substance use (post-treatment: standardized mean difference (SMD) = 0.05, 95% CI -0.37 to 0.47, 4 RCTs, 248 participants; follow-up: SMD = 0.21, 95% CI -0.12 to 0.54, 3 RCTs, 167 participants); and consumed amount (post-treatment: SMD = 0.10, 95% CI -0.31 to 0.52, 3 RCTs, 221 participants; follow-up: SMD = 0.33, 95% CI 0.00 to 0.66, 2 RCTs, 142 participants). Evidence was uncertain for craving intensity and serious adverse events. Analysis of treatment acceptability indicated MBIs result in little to no increase in study attrition relative to no treatment (RR = 1.04, 95% CI 0.77 to 1.40, 21 RCTs, 1087 participants). Certainty of evidence for all other outcomes was very low due to imprecision, risk of bias, and/or inconsistency. Data were unavailable to evaluate adverse events. Mindfulness-based interventions (MBIs) versus other treatments (standard of care, cognitive behavioral therapy, psychoeducation, support group, physical exercise, medication) Nineteen RCTs included a comparison between MBI and another treatment. The evidence was very uncertain about the effects of MBIs relative to other treatments on continuous abstinence rate at post-treatment (RR = 0.80, 95% CI 0.45 to 1.44, 1 RCT, 286 participants) and follow-up (RR = 0.57, 95% CI 0.28 to 1.16, 1 RCT, 286 participants), and on consumed amount at post-treatment (SMD = -0.42, 95% CI -1.23 to 0.39, 1 RCT, 25 participants) due to imprecision and risk of bias. The evidence suggests that MBIs reduce percentage of days with substance use slightly relative to other treatments at post-treatment (SMD = -0.21, 95% CI -0.45 to 0.03, 5 RCTs, 523 participants) and follow-up (SMD = -0.39, 95% CI -0.96 to 0.17, 3 RCTs, 409 participants). The evidence was very uncertain about the effects of MBIs relative to other treatments on craving intensity due to imprecision and inconsistency. Analysis of treatment acceptability indicated MBIs result in little to no increase in attrition relative to other treatments (RR = 1.06, 95% CI 0.89 to 1.26, 14 RCTs, 1531 participants). Data were unavailable to evaluate adverse events.
In comparison with no treatment, the evidence is uncertain regarding the impact of MBIs on SUD-related outcomes. MBIs result in little to no higher attrition than no treatment. In comparison with other treatments, MBIs may slightly reduce days with substance use at post-treatment and follow-up (4 to 10 months). The evidence is uncertain regarding the impact of MBIs relative to other treatments on abstinence, consumed substance amount, or craving. MBIs result in little to no higher attrition than other treatments. Few studies reported adverse events.
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