Time-Based and Event-Based Prospective Memory in Mild Cognitive Impairment and Alzheimer's Disease Patients: A Systematic Review and Meta-analysis.

Prospective memory (PM) is the ability to remember to perform planned actions in a future moment and it is of fundamental importance for an independent and autonomous lifestyle from development to late adulthood. Deficits in episodic memory and executive functions, which are involved in PM are characteristic features of mild cognitive impairment (MCI) and Alzheimer's disease (AD). Considering that the number of older adults is drastically increasing over the next decades, it is of great interest to understand how PM decline in healthy older adults and patients with different degree of cognitive decline. The present meta-analysis included 46 studies investigating PM performance in AD patients (17 studies) and people with MCI (24 studies); 5 studies included both clinical conditions in the same article. The 46 studies contributed a total of 63 independent samples and 129 effect sizes from 4668 participants (2115 patients and 2553 controls). Unlike previous reviews of the literature, our results with a larger and updated sample of studies confirmed lower PM abilities in AD compared to MCI and controls, although we did not observe conclusive differences between event-based and time-based PM in patients. Surprisingly, PM deficits shown by MCI and AD patients have decreased across years, in parallel to a reduction of the evidence of publication bias and an increase in the number of observations per task. We propose the use of more reliable research designs as one plausible explanation for the reduction of PM impairments.

The effect of emotion intensity on time perception: a study with transcranial random noise stimulation.

Emotional facial expressions provide cues for social interactions and emotional events can distort our sense of time. The present study investigates the effect of facial emotional stimuli of anger and sadness on time perception. Moreover, to investigate the causal role of the orbitofrontal cortex (OFC) in emotional recognition, we employed transcranial random noise stimulation (tRNS) over OFC and tested the effect on participants' emotional recognition as well as on time processing. Participants performed a timing task in which they were asked to categorize as "short" or "long" temporal intervals marked by images of people expressing anger, sad or neutral emotional facial expressions. In addition, they were asked to judge if the image presented was of a person expressing anger or sadness. The visual stimuli were facial emotional stimuli indicating anger or sadness with different degrees of intensity at high (80%), medium (60%) and low (40%) intensity, along with neutral emotional face stimuli. In the emotional recognition task, results showed that participants were faster and more accurate when emotional intensity was higher. Moreover, tRNS over OFC interfered with emotion recognition, which is in line with its proposed role in emotion recognition. In the timing task, participants overestimated the duration of angry facial expressions, although neither emotional intensity not OFC stimulation significantly modulated this effect. Conversely, as the emotional intensity increased, participants exhibited a greater tendency to overestimate the duration of sad faces in the sham condition. However, this tendency disappeared with tRNS. Taken together, our results are partially consistent with previous findings showing an overestimation effect of emotionally arousing stimuli, revealing the involvement of OFC in emotional distortions of time, which needs further investigation.

Psychophysiological stress influences temporal accuracy.

Distortions of duration perception are often observed in response to highly arousing stimuli, but the exact mechanisms that evoke these variations are still under debate. Here, we investigate the effect of induced physiological arousal on time perception. Thirty-eight university students (22.89 ± 2.5; 28 females) were tested with spontaneous finger-tapping tasks and a time bisection task (with stimuli between 300 and 900 ms). Before the time bisection task, half of the participants (STRESS group) performed a stress-inducing task, i.e., the Paced Auditory Serial Addition Test (PASAT), whereas the other participants (CONTROL group) performed a control task, the Paced Auditory Number Reading Task (PANRAT). The PASAT induced a greater heart rate, but not electrodermal, increase, as well as a more unpleasant and arousing state compared to the PANRAT. Moreover, although the two groups presented a similar performance at the finger-tapping tasks, participants in the STRESS group showed better temporal performance at the time bisection task (i.e., lower constant error) than the controls. These results indicate that psychophysiological stress may alter the subsequent perception of time.

Subjective experience of time in dementia with Lewy bodies during COVID-19 lockdown.

Dementia with Lewy bodies (DLB) is a neurodegenerative disease characterized by cognitive, behavioral and motor symptoms and has a more challenging clinical management and poorer prognosis compared to other forms of dementia. The experience of lockdown leads to negative psychological outcomes for fragile people such as elderly with dementia, particularly for DLB, causing a worsening of cognitive and neuropsychiatric symptoms. Since an individual's feeling of time passage is strongly related to their cognitive and emotional state, it is conceivable to expect alterations of this construct in people with DLB during such a difficult period. We therefore assessed the subjective experience of the passage of time for present and past time intervals (Subjective Time Questionnaire, STQ) during the lockdown due to coronavirus disease (COVID-19) in 22 patients with DLB (17 of which were re-tested in a post-lockdown period) and compared their experience with that of 14 caregivers with similar age. Patients showed a significantly slower perception of present and past time spent under lockdown restrictions. We argue that these alterations might be related to the distinctive features of DLB and their exacerbation recorded by the patients' caregivers during the period of lockdown, though our results show that the patients' experience of time passage in a post-lockdown period remained similarly slow. Overall, we show an impairment of the subjective perception of time passage in DLB tested during the COVID-19 lockdown. Supplementary Information: The online version contains supplementary material available at 10.1007/s12144-021-01811-7.

Maintaining social support while social distancing: The longitudinal benefit of basic psychological needs for symptoms of anxiety during the COVID-19 outbreak.

Although social distancing measures could be potentially perceived as thwarting conditions for basic psychological needs and thus causing psychological distress, off(on)line social support could compensate for this frustration by providing psychological proximity. Using self-determination theory, in this study, we aimed (a) to evaluate the change of perception in need satisfaction over time (before and during home-confinement and after a month of lockdown) and (b) to test the short-term longitudinal association between off(on)line social support, basic needs, and anxiety during social distancing measures in response to the COVID-19 outbreak. During the lockdown period decreed by Italy in March 2019 to confront the COVID-19 emergency, 1344 participants completed an online questionnaire and 131 participants completed a follow-up after 1 month. Results showed a decrease in need satisfaction during home confinement and a further reduction after a month of lockdown. Cross-sectional path analysis showed that both online and offline social support were associated with higher need satisfaction, which, in turn, was related to a lower level of anxiety. Longitudinal paths also confirmed the association between need satisfaction and anxiety. Collectively, these results suggest that maintaining psychological proximity despite social distancing measures may provide important avenues for reducing negative outcomes during forced home confinement.

Sleep and Psychological Difficulties in Italian School-Age Children During COVID-19 Lockdown.

OBJECTIVE: On March 10, 2020, the Italian Government ordered a national lockdown to limit the viral transmission of coronavirus disease 2019 infections. This study investigated how these restrictive measures have impacted sleep quality, timing, and psychological difficulties in school-age children and their mothers during the lockdown. METHODS: In an online survey, 299 mothers reported their sleep habits, experience of time, and psychological difficulties as well as those of their children (6-10 years old) during and, retrospectively, before the lockdown. RESULTS: During the lockdown, children showed a marked delay in sleep timing-that is, later bedtime and rise time-and a mild worsening in sleep quality. They were less prone to respect daily routines or to keep track of the passage of time. They showed increased emotional, conduct, and hyperactive symptoms, and the increase in these psychological difficulties was predicted by the change in sleep quality, boredom, and mothers' psychological difficulties. In addition, mothers showed a delayed sleep timing and worsening of sleep quality during the lockdown, in varying degrees depending on their working conditions. Mothers who kept working regularly outside their homes during lockdown reported more regular sleep patterns, whereas mothers who stopped working showed more emotional symptoms and relevant changes in their perception of time. CONCLUSIONS: Overall, given the evidence of the adverse behavioral and psychological impact of home confinement and social restrictions, effective measures needed to be in place to mitigate long-term effects on children and their mothers, especially those who have had to stop working during lockdown.

Do I dislike what you dislike? Investigating the effect of disgust on time processing.

Time perception can be distorted by emotional stimuli. The present study aims to investigate the effect of disgust on time perception in young adults. Here, we report two experiments in which a time bisection task was used with intervals lasting 400 ms (short standard) to 1600 ms (long standard). In Experiment 1, temporal intervals were marked by neutral images or images from food (rotten, joyful), and facial (disgust, happy) categories. In Experiment 2, disgust-eliciting and neutral stimuli belonging to seven different domains were used: faces, food, animals, body products, injury/infections, death and hygiene. Results showed temporal overestimations when, compared to neutral conditions, disgusted faces (Experiments 1 and 2) and disgusting death and hygiene stimuli (Experiment 2) were used, and a temporal underestimation when images of rotten food (Experiment 1) were used. Results are discussed in terms of arousal-based and attention-based processes and showed that the degree of the emotional component influences time perception.

Probing the effect of the expected-speed violation illusion.

Motion perception is complex for the brain to process, involving interacting computations of distance, time, and speed. These computations can be biased by the context and the features of the perceived moving object, giving rise to several types of motion illusions. Recent research has shown that, in addition to object features and context, lifelong priors can bias attributes of perception. In the present work, we investigated if such long acquired expectations can bias speed perception. Using a two-interval forced-choice (2-IFC) task, we asked 160 participants in different experiments to judge which of two vehicles, one archetypically fast (e.g. a motorbike), and one comparatively slower (e.g. a bike), was faster. By varying the objective speeds of the two-vehicle types, and measuring the participants' point of subjective equality, we observed a consistent bias in participants' speed perception. Counterintuitively, in the first three experiments the speed of an archetypically slow vehicle had to be decreased relative to that of an archetypically fast vehicle, for the two to be judged as the same. Similarly, in the next three experiments, an archetypically fast vehicle's speed had to be increased relative to an archetypically slow vehicle's speed, for the two to be perceived as equal. Four additional control experiments replicated our results. We define this newly found bias as the expected-speed violation illusion (ESVI). We believe the ESVI as conceptually very similar to the size-weight illusion, and discuss it within the Bayesian framework of human perception.

The interplay between mothers' and children behavioral and psychological factors during COVID-19: an Italian study.

Italy has been the first nation outside of Asia to face the COVID-19 outbreak. To limit viral transmission of infection, by March 10th, 2020, the Italian Government has ordered a national lockdown, which established home confinement, home (smart) working, and temporary closure of non-essential businesses and schools. The present study investigated how these restrictive measures impacted mothers and their pre-school children's behavioral habits (i.e., sleep timing and quality, subjective time experience) and psychological well-being (i.e., emotion regulation, self-regulation capacity). An online survey was administered to 245 mothers with pre-school children (from 2 to 5 years). Mothers were asked to fill the survey thinking both on their habits, behaviors, and emotions and on those of their children during the quarantine, and retrospectively, before the national lockdown (i.e., in late February). A general worsening of sleep quality and distortion of time experience in both mothers and children, as well as increasing emotional symptoms and self-regulation difficulties in children, was observed. Moreover, even when the interplay between the behavioral and psychological factors was investigated, the factor that seems to mostly impact both mothers' and children's psychological well-being was their sleep quality. Overall, central institutions urgently need to implementing special programs for families, including not only psychological support to sustain families with working parents and ameliorating children's management.

Changes in sleep pattern, sense of time and digital media use during COVID-19 lockdown in Italy.

Italy is one of the major COVID-19 hotspots. To reduce the spread of the infections and the pressure on Italian healthcare systems, since March 10, 2020, Italy has been under a total lockdown, forcing people into home confinement. Here we present data from 1,310 people living in the Italian territory (Mage  = 23.91 ± 3.60 years, 880 females, 501 workers, 809 university students), who completed an online survey from March 24 to March 28, 2020. In the survey, we asked participants to think about their use of digital media before going to bed, their sleep pattern and their subjective experience of time in the previous week (March 17-23, which was the second week of the lockdown) and up to the first week of February (February 3-10, before any restriction in any Italian area). During the lockdown, people increased the usage of digital media near bedtime, but this change did not affect sleep habits. Nevertheless, during home confinement, sleep timing markedly changed, with people going to bed and waking up later, and spending more time in bed, but, paradoxically, also reporting a lower sleep quality. The increase in sleep difficulties was stronger for people with a higher level of depression, anxiety and stress symptomatology, and associated with the feeling of elongation of time. Considering that the lockdown is likely to continue for weeks, research data are urgently needed to support decision making, to build public awareness and to provide timely and supportive psychosocial interventions.

The role of time-monitoring behaviour in time-based prospective memory performance in younger and older adults.

Time-based prospective memory (TB-PM) is the ability to remember to perform an action at a specific moment in the future. Accurate TB-PM performance requires several cognitive processes that are known to decline in normal ageing. This study aimed to examine associations between TB-PM performance and executive functions and time perception in younger and older adults. TB-PM was assessed with the Virtual Week paradigm. Using a within-subjects experimental manipulation, participants performed TB-PM tasks both when a clock was in constant view and when it was hidden behind a button. Results showed that younger adults performed significantly better than older adults on all TB-PM task types, and checked the clock more often, and more strategically. Clock availability improved TB-PM performance in all participants. Correlational analyses showed that TB-PM accuracy was positively related to clock-checking frequency but unrelated to time perception. Relationships between executive functions and TB-PM differed across age groups as well as TB-PM task types. The findings suggest that different cognitive processes are required for different types of TB-PM tasks and in different ages. These results highlight the importance of considering TB-PM task parameters when investigating the role of cognitive processes in PM performance and their contribution to age-related PM decline.

Time perception in childhood absence epilepsy: Findings from a pilot study.

OBJECTIVES: With this explorative study, we aimed to examine time perception in children with childhood absence epilepsy (CAE) and to compare those children with a matched control group. The study also investigated the association between the neuropsychological performance of the group with CAE and time judgment. We hypothesize that children with CAE could fail in time perception and that this may be because of a common underlying substrate with executive impairments. METHODS: Thirteen children with CAE, aged 6-13 years, and 17 healthy children were recruited. All children performed the time bisection task; the children with CAE also performed a cognitive and neuropsychological assessment. We performed a univariate analysis using each parameter of the bisection task (bisection point [BP]) and Weber ratio (WR) as dependent variables, the group (patients vs. controls) as fixed factors and age at evaluation and vocabulary scores as covariates. In the subgroup of patients, we correlated bisection task parameters with neuropsychological tests using a nonparametric partial correlation; the analysis has corrected for age at evaluation. RESULTS: The BP and WR measures differed between controls and patients with CAE. In the subgroup of patients also performing a neuropsychological assessment, we found a correlation between the WR measure and performance on the inhibition test (r = -0.641, p = .025), coding test (r = -0.815, p = .014), and Trail Making Test B (TMT B) (r = 0.72, p = .042). CONCLUSIONS: We found an altered time perception in a pilot study of a small group of children with CAE. A neurophysiological mechanism underlying CAE seems to influence cognitive and behavioral deficits and time sensibility.

Difficulties of children with symptoms of attention-deficit/hyperactivity disorder in processing temporal information concerning everyday life events.

It has been hypothesized that children with attention-deficit/hyperactivity disorder (ADHD) present difficulties in processing time durations. However, so far evidence on this difficulty and its related mechanisms has been unclear and collected only with rating scales or laboratory experimental tasks. The current study examined whether this difficulty can be seen in children carrying out everyday actions (e.g., telephone calls, cooking activities) and to what extent it is influenced by working memory (WM) abilities. In total, 182 children aged 7 to 10 years were included in the study: 91 children with ADHD symptoms and 91 typically developing (TD) children matched for gender and other characteristics. We administered sequence reordering, time reproduction, and duration comparison tasks, and as stimuli we used six movies lasting 10 to 60 s showing three women completing six different actions. We also collected measures of verbal and visuospatial WM tests (digit span and Corsi task). Children with ADHD symptoms tended to underestimate the long durations and were less accurate than TD children in remembering the exact order of events and in comparing the duration of two different events. These difficulties appeared to be related to WM abilities.

Improving prospective memory performance with future event simulation in traumatic brain injury patients.

OBJECTIVE: Previous studies have shown that traumatic brain injury (TBI) patients have difficulties with prospective memory (PM). Considering that PM is closely linked to independent living it is of primary interest to develop strategies that can improve PM performance in TBI patients. METHOD: This study employed Virtual Week task as a measure of PM, and we included future event simulation to boost PM performance. Study 1 evaluated the efficacy of the strategy and investigated possible practice effects. Twenty-four healthy participants performed Virtual Week in a no strategy condition, and 24 healthy participants performed it in a mixed condition (no strategy - future event simulation). In Study 2, 18 TBI patients completed the mixed condition of Virtual Week and were compared with the 24 healthy controls who undertook the mixed condition of Virtual Week in Study 1. All participants also completed a neuropsychological evaluation to characterize the groups on level of cognitive functioning. RESULTS: Study 1 showed that participants in the future event simulation condition outperformed participants in the no strategy condition, and these results were not attributable to practice effects. Results of Study 2 showed that TBI patients performed PM tasks less accurately than controls, but that future event simulation can substantially reduce TBI-related deficits in PM performance. The future event simulation strategy also improved the controls' PM performance. CONCLUSIONS: These studies showed the value of future event simulation strategy in improving PM performance in healthy participants as well as in TBI patients. PRACTITIONER POINTS: TBI patients performed PM tasks less accurately than controls, confirming prospective memory impairment in these patients. Participants in the future event simulation condition out-performed participants in the no strategy condition. Future event simulation can substantially reduce TBI-related deficits in PM performance. Future event simulation strategy also improved the controls' PM performance.

Virtual Week: Translation and adaptation for the Italian population.

The present study adapted a computerised version of Virtual Week, a laboratory measure of prospective memory designed to simulate the kinds of prospective memory tasks encountered in daily life. In particular, this study aimed to translate and adapt Virtual Week for an Italian population. We collected data from 198 subjects that were divided into five groups based on age: young-young adults (20-29 years, n = 47), young adults (30-45 years, n = 32), middle-age adults (46-59 years, n = 32), young-old adults (60-69 years, n = 41), and old-old adults (70 years plus, n = 39). Results showed that PM performance was best in younger adults, relatively stable over middle adulthood and then decreased with age, with older adults performing the least accurately, in particular for the time-based condition. Results also demonstrated good reliability estimates across a range of ages and task types. Thus, the adaptation of Virtual Week into Italian appears to be a reliable measure of prospective memory for the Italian population.

Effects of Emotional Facial Expression on Time Perception in Patients with Parkinson's Disease.

Previous studies have demonstrated that emotional facial expressions alter temporal judgments. Moreover, while some studies conducted with Parkinson's disease (PD) patients suggest dysfunction in the recognition of emotional facial expression, others have shown a dysfunction in time perception. In the present study, we investigate the magnitude of temporal distortions caused by the presentation of emotional facial expressions (anger, shame, and neutral) in PD patients and controls. Twenty-five older adults with PD and 17 healthy older adults took part in the present study. PD patients were divided into two sub-groups, with and without mild cognitive impairment (MCI), based on their neuropsychological performance. Participants were tested with a time bisection task with standard intervals lasting 400 ms and 1600 ms. The effect of facial emotional stimuli on time perception was evident in all participants, yet the effect was greater for PD-MCI patients. Furthermore, PD-MCI patients were more likely to underestimate long and overestimate short temporal intervals than PD-non-MCI patients and controls. Temporal impairment in PD-MCI patients seem to be mainly caused by a memory dysfunction. (JINS, 2016, 22, 890-899).

Prospective memory performance in traumatic brain injury patients: a study of implementation intentions.

Traumatic brain injury (TBI) patients often present with prospective memory (PM) dysfunction. Forgetting to complete tasks may result in a loss of independence, limited employment prospects and anxiety, therefore, it is important to develop programs to improve PM performance in TBI patients. A strategy which may improve PM performance is implementation intentions. It involves making explicit plans specifying when, where and how one will perform a task in the future. In the present study, a group of 36 TBI patients and a group of 34 controls performed Virtual Week using either implementation intentions or no strategy. The results showed that the PM performance of TBI patients was less accurate than controls, in particular when the PM cue was time-based. No effect of implementation intentions was observed for TBI patients, however, controls improved their PM performance when the task was time-based. The findings suggest that strategies to improve PM in this clinical group are likely to be more complex than those that benefit healthy adults and may involve targeting phases of the PM process other than, or in addition to, the intention formation phase.

Heart rate variability helps tracking time more accurately.

Adequate temporal abilities are crucial for adaptive behavior. In time processing, variations in the rate of pulses' emission by the pacemaker are often reported to be an important cause of temporal errors. These variations are often associated with physiological changes, and recently it has also been proposed that physiological changes may not just vary the pulses' emission, but they can work as a timekeeper themselves. In the present study we further explore the relationship between temporal abilities with autonomic activity and interoceptive awareness in a group of thirty healthy young adults (mean age 24.18 years; SD=2.1). Using electrocardiogram, impedance cardiography and skin conductance measures, we assessed the relationship between the autonomic profile at rest and temporal abilities in two temporal tasks (time bisection and finger tapping tasks). Results showed that heart rate variability affects time perception. We observed that increased heart rate variability (HRV) was associated with higher temporal accuracy. More specifically, we found that higher vagal control was associated with lower error in producing 1-s tempo, whereas higher overall HRV was related with lower error (measured by the constant error) in the time bisection task. Our results support the idea that bodily signals may shape our perception of time.

Test-retest consistency of Virtual Week: A task to investigate prospective memory.

The present study reports test-retest consistency of Virtual Week, a well-known measure of prospective memory (PM) performance. PM is the memory associated with carrying out actions at a specific moment in the future. Patients with neurological disorders as well as healthy older adults often report PM dysfunctions that affect their everyday living. In Experiment 1, 19 younger and 20 older adults undertook the standard version of Virtual Week (version A). Older adults showed lower performance compared to younger participants. However, the discrepancy between groups was eliminated at retest. Experiment 2 was conducted to investigate if remembering of PM content determined the improvement observed in older adults at retest in Experiment 1. To this end we created a parallel version (version B) in which we varied the content of the PM actions. Fifty older adults were assigned to one of the two experimental conditions: Version A at test and version B at retest or vice versa (25 participants in each condition). Results showed no group differences in PM performance between version A and version B; moreover, no effect of test-retest was found. The study confirmed that Virtual Week is a reliable measure of PM performance and also provided a new parallel version that can be useful in clinical setting.

Monitoring behaviour in a time-based prospective memory task: the involvement of executive functions and time perception.

This study investigated time-based prospective memory (PM) performance in 76 younger and 76 older adults with a time-monitoring task in which participants were required to press a designated key every 5 minutes while watching a movie. Participants were assigned to two conditions, free and fixed monitoring. In free monitoring participants could check a clock when they wanted, but in fixed monitoring they were restricted a maximum of six times every 5 minutes. We also investigated the involvement of time perception, inhibition, and updating in time-based PM performance. We hypothesised that participants with inefficiencies in those three cognitive functions would have less strategic monitoring behaviour and would also be less accurate at the target time. In the free-monitoring condition older adults checked the clock more frequently than younger participants, but presented with a similar pattern of monitoring behaviour and increased their frequency of clock checking closer to the target time. In the fixed-monitoring condition younger participants checked the clock more frequently than older adults and showed a strategic pattern of monitoring. Older adults did not show strategic use of clock checking and their monitoring function remained unchanged. Differences in PM accuracy and monitoring behaviour are discussed according to different involvement of cognitive abilities.