Characteristics of the time processing of adults' strongest sustained attentional bias toward neutral infant faces

Previous studies have shown that adults exhibit the strongest attentional bias toward neutral infant faces when viewing faces with different expressions at different attentional processing stages due to different stimulus presentation times. However, it is not clear how the characteristics of the temporal processing associated with the strongest effect change over time. Thus, we combined a free-viewing task with eye-tracking technology to measure adults' attentional bias toward infant and adult faces with happy, neutral, and sad expressions of the same face. The results of the analysis of the total time course indicated that the strongest effect occurred during the strategic processing stage. However, the results of the analysis of the split time course revealed that sad infant faces first elicited adults' attentional bias at 0 to 500 ms, whereas the strongest effect of attentional bias toward neutral infant faces was observed at 1000 to 3000 ms, peaking at 1500 to 2000 ms. In addition, women and men had no differences in their responses to different expressions. In summary, this study provides further evidence that adults' attentional bias toward infant faces across stages of attention processing is modulated by expressions. Specifically, during automatic processing adults' attentional bias was directed toward sad infant faces, followed by a shift to the processing of neutral infant faces during strategic processing, which ultimately resulted in the strongest effect. These findings highlight that this strongest effect is dynamic and associated with a specific time window in the strategic process.

The neural basis of somatosensory temporal discrimination threshold as a paradigm for time processing in the sub-second range: An updated review

BACKGROUND AND OBJECTIVE

The temporal aspect of somesthesia is a feature of any somatosensory process and a pre-requisite for the elaboration of proper behavior. Time processing in the milliseconds range is crucial for most of behaviors in everyday life. The somatosensory temporal discrimination threshold (STDT) is the ability to perceive two successive stimuli as separate in time, and deals with time processing in this temporal range. Herein, we focus on the physiology of STDT, on a background of the anatomophysiology of somesthesia and the neurobiological substrates of timing.

METHODS

A review of the literature through PubMed & Cochrane databases until March 2023 was performed with inclusion and exclusion criteria following PRISMA recommendations.

RESULTS

1151 abstracts were identified. 4 duplicate records were discarded before screening. 957 abstracts were excluded because of redundancy, less relevant content or not English-written. 4 were added after revision. Eventually, 194 articles were included.

CONCLUSIONS

STDT encoding relies on intracortical inhibitory S1 function and is modulated by the basal ganglia-thalamic-cortical interplay through circuits involving the nigrostriatal dopaminergic pathway and probably the superior colliculus.

Me, myself and you: How self-consciousness influences time perception

Several investigations have shown that the processing of self-relevant information differs from processing objective information. The present study aimed to investigate the effect of social stimuli on subjective time processing. Here, social stimuli are images of an unknown male and female person and an image of participants' self. Forty university students were tested with a time reproduction task in which they were asked to reproduce the duration of the stimulus previously presented. Images of others or themselves were used to mark the temporal intervals. Participants also performed questionnaires to evaluate the level of anxiety and depression as well as self-consciousness. A generalised linear mixed-effects model approach was adopted. Results showed that male participants with higher Private Self-Consciousness scores showed higher time perception accuracy than females. Also, female participants reported higher scores for the Public Self-Consciousness subscale than male participants. The findings are discussed in terms of social context models of how attention is solicited and arousal is generated by social stimuli, highlighting the effect of social context on subjective perception of time.

Temporal features of concepts are grounded in time perception neural networks: An EEG study

Experimental evidence suggests that modality-specific concept features such as action, motion, and sound partially rely on corresponding action/perception neural networks in the human brain.Little is known, however, about time-related features of concepts. We examined whether temporal features of concepts recruit networks that subserve time perception in the brain in an EEG study using event and object nouns. Results showed significantly larger ERPs for event duration vs object size judgments over right parietal electrodes, a region associated with temporal processing. Additionally, alpha/beta (10-15 Hz) neural oscillation showed a stronger desynchronization for event duration compared to object size in the right parietal electrodes. This difference was not seen in control tasks comparing event vs object valence, suggesting that it is not likely to reflect a general difference between event and object nouns. These results indicate that temporal features of words may be subserved by time perception circuits in the human brain.

The striatum in time production: The model of Huntington's disease in longitudinal study

The unified model of time processing suggests that the striatum is a central structure involved in all tasks that require the processing of temporal durations. Patients with Huntington's disease exhibit striatal degeneration and a deficit in time perception in interval timing tasks (i.e. for duration ranging from hundreds of milliseconds to minutes), but whether this deficit extends to time production remains unclear. In this study, we investigated whether symptomatic patients (HD, N = 101) or presymptomatic gene carriers (Pre-HD, N = 31) of Huntington's disease had a deficit in time production for durations between 4 and 10 s compared to healthy controls and whether this deficit developed over a year for patients. We found a clear deficit in temporal production for HD patients, whereas Pre-HD performed similarly to Controls. For HD patients and Pre-HD participants, task performance was correlated with grey matter volume in the amygdala and caudate, bilaterally. These results confirm that the striatum is involved in interval timing not only in perception but also in production, in accordance with the unified model of time processing. Furthermore, exploratory factor analyses on our data indicated that temporal production was associated with clinical assessments of psychomotor and executive functions. Finally, when retested twelve months later, the deficit of HD patients remained stable, although striatal degeneration was more pronounced. Thus, the simple, short and language-independent temporal production task may be a useful clinical tool to detect striatal degeneration in patients in early stages of Huntington's disease. However, its usefulness to detect presymptomatic stages or for monitoring the evolution of HD over a year seems limited.

A momentum effect in temporal arithmetic

The mental representation of brief temporal durations, when assessed in standard laboratory conditions, is highly accurate. Here we show that adding or subtracting temporal durations systematically results in strong and opposite biases, namely over-estimation for addition and under-estimation for subtraction. The difference with respect to a baseline temporal reproduction task changed across durations in an operation-specific way and survived correcting for the effect due to operation sign alone, indexing a reliable signature of arithmetic processing on time representation. A second experiment replicated these findings with a different set of stimuli. This novel behavioral marker conceptually mirrors in the time domain the representational momentum found with motion, whereby the estimated spatial position of a visual target is displaced in the direction of motion itself. This momentum effect in temporal arithmetic suggests a striking analogy between time processing and visuospatial processing, which might index the presence of common computational principles.

Frontotemporal dementia patients exhibit deficits in predictive saccades

Prediction and time estimation are all but required for motor function in everyday life. In the context of eye movements, for instance, they allow predictive saccades and eye re-acceleration in anticipation of a target re-appearance. While the neural pathways involved are not fully understood, it is known that the frontal lobe plays an important role. As such, neurological disorders that affect it, such as frontotemporal (FTD) dementia, are likely to induce deficits in such movements. In this work, we study the performances of frontotemporal dementia patients in an oculomotor task designed to elicit predictive saccades at different rates, and compare them to young and older adults. Clear deficits in the production of predictive saccades were found in patients, in particular when the time between saccades was short (~500 ms). Furthermore, one asymptomatic C9ORF72 mutation bearer showed patterns of oculomotor behavior similar to FTD patients. He exhibited FTD symptoms within 3 years post-measure, suggesting that an impairment of oculomotor function could be an early clinical sign. Taken together, these results argue in favor of a role of the frontal lobe in predictive movements timing over short timescales, and suggest that predictive saccades in FTD patients warrant further investigation to fully assess their potential as a diagnostic aid.

Time perception is not for the faint-hearted? Physiological arousal does not influence duration categorisation

Distortions of duration perception provoked by emotion-induced arousal changes are explained by modifications of an internal clock pace. Yet, uncertainty still abounds regarding whether changes of arousal induced by physical exercise yield such temporal distortions. Here, we report two experiments aiming to test separately the impact of, on the one hand, a physical induction of arousal and, on the other hand, a task delay on duration categorisation. In Experiment 1, participants performed a duration categorisation task before and after heart-rate manipulation (increase, decrease, or no change). Duration overestimation was observed after HR manipulation, irrespective of the condition, implying that changes of physiological arousal alone cannot explain the temporal bias observed. In Experiment 2, participants performed the duration task twice without delay or arousal manipulation, and no overestimation was observed. Together, these results suggest that the overestimation observed in the context of a delayed duration categorisation task is related to a distortion of memorised standard durations caused by time lag rather than by a physiological arousal effect.

The faster internal clock in ADHD is related to lower processing speed: WISC-IV profile analyses and time estimation tasks facilitate the distinction between real ADHD and pseudo-ADHD

Alterations in temporal processing may represent a primary cause of key symptoms in ADHD. This study is aimed at investigating the nature of time-processing alterations in ADHD and assessing the possible utility of testing time estimation for clinical diagnostics. Retrospective verbal time estimation in the range of several minutes was examined in 50 boys with ADHD and 53 boys with other mental disorders. All participants (age 7-16) attended an outpatient clinic for ADHD diagnostics. The diagnostic assessment included the WISC-IV. Subjects with ADHD made longer and less accurate duration estimates than the clinical control group. The ADHD group showed a specific WISC-IV profile with processing speed deficits. In the ADHD group there was a correlation between processing speed and quality of time estimation that was not observed in the comparison group: higher processing speed indices were related to more accurate duration estimates. The findings provide support for the presence of a faster internal clock in subjects with ADHD and lend further support to the existence of a specific WISC-IV profile in subjects with ADHD. The results show that analyzing WISC-IV profiles and time estimation tasks are useful differential diagnosis tools, particularly when it comes to distinguishing between "real ADHD" and pseudo-ADHD.

Temporal estimation of threatening stimuli in social anxiety disorder: investigation of the effects of state anxiety and fearfulness

BACKGROUND AND OBJECTIVES

Prior studies suggest that particularly negative emotional events tend to be experienced as temporally dilated. Perceptual characteristics of the threat cue (averted or directed angry face), state as well as individual anxiety levels have been shown to contribute to the temporal distortions, but the interplay between these factors is not well understood. The present study investigated the relative contributions of these factors in a first study using clinical sample with social anxiety disorder (SAD) and healthy controls (HC).

METHODS

Participants performed a temporal bisection task (TBT) before and after a stress provocation phase, which served to induce state anxiety. During the TBT task, angry and neutral faces with averted vs. direct gaze were presented for the length of 600, 800, 1000, 1200, 1400, 1600 ms, and judged regarding their similarity to the standard durations.

RESULTS

A temporal overestimation effect for angry vs. neutral facial expressions was evident in both the HC and the SAD groups. An effect of experimentally induced state anxiety was evident solely in the SAD group, reflected in an overall increased temporal overestimation of angry vs. neutral expressions following the mood manipulation.

LIMITATIONS

The clinical sample may represent a high-functioning group, as the study was conducted on college students. Replication in more heterogeneous SAD samples is needed in order to draw further conclusions.

CONCLUSIONS

These results may be relevant for the understanding of the etiology and maintenance of SAD and potentially for the development of novel intervention methods.

The perception of time in childhood migraine

INTRODUCTION

Migraine is a syndrome rather common in children. Recent results have accounted evidence of altered activity corresponding to the supplemental motor area in this pediatric population. Given the role of this region in the motor timing of supra-second temporal intervals, we hypothesized that time representation is abnormal in childhood migraine.

SUBJECTS AND METHODS

We compared time-processing abilities between 11 children with migraine and 11 age-matched healthy children, employing a time reproduction task in which subjects actively reproduced different supra-second temporal intervals.

RESULTS

We show that children with migraine are less accurate (overestimate) and more variable in reproducing time intervals.

CONCLUSION

Results are discussed on the basis of the recent evidence about abnormal cortical and neurochemical activity in childhood migraine, but also in relation to a possible alteration of spatial attention mechanisms in this clinical population. The low number of patients examined represents a limit of this study and indicates that further investigation is needed.