Bridging the gap between aberrant time processing and cognitive dysfunction in schizophrenia: a potential core feature?

The study of temporal perception and its disruptions in schizophrenia has long been studied in experimental psychology. As early as the late 19th century, Wilhelm Wundt explored fundamental perceptual processes, including temporal discrimination, establishing a foundation for the modern understanding of how the brain processes time¹. In the early 20th century, phenomenologists deepened this line of enquiry, focusing on how individuals with psychopathological disorders, particularly schizophrenia, experience distortions in time. Minkowski introduced the concept of an “absence of the feeling of duration”², and Jaspers examined how time perception is altered across various mental disorders, providing essential insights into the lived experiences of patients with schizophrenia³.

Since the 1960s, proposals regarding the neural mechanisms of time processing have suggested the existence of clock-like brain oscillators^4,5. These proposals led to the development of new experimental paradigms, the most characteristic of which is interval timing—i.e., the ability to process and measure the duration between events⁶. Despite these early neuroscientific contributions, the study of temporal processing in mental disorders, particularly the neural substrates involved in time processing and its relationship with other cognitive variables, fell into relative obscurity during the mid-20th century⁷.

This shift occurred as research in neuropsychopathology increasingly focused on more complex cognitive constructs, such as executive functions and social cognition, especially in studies related to schizophrenia^8,9. In the field of neurocognition, studies focusing on processing speed, verbal learning and memory, visuospatial learning and memory, working memory, attention/vigilance, and reasoning and problem-solving have gained prominence¹⁰. In the last two decades, there has been growing interest in the study of social cognition impairments in schizophrenia, especially in the areas of emotion processing, social perception, and attributional bias¹¹. Studies on perceptual impairments in schizophrenia have focused on paradigms emphasising visual¹² and auditory¹³ information processing, in which, according to several paradigms, temporal processing is thought to play a crucial role.

In recent years, however, there has been a significant resurgence of interest in temporal perception within neuropsychology, particularly in normative contexts¹⁴. This renewed focus is gradually extending to the study of cognitive dysfunction in schizophrenia^15,16,17,18.

Over the past two decades, various studies—including neuroimaging, EEG, experimental paradigms, psychophysiological assessments, and behavioural research—have investigated the dysfunctions in neural circuits supporting temporal processing and their contribution to these cognitive deficits. The primary objective of this Perspective is to present and discuss the hypothesis that disruptions in temporal processing may underlie the cognitive deficits observed in schizophrenia¹⁹. We propose that these temporal deficits—such as difficulties in processing time intervals and managing duration, order, and regularity—are not merely secondary manifestations but are rather foundational to the broader cognitive impairments seen in the disorder.

This manuscript examines key studies providing evidence for this hypothesis and discusses the implications of these findings. In addition, we aim to outline areas for further research and explore possible interventions for these specific disruptions.

Time perception research employs various experimental paradigms and methods to understand how humans perceive and estimate time^20,21,22. These tools include motor timing tasks^23,24,25, which assess behavioural sequence and timing control via finger tapping or rhythm tasks; time estimation²⁶ and temporal production/reproduction tasks, in which participants are asked to gauge or replicate time intervals²⁷; and time or rhythm discrimination tasks, in which participants must discriminate between two different temporal intervals^28,29.

Experimental approaches can be classified into explicit and implicit timing tasks^30,31. In explicit timing tasks, participants are fully aware that they are engaging in time measurement or estimation^30,31: they are often instructed to accurately judge or record the duration of a time interval. Selective attention to time is the primary variable of interest.

In implicit timing tasks, on the other hand, participants are not aware that they are engaged in a time measurement task³². Time estimation occurs automatically and often unconsciously, without deliberately focusing on measuring time, as part of a broader task that is often linked to performing an action or making decisions.

This article emphasises time discrimination (TD) as one of the most relevant explicit timing tasks for studying time. TD involves the cognitive ability to detect, assess, and quantify the time interval between two stimuli. Participants are presented with auditory stimuli of the same pitch, separated by varying time intervals, and are asked to identify which intervals are longer or shorter³³. Typically, the length of intervals ranges from seconds to sub-second durations.

In recent years, functional neuroimaging studies have employed various experimental tests to investigate temporal perception and its neural correlates³⁴. For example, Capizzi et al.³⁰ explored age-related changes in neural activation patterns and timing performance by comparing both explicit and implicit timing tasks in healthy and pathological older adults. Similarly, Livesey et al.³⁵ examined neural activation during duration discrimination tasks under varying levels of task difficulty. Their fMRI results revealed that while multiple brain regions were activated during duration discrimination—including the prefrontal cortex, cerebellum, and striatum—the activity was not specific to timing functions but was influenced by the cognitive demands of the task. However, certain regions, such as the inferior frontal gyrus, anterior insula, and putamen, showed sustained activation regardless of task difficulty, suggesting their direct involvement in temporal judgements.

Using fMRI and related techniques, researchers have identified several key brain regions as particularly involved in temporal processing. The basal ganglia^20,36, the supplementary motor area (SMA), and the prefrontal cortex are often highlighted as crucial structures in cognitively demanding temporal tasks^37,38. For instance, the cortico-cerebellar-thalamic loop has been identified as central to processing timing tasks in healthy individuals, with studies suggesting that these circuits are engaged during tasks involving both motor and cognitive components^19,39,40.

Despite these advancements, the variability across these experimental studies remains high due to factors such as the range of time intervals studied (from milliseconds to seconds), differences in the paradigms employed, and the inclusion of motor and perceptual components. Interestingly, in recent years, several meta-analyses have attempted to consolidate the available evidence and identify the areas consistently implicated in temporal processing, including both cortical regions—such as the SMA, prefrontal cortex, parietal cortex, and insula—and subcortical structures like the putamen, thalamus, and cerebellum^{19,21,38,41,42,43,44,45}.

A meta-analysis by Wiener et al.³⁸ revealed that key areas, such as the SMA and right inferior frontal gyrus (rIFG), were consistently activated across a variety of timing tasks, particularly in explicit timing tasks. This meta-analysis suggested that the SMA plays a central role in both motor and perceptual timing, while the rIFG is crucial for higher-order cognitive functions associated with time processing. Further meta-analytic work, such as that by Radua et al.²¹, also identified significant overlap between the brain regions involved in time perception and those associated with cognitive effort, including areas of the prefrontal and parietal cortices.

A more recent meta-analysis by Nani et al.⁴² replicated these findings and provided a more nuanced view by categorising studies into subsecond and suprasecond intervals, and motor and perceptual domains. This analysis highlighted the central role of the SMA and prefrontal cortex in timing tasks while revealing that the cerebellum and inferior parietal cortices were less frequently activated, particularly in subsecond motor tasks.

Time discrimination ability relies on a sophisticated neural network that integrates sensory data, enabling consistent performance across a wide range of tasks^37,46,47. The growing body of evidence suggests that this network is flexible, adapting to task demands and contributing to broader cognitive and motor functions essential for everyday activities.

Temporal processing is a fundamental cognitive ability suggested to underlie a wide range of functions, from sensory perception to higher-order cognitive tasks. It is not an isolated process but rather interacts with several other cognitive domains, such as working memory (WM), attention, and cognitive control. Several studies have attempted to detail the interrelationship between these processes.

Using fMRI during a visual paradigm, Üstün et al.⁴⁶ found that time perception activated the right dorsolateral prefrontal cortex, intraparietal cortex, anterior cingulate cortex, anterior insula, and basal ganglia. At the same time, WM engaged the left prefrontal cortex, left superior parietal cortex, and cerebellum. Both processes showed activity in the intraparietal sulcus and posterior cingulate cortex, suggesting a shared neural network for time perception and WM.

Broadway et al.⁴⁸ found that individuals with greater WM capacity were more sensitive to temporal differences between intervals, suggesting that WM capacity plays a significant role in temporal judgement within the milliseconds-to-seconds range. These results underscore the critical role of attention and working memory in temporal discrimination tasks, aligning with theories that propose that temporal judgement relies on the ability to discriminate memory representations by multiple attributes, with time being a key component¹⁴.

Temporal processing and attention are closely linked, as both are essential for efficiently managing and responding to stimuli in our environment⁴⁹. Attention is critical in modulating how we perceive and organise temporal information^50,51. Previous studies have examined how the perception of time varies when attention is explicitly directed toward temporal stimuli, with findings indicating that the perceived duration of these stimuli is enhanced^14,50,51. Furthermore, attention facilitates the detection of temporal changes, enabling the brain to adapt to varying time intervals and demands.

Temporal and non-temporal cognitive processes are linked by a shared mechanism for detecting changes, with paradigms such as the oddball task and salience detection highlighting this connection. Both processes rely on a common mechanism for detecting deviations or changes in stimuli, whether temporal (as in duration discrimination) or non-temporal (as in detecting unexpected events). These paradigms consistently activate brain regions involved in temporal tasks, suggesting a common network supporting both time and change detection functions^47,52,53. This network may also be related to other non-temporal tasks and cognitive control processes, as both types of functions require the capacity to detect changes in stimuli^21,54,55,56.

In a recent fMRI study, Goena et al.⁵⁷ designed an experimental auditory test that combined TD and oddball detection (OD) tasks. Both tasks were found to engage interrelated brain areas, further supporting the idea that temporal processing and change detection are linked and may share a common brain network. The activation patterns during TD and OD tasks overlapped in areas traditionally associated with cognitive control, including the prefrontal cortex, parietal regions, and basal ganglia. Notably, activation in cerebellar regions occurred when the difficulty of the TD tasks increased, suggesting that these areas are involved not only in temporal perception but also in more complex cognitive processes, such as executive functions.

Recent meta-analytic studies have further emphasised the interconnectedness of temporal processing with other cognitive functions. Garcés et al.⁴⁷ found that tasks involving timing and OD engage overlapping brain areas, particularly in regions associated with both timing and salience networks. Similarly, Radua et al.²¹ showed that brain regions involved in working memory and executive functions are also activated during time estimation tasks, proposing that the degree of cognitive effort might mediate the relationship between these domains.

In summary, the evidence suggests that the brain does not compartmentalise time processing from other cognitive demands but instead utilises overlapping neural resources to perform tasks requiring cognitive control and time perception. This provides a plausible explanation of how dysfunctions in temporal processing networks might contribute to the broader cognitive impairments observed in schizophrenia, especially in tasks requiring adaptive responses to changes in task difficulty or stimuli⁵⁸.

In schizophrenia, temporal processing is disrupted, affecting how time is experienced and how it influences cognitive abilities. From a phenomenological point of view, key symptoms in schizophrenia can be seen as disruptions in the way individuals experience “inner time” or their sense of time⁵⁹. These disruptions in how time is processed affect not just the perception of time itself but also how individuals with schizophrenia experience their sense of self, control their actions, and understand reality. These temporal distortions significantly impact the experience of symptoms such as thought disorder, thought insertion, and passive experiences, which can be conceptualised as difficulties in organising and integrating internal time⁶⁰.

At the experimental level, numerous studies have documented significant impairments in temporal processing in individuals with schizophrenia⁶¹. Carroll et al.¹⁵ found that while both schizophrenia and control groups exhibited greater variability in visual timing, individuals with schizophrenia had lower precision than controls in auditory timing. In a follow-up study, Carroll et al.⁶² observed increased variability in estimations of time durations (across both millisecond and several-second intervals) in individuals with schizophrenia, indicating a general disruption in temporal processing. In another study, Turgeon et al.⁶³ reported that individuals with schizophrenia were significantly impaired at detecting phase shifts in intervals ranging from 300 to 900 ms, a key process for predicting and identifying temporal deviations.

Neurophysiological markers, such as mismatch negativity (MMN) and chirp-evoked potentials (ASSR), are potential indicators of temporal processing dysfunction in schizophrenia. MMN, elicited by auditory stimuli, reflects the brain’s ability to detect changes in the environment, particularly concerning automatic change detection and pre-attentional processing. Research has shown that the reduction in auditory MMN in schizophrenia is most pronounced when the detected change involves the duration of the stimulus⁶⁴, supporting the hypothesis that MMN is associated with timing circuits⁶⁵. Similarly, deficits in gamma-band ASSR have been linked to working memory impairments in schizophrenia⁶⁶, reflecting reduced functionality in frontotemporal circuits involved in cognitive control and temporal processing⁶⁷.

Recent research has shed light on the neurobiological underpinnings of temporal processing deficits in schizophrenia, particularly using timing tasks. Davalos et al.⁶⁸ examined temporal judgement in individuals with schizophrenia using a temporal discrimination task with varying difficulty levels. Individuals with schizophrenia performed worse than healthy controls at both levels of difficulty, and fMRI revealed notable differences in brain activation patterns. Specifically, the schizophrenia group exhibited reduced activation in key regions involved in temporal processing, such as the SMA and insula/opercula, during the easier task. The differences in brain activation became more pronounced under the more difficult condition, with the striatum showing lower activity in individuals with schizophrenia than in controls. These results suggest that although temporal judgement deficits in schizophrenia become more pronounced under more challenging conditions, they are not only related to task difficulty but also to broader dysfunctions within the brain networks that support temporal processing, particularly under more challenging conditions.

Similarly, Volz et al.⁶⁹ used fMRI to examine temporal processing in patients with schizophrenia during an auditory time estimation task. Although patients performed at the same difficulty level as controls, the schizophrenia group exhibited reduced activation in the prefrontal cortex and caudate nucleus, key regions involved in time estimation. In addition, specific differences between the timing and pitch discrimination tasks were observed in the posterior putamen, anterior thalamus, and right medial prefrontal cortex, where patients displayed relative hypoactivity. These findings suggest a dysfunction in the fronto-thalamo-striatal circuit, which is thought to mediate impairments in time estimation in schizophrenia, further reinforcing the idea that temporal processing deficits are linked to specific neural network dysfunctions rather than merely to task difficulty.

Recent studies have highlighted the role of the cerebellum in the timing deficits observed in schizophrenia, with particular emphasis on its involvement in the coordination of motor and cognitive functions⁴⁰. Losak et al.⁷⁰ found that individuals with schizophrenia showed accelerated time processing, which correlated positively with the severity of positive symptoms and decreased with higher antipsychotic doses. This accelerated processing was linked to altered BOLD signal activity in brain regions involved in timing, such as the basal ganglia, cerebellum, and SMA, with cerebellar vermis activity negatively associated with time processing acceleration. Similarly, Moussa-Took et al.⁷¹ examined cerebellar connectivity during sensorimotor synchronisation and found that, relative to healthy control subjects, individuals with schizophrenia exhibited diminished temporal coordination, particularly during self-paced tasks. Although the cerebellum was activated in both groups, the schizophrenia group showed decreased connectivity between the cerebellum and primary motor cortex, alongside increased connectivity between the cerebellum and the thalamus. This disrupted connectivity suggests that cerebellar dysfunction impairs motor coordination and contributes to greater cognitive and motor deficits.

In line with these findings, Ortuño et al.¹⁹ conducted an activation likelihood estimation (ALE) meta-analysis to elucidate the neural circuits involved in time estimation and to examine their possible dysfunction in schizophrenia. The study replicated the identification of a cortico-cerebellar-thalamic circuit responsible for time estimation in healthy individuals. With regard to dysfunction in schizophrenia, the meta-analysis revealed significantly lower activation in most right hemisphere regions of this circuit, suggesting a dysconnectivity pattern that impairs the accurate processing of time.

Is temporal processing dysfunction in schizophrenia a secondary symptom of broader cognitive deficits? Or could it be a primary factor underlying cognitive difficulties observed in the disorder? Some studies propose that temporal dysfunction may be a primary mechanism contributing to difficulties in other cognitive domains^18,19,72. A recent review by Croce et al.⁷³ pointed out that while the correlation between temporal dysfunction and cognitive deficits is well established, many studies have failed to demonstrate a clear causal relationship.

Ciullo et al.⁷⁴ suggested that temporal dysfunction might be influenced by neuropsychological deficits inherent to schizophrenia rather than representing a standalone impairment. Their meta-analysis, which included data from 24 studies comprising 747 individuals with schizophrenia and 808 healthy controls, found that individuals with schizophrenia were less accurate than controls in estimating time duration across a variety of tasks. Notably, the study demonstrated that the timing deficits in schizophrenia were consistent across different task types and durations, both automatic and cognitively controlled, as well as in perceptual and motor timing tasks. This suggests that the disturbances in time perception in schizophrenia are not merely task-specific but represent a more generalised issue independent of broader cognitive impairments.

Alústiza et al.⁷⁵ conducted a meta-analysis of neuroimaging studies to investigate how temporal processing is linked to other cognitive tasks requiring cognitive control. Their analysis revealed that timing and cognitive control functions share overlapping neural networks, particularly in regions of the right hemisphere, such as the SMA. The study suggested that individuals with schizophrenia exhibit reduced activation in these regions, particularly during tasks involving increased difficulty or cognitive effort. This reduced activation pattern indicates a potential dysconnectivity of the temporal processing circuit, particularly in the SMA, which may serve as a trait marker of the cognitive profile observed in schizophrenia.

The correlation between cognitive impairments and temporal processing deficits together with the aberrant brain activity involved in these processes, may suggest that both share common neurobiological mechanisms. This aligns with Andreasen’s cognitive dysmetria hypothesis⁷⁶, which proposes a difficulty in prioritising, processing, coordinating, and responding to information due to dysfunction in cortical-subcortical-cerebellar circuitry, which is crucial for both temporal processing and higher-order cognitive functions.

In our view, a key factor in testing these hypotheses and accurately interpreting results is the careful design of future studies. Specifically, there is a lack of research on temporal processing in individuals with schizophrenia who meet clinical remission criteria. The presence of acute symptoms, such as intensified positive symptoms (delusions, hallucinations, or disorganised thinking) and exacerbated negative symptoms, can significantly impact sensory-perceptual alterations and other fundamental cognitive mechanisms. Additionally, it is important to control for confounding variables such as antipsychotic medication use or baseline cognitive reserve. It would also be valuable to include other populations, such as first-degree relatives or individuals with other psychiatric disorders presenting psychotic features distinct from schizophrenia. This could provide further insights into the nature of temporal processing dysfunction and its broader implications.

Despite the importance of time perception in cognitive functioning, it has not been considered a central domain in schizophrenia research, and no timing tests have been integrated into the standard cognitive batteries used to assess dysfunction in schizophrenia¹⁰. We believe it is crucial to address this gap in order to develop therapeutic strategies and new treatments to restore cognitive performance. Studying performance on tests specifically designed to measure temporal processing, along with tracking changes in brain activity involved in temporal discrimination processes, could provide valuable insights and significantly enhance treatment approaches.

There have been promising results with non-invasive brain stimulation techniques⁷⁷, which may effectively modify brain function parameters related to cognitive dysfunction in schizophrenia. One study demonstrated that high-frequency repeated transcranial magnetic stimulation (rTMS) could reconfigure functional dynamics in cortico-thalamic-cerebellar circuits in schizophrenia⁷⁸. A recent double-blind, randomised, sham-controlled trial of active rTMS to the dorsolateral prefrontal cortex in individuals with schizophrenia showed a reduction in individual variability in brain function, potentially normalising brain activity during working memory tasks and improving cognitive performance⁷⁹.

To our knowledge, only one study specifically addresses the effects of TMS on temporal discrimination⁸⁰. The authors examined the effects of cerebellar theta burst stimulation (TBS) on temporal discrimination in patients with psychosis, including patients with schizophrenia, schizoaffective disorder, and bipolar disorder with psychotic features. Their study demonstrated that intermittent TBS (iTBS) significantly improved reaction time in temporal discrimination tasks. The cerebellum, a key structure in time processing⁴⁰, is considered a potential target for cognitive deficits, particularly in temporal processing, in psychotic disorders. However, further research is required to consolidate these findings and their broader clinical applications.

We propose that time perception should be recognised as a valuable cognitive domain in the study of cognitive dysfunction in schizophrenia, as it appears to represent a potentially primary deficit. A thorough understanding of temporal processing may also provide a framework for exploring potential therapeutic strategies for cognitive remediation in this disorder. By addressing the complexities of time perception, interventions could be more effectively tailored to improve cognitive outcomes for individuals with schizophrenia.