The Illusions of Time Passage: Why Time Passage is Real

2021 ◽  
Author(s):  
Carlos Montemayor ◽  
Marc Wittmann

Philosophers and scientists alike often endorse the view that the passage of time is an illusion. Here we instead account for the phenomenology of passage as a real psycho-biological phenomenon. We argue that the experience of time passage has a real and measurable basis as it arises from an internal generative model for anticipating upcoming events. The experience of passage is not representation by a passive recipient of sensory stimulation but is generated by predictive processes of the brain and proactive sensorimotor activity of the whole body. The biological basis of the passage of time has not been examined in the metaphysics of time or the epistemology of time perception from a scientific perspective. This paper proposes to remedy this omission.

2009 ◽  
Vol 364 (1525) ◽  
pp. 1955-1967 ◽  
Author(s):  
Marc Wittmann

The striking diversity of psychological and neurophysiological models of ‘time perception’ characterizes the debate on how and where in the brain time is processed. In this review, the most prominent models of time perception will be critically discussed. Some of the variation across the proposed models will be explained, namely (i) different processes and regions of the brain are involved depending on the length of the processed time interval, and (ii) different cognitive processes may be involved that are not necessarily part of a core timekeeping system but, nevertheless, influence the experience of time. These cognitive processes are distributed over the brain and are difficult to discern from timing mechanisms. Recent developments in the research on emotional influences on time perception, which succeed decades of studies on the cognition of temporal processing, will be highlighted. Empirical findings on the relationship between affect and time, together with recent conceptualizations of self- and body processes, are integrated by viewing time perception as entailing emotional and interoceptive (within the body) states. To date, specific neurophysiological mechanisms that would account for the representation of human time have not been identified. It will be argued that neural processes in the insular cortex that are related to body signals and feeling states might constitute such a neurophysiological mechanism for the encoding of duration.


Author(s):  
Philip S. Murphy ◽  
Neel Patel ◽  
Timothy J. McCarthy

Pharmaceutical research and development requires a systematic interrogation of a candidate molecule through clinical studies. To ensure resources are spent on only the most promising molecules, early clinical studies must understand fundamental attributes of the drug candidate, including exposure at the target site, target binding and pharmacological response in disease. Molecular imaging has the potential to quantitatively characterize these properties in small, efficient clinical studies. Specific benefits of molecular imaging in this setting (compared to blood and tissue sampling) include non-invasiveness and the ability to survey the whole body temporally. These methods have been adopted primarily for neuroscience drug development, catalysed by the inability to access the brain compartment by other means. If we believe molecular imaging is a technology platform able to underpin clinical drug development, why is it not adopted further to enable earlier decisions? This article considers current drug development needs, progress towards integration of molecular imaging into studies, current impediments and proposed models to broaden use and increase impact. This article is part of the themed issue ‘Challenges for chemistry in molecular imaging’.


Author(s):  
Audrey Rousseaud ◽  
Stephanie Moriceau ◽  
Mariana Ramos-Brossier ◽  
Franck Oury

AbstractReciprocal relationships between organs are essential to maintain whole body homeostasis. An exciting interplay between two apparently unrelated organs, the bone and the brain, has emerged recently. Indeed, it is now well established that the brain is a powerful regulator of skeletal homeostasis via a complex network of numerous players and pathways. In turn, bone via a bone-derived molecule, osteocalcin, appears as an important factor influencing the central nervous system by regulating brain development and several cognitive functions. In this paper we will discuss this complex and intimate relationship, as well as several pathologic conditions that may reinforce their potential interdependence.


2013 ◽  
Vol 34 (6) ◽  
pp. 540-543 ◽  
Author(s):  
Kuruva Manohar ◽  
Anish Bhattacharya ◽  
Bhagwant R. Mittal
Keyword(s):  
Fdg Pet ◽  
Pet Ct ◽  
18F Fdg ◽  

Author(s):  
Alison Pienciak-Siewert ◽  
Alaa A Ahmed

How does the brain coordinate concurrent adaptation of arm movements and standing posture? From previous studies, the postural control system can use information about previously adapted arm movement dynamics to plan appropriate postural control; however, it is unclear whether postural control can be adapted and controlled independently of arm control. The present study addresses that question. Subjects practiced planar reaching movements while standing and grasping the handle of a robotic arm, which generated a force field to create novel perturbations. Subjects were divided into two groups, for which perturbations were introduced in either an abrupt or gradual manner. All subjects adapted to the perturbations while reaching with their dominant (right) arm, then switched to reaching with their non-dominant (left) arm. Previous studies of seated reaching movements showed that abrupt perturbation introduction led to transfer of learning between arms, but gradual introduction did not. Interestingly, in this study neither group showed evidence of transferring adapted control of arm or posture between arms. These results suggest primarily that adapted postural control cannot be transferred independently of arm control in this task paradigm. In other words, whole-body postural movement planning related to a concurrent arm task is dependent on information about arm dynamics. Finally, we found that subjects were able to adapt to the gradual perturbation while experiencing very small errors, suggesting that both error size and consistency play a role in driving motor adaptation.


2017 ◽  
Vol 118 (4) ◽  
pp. 2499-2506 ◽  
Author(s):  
A. Pomante ◽  
L. P. J. Selen ◽  
W. P. Medendorp

The vestibular system provides information for spatial orientation. However, this information is ambiguous: because the otoliths sense the gravitoinertial force, they cannot distinguish gravitational and inertial components. As a consequence, prolonged linear acceleration of the head can be interpreted as tilt, referred to as the somatogravic effect. Previous modeling work suggests that the brain disambiguates the otolith signal according to the rules of Bayesian inference, combining noisy canal cues with the a priori assumption that prolonged linear accelerations are unlikely. Within this modeling framework the noise of the vestibular signals affects the dynamic characteristics of the tilt percept during linear whole-body motion. To test this prediction, we devised a novel paradigm to psychometrically characterize the dynamic visual vertical—as a proxy for the tilt percept—during passive sinusoidal linear motion along the interaural axis (0.33 Hz motion frequency, 1.75 m/s2peak acceleration, 80 cm displacement). While subjects ( n=10) kept fixation on a central body-fixed light, a line was briefly flashed (5 ms) at different phases of the motion, the orientation of which had to be judged relative to gravity. Consistent with the model’s prediction, subjects showed a phase-dependent modulation of the dynamic visual vertical, with a subject-specific phase shift with respect to the imposed acceleration signal. The magnitude of this modulation was smaller than predicted, suggesting a contribution of nonvestibular signals to the dynamic visual vertical. Despite their dampening effect, our findings may point to a link between the noise components in the vestibular system and the characteristics of dynamic visual vertical.NEW & NOTEWORTHY A fundamental question in neuroscience is how the brain processes vestibular signals to infer the orientation of the body and objects in space. We show that, under sinusoidal linear motion, systematic error patterns appear in the disambiguation of linear acceleration and spatial orientation. We discuss the dynamics of these illusory percepts in terms of a dynamic Bayesian model that combines uncertainty in the vestibular signals with priors based on the natural statistics of head motion.


Healthcare ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Norbert Hosten ◽  
Robin Bülow ◽  
Henry Völzke ◽  
Martin Domin ◽  
Carsten Oliver Schmidt ◽  
...  

The Study of Health in Pomerania (SHIP), a population-based study from a rural state in northeastern Germany with a relatively poor life expectancy, supplemented its comprehensive examination program in 2008 with whole-body MR imaging at 1.5 T (SHIP-MR). We reviewed more than 100 publications that used the SHIP-MR data and analyzed which sequences already produced fruitful scientific outputs and which manuscripts have been referenced frequently. Upon reviewing the publications about imaging sequences, those that used T1-weighted structured imaging of the brain and a gradient-echo sequence for R2* mapping obtained the highest scientific output; regarding specific body parts examined, most scientific publications focused on MR sequences involving the brain and the (upper) abdomen. We conclude that population-based MR imaging in cohort studies should define more precise goals when allocating imaging time. In addition, quality control measures might include recording the number and impact of published work, preferably on a bi-annual basis and starting 2 years after initiation of the study. Structured teaching courses may enhance the desired output in areas that appear underrepresented.


2020 ◽  
Vol 11 (SPL4) ◽  
pp. 96-99
Author(s):  
Gopalakrishnan B ◽  
Karpagam K ◽  
KalaBarathi S

Stroke or brain attack is the effect of lack of blood circulation to the brain. Deficient blood delivery to brain results in lack of oxygen and nutrients. Brain cells are very sensitive to hypoxia. They stop working within 3-5 minutes if they are not getting oxygen and nutrients. This cell death results in stroke.  Stroke is a medical emergency. Immediate treatment can reduce injury to the brain and possible complications. About half of stroke patients experience the ill effects of the problem of awareness with such antagonistic impacts as tangible hardship. The arrangement of a consideration program comprising of straightforward and safe incitements can forestall tangible hardship and improve the patient's sensory capacity. Hence the study aimed to assess the effectiveness of sensory stimulation on the sensory function among patients with stroke. Pre experimental design-One group pre and post design was adopted for the study with 30 samples which matched the inclusion criteria were selected by non-probability convenience sampling technique. Demographic variables data were collected by using a multiple-choice questionnaire followed by assessing the sensory function by using the SMART scale. The findings of the study Out of 30 samples in the experimental group, 26 (86.7%) had moderate level of sensory dysfunction and 4 (13.3%) had mild level of sensory dysfunction. After giving the intervention of sensory stimulation post test shows 24 (80%) had mild level of sensory dysfunction and 6(20%) had normal sensory function. Sensory stimulation is effective and the patient with sensory function among stroke. This study indicates that sensory stimulation which containing certain stimulation was an effective, inexpensive, simple measure for improving sensory dysfunction among patients with stroke.


2013 ◽  
Vol 15 (1) ◽  
pp. 99-108 ◽  

The human brain shrinks with advancing age, but recent research suggests that it is also capable of remarkable plasticity, even in late life. In this review we summarize the research linking greater amounts of physical activity to less cortical atrophy, better brain function, and enhanced cognitive function, and argue that physical activity takes advantage of the brain's natural capacity for plasticity. Further, although the effects of physical activity on the brain are relatively widespread, there is also some specificity, such that prefrontal and hippocampal areas appear to be more influenced than other areas of the brain. The specificity of these effects, we argue, provides a biological basis for understanding the capacity for physical activity to influence neurocognitive and neuropsychiatric disorders such as depression. We conclude that physical activity is a promising intervention that can influence the endogenous pharmacology of the brain to enhance cognitive and emotional function in late adulthood.


2010 ◽  
Author(s):  
Αικατερίνη Χαραλαμποπούλου

In this study I have attempted to present a linguistic investigation into the nature and structure of time, based on proposals developed in Evans (2004). Accordingly, as linguistic structure and particularly patterns of elaboration reflect conceptual structure conventionalized into a format encodable in language, this study presents an examination of the human conceptual system for time. Indeed, an examination of the ways in which language lexicalizes time provides important insights into the nature and organization of time. That is, given the widely held assumption that semantic structure derives from and reflects, at least partially, conceptual structure, language offers a direct way of investigating the human conceptual system. However, how time is realized at the conceptual level, that is, how we represent time as revealed by the way temporal concepts are encoded in language, does not tell the whole story, if we are to uncover the nature and structure of time. Research in cognitive science suggests that phenomenological experience and the nature of the external world of sensory experience to which subjective experience constitutes a response, give rise to our pre- conceptual experience of time. In other words, as Evans (2004) says, time is not restricted to one particular layer of experience but it rather “constitutes a complex range of phenomena and processes which relate to different levels and kinds of experience” (ibid.: 5). Accordingly, while my focus in this study is on the temporal structure, which is to say the organization and structuring of temporal concepts, at the conceptual level, I have also attempted to present an examination of the nature of temporal experience at the pre-conceptual level (prior to representation in conceptual structure). In this regard, I have examined the results of research from neuroscience, cognitive psychology and social psychology. More specifically and with respect to evidence from neuroscience, it is suggested that temporal experience is ultimately grounded in neurological mechanisms necessary for regulating and facilitating perception (e.g., Pöppel 1994). That is, perceptual processing is underpinned by the occurrence of neurologically instantiated temporal intervals, the perceptual moments, which facilitate the integration of sensory information into coherent percepts. As we have seen, there is no single place in the brain where perceptual input derived from different modalities, or even information from within the same modality, can be integrated. In other words, there is no one place where spatially distributed sensory information associated with the distinct perceptual processing areas of the brain, are integrated in order to produce a coherent percept. Rather, what seems to be the case is that the integration of sensory information into coherent percepts is enabled by the phenomena of periodic perceptual moments. Such a mechanism enables us to perceive, in that the nature of our percepts are in an important sense ‘constructed’. Put another way, perception is a kind of constructive process which updates successive perceptual information to which an organism has access. The updating occurs by virtue of innate timing mechanisms, the perceptual moments, which occur at all levels of neurological processing and range from a fraction of second up to an outer limit of about three seconds. It is these timing mechanisms which form the basis of our temporal experience. As Gell says, “perception is intrinsically time-perception, and conversely, time-perception, or internal time-consciousness, is just perception itself...That is to say, time is not something we encounter as a feature of contingent reality, as if it lay outside us, waiting to be perceived along with tables and chairs and the rest of the perceptible contents of the universe. Instead, subjective time arises as inescapable feature of the perceptual process itself, which enters into the perception of anything whatsoever” (1992: 231). In other words, our experience of time is a consequence of the various innate ‘timing mechanisms' in the brain which give rise to a range of perceptual moments, which are in turn necessary for and underpin perceptual processing. In this way, time exists into the experience of everything as it is fundamental to the way in which perceptual process operates. […]


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