scholarly journals Causal Role of Beta Oscillations in Time Estimation

2017 ◽  
Author(s):  
Martin Wiener ◽  
Alomi Parikh ◽  
Arielle Krakow ◽  
H. Branch Coslett
Keyword(s):  
Time Estimation ◽  
Causal Connection ◽  
Choice Data ◽  
Beta Oscillations ◽  
Healthy Human ◽  
Beta Power ◽  
Starting Point ◽  
Temporal Intervals ◽  
Transcranial Alternating Current Stimulation ◽  
Perception Of Time

AbstractThe neural mechanisms underlying time perception are of vital importance to a comprehensive understanding of behavior and cognition. Recent work has pointed to a supramodal role for beta oscillations in coordinating endogenous timing mechanisms for the purpose of measuring temporal intervals. However, the majority of this work has employed paradigms relying on timed motor responses, which are confounded by beta’s established role in motor movement. Further, no study to date has tested if the alteration of beta oscillations subsequently impacts timing. Here, we address these concerns and demonstrate for the first time a causal connection between beta oscillations and timing. To accomplish this, we first re-analyzed two, separate EEG datasets from psychophysical experiments (Wiener, et al. 2012; 2015) demonstrating that beta oscillations are associated with the retention and comparison of a memory standard for duration, and that transcranial magnetic stimulation (TMS) of the right supramarginal gyrus leads to an increase in midline beta power during the encoding of a temporal interval, corresponding with a longer perceived interval of time. Next, we conducted a study of 20 healthy human participants using transcranial alternating current stimulation (tACS), over frontocentral cortex, at alpha (10Hz) and beta (20Hz) frequencies, during a visual temporal bisection task, demonstrating that beta stimulation exclusively shifts the perception of time such that stimuli are reported as longer in length, while preserving precision. Finally, we decomposed trial-by-trial choice data with a drift diffusion model of decision making and temporal encoding that reveals the shift in timing is caused by a change in the starting point of accumulation, rather than the drift rate or threshold. Our results provide causal evidence of beta’s involvement in the perception of time, and point to a specific role for beta oscillations in the encoding and retention of memory for temporal intervals.

scholarly journals Scale Invariance, Horizons, and Inflation

2021 ◽  
Author(s):  
Andre Maeder ◽  
Vesselin G Gueorguiev
Keyword(s):  
Scalar Field ◽  
Scale Invariance ◽  
Maxwell Equations ◽  
High Redshift ◽  
Empty Space ◽  
Causal Connection ◽  
Cosmological Constant Problem ◽  
Scale Invariant ◽  
Starting Point ◽  
Final Answer

Abstract Maxwell equations and the equations of General Relativity are scale invariant in empty space. The presence of charge or currents in electromagnetism or the presence of matter in cosmology are preventing scale invariance. The question arises on how much matter within the horizon is necessary to kill scale invariance. The scale invariant field equation, first written by Dirac in 1973 and then revisited by Canuto et al. in 1977, provides the starting point to address this question. The resulting cosmological models show that, as soon as matter is present, the effects of scale invariance rapidly decline from ϱ = 0 to ϱc, and are forbidden for densities above ϱc. The absence of scale invariance in this case is consistent with considerations about causal connection. Below ϱc, scale invariance appears as an open possibility, which also depends on the occurrence of in the scale invariant context. In the present approach, we identify the scalar field of the empty space in the Scale Invariant Vacuum (SIV) context to the scalar field ϕ in the energy density $\varrho = \frac{1}{2} \dot{\varphi }^2 + V(\varphi )$ of the vacuum at inflation. This leads to some constraints on the potential. This identification also solves the so-called “cosmological constant problem”. In the framework of scale invariance, an inflation with a large number of e-foldings is also predicted. We conclude that scale invariance for models with densities below ϱc is an open possibility; the final answer may come from high redshift observations, where differences from the ΛCDM models appear.

Pietas and Victoria: the Emperor and the Citizen

1943 ◽  
Vol 33 (1-2) ◽  
pp. 1-10 ◽  
Author(s):  
M. P. Charlesworth
Keyword(s):  
Causal Connection ◽  
Intimate Connection ◽  
American Scholar ◽  
Starting Point ◽  
Look Back ◽  
Roman People ◽  
It Success

In dealing with so wide-ranging a subject, a remark of an American scholar, Mr. Hoey, on the intimate connection between the titles pius, felix, and invictus provides a convenient starting-point.The first observation I would make is to call your attention to the consecutive (and almost causal) connection of these adjectives : because the Emperor is pius the gods will render him felix (for felicitas is their gift to their favourites) and his felicitas is best demonstrated in his being invictus. Nearly every nation of antiquity believed and hoped that its gods would bring it success : the Roman People, with seven centuries of expansion and increasing power to look back on, were convinced that their scrupulous attention to the due performance of the proper rites had won them this success, that their pietas had secured to them victoria; if the Emperor could be termed pius felix invictus, it was because he summed up and incarnated there the Roman People.

scholarly journals Cross-frequency Phase–Amplitude Coupling as a Mechanism for Temporal Orienting of Attention in Childhood

2018 ◽  
Vol 30 (4) ◽  
pp. 594-602 ◽  
Author(s):  
Giovanni Mento ◽  
Duncan E. Astle ◽  
Gaia Scerif
Keyword(s):  
Inverse Correlation ◽  
Human Cognition ◽  
Response Preparation ◽  
Strongly Coupled ◽  
Oscillatory Dynamics ◽  
Beta Power ◽  
Temporal Intervals ◽  
Phase Amplitude ◽  
Frequency Phase ◽  
Temporal Orienting

Temporal orienting of attention operates by biasing the allocation of cognitive and motor resources in specific moments in time, resulting in the improved processing of information from expected compared with unexpected targets. Recent findings have shown that temporal orienting operates relatively early across development, suggesting that this attentional mechanism plays a core role for human cognition. However, the exact neurophysiological mechanisms allowing children to attune their attention over time are not well understood. In this study, we presented 8- to 12-year-old children with a temporal cueing task designed to test (1) whether anticipatory oscillatory dynamics predict children's behavioral performance on a trial-by-trial basis and (2) whether anticipatory oscillatory neural activity may be supported by cross-frequency phase–amplitude coupling as previously shown in adults. Crucially, we found that, similar to what has been reported in adults, children's ongoing beta rhythm was strongly coupled with their theta rhythm and that the strength of this coupling distinguished validly cued temporal intervals, relative to neutral cued trials. In addition, in long trials, there was an inverse correlation between oscillatory beta power and children's trial-by-trial reaction, consistent with oscillatory beta power reflecting better response preparation. These findings provide the first experimental evidence that temporal attention in children operates by exploiting oscillatory mechanism.

scholarly journals On the Effectiveness of Event-related Beta tACS on Episodic Memory Formation and Motor Cortex Excitability

2016 ◽  
Author(s):  
Verena Braun ◽  
Rodika Sokoliuk ◽  
Simon Hanslmayr
Keyword(s):  
Motor Cortex ◽  
Episodic Memory ◽  
Inferior Frontal Gyrus ◽  
Memory Formation ◽  
Frequency Range ◽  
Beta Oscillations ◽  
Healthy Human ◽  
Sham Stimulation ◽  
Motor Cortex Excitability ◽  
Beta Frequency

AbstractBackgroundTranscranial alternating current stimulation (tACS) is widely used to entrain or modulate brain oscillations in order to investigate causal relationships between oscillations and cognition.ObjectiveIn a series of experiments we here addressed the question of whether event-related, transient tACS in the beta frequency range can be used to entrain beta oscillations in two different domains: episodic memory formation and motor cortex excitability.MethodsIn experiments 1 and 2, 72 healthy human participants engaged in an incidental encoding task of verbal and non-verbal material while receiving tACS to the left and right inferior frontal gyrus (IFG) at 6.8Hz, 10.7Hz, 18.5Hz, 30Hz, 48Hz and sham stimulation for 2s during stimulus presentation.In experiment 3, tACS was administered to M1 at the individual motor beta frequency of eight subjects. We investigated the relationship between the size of TMS induced MEPs and tACS phase.ResultsBeta tACS did not affect memory performance compared to sham stimulation in experiments 1 and 2. Likewise, in experiment 3, MEP size was not modulated by the tACS phase.ConclusionsOur findings suggest that event-related, transient tACS in the beta frequency range cannot be used to modulate the formation of episodic memories or motor cortex excitability. These null-results question the effectiveness of event-related tACS to entrain beta oscillations and modulate cognition.

scholarly journals Endogenous and exogenous electric fields as modifiers of brain activity: rational design of noninvasive brain stimulation with transcranial alternating current stimulation

2014 ◽  
Vol 16 (1) ◽  
pp. 93-102 ◽  
Keyword(s):  
Electric Fields ◽  
Brain Stimulation ◽  
Rational Design ◽  
Brain Activity ◽  
Field Potential ◽  
Alternating Current ◽  
Noninvasive Brain Stimulation ◽  
Starting Point ◽  
Recent Developments ◽  
Transcranial Alternating Current Stimulation

Synchronized neuronal activity in the cortex generates weak electric fields that are routinely measured in humans and animal models by electroencephalography and local field potential recordings. Traditionally, these endogenous electric fields have been considered to be an epiphenomenon of brain activity. Recent work has demonstrated that active cortical networks are surprisingly susceptible to weak perturbations of the membrane voltage of a large number of neurons by electric fields. Simultaneously, noninvasive brain stimulation with weak, exogenous electric fields (transcranial current stimulation, TCS) has undergone a renaissance due to the broad scope of its possible applications in modulating brain activity for cognitive enhancement and treatment of brain disorders. This review aims to interface the recent developments in the study of both endogenous and exogenous electric fields, with a particular focus on rhythmic stimulation for the modulation of cortical oscillations. The main goal is to provide a starting point for the use of rational design for the development of novel mechanism-based TCS therapeutics based on transcranial alternating current stimulation, for the treatment of psychiatric illnesses.

scholarly journals An Intrinsic Role of Beta Oscillations in Memory for Time Estimation

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Martin Wiener ◽  
Alomi Parikh ◽  
Arielle Krakow ◽  
H. Branch Coslett
Keyword(s):  
Time Estimation ◽  
Beta Oscillations

scholarly journals "Dual causation accident": a third type of work-related accident and its importance for occupational health surveillance

2014 ◽  
Vol 19 (12) ◽  
pp. 4699-4708 ◽  
Author(s):  
Lenz Alberto Alves Cabral ◽  
Zaida Aurora Sperli Geraldes Soler ◽  
José Carlos Lopes
Keyword(s):  
Occupational Health ◽  
National Policy ◽  
Health Surveillance ◽  
Occupational Accidents ◽  
Causal Connection ◽  
Work Related ◽  
Unified Health System ◽  
Labor Legislation ◽  
Starting Point ◽  
Occupational Health Surveillance

The scope of this study is to contribute to the improvement of Occupational Health Surveillance in the Unified Health System (UHS), through the recognition and inclusion of a third type of work-related accident in the current Brazilian legislation classification: the dual causation accident. This classification aims at facilitating the establishment of a causal connection, thus broadening the understanding of the relationship between work process and the production of diseases. It also aims at improving legal rules to protect the health of workers. This approach, besides enabling the identification of sentinel events (starting point of surveillance activities), might contribute not only to a decrease in underreporting of work-related accidents, but also to the uniformity of concepts and the implementation of integrated actions of the National Social Security Institute (NISS), the UHS, the Ministry of Labor (MLE) and the Judiciary for the protection of workers. To propose a third type of occupational accident, a study of occupational accidents and causes of underreporting was conducted, with reference to the Brazilian labor legislation in the context of the National Policy on Occupational Health and the UHS.

scholarly journals Modulation of Individual Alpha Frequency with tACS shifts Time Perception

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Giovanna Mioni ◽  
Adam Shelp ◽  
Candice T Stanfield-Wiswell ◽  
Keri A Gladhill ◽  
Farah Bader ◽  
...  
Keyword(s):  
Time Perception ◽  
Human Subjects ◽  
Peak Frequency ◽  
Alpha Oscillations ◽  
Standard Interval ◽  
Alpha Frequency ◽  
Temporal Intervals ◽  
Transcranial Alternating Current Stimulation ◽  
Speed Effect ◽  
Individual Alpha Frequency

Abstract Previous studies have linked brain oscillation and timing, with evidence suggesting that alpha oscillations (10 Hz) may serve as a “sample rate” for the visual system. However, direct manipulation of alpha oscillations and time perception has not yet been demonstrated. To test this, we had 18 human subjects perform a time generalization task with visual stimuli. Additionally, we had previously recorded resting-state EEG from each subject and calculated their individual alpha frequency (IAF), estimated as the peak frequency from the mean spectrum over posterior electrodes between 8 and 13 Hz. Participants first learned a standard interval (600 ms) and were then required to judge if a new set of temporal intervals were equal or different compared with that standard. After learning the standard, participants performed this task while receiving occipital transcranial Alternating Current Stimulation (tACS). Crucially, for each subject, tACS was administered at their IAF or at off-peak alpha frequencies (IAF ± 2 Hz). Results demonstrated a linear shift in the psychometric function indicating a modification of perceived duration, such that progressively “faster” alpha stimulation led to longer perceived intervals. These results provide the first evidence that direct manipulations of alpha oscillations can shift perceived time in a manner consistent with a clock speed effect.

Spike Phase Shift Relative to Beta Oscillations Mediates Modality Selection

2020 ◽  
Vol 30 (10) ◽  
pp. 5431-5448
Author(s):  
Yanfang Zuo ◽  
Yanwang Huang ◽  
Dingcheng Wu ◽  
Qingxiu Wang ◽  
Zuoren Wang
Keyword(s):  
Phase Shift ◽  
Posterior Parietal Cortex ◽  
Visual Stimuli ◽  
Spike Timing ◽  
Male Rats ◽  
Top Down ◽  
Beta Oscillations ◽  
Neuronal Spike ◽  
Beta Power ◽  
The Brain

Abstract How does the brain selectively process signals from stimuli of different modalities? Coherent oscillations may function in coordinating communication between neuronal populations simultaneously involved in such cognitive behavior. Beta power (12–30 Hz) is implicated in top-down cognitive processes. Here we test the hypothesis that the brain increases encoding and behavioral influence of a target modality by shifting the relationship of neuronal spike phases relative to beta oscillations between primary sensory cortices and higher cortices. We simultaneously recorded neuronal spike and local field potentials in the posterior parietal cortex (PPC) and the primary auditory cortex (A1) when male rats made choices to either auditory or visual stimuli. Neuronal spikes exhibited modality-related phase locking to beta oscillations during stimulus sampling, and the phase shift between neuronal subpopulations demonstrated faster top-down signaling from PPC to A1 neurons when animals attended to auditory rather than visual stimuli. Importantly, complementary to spike timing, spike phase predicted rats’ attended-to target in single trials, which was related to the animals’ performance. Our findings support a candidate mechanism that cortices encode targets from different modalities by shifting neuronal spike phase. This work may extend our understanding of the importance of spike phase as a coding and readout mechanism.

On the Relation between Time Perception and the Timing of Motor Action: Evidence for a Temporal Oscillator Controlling the Timing of Movement

1992 ◽  
Vol 45 (2) ◽  
pp. 235-263 ◽  
Author(s):  
Michel Treisman ◽  
Andrew Faulkner ◽  
Peter L. N. Naish
Keyword(s):  
Reaction Time ◽  
Time Perception ◽  
Choice Reaction Time ◽  
Characteristic Frequency ◽  
Motor Performance ◽  
Time Estimation ◽  
Internal Clock ◽  
Motor Timing ◽  
Motor Action ◽  
Perception Of Time

Studies of time estimation have provided evidence that human time perception is determined by an internal clock containing a temporal oscillator and have also provided estimates of the frequency of this oscillator (Treisman, Faulkner, Naish, & Brogan, 1992; Treisman & Brogan, 1992). These estimates were based on the observation that when the intervals to be estimated are accompanied by auditory clicks that recur at certain critical rates, perturbations in time estimation occur. To test the hypothesis that the mechanisms that underlie the perception of time and those that control the timing of motor performance are similar, analogous experiments were performed on motor timing, with the object of seeing whether evidence for a clock would be obtained and if so whether its properties resemble those of the time perception clock. The prediction was made that perturbations in motor timing would be seen at the same or similar critical auditory click rates. The experiments examined choice reaction time and typing. The results support the hypothesis that a temporal oscillator paces motor performance and that this oscillator is similar to the oscillator underlying time perception. They also provide an estimate of the characteristic frequency of the oscillator.

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