Neural Representation of Information Measure in the Primate Premotor Cortex

2006 ◽  
Vol 96 (1) ◽  
pp. 478-485 ◽  
Author(s):  
Kiyohiko Nakamura
Keyword(s):  
Premotor Cortex ◽  
Information Value ◽  
Neural Representation ◽  
Information Measure ◽  
Limited Information ◽  
Information Theoretic ◽  
Information Measures ◽  
Independent Events ◽  
To Receive ◽  
The Brain

Animals seek information to reduce their efforts to receive rewards and perform actions that enable them to gain more information. The ability of seeking information subserves higher cognition processes such as planning and reasoning. There exists limited information on how the brain measures and seeks information. In this study, I discuss results indicating that the brain quantifies information by using the information-theoretic measure. The monkeys were trained to perform saccadic eye movement to one of the visual targets. When required to choose from the targets that included varying amounts of information regarding the goal, the animals selected the most informative target. While making a choice, the neurons in the dorsal premotor cortex exhibited activity that reflected the corresponding information value. The population response of these neurons was examined using the following three measures: the information-theoretic measure, probability gain, and absolute change in beliefs. Changes in this response exhibited relatively similar proportionality to the three measures. An analysis of two intuitive conditions for information measures, decreasing monotonicity on probability and additivity between independent events, showed that only the information-theoretic measure satisfies both the conditions. These results suggest that in comparison with the other measures, the information-theoretic measure is more plausible for information measure in the brain.

Neural representation of sensory data

2002 ◽  
Vol 25 (2) ◽  
pp. 207-208
Author(s):  
Jonathan Polimeni ◽  
Eric Schwartz
Keyword(s):  
Object Recognition ◽  
Visual Imagery ◽  
Symbolic Representation ◽  
Ventral Stream ◽  
Neural Representation ◽  
Theoretic Analysis ◽  
Information Theoretic ◽  
Sensory Data ◽  
Target Article ◽  
The Brain

In the target article Pylyshyn revives the spectre of the “little green man,” arguing for a largely symbolic representation of visual imagery. To clarify this problem, we provide precise definitions of the key term “picture,” present some examples of our definition, and outline an information-theoretic analysis suggesting that the problem of addressing data in the brain requires a partially analogue and partially symbolic solution. This is made concrete in the ventral stream of object recognition, from V1 to IT cortex.

scholarly journals Surprise!

2020 ◽  
Author(s):  
Stephen R Cole ◽  
Jessie K Edwards ◽  
Sander Greenland
Keyword(s):  
Noisy Data ◽  
Information Value ◽  
Shannon Information ◽  
Limited Information ◽  
P Values ◽  
Interval Estimates ◽  
Information Measures

Abstract Measures of information and surprise, such as the Shannon information value (S value), quantify the signal present in a stream of noisy data. We illustrate the use of such information measures in the context of interpreting P values as compatibility indices. S values help communicate the limited information supplied by conventional statistics and cast a critical light on cutoffs used to judge and construct those statistics. Misinterpretations of statistics may be reduced by interpreting P values and interval estimates using compatibility concepts and S values instead of “significance” and “confidence.”

scholarly journals Comparison of Different Analytical Methods for the On-Site Analysis of Traces at Clandestine Drug Laboratories

2021 ◽  
Vol 11 (9) ◽  
pp. 3754
Author(s):  
René Reiss ◽  
Frank Hauser ◽  
Sven Ehlert ◽  
Michael Pütz ◽  
Ralf Zimmermann
Keyword(s):  
Large Scale ◽  
Ambient Pressure ◽  
Relevant Information ◽  
Information Value ◽  
Site Analysis ◽  
Complex Information ◽  
Skilled Operator ◽  
Validation Parameters ◽  
Clandestine Laboratories ◽  
To Receive

While fast and reliable analytical results are crucial for first responders to make adequate decisions, these can be difficult to establish, especially at large-scale clandestine laboratories. To overcome this issue, multiple techniques at different levels of complexity are available. In addition to the level of complexity their information value differs as well. Within this publication, a comparison between three techniques that can be applied for on-site analysis is performed. These techniques range from ones with a simple yes or no response to sophisticated ones that allows to receive complex information about a sample. The three evaluated techniques are immunoassay drug tests representing easy to handle and fast to explain systems, ion mobility spectrometry as state-of-the-art equipment that needs training and experience prior to use and ambient pressure laser desorption with the need for a highly skilled operator as possible future technique that is currently under development. In addition to the measurement of validation parameters, real case samples are investigated to obtain practically relevant information about the capabilities and limitations of these techniques for on-site operations. Results demonstrate that in general all techniques deliver valid results, but the bandwidth of information widely varies between the investigated techniques.

scholarly journals Ibudilast, a neuroimmune modulator, reduces heavy drinking and alcohol cue-elicited neural activation: a randomized trial

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Erica N. Grodin ◽  
Spencer Bujarski ◽  
Brandon Towns ◽  
Elizabeth Burnette ◽  
Steven Nieto ◽  
...  
Keyword(s):  
Macrophage Migration Inhibitory Factor ◽  
Alcohol Use Disorder ◽  
Cue Reactivity ◽  
Negative Mood ◽  
Heavy Drinking ◽  
Neural Activation ◽  
Daily Diary Study ◽  
Alcohol Cues ◽  
To Receive ◽  
The Brain

AbstractIbudilast, a neuroimmune modulator which selectively inhibits phosphodiesterases (PDE)-3, -4, -10, and -11, and macrophage migration inhibitory factor (MIF), shows promise as a novel pharmacotherapy for alcohol use disorder (AUD). However, the mechanisms of action underlying ibudilast’s effects on the human brain remain largely unknown. Thus, the current study examined the efficacy of ibudilast to improve negative mood, reduce heavy drinking, and attenuate neural reward signals in individuals with AUD. Fifty-two nontreatment-seeking individuals with AUD were randomized to receive ibudilast (n = 24) or placebo (n = 28). Participants completed a 2-week daily diary study during which they filled out daily reports of their past day drinking, mood, and craving. Participants completed an functional magnetic resonance imaging (fMRI) alcohol cue-reactivity paradigm half-way through the study. Ibudilast did not have a significant effect on negative mood (β = −0.34, p = 0.62). However, ibudilast, relative to placebo, reduced the odds of heavy drinking across time by 45% (OR = 0.55, (95% CI: 0.30, 0.98)). Ibudilast also attenuated alcohol cue-elicited activation in the ventral striatum (VS) compared to placebo (F(1,44) = 7.36, p = 0.01). Alcohol cue-elicited activation in the VS predicted subsequent drinking in the ibudilast group (F(1,44) = 6.39, p = 0.02), such that individuals who had attenuated ventral striatal activation and took ibudilast had the fewest number of drinks per drinking day in the week following the scan. These findings extend preclinical and human laboratory studies of the utility of ibudilast to treat AUD and suggest a biobehavioral mechanism through which ibudilast acts, namely, by reducing the rewarding response to alcohol cues in the brain leading to a reduction in heavy drinking.

scholarly journals Temporal trends in treatment and outcomes of patients with acute coronary syndrome and concomitant moderate to severe renal failure

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Bossard ◽  
F Witassek ◽  
D Radovanovic ◽  
F Moccetti ◽  
P Erne ◽  
...  
Keyword(s):  
Renal Failure ◽  
Temporal Trends ◽  
Limited Information ◽  
Severe Renal Failure ◽  
P2y12 Inhibitors ◽  
Coronary Syndrome ◽  
Number Of Patients ◽  
Percutaneous Coronary ◽  
Coronary Syndromes ◽  
To Receive

Abstract Introduction Limited information about the management and outcomes of patients with acute coronary syndromes (ACS) and moderate to severe renal failure (RF) is available owing to underrepresentation of this population in most studies. Methods We evaluated the use of guideline-recommended therapies and in-hospital outcomes of totally 49'191 ACS patients with normal-mild renal failure (RF) (defined as eGFR >45ml/min/m2) versus moderate-severe RF (eGFR <45ml/min/m2) enrolled in the prospective Acute Myocardial Infarction in Switzerland (AMIS) cohort between 2002 and 2019 according to 2-year periods. Results Overall, 3'478 (7.1%) patients had moderate-severe RF. They were older (65.2+12.9 versus 77.2+10.6 years) and had significantly more comorbidities (including heart failure, cerebrovascular and peripheral vascular disease). Moderate-severe RF patients received less frequently guideline-recommended drugs, including P2Y12 inhibitors, ACEI/ARBs and statins (p<0.0001). Between the first and last 2-year periods, the number of patients with moderate-severe RF and number of performed percutaneous coronary interventions (PCI) increased in this cohort (p-for-trend=0.001). At the same time, in-hospital mortality significantly decreased among ACS patients with and without RF (17.5% to 10.5% and 6.0% to 3.9%, respectively, p-for-trend=0.001 for both, see Figure). Similar trends were observed for other complications, namely cardiogenic shock and reinfarction. However, major bleedings increased significantly over time in patients with and without RF (p-for-trend=0.038 and <0.001, respectively). Conclusions Outcomes of ACS patients with moderate to severe RF improved over the last two decades. Even though the rate of PCI increased in ACS patients with moderate-severe RF, they were less likely to receive guideline-recommended therapies and still suffer a high in-hospitality mortality (>10%). With respect to the increasing burden of ACS patients with RF, our study implicates that more efforts should be undertaken to further improve outcomes of those patients. Funding Acknowledgement Type of funding source: None

Effect of Subarachnoid Bupivacaine Block on Anesthetic Requirements for Thiopental in Rats 

1998 ◽  
Vol 88 (4) ◽  
pp. 1036-1042 ◽  
Author(s):  
Sunil Eappen ◽  
Igor Kissin
Keyword(s):  
Local Anesthetic ◽  
Direct Action ◽  
Afferent Input ◽  
Crossover Design ◽  
Hemodynamic Parameters ◽  
Motor Responses ◽  
Withdrawal Reflex ◽  
Corneal Reflex ◽  
To Receive ◽  
The Brain

Background Subarachnoid bupivacaine blockade has been reported to reduce thiopental and midazolam hypnotic requirements in patients. The purpose of this study was to examine if local anesthetically induced lumbar intrathecal blockade would reduce thiopental requirements for blockade of motor responses to noxious and nonnoxious stimuli in rats. Methods After intrathecal and external jugular catheter placement, rats were assigned randomly to two groups in a crossover design study, with each rat to receive either 10 microl of 0.75% bupivacaine or 10 microl of normal saline intrathecally. The doses of intravenously administered thiopental required to ablate the eyelid reflex, to block the withdrawal reflex of a front limb digit, and to block the corneal reflex were compared. In two separate groups of animals, hemodynamic parameters and concentrations of thiopental in the brain were compared between intrathecally administered bupivacaine and saline. Results The thiopental dose required to block the described responses was decreased with intrathecally administered bupivacaine versus intrathecally administered saline from (mean +/- SD) 40 +/- 5 to 24 +/- 4 mg/kg (P < 0.001) for the eyelid reflex, from 51 +/- 6 to 29 +/- 6 mg/kg (P < 0.005) for front limb withdrawal, and from 67 +/- 8 to 46 +/- 8 mg/kg (P < 0.01) for the corneal reflex. The concentration of thiopental in the brain at the time of corneal reflex blockade for the group given bupivacaine was significantly lower than in the group given saline (24.1 vs. 35.8 microg/g, P = 0.02). Conclusion This study demonstrates that lumbar intrathecally administered local anesthetic blockade decreases anesthetic requirements for thiopental for a spectrum of end points tested. This effect is due neither to altered pharmacokinetics nor to a direct action of the local anesthetic on the brain; rather, it is most likely due to decreased afferent input.

Phase II study of nivolumab and salvage nivolumab + ipilimumab in treatment-naïve patients (pts) with advanced non-clear cell renal cell carcinoma (nccRCC) (HCRN GU16-260-Cohort B).

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 4510-4510
Author(s):  
Michael B. Atkins ◽  
Opeyemi Jegede ◽  
Naomi B. Haas ◽  
David F. McDermott ◽  
Mehmet Asim Bilen ◽  
...  
Keyword(s):  
Clear Cell ◽  
Metastatic Lesion ◽  
Limited Information ◽  
Cell Renal Cell Carcinoma ◽  
Best Response ◽  
Treatment Naïve ◽  
Correlative Studies ◽  
Grade 3 ◽  
To Receive ◽  
Clinical Trial Information

4510 Background: The HCRN GU16-260 trial reported on the efficacy and toxicity of nivo monotherapy in treatment naïve clear cell RCC (Cohort A) and the efficacy of nivo/ipi salvage therapy in pts with tumors resistant to initial nivo monotherapy (Atkins JCO 2020.38.15_suppl.5006). Limited information is available on the effects of such an approach in pts with advanced nccRCC. Methods: Eligible pts with treatment-naïve nccRCC received nivo 240mg IV q2 wk x 6 doses followed by 360mg IV q3 wk x 4 doses followed by 480 mg q4 wk until progressive disease (PD), toxicity, or completion of 96 wks of treatment (Part A). Pts with PD prior to or stable disease (SD) at 48 wks (pSD) were potentially eligible to receive salvage nivo (3mg/kg) /ipi (1 mg/kg) q3 wk x 4 doses followed by q4 wk nivo maintenance for up to 48 wks (Part B). All pts were required to submit tissue from a metastatic lesion obtained within 12 months (mo) prior to study entry and prior to enrolling on Part B for correlative studies. Results: 35 pts with nccRCC were enrolled between 5/2017 and 12/2019 at 12 participating HCRN sites. Median age 63 (range 35-84 years); 89% male. IMDC favorable 8 (23%), intermediate 18 (51%) and poor risk 9 (26%). Of the 35 pts 19 (54%) had papillary, 6 (17%) chromophobe and 10 (29%) unclassified histology. RECIST defined ORR was 5 of 35 (14.3%) [CR 2 (5.7%), PR 3 (8.6%)], SD 16 (45.7%), PD 14 (40.0%). Immune-related ORR was 8 of 35 (22.9%). RECIST ORR by histology was: papillary - 1/19 (5%); chromophobe - 1/6 (17%); unclassified - 3/10 (30%). 9 pts (26%) had tumors with sarcomatoid features with 3 (33%) (2 unclassified, 1 papillary) responding. Median PFS was 4.0 (2.7, 4.3) mo. 21 pts remain alive. None of the responders have progressed or died. 28 pts (25 PD, 3 pSD) were potentially eligible for salvage nivo/ipi (Part B), but 12 did not enroll due to symptomatic PD (2), grade 3-4 toxicity on nivo (3), or other including no biopsy tissue (7). In the 16 Part B pts, best response to nivo/ipi was: PR (1, 6%) – (unclassified/non-sarcomatoid); SD (7, 44%); PD (8, 50%). Grade 3 Treatment-related adverse events (TrAEs) were seen in 7/35 (20%) on nivo. Grade 3-5 TrAEs were seen in 7/16 (44%) on nivo/ipi with 1 pt experiencing sudden death. Correlative studies including PD-L1 status, WES and RNAseq are pending. Conclusions: Nivo monotherapy has limited activity in treatment naïve nccRCC with most responses (4 of 5) seen in pts with sarcomatoid and/or unclassified tumors. Toxicity is consistent with prior nivo studies. Salvage treatment with nivo/ipi was provided in 16 of 28 (57%) pts with PD/pSD on nivo monotherapy, with 1 response observed. Clinical trial information: NCT03117309.

scholarly journals Information Guided Exploration of Scalar Values and Isocontours in Ensemble Datasets

Entropy ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 540 ◽  
Author(s):  
Subhashis Hazarika ◽  
Ayan Biswas ◽  
Soumya Dutta ◽  
Han-Wei Shen
Keyword(s):  
Weather Forecasting ◽  
Conditional Entropy ◽  
Specific Information ◽  
Theoretic Approach ◽  
Information Theoretic ◽  
Information Measures ◽  
New Information ◽  
Real World Datasets ◽  
The Individual ◽  
Information Theoretic Approach

Uncertainty of scalar values in an ensemble dataset is often represented by the collection of their corresponding isocontours. Various techniques such as contour-boxplot, contour variability plot, glyphs and probabilistic marching-cubes have been proposed to analyze and visualize ensemble isocontours. All these techniques assume that a scalar value of interest is already known to the user. Not much work has been done in guiding users to select the scalar values for such uncertainty analysis. Moreover, analyzing and visualizing a large collection of ensemble isocontours for a selected scalar value has its own challenges. Interpreting the visualizations of such large collections of isocontours is also a difficult task. In this work, we propose a new information-theoretic approach towards addressing these issues. Using specific information measures that estimate the predictability and surprise of specific scalar values, we evaluate the overall uncertainty associated with all the scalar values in an ensemble system. This helps the scientist to understand the effects of uncertainty on different data features. To understand in finer details the contribution of individual members towards the uncertainty of the ensemble isocontours of a selected scalar value, we propose a conditional entropy based algorithm to quantify the individual contributions. This can help simplify analysis and visualization for systems with more members by identifying the members contributing the most towards overall uncertainty. We demonstrate the efficacy of our method by applying it on real-world datasets from material sciences, weather forecasting and ocean simulation experiments.

scholarly journals Comparative Analysis of Methods for Estimation of Undirected Coupling from Time Series of Intracranial Eegs of Cortex of Rats-Genetic Models of Absence Epilepsy

2017 ◽  
Vol 12 (2) ◽  
pp. 317-326
Author(s):  
А.А. Грищенко ◽  
A.A. Grishchenko
Keyword(s):  
Time Window ◽  
Surrogate Data ◽  
Epileptic Activity ◽  
Absence Epilepsy ◽  
Information Function ◽  
Brain Areas ◽  
To Receive ◽  
Intracranial Recordings ◽  
The Brain ◽  
Mutual Information Function

Studying coupling between brain areas from its electromagnetic activity is one of the key approaches in epilepsy research now, since epileptic activity has been considered to be a result of pathological synchronization in the brain. Often, research is conducted on animal models, because this allows to perform intracranial measurement, and to get rid of interference caused by the skull and to receive signals from deeper regions of the brain such as thalamus or hippocampus. In this study, the intracranial recordings from the frontal and parietal areas of cortex are investigated with a nonlinear correlation coefficient and a mutual information function in a sliding time window. The coupling estimates obtained were subjected for statistical analysis for significance using surrogate data. The dynamics of connectivity between the frontal cortex and the parietal cortex was shown to vary from seizure to seizure and from animal to animal. Therefore, estimates of the significant change in connectivity associated with initiation of the absense seizure, found previously based on averaging over a large number of animals and a large number of seizures for an each animal, can be a result of contribution of a relatively small number of seizures (less than a half of considered), for which the changes are significant.

scholarly journals Subjective value and decision entropy are jointly encoded by aligned gradients across the human brain

2020 ◽  
Author(s):  
Sebastian Bobadilla-Suarez ◽  
Olivia Guest ◽  
Bradley C. Love
Keyword(s):  
Prefrontal Cortex ◽  
Human Brain ◽  
Ventromedial Prefrontal Cortex ◽  
Neural Representation ◽  
Retrospective Evaluation ◽  
Systematic Fashion ◽  
Subjective Value ◽  
Fmri Analysis ◽  
The Relationship ◽  
The Brain

AbstractRecent work has considered the relationship between value and confidence in both behavior and neural representation. Here we evaluated whether the brain organizes value and confidence signals in a systematic fashion that reflects the overall desirability of options. If so, regions that respond to either increases or decreases in both value and confidence should be widespread. We strongly confirmed these predictions through a model-based fMRI analysis of a mixed gambles task that assessed subjective value (SV) and inverse decision entropy (iDE), which is related to confidence. Purported value areas more strongly signalled iDE than SV, underscoring how intertwined value and confidence are. A gradient tied to the desirability of actions transitioned from positive SV and iDE in ventromedial prefrontal cortex to negative SV and iDE in dorsal medial prefrontal cortex. This alignment of SV and iDE signals could support retrospective evaluation to guide learning and subsequent decisions.

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