scholarly journals Information-based taste maps in insular cortex are shaped by stimulus concentration

2019 ◽  
Author(s):  
E Porcu ◽  
KM Benz ◽  
F Ball ◽  
C Tempelmann ◽  
M Hanke ◽  
...  
Keyword(s):  
Complex Function ◽  
Insular Cortex ◽  
Population Level ◽  
Ingestive Behavior ◽  
Current Evidence ◽  
High Concentration ◽  
Potential Harm ◽  
Taste Processing ◽  
Human Participants ◽  
Multivariate Pattern

AbstractTaste processing is an essential ability in all animals signaling potential harm or benefit of ingestive behavior. Although the peripheral taste coding is well understood, current evidence for central taste processing remains contradictory. To address this issue, human participants judged pleasantness and intensity of low and high-concentration tastes (salty, sweet, sour, bitter) in two fMRI-experiments. High-resolution fMRI and multivariate pattern analysis were used to characterize taste-related informational content in human gustatory cortex (GC). Clusters within GC were narrowly tuned to specific tastants consistently across tasks. Importantly, taste concentrations completely altered the spatial layout of putative taste-specific maps with distinct, non-overlapping patterns for each taste category at different concentration levels. Together, our results point at population-level representations in human GC as a complex function of taste category and concentration.

scholarly journals Macroscopic information-based taste representations in insular cortex are shaped by stimulus concentration

2020 ◽  
Vol 117 (13) ◽  
pp. 7409-7417 ◽  
Author(s):  
Emanuele Porcu ◽  
Karsta M. Benz ◽  
Felix Ball ◽  
Claus Tempelmann ◽  
Michael Hanke ◽  
...  
Keyword(s):  
Complex Function ◽  
Insular Cortex ◽  
Ingestive Behavior ◽  
Current Evidence ◽  
Multivariate Pattern Analysis ◽  
High Concentration ◽  
Potential Harm ◽  
Taste Processing ◽  
Human Participants ◽  
Multivariate Pattern

Taste processing is an essential ability in all animals signaling potential harm or benefit of ingestive behavior. However, current evidence for cortical taste representations remains contradictory. To address this issue, high-resolution functional MRI (fMRI) and multivariate pattern analysis were used to characterize taste-related informational content in human insular cortex, which contains primary gustatory cortex. Human participants judged pleasantness and intensity of low- and high-concentration tastes (salty, sweet, sour, and bitter) in two fMRI experiments on two different days to test for task- and concentration-invariant taste representations. We observed patterns of fMRI activity within insular cortex narrowly tuned to specific tastants consistently across tasks in all participants. Fewer patterns responded to more than one taste category. Importantly, changes in taste concentration altered the spatial layout of putative taste-specific patterns with distinct, almost nonoverlapping patterns for each taste category at different concentration levels. Together, our results point at macroscopic representations in human insular cortex as a complex function of taste category and concentration rather than representations based solely on taste identity.

scholarly journals Overlapping Representation of Basic Tastes in the Human Gustatory Cortex

2021 ◽  
Author(s):  
Du Zhang ◽  
Xiaoxiao Wang ◽  
Yanming Wang ◽  
Benedictor Alexander Nguchu ◽  
Zhoufang Jiang ◽  
...  
Keyword(s):  
Fundamental Property ◽  
Insular Cortex ◽  
Taste Preference ◽  
Topological Representation ◽  
Activation Patterns ◽  
Gustatory Cortex ◽  
Taste Response ◽  
Neural Activities ◽  
Sensory Cortices ◽  
Multivariate Pattern

The topological representation is a fundamental property of human primary sensory cortices. The human gustatory cortex (GC) responds to the five basic tastes: bitter, salty, sweet, umami, and sour. However, the topological representation of the human gustatory cortex remains controversial. Through functional magnetic resonance imaging(fMRI) measurements of human responses to the five basic tastes, the current study aimed to delineate the taste representations within the GC. During the scanning, the volunteers tasted solutions of the five basic tastes, then washed their mouths with the tasteless solution. The solutions were then sucked from the volunteers' mouths, eliminating the action of swallowing. The results showed that the bilateral mid-insula activated most during the taste task, and the active areas were mainly in the precentral and central insular sulcus. However, the regions responding to the five basic tastes are substantially overlapped, and the analysis of contrasts between each taste response and the averaged response to the remaining tastes does not report any significant results. Furthermore, in the gustatory insular cortex, the multivariate pattern analysis (MVPA) was unable to distinguish the activation patterns of the basic tastes, suggesting the possibility of weakly clustered distribution of the taste-preference neural activities in the human insular cortex. In conclusion, the presented results suggest overlapping representations of the basic tastes in the human gustatory insular cortex.

scholarly journals How fast is fast enough? Walking cadence (steps/min) as a practical estimate of intensity in adults: a narrative review

2018 ◽  
Vol 52 (12) ◽  
pp. 776-788 ◽  
Author(s):  
Catrine Tudor-Locke ◽  
Ho Han ◽  
Elroy J Aguiar ◽  
Tiago V Barreira ◽  
John M Schuna Jr ◽  
...  
Keyword(s):  
Population Level ◽  
Strong Relationship ◽  
Epidemiological Studies ◽  
Moderate Intensity ◽  
Current Evidence ◽  
Free Living ◽  
Metabolic Equivalents ◽  
Registration Number ◽  
Comprehensive Search ◽  
Comprehensive Search Strategy

BackgroundCadence (steps/min) may be a reasonable proxy-indicator of ambulatory intensity. A summary of current evidence is needed for cadence-based metrics supporting benchmark (standard or point of reference) and threshold (minimums associated with desired outcomes) values that are informed by a systematic process.ObjectiveTo review how fast, in terms of cadence, is enough, with reference to crafting public health recommendations in adults.MethodsA comprehensive search strategy was conducted to identify relevant studies focused on walking cadence and intensity for adults. Identified studies (n=38) included controlled (n=11), free-living observational (n=18) and intervention (n=9) designs.ResultsThere was a strong relationship between cadence (as measured by direct observation and objective assessments) and intensity (indirect calorimetry). Despite acknowledged interindividual variability, ≥100 steps/min is a consistent heuristic (e.g, evidence-based, rounded) value associated with absolutely defined moderate intensity (3 metabolic equivalents (METs)). Epidemiological studies report notably low mean daily cadences (ie, 7.7 steps/min), shaped primarily by the very large proportion of time (13.5 hours/day) spent between zero and purposeful cadences (<60 steps/min) at the population level. Published values for peak 1-min and 30-min cadences in healthy free-living adults are >100 and >70 steps/min, respectively. Peak cadence indicators are negatively associated with increased age and body mass index. Identified intervention studies used cadence to either prescribe and/or quantify ambulatory intensity but the evidence is best described as preliminary.ConclusionsA cadence value of ≥100 steps/min in adults appears to be a consistent and reasonable heuristic answer to ’How fast is fast enough?' during sustained and rhythmic ambulatory behaviour.Trial registration numberNCT02650258

scholarly journals Antimicrobial Resistance Following Azithromycin Mass Drug Administration: Potential Surveillance Strategies to Assess Public Health Impact

2019 ◽  
Vol 70 (7) ◽  
pp. 1501-1508 ◽  
Author(s):  
Ines Mack ◽  
Mike Sharland ◽  
James A Berkley ◽  
Nigel Klein ◽  
Surbhi Malhotra-Kumar ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Controlled Trial ◽  
Population Level ◽  
Health Impact ◽  
Childhood Mortality ◽  
World Health ◽  
Current Evidence ◽  
Multiresistant Pathogens ◽  
Microbiological Techniques

Abstract The reduction in childhood mortality noted in trials investigating azithromycin mass drug administration (MDA) for trachoma control has been confirmed by a recent large randomized controlled trial. Population-level implementation of azithromycin MDA may lead to selection of multiresistant pathogens. Evidence suggests that repeated azithromycin MDA may result in a sustained increase in macrolide and other antibiotic resistance in gut and respiratory bacteria. Current evidence comes from standard microbiological techniques in studies focused on a time-limited intervention, while MDA implemented for mortality benefits would likely repeatedly expose the population over a prolonged period and may require a different surveillance approach. Targeted short-term and long-term surveillance of resistance emergence to key antibiotics, especially those from the World Health Organization Access group, is needed throughout any implementation of azithromycin MDA, focusing on a genotypic approach to overcome the limitations of resistance surveillance in indicator bacteria.

scholarly journals Taste coding strategies in insular cortex

2020 ◽  
Vol 245 (5) ◽  
pp. 448-455
Author(s):  
Stephanie M Staszko ◽  
John D Boughter ◽  
Max L Fletcher
Keyword(s):  
Spatial Organization ◽  
Temporal Dynamics ◽  
Insular Cortex ◽  
Taste Quality ◽  
Temporal Organization ◽  
Cortical Representation ◽  
Sensory Stimuli ◽  
Coding Strategies ◽  
Taste Processing ◽  
Taste Coding

While the cortical representation of sensory stimuli is well described for some sensory systems, a clear understanding of the cortical representation of taste stimuli remains elusive. Recent investigations have focused on both spatial and temporal organization of taste responses in the putative taste region of insular cortex. This review highlights recent literature focused on spatiotemporal coding strategies in insular cortex. These studies are examined in the context of the organization and function of the entire insular cortex, rather than a specific gustatory region of insular cortex. In regard to a taste quality-specific map, imaging studies have reported conflicting results, whereas electrophysiology studies have described a broad distribution of taste-responsive neurons found throughout insular cortex with no spatial organization. The current collection of evidence suggests that insular cortex may be organized into a hedonic or “viscerotopic” map, rather than one ordered according to taste quality. Further, it has been proposed that cortical taste responses can be separated into temporal “epochs” representing stimulus identity and palatability. This coding strategy presents a potential framework, whereby the coordinated activity of a population of neurons allows for the same neurons to respond to multiple taste stimuli or even other sensory modalities, a well-documented phenomenon in insular cortex neurons. However, these representations may not be static, as several studies have demonstrated that both spatial representation and temporal dynamics of taste coding change with experience. Collectively, these studies suggest that cortical taste representation is not organized in a spatially discrete map, but rather is plastic and spatially dispersed, using temporal information to encode multiple types of information about ingested stimuli. Impact statement The organization of taste coding in insular cortex is widely debated. While early work has focused on whether taste quality is encoded via labeled line or ensemble mechanisms, recent work has attempted to delineate the spatial organization and temporal components of taste processing in insular cortex. Recent imaging and electrophysiology studies have reported conflicting results in regard to the spatial organization of cortical taste responses, and many studies ignore potentially important temporal dynamics when investigating taste processing. This review highlights the latest research in these areas and examines them in the context of the anatomy and physiology of the insular cortex in general to provide a more comprehensive description of taste coding in insular cortex.

scholarly journals A Distinct Role of the Temporal-Parietal Junction in Predicting Socially Guided Decisions

Science ◽  
2012 ◽  
Vol 337 (6090) ◽  
pp. 109-111 ◽  
Author(s):  
R. McKell Carter ◽  
Daniel L. Bowling ◽  
Crystal Reeck ◽  
Scott A. Huettel
Keyword(s):  
Pattern Analysis ◽  
Multivariate Pattern Analysis ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Incentive Compatible ◽  
Future Behavior ◽  
Human Participants ◽  
Multivariate Pattern ◽  
Distinct Role

To make adaptive decisions in a social context, humans must identify relevant agents in the environment, infer their underlying strategies and motivations, and predict their upcoming actions. We used functional magnetic resonance imaging, in conjunction with combinatorial multivariate pattern analysis, to predict human participants’ subsequent decisions in an incentive-compatible poker game. We found that signals from the temporal-parietal junction provided unique information about the nature of the upcoming decision, and that information was specific to decisions against agents who were both social and relevant for future behavior.

scholarly journals Theoretical and empirical evidence for the impact of inductive biases on cultural evolution

2008 ◽  
Vol 363 (1509) ◽  
pp. 3503-3514 ◽  
Author(s):  
Thomas L Griffiths ◽  
Michael L Kalish ◽  
Stephan Lewandowsky
Keyword(s):  
Empirical Evidence ◽  
Cultural Evolution ◽  
Empirical Work ◽  
Biological Evolution ◽  
Population Level ◽  
The People ◽  
Behavioural Experiments ◽  
Human Participants ◽  
A Chain ◽  
The Impact

The question of how much the outcomes of cultural evolution are shaped by the cognitive capacities of human learners has been explored in several disciplines, including psychology, anthropology and linguistics. We address this question through a detailed investigation of transmission chains, in which each person passes information to another along a chain. We review mathematical and empirical evidence that shows that under general conditions, and across experimental paradigms, the information passed along transmission chains will be affected by the inductive biases of the people involved—the constraints on learning and memory, which influence conclusions from limited data. The mathematical analysis considers the case where each person is a rational Bayesian agent. The empirical work consists of behavioural experiments in which human participants are shown to operate in the manner predicted by the Bayesian framework. Specifically, in situations in which each person's response is used to determine the data seen by the next person, people converge on concepts consistent with their inductive biases irrespective of the information seen by the first member of the chain. We then relate the Bayesian analysis of transmission chains to models of biological evolution, clarifying how chains of individuals correspond to population-level models and how selective forces can be incorporated into our models. Taken together, these results indicate how laboratory studies of transmission chains can provide information about the dynamics of cultural evolution and illustrate that inductive biases can have a significant impact on these dynamics.

scholarly journals Evidence Based Surgical Approach to Locally Advanced Gastric Cancer

2019 ◽  
Vol 17 (2) ◽  
pp. 133-140
Author(s):  
Binay Thakur ◽  
Mukti Devkota ◽  
Amit Sharma ◽  
Manish Chaudhary
Keyword(s):  
Gastric Cancer ◽  
Soviet Union ◽  
Advanced Gastric Cancer ◽  
Former Soviet Union ◽  
Locally Advanced ◽  
Population Level ◽  
Multimodality Treatment ◽  
Current Evidence ◽  
Curative Surgery ◽  
Locally Advanced Gastric Cancer

Gastric cancer is endemic in China, Japan, Korea, Brazil and Former Soviet Union. Patients are diagnosed usually in locally advanced stage. Endoscopy, Positron Emission Therapy- Computed Tomography, Endoscopic ultrasound and staging laparoscopy are the tools for proper evaluation of such patients. Locally advanced gastric cancer (T2-4N0 or TanyN+) requires multimodality treatment including surgery. Resection is the cornerstone of cure for gastric adenocarcinoma; however, several aspects of surgical intervention remain controversial or are suboptimally applied at a population level. Current evidence shows a D2 gastrectomy has got the best survival results. At least 15 lymph nodes should be assessed for adequate staging. Laparoscopic resections should be performed to the same standards as those for for open resections, by surgeons who are experienced in both advanced laparoscopic surgery and gastric cancer management.Keywords: Curative surgery; gastrectomy; stomach neoplasms.

scholarly journals Hydration, arginine vasopressin, and gluco-regulatory health in humans: A critical perspective

2019 ◽  
Author(s):  
Harriet A Carroll ◽  
Lewis J James
Keyword(s):  
Public Health ◽  
Arginine Vasopressin ◽  
Dietary Guidelines ◽  
Current Evidence ◽  
Future Research ◽  
Hydration Status ◽  
Genetic Associations ◽  
Blood Concentrations ◽  
Regulatory Effects ◽  
Human Participants

Gluco-regulatory diseases, such as type 2 diabetes are currently a key public health priority. Public health messages have started to include the addition of water in their dietary guidelines. Such guidelines however are not based on causal evidence pertaining to the health effects of increased water intake, but rather more heavily based upon non-causal or mechanistic data. One line of thinking linking fluid intake and health is that hypohydration induces elevated blood concentrations of arginine vasopressin (AVP). Research in the 1970s and 1980s implicated AVP in gluco-regulation, supported by observational evidence. This important area of research subsequently appeared to stop until this century during which interest in hypertonic saline infusion studies, animal AVP receptor knockout models, dietary and genetic associations, and human interventions manipulating hydration status have resurged. This narrative review briefly describes and critically evaluates the usefulness of the current AVP-gluco-regulatory research. We offer suggestions on how to test the independent gluco-regulatory effects of body mass reductions versus elevated circulating AVP concentrations, such as investigating hydration manipulations using 3,4-Methylenedioxymethamphetamine. Whilst much research is still needed before making firm conclusions, the current evidence suggests that although AVP may only be partially implicated in gluco-regulation; more ecologically valid models using human participants suggests this effect is independent of hydration status. The key implication of this hypothesis if confirmed in future research is that manipulating hydration status to reduce circulating AVP concentrations may not be an effective method to improve gluco-regulatory health.

Sodium intake, health implications, and the role of population-level strategies

2020 ◽  
Author(s):  
Ghadeer S Aljuraiban ◽  
Arun Pulikkottil Jose ◽  
Priti Gupta ◽  
Krithiga Shridhar ◽  
Dorairaj Prabhakaran
Keyword(s):  
Sodium Intake ◽  
Population Level ◽  
World Health ◽  
Current Evidence ◽  
Health Implications ◽  
High Sodium ◽  
Reduce Sodium Intake ◽  
Matters Of Concern

Abstract Evidence to date suggests that high sodium intake affects health adversely, yet the role of a population-level strategy to reduce sodium intake is often contested. This review focuses on current available evidence on regional sodium intake levels, health implications of sodium intake, and population-level strategies implemented worldwide. The limitations in evidence, the difficulties in implementing population-wide strategies to reduce sodium intake, and the need for such strategies are critically reviewed. Evidence clearly shows that sodium has an adverse effect on blood pressure, cardiovascular disease, and mortality. However, whether reduced sodium intake benefits all individuals or only hypertensive individuals is still unclear. Methodological issues and publication bias in current evidence are other matters of concern in sodium-related research. While it is essential to continue working toward the World Health Organization’s target of 30% reduction in sodium intake, due consideration should be given to improving the quality of research, reducing bias in publications, and reviewing evidence more critically.

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