Predicting multisensory enhancement in neuronal responses

2012 ◽  
Vol 25 (0) ◽  
pp. 3
Author(s):  
Benjamin A. Rowland
Keyword(s):  
Alternative Hypothesis ◽  
Initial Response ◽  
Neuronal Responses ◽  
Experimental Conditions ◽  
Sensory Modalities ◽  
Response Enhancement ◽  
Multisensory Enhancement ◽  
Response Profiles ◽  
The Individual ◽  
Statistical Noise

The most dramatic physiological example of multisensory integration is response enhancement, where the integration of concordant signals across multiple sensory modalities leads to a larger and more reliable response. In the model system of the superior colliculus, the largest enhancements (often greater than the predicted sum) are observed when the individual signals being combined are weak. This principle conforms to expectations based on signal detection theory, and also as expected, enhancement is not uniform throughout any response. Typically it is greatest near its onset, when the unisensory inputs are at their weakest (Initial Response Enhancement, see Rowland et al., 2007; Rowland and Stein, 2008). Despite the general accuracy of this heuristic, however, there is a substantial amount of variance in the degree of observed enhancement at all levels of responsiveness. This observation appears to violate standard Bayesian predictions that are based on overall response magnitude. Aside from statistical noise, a possible explanation is that individual neurons in the dataset are calibrated to different ‘computational modes’. An alternative hypothesis is that the amount of enhancement is influenced greatly by response properties other than magnitude, specifically, the temporal profile of the response. The present analysis advances the latter hypothesis. We present a mechanistic framework that explains these findings and extends the standard Bayesian approach to generate an accurate prediction for the multisensory response profile given known unisensory response profiles. These predictions offer a ‘null hypothesis’ that can be used to quantify the circumstances and timing of anomalies in the integrative processes in different experimental conditions; for example, when it is developing under different conditions, or when it is disrupted by experimental or surgical intervention at any stage of life.

Differential Gurmarin Suppression of Sweet Taste Responses in Rat Solitary Nucleus Neurons

2003 ◽  
Vol 90 (2) ◽  
pp. 911-923 ◽  
Author(s):  
Christian H. Lemon ◽  
Toshiaki Imoto ◽  
David V. Smith
Keyword(s):  
Cluster Analysis ◽  
Sucrose Concentration ◽  
Hierarchical Cluster ◽  
Initial Response ◽  
Sweet Taste ◽  
Induced Response ◽  
Response Suppression ◽  
Response Profiles ◽  
Neuronal Type ◽  
Concentration Series

We examined the effect of the sweet transduction blocker gurmarin on taste responses recorded from neurons in the rat solitary nucleus (NST) to determine how gurmarin sensitivity is distributed across neuronal type. Initially, responses evoked by washing the anterior tongue and palate with 0.5 M sucrose, 0.1 M NaCl, 0.01 M HCl, and 0.01 M quinine-HCl were recorded from 35 neurons. For some cells, responses to a sucrose concentration series (0.01–1.0 M) or an array of sweet-tasting compounds were also measured. Gurmarin (10 μg/ml, 2–4 ml) was then applied to the tongue and palate. Stimuli were reapplied after 10–15 min. Neurons were segregated into groups based on similarities among their initial response profiles using hierarchical cluster analysis (HCA). Results indicated that sucrose responses recorded from neurons representative of each HCA-defined class were suppressed by gurmarin. However, a disproportionate percentage of cells in each group displayed sucrose responses that were substantially attenuated after gurmarin treatment. Postgurmarin sucrose responses recorded from neurons that composed 57% of class S, 40% of class N, and 33% of class H were suppressed by ≥50% relative to control. On average, attenuation was statistically significant only in class S and N neurons. Although the magnitude of gurmarin-induced response suppression did not differ across sucrose concentration, responses to different sweet-tasting compounds were differentially affected. Responses to NaCl, HCl, or quinine were not suppressed by gurmarin. Results suggest that information from gurmarin-sensitive and -insensitive receptor processes converges onto single NST neurons.

Heat Transfer in Reciprocating Planar Curved Tube With Piston Cooling Application

2005 ◽  
Vol 128 (1) ◽  
pp. 219-229 ◽  
Author(s):  
Shyy Woei Chang ◽  
Yao Zheng
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Interactive Effects ◽  
Experimental Conditions ◽  
Nusselt Numbers ◽  
Curved Tube ◽  
The Individual ◽  
Cooling Passage ◽  
Piston Cooling

This paper describes an experimental study of heat transfer in a reciprocating planar curved tube that simulates a cooling passage in piston. The coupled inertial, centrifugal, and reciprocating forces in the reciprocating curved tube interact with buoyancy to exhibit a synergistic effect on heat transfer. For the present experimental conditions, the local Nusselt numbers in the reciprocating curved tube are in the range of 0.6–1.15 times of static tube levels. Without buoyancy interaction, the coupled reciprocating and centrifugal force effect causes the heat transfer to be initially reduced from the static level but recovered when the reciprocating force is further increased. Heat transfer improvement and impediment could be superimposed by the location-dependent buoyancy effect. The empirical heat transfer correlation has been developed to permit the evaluation of the individual and interactive effects of inertial, centrifugal, and reciprocating forces with and without buoyancy interaction on local heat transfer in a reciprocating planar curved tube.

scholarly journals A Prologue to Development: Establishing the legitimacy of the rule of law in post-conflict Solomon Islands

2021 ◽  
Author(s):  
◽  
Finbar Benedict Kiddle
Keyword(s):  
Capacity Building ◽  
Rule Of Law ◽  
Solomon Islands ◽  
Initial Response ◽  
The State ◽  
Western World ◽  
The Rule Of Law ◽  
Shared Beliefs ◽  
Post Conflict ◽  
The Individual

<p>The rule of law forms the bedrock for societal and institutional organisation in the Western world. International actors see its establishment in developing countries as a means to facilitate wider development work and an end in and of itself. However, development of the legitimacy of the rule of law is not well understood, especially in post-conflict environments where it is most lacking. Despite the best efforts of international interventions, the rule of law is often not in the paramount position it requires: it lacks legitimacy amongst the people. To understand why this is the case there is a need for a better understanding of how interventions develop legitimacy in the rule of law. This research develops that understanding and asks the question ‘how does the contemporary peacebuilding agenda develop the legitimacy of the rule of law in post-conflict states?’ To do this the research undertakes a case study investigation of a particular intervention: the Regional Assistance Mission to Solomon Islands. Discourse and content analyses, carried out on interview transcripts and a wealth of documentation, reveal the different forces exerted by the intervention to develop legitimacy in the rule of law. These are interpreted through a particular lens: a modified version of Luke’s three faces of power that also draws on concepts of governmentality. A four-dimensional definition of legitimacy also allows for greater analytical depth. The research shows that the contemporary peacebuilding agenda can do some things very well. It is especially effective at the initial response to crisis. It is after the establishment of this basic security/performance dimension of the rule of law that interventions begin to develop their institutional/process dimension through capacity building. Capacity building divides into three levels: the individual, the organisation, and the state. It integrates the rule of law across the state edifice and establishes it as a foundational element of the system. However, the most important aspect of building legitimacy is the development of shared beliefs, as it is these that establish what is ‘true’ amongst a society. Contemporary peacebuilding interventions portray the rule of law as intrinsically legitimate and the correct, rational way of organising society. This idea permeates through their structures, discourses, and methods. However, the rule of law is not intrinsically legitimate. It is a culturally constructed concept that in many countries is in opposition with alternative ways of organising society and resolving conflict. Developing legitimacy in the rule of law is then a struggle between competing organisational systems. Such conflict jeopardises gains made by interventions, as the rule of law is fighting an uphill battle against other internalised, and often more locally reverent, norms. If it is to establish in post-conflict environments, the rule of law and competing systems need to interact to produce a locally relevant, hybrid, conception of the rule of law. One that is recognisable to all sides, but unique to the context. This leads to peace.</p>

scholarly journals ‘What would you do if you were me, doctor?’: randomised trial of psychiatrists' personal v. professional perspectives on treatment recommendations

2010 ◽  
Vol 197 (6) ◽  
pp. 441-447 ◽  
Author(s):  
Rosmarie Mendel ◽  
Johannes Hamann ◽  
Eva Traut-Mattausch ◽  
Markus Bühner ◽  
Werner Kissling ◽  
...  
Keyword(s):  
Watchful Waiting ◽  
Randomised Trial ◽  
Specific Treatment ◽  
The Self ◽  
Personal Perspective ◽  
Experimental Conditions ◽  
Appropriate Treatment ◽  
Professional Perspectives ◽  
Oral Antipsychotic ◽  
The Individual

BackgroundIf patients are unsure whether a specific treatment is really good for them, they often pose the question, ‘What would you do if you were me, doctor?’ Patients want their psychiatrists to put themselves in their shoes and not to give a ‘standard recommendation’.AimsTo study whether this question really leads psychiatrists to reveal their personal preferences.MethodRandomised experimental study with 515 psychiatrists incorporating two decision scenarios (depression scenario: antidepressant v. watchful waiting; schizophrenia scenario: depot v. oral antipsychotic) and three experimental conditions (giving a recommendation to a patient asking, ‘What would you do if you were me, doctor?’; giving a regular recommendation to a patient without being asked this question; and imagining being ill and deciding for yourself). Main outcome measures were the treatments chosen or recommended by physicians.ResultsPsychiatrists choosing treatment for themselves predominantly selected other treatments (mostly watchful waiting and oral antipsychotics respectively) than what psychiatrists recommended to patients when asked in the ‘regular recommendation role’ (i.e. antidepressant and depot respectively). Psychiatrists in the ‘what-would-you-do role’ gave recommendations similar to the ‘regular recommendation role’ (depression scenario: χ2 = 0.12, P = 0.73; schizophrenia scenario: χ2 = 2.60, P = 0.11) but distinctly different from the ‘self role’.ConclusionsThe question ‘What would you do if you were me, doctor?’ does not motivate psychiatrists to leave their professional recommendation role and to take a more personal perspective. Psychiatrists should try to find out why individuals are asking this question and, together with the individual, identify the most appropriate treatment option.

Modeling the Intellect from a Coordination Perspective

2011 ◽  
pp. 413-454 ◽  
Author(s):  
Lars Taxén
Keyword(s):  
Research Program ◽  
Social Dimensions ◽  
Central Task ◽  
The Social ◽  
Sensory Modalities ◽  
Mind And Body ◽  
Research Questions ◽  
Preliminary Research ◽  
The Individual ◽  
Point Of Departure

Usually, models of the intellect take the individual mind and body as the point of departure and proceed outward towards the social and natural environment in which the individual is immersed. As a consequence, important social dimensions contributing to the epigenetic development of the individual are less articulated. This chapter suggests modeling the intellect from a more balanced perspective that recognizes both social and individual aspects–the coordination of actions. The author argues that coordination is made possible by certain innate dispositions called activity modalities: contextualization, spatialization, temporalization, stabilization, and transition. Consequently, a central task for modeling the intellect is to understand how perceptions received through sensory modalities are related to the activity modalities. To this end, the author proposes a research program for modeling the intellect, based on the concept of “activity” in the Russian Activity Theory and the activity modalities. Provisional arguments for the relevance of these modalities are discussed in three different realms associated with the intellect: the social, conceptual, and neural ones. The chapter is concluded with some preliminary research questions, pertinent for the research program.

Brain stem responses to electrical stimulation of ventral vagal gastric fibers

1989 ◽  
Vol 257 (1) ◽  
pp. G24-G29
Author(s):  
W. D. Barber ◽  
C. S. Yuan
Keyword(s):  
Electrical Stimulation ◽  
Brain Stem ◽  
Time Of Arrival ◽  
Neuronal Responses ◽  
Proximal Stomach ◽  
Afferent Fibers ◽  
Sensory Modalities ◽  
The Mean ◽  
The Brain ◽  
Stimulation Of

The brain stem neuronal responses to electrical stimulation of gastric branches of the ventral vagal trunk serving the proximal stomach were localized and evaluated in anesthetized cats. The responses were equally distributed bilaterally in the region of nucleus solitarius in the caudal brain stem. The mean latency of the response was 289 +/- 46 (SD) ms, which translated into a conduction velocity of less than 1 m/s based on the distance between the stimulating and recording electrodes. The responses consisted of single and multiple spikes that showed slight variability in the latency, indicating orthodromic activation via a synapse in approximately 98% of the responses recorded. Forty two percent of the units tested showed evidence of convergence of input from vagal afferent fibers in different branches of the ventral vagal trunk that served the proximal stomach. The resultant activity pattern of the unitary response appeared to be the product of 1) the gastric sensory input or modality conveyed by the afferent source and 2) the time of arrival and diversity of modalities served by other gastric afferents impinging on the unit. This provides a mechanism capable of responding on the basis of specific sensory modalities that dynamically reflect ongoing events monitored and conveyed by other gastric afferents in the region.

scholarly journals Comparison of Twelve Ant Species and Their Susceptibility to Fungal Infection

Insects ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 271 ◽  
Author(s):  
Nick Bos ◽  
Viljami Kankaanpää-Kukkonen ◽  
Dalial Freitak ◽  
Dimitri Stucki ◽  
Liselotte Sundström
Keyword(s):  
Entomopathogenic Fungi ◽  
Behavioral Response ◽  
Complex Disease ◽  
Experimental Conditions ◽  
Metapleural Gland ◽  
Eusocial Insects ◽  
Fungal Exposure ◽  
The Individual ◽  
Study Species ◽  
Colony Level

Eusocial insects, such as ants, have access to complex disease defenses both at the individual, and at the colony level. However, different species may be exposed to different diseases, and/or deploy different methods of coping with disease. Here, we studied and compared survival after fungal exposure in 12 species of ants, all of which inhabit similar habitats. We exposed the ants to two entomopathogenic fungi (Beauveria bassiana and Metarhizium brunneum), and measured how exposure to these fungi influenced survival. We furthermore recorded hygienic behaviors, such as autogrooming, allogrooming and trophallaxis, during the days after exposure. We found strong differences in autogrooming behavior between the species, but none of the study species performed extensive allogrooming or trophallaxis under the experimental conditions. Furthermore, we discuss the possible importance of the metapleural gland, and how the secondary loss of this gland in the genus Camponotus could favor a stronger behavioral response against pathogen threats.

scholarly journals Tandem catalysis of ring-closing metathesis/atom transfer radical reactions with homobimetallic ruthenium–arene complexes

2010 ◽  
Vol 6 ◽  
pp. 1167-1173 ◽  
Author(s):  
Yannick Borguet ◽  
Xavier Sauvage ◽  
Guillermo Zaragoza ◽  
Albert Demonceau ◽  
Lionel Delaude
Keyword(s):  
Mixed Valence ◽  
Active Species ◽  
Radical Reactions ◽  
Catalyst Precursor ◽  
Atom Transfer ◽  
Tandem Catalysis ◽  
Ring Closing Metathesis ◽  
Experimental Conditions ◽  
Mixed Valence Compound ◽  
The Individual

The tandem catalysis of ring-closing metathesis/atom transfer radical reactions was investigated with the homobimetallic ruthenium–indenylidene complex [(p-cymene)Ru(μ-Cl)3RuCl(3-phenyl-1-indenylidene)(PCy3)] (1) to generate active species in situ. The two catalytic processes were first carried out independently in a case study before the whole sequence was optimized and applied to the synthesis of several polyhalogenated bicyclic γ-lactams and lactones from α,ω-diene substrates bearing trihaloacetamide or trichloroacetate functionalities. The individual steps were carefully monitored by 1H and 31P NMR spectroscopies in order to understand the intimate details of the catalytic cycles. Polyhalogenated substrates and the ethylene released upon metathesis induced the clean transformation of catalyst precursor 1 into the Ru(II)–Ru(III) mixed-valence compound [(p-cymene)Ru(μ-Cl)3RuCl2(PCy3)], which was found to be an efficient promoter for atom transfer radical reactions under the adopted experimental conditions.

scholarly journals Prediction Modeling and Analysis of Knocking Combustion using an Improved 0D RGF Model and Supervised Deep Learning

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 844 ◽  
Author(s):  
Seokwon Cho ◽  
Jihwan Park ◽  
Chiheon Song ◽  
Sechul Oh ◽  
Sangyul Lee ◽  
...  
Keyword(s):  
Deep Learning ◽  
System Analysis ◽  
Combustion Engine ◽  
Cylinder Pressure ◽  
Estimation Model ◽  
Experimental Conditions ◽  
Modeling And Analysis ◽  
Residual Gas Fraction ◽  
Residual Gas ◽  
The Individual

The knock phenomenon is one of the major hindrances for enhancing the thermal efficiency in spark-ignited engines. Due to the stochastic behavior of knocking combustion, analytical cycle studies are required. However, there are many problems to be addressed with regard to the individual cycle analysis of in-cylinder pressure data. This study thus proposes novel, comprehensive and efficient methodologies for evaluating the knocking combustion in the internal combustion engine. The proposed methodologies include a filtering method for the in-cylinder pressure, the determination of the knock onset, and the calculation of the residual gas fraction. Consequently, a smart knock onset model with high accuracy could be developed using a supervised deep learning that was not available in the past. Moreover, an improved zero-dimensional (0D) estimation model for the residual gas fraction was developed to obtain better accuracy for closed system analysis. Finally, based on a cyclic analysis, a knock prediction model is suggested; the model uses 0D ignition delay correlation under various experimental conditions including aggressive cam phase shifting by a dual variable valve timing (VVT) system. Using the proposed analysis method, insight into stochastic knocking combustion can be obtained, and a faster combustion speed can lead to a higher knock intensity in a steady-state operation.

Amplitude and Direction of Saccadic Eye Movements Depend on the Synchronicity of Collicular Population Activity

2004 ◽  
Vol 92 (1) ◽  
pp. 424-432 ◽  
Author(s):  
Michael Brecht ◽  
Wolf Singer ◽  
Andreas K. Engel
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Brain Structures ◽  
High Temporal Resolution ◽  
Temporal Relations ◽  
Neuronal Responses ◽  
Population Activity ◽  
Neuronal Processing ◽  
The Individual ◽  
Cat Superior Colliculus

Synchronization of neuronal discharges has been observed in numerous brain structures, but opinions diverge regarding its significance in neuronal processing. Here we investigate whether the motion vectors of saccadic eye movements evoked by electrical multisite stimulation of the cat superior colliculus (SC) are influenced by varying the degree of synchrony between the stimulus trains. With synchronous activation of SC sites, the vectors of the resulting saccades correspond approximately to the averages of the vectors of saccades evoked from each site alone. In contrast, when the pulses of trains applied to the different sites are temporally offset by as little as 5–10 ms, the vectors of the resulting saccades come close to the sum of the individual vectors. Thus saccade vectors depend not only on the site and amplitude of collicular activation but also on the precise temporal relations among the respective spike trains. These data indicate that networks within or downstream from the SC discriminate with high temporal resolution between synchronous and asynchronous population responses. This supports the hypothesis that information is encoded not only in the rate of neuronal responses but also in the precise temporal relations between discharges.

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