Chakras are a basic concept of yoga but typically are ignored by scientific research on yoga, probably because descriptions of chakras can appear like a fanciful mythology. Chakras are commonly considered to be centers of concentrated metaphysical energy. Although clear physiological effects exist for yoga practices, no explanation of how chakras influence physiological function has been broadly accepted either in the scientific community or among yoga scholars. This problem is exacerbated by the fact that yoga is based on subjective experience, (...) and practitioners often shun objective descriptions. This essay builds on earlier work hypothesizing that intercellular gap junction connections provide a physiological mechanism underlying subtle energy systems described in yoga as well as other disciplines such as acupuncture. Three physical aspects of chakras are distinguished that are integrated through gap junction mechanisms and are proposed to have arisen during embryological development. Furthermore, electrical conductance associated with a high concentration of gap junctions could generate phenomena that, when subjectively experienced, have the radiant qualities attributed to chakras. This theory provides a scientific rationale for previously unexplained details of chakra theory and offers a new orientation to conceptualizing and studying such subjective phenomena. (shrink)

The 'Conscious Pilot' is a new model of the neural correlate of consciousness (NCC) consistent with the Orch OR model. The basic idea is that spatiotemporal envelopes of dendritic gamma synchrony move through the brain's neuronal networks. The movement is sideways to neurocomputational flow, occurring via dendritic dendritic gap junction electrical synapses. A conscious pilot moving around an airplane while it flies on auto pilot is used as a metaphor for dendritic synchrony moving through the brain's neurocomputational networks, conveying (...) conscious experience and choice to otherwise non conscious cognitive modes. (shrink)

Capacity of conscious agents to perform genuine choices among future alternatives is a prerequisite for moral responsibility. Determinism that pervades classical physics, however, forbids free will, undermines the foundations of ethics, and precludes meaningful quantification of personal biases. To resolve that impasse, we utilize the characteristic indeterminism of quantum physics and derive a quantitative measure for the amount of free will manifested by the brain cortical network. The interaction between the central nervous system and the surrounding environment is shown to (...) perform a quantum measurement upon the neural constituents, which actualize a single measurement outcome selected from the resulting quantum probability distribution. Inherent biases in the quantum propensities for alternative physical outcomes provide varying amounts of free will, which can be quantified with the expected information gain from learning the actual course of action chosen by the nervous system. For example, neuronal electric spikes evoke deterministic synaptic vesicle release in the synapses of sensory or somatomotor pathways, with no free will manifested. In cortical synapses, however, vesicle release is triggered indeterministically with probability of 0.35 per spike. This grants the brain cortex, with its over 100 trillion synapses, an amount of free will exceeding 96 terabytes per second. Although reliable deterministic transmission of sensory or somatomotor information ensures robust adaptation of animals to their physical environment, unpredictability of behavioral responses initiated by decisions made by the brain cortex is evolutionary advantageous for avoiding predators. Thus, free will may have a survival value and could be optimized through natural selection. (shrink)

Almost all computational models of the mind and brain ignore details about neurotransmitters, hormones, and other molecules. The neglect of neurochemistry in cognitive science would be appropriate if the computational properties of brains relevant to explaining mental functioning were in fact electrical rather than chemical. But there is considerable evidence that chemical complexity really does matter to brain computation, including the role of proteins in intracellular computation, the operations of synapses and neurotransmitters, and the effects of neuromodulators such as (...) hormones. Neurochemical computation has implications for understanding emotions, cognition, and artificial intelligence. (shrink)

Synaptic ribbons, the organelles identified in electron micrographs of the sensory synapses involved in vision, hearing, and balance, have long been hypothesized to play an important role in regulating presynaptic function because they associate with synaptic vesicles at the active zone. Their physiology and molecular composition have, however, remained largely unknown. Recently, a series of elegant studies spurred by technical innovation have finally begun to shed light on the ultrastructure and function of ribbon synapses. Electrical capacitance measurements have provided (...) sub‐millisecond resolution of exocytosis, evanescent‐wave microscopy has filmed the fusion of single 30 nm synaptic vesicles, electron tomography has revealed the 3D architecture of the synapse, and molecular cloning has begun to identify the proteins that make up ribbons. These results are consistent with the ribbon serving as a vesicle “conveyor belt” to resupply the active zone, and with the suggestion that ribbon and conventional chemical synapses have much in common. BioEssays 23:831–840, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

Brain function depends on the cooperation between highly specialized cells. Neurons generate electrical signals and glial cells provide structural and metabolic support. Here, I propose a new kind of job‐sharing between neurons and astrocytes. Recent studies on primary cultures of highly purified neurons from the rodent central nervous system (CNS) suggest that, during development, neurons reduce or even abandon cholesterol synthesis to save energy and import cholesterol from astrocytes via lipoproteins. The cholesterol shuttle may be restricted to compartments distant (...) from the soma including synapses and may be regulated by electrical activity. Testing these hypotheses will help to improve our still insufficient understanding of brain cholesterol metabolism and its role in neurodegeneration. BioEssays 25:72–78, 2003. © 2002 Wiley Periodicals, Inc. (shrink)

A key characteristic of an animal's nervous system is that it can respond to brief environmental stimuli with lasting changes in its structure and function. These changes are triggered by specific patterns of neuronal electrical activity and are manifested as changes in the strength and patterns of synaptic connectivity between activated neurons. The biochemical mechanisms that control these changes are unclear, but cytoplasmic rises in Ca2+ levels may play a critical role, especially in regulating neuronal gene expression for making (...) activity‐induced synaptic changes permanent. Recently, two reports have explored the spatial features by which activity‐induced rises in Ca2+ levels activate transcription factors and gene expression(1,2). The reports suggest that Ca2+ influx acts both locally at the synapse and distantly within the nucleus to regulate transcription factors and gene expression. The results also show that regulatory elements within genes can respond differentially, depending on spatial differences in intracellular Ca2+ rises. These reports suggest new spatial mechanisms by which Ca2+‐dependent gene expression could contribute to activity‐dependent synaptic changes. (shrink)

A model of an intentional self-observing system is proposed based on the structure and functions of astrocyte-synapse interactions in tripartite synapses. Astrocyte-synapse interactions are cyclically organized and operate via feedforward and feedback mechanisms, formally described by proemial counting. Synaptic, extrasynaptic and astrocyte receptors are interpreted as places with the same or different quality of information processing described by the combinatorics of tritograms. It is hypothesized that receptors on the astrocytic membrane may embody intentional programs that select corresponding synaptic (...) and extrasynaptic receptors for the formation of receptor-receptor complexes. Basically, the act of self-observation is generated if the actual environmental information is appropriate to the intended observation processed by receptor-receptor complexes. This mechanism is implemented for a robot brain enabling the robot to experience environmental information as “its own”. It is suggested that this mechanism enables the robot to generate matches and mismatches between intended observations and the observations in the environment, based on the cyclic organization of the mechanism. In exploring an unknown environment the robot may stepwise construct an observation space, stored in memory, commanded and controlled by the intentional self-observing system. Finally, the role of self-observation in machine consciousness is shortly discussed. (shrink)

The self, Joseph LeDoux tells us, is “the totality of the living organism”. Most disciplines in the natural sciences focus on only one or two levels of organization. Indeed, Dmitri Mendeleev figured out the periodic table of the elements without knowing any of the underlying quantum mechanics or stereochemistry. There are, however, at least a dozen levels of organization within the neurosciences — and, if we use a metaphor, we temporarily create yet another. This leads to considerable confusion and arguments (...) at cross purposes over whether learning is an alteration at the level of gene expression, ion channels, synapses, neurons or circuits. Each neuron has thousands of synapses, which produce currents that summate to form an impulse train. But only rarely is the activity of a single neuron sufficient to cause a perception or trigger an action. Neurons usually act as members of ‘committees’ — what Donald Hebb in 1949 called cellassemblies. Just as in academia, one individual may function in different committees on different occasions. A concept, including any explicit memory that we can talk about, is probably formed by such a committee. Implicit memories are less differentiated — they are part of the ‘feltwork’, together with motivations and emotions, that biases the choice of one’s next act. In this well-written 400-page appreciation of behavioural neuroscience, LeDoux argues that synapses are the seat of self. He says, in effect, that you are your memories; that it is the uniqueness of an array of synaptic strengths that distinguishes one twin from another. Fair enough, but why not instead focus on one’s unique array of ion channels? Or neurons, because a neuron is the closest thing we have to a computational unit? Or one’s unique arrangement of those overlapping, redundant hebbian committees? None of these make for a catchy book title, but relating other things to the synapses proves to be a good way of covering a lot of fascinating material at the overlying levels, including a few updates to LeDoux’s earlier book The Emotional Brain. (shrink)

Phillips & Silverstein emphasize the gain-control properties of NMDA synapses in cognitive coordination. We endorse their view and suggest that NMDA synapses play a crucial role in biased attentional competition and (visual) working memory. Our simulations show that NMDA synapses can control the storage rate of visual objects. We discuss specific predictions of our model about cognitive effects of NMDA-antagonists and schizophrenia.

This selective review explores biologically inspired learning as a model for intelligent robot control and sensing technology on the basis of specific examples. Hebbian synaptic learning is discussed as a functionally relevant model for machine learning and intelligence, as explained on the basis of examples from the highly plastic biological neural networks of invertebrates and vertebrates. Its potential for adaptive learning and control without supervision, the generation of functional complexity, and control architectures based on self-organization is brought forward. Learning without (...) prior knowledge based on excitatory and inhibitory neural mechanisms accounts for the process through which survival-relevant or task-relevant representations are either reinforced or suppressed. The basic mechanisms of unsupervised biological learning drive synaptic plasticity and adaptation for behavioral success in living brains with different levels of complexity. The insights collected here point toward the Hebbian model as a choice solution for “intelligent” robotics and sensor systems. Keywords: Hebbian learning; synaptic plasticity; neural networks; self-organization; brain; reinforcement; sensory processing; robot control . (shrink)

No overarching hypotheses tie the basic mechanisms of mitochondrial reactive oxygen species (ROS) production to activity dependent synapse pruning—a fundamental biological process in health and disease. Neuronal activity divergently regulates mitochondrial ROS: activity decreases whereas inactivity increases their production, respectively. Placing mitochondrial ROS as innate synaptic activity sentinels informs the novel hypothesis that: (1) at an inactive synapse, increased mitochondrial ROS production initiates intrinsic apoptosis dependent pruning; and (2) at an active synapse, decreased mitochondrial ROS production masks (...) intrinsic apoptosis dependent pruning. Immature antioxidant defense may enable the developing brain to harness mitochondrial ROS to prune weak synapses. Beyond development, endogenous antioxidant defense constrains mitochondrial (ROS) to mask pruning. Unwanted age‐related synapse loss may arise when mitochondrial ROS aberrantly recapitulate developmental pruning. Placing mitochondrial ROS with their hands on the shears is beneficial in early but deleterious in later life. (shrink)

. Progress in technology has allowed dynamic research on the development of the human brain that has revolutionized concepts. Particularly, the notions of plasticity, neuronal selection, and the effects of afferent stimuli have entered into thinking about brain development. Here I focus on development from the age of four years to early adulthood, during which a 30 percent reduction in some brain synapses occurs that is out of proportion to changes in neuronal numbers. This corresponds temporally with changes in normal (...) child behavior from the loose‐associative, almost schizoid, thinking and art of the four‐year‐old to the more trained, or disciplined, or acculturated—and restrained—personality of the young adult. I propose that the synaptic changes can best be thought of as a winnowing process likely subject to environmental influences. Acquisition of language and the ability to link linguistic cognition to the plastic development of the brain provide a potentially powerful means of explaining the evolutionally explosive development of human cognition and culture. Schizophrenia, a disease that can be envisioned as representing a derangement of synaptic maturation, may provide an entry into the search for genes controlling the processes mediating the unprecedented development of Homo sapiens over the past 40,000 to 70,000 years. The recently completed mapping of the genome of the chimpanzee provides a new frame of reference that may speed the search. (shrink)

In the last decade there has been an upsurge in the popularity of electric mountain bikes. However, opinion is divided regarding the implications of this emerging technology. Critics warn of the dangers they pose to landscapes, habitats, and ecological diversity, whilst advocates highlight their potential in increasing the accessibility of the outdoors for riders who would otherwise be socially and/or physically excluded. Drawing on interview data with 30 electric mountain bike users in England, this paper represents one of the first (...) attempts to empirically explore the experiential, ecological and socio-cultural implications of this activity. Utilising Stiegler’s (2013a) account of the pharmakon, in which technology is positioned as both remedy and poison, we suggest that the e-mountain bike’s role in the promotion of social and environmental responsibility is both complex and contradictory. Specifically, findings indicate that while this assistive technology can play a key role in facilitating deeper connections between riders as well as an ethic of care towards others, it can, at the same time, generate more individualised and automated experiences of recreational mobility in outdoor environments. (shrink)

This paper argues that cultural analyses of electric light, including aspects of actor-network theory, may raise the spectre of complexity, but do not do it justice when they omit to provide analysis of the intertwined roles of culture and political economy in the formation of the provision and use of electric light. The essay looks at the marketization of electric power, at outages in the eastern and western US megacities, at the collapse of the public utility model and chaotic implementation (...) of market models in Mumbai, Lagos and other poor megacities, and concludes that while theft of power provides a temporary solution, abandoning centralized market models in favour of microgrids is the only sure way to return agency to slum dwellers. (shrink)

We recently described a novel form of stress‐associated bidirectional plasticity at GABA synapses onto hypothalamic parvocellular neuroendocrine cells (PNCs), the apex of the hypothalamus‐pituitary‐adrenal axis. This plasticity may contribute to neuroendocrine adaptation. However, this GABA synapse plasticity likely does not translate into a simple more and less of inhibition because the ionic driving force for Cl−, the primary charge carrier for GABAA receptors, is dynamic. Specifically, stress impairs a Cl− extrusion mechanism in PNCs. This not only renders the steady‐state (...) GABA response less hyperpolarizing but also makes PNCs susceptible to the activity‐dependent accumulation of Cl−. Accordingly, GABA synapse plasticity impacts both the robustness of GABA voltage response and dynamic Cl− loading, imposing nonlinear influences on PNC excitability during circuit activities. This theoretical consideration predicts roles for GABA transmission far more versatile than canonical inhibition. We propose potential impacts of GABA synapse plasticity on the experience‐dependent fine‐tuning of neuroendocrine stress responses. (shrink)

Neuroscience has studied deductive reasoning over the last 20 years under the assumption that deductive inferences are not only de jure but also de facto distinct from other forms of inference. The objective of this research is to verify if logically valid deductions leave any cerebral electrical trait that is distinct from the trait left by non-valid deductions. 23 subjects with an average age of 20.35 years were registered with MEG and placed into a two conditions paradigm (100 trials (...) for each condition) which each presented the exact same relational complexity (same variables and content) but had distinct logical complexity. Both conditions show the same electromagnetic components (P3, N4) in the early temporal window (250–525 ms) and P6 in the late temporal window (500–775 ms). The significant activity in both valid and invalid conditions is found in sensors from medial prefrontal regions, probably corresponding to the ACC or to the medial prefrontal cortex. The amplitude and intensity of valid deductions is significantly lower in both temporal windows (p = 0.0003). The reaction time was 54.37% slower in the valid condition. Validity leaves a minimal but measurable hypoactive electrical trait in brain processing. The minor electrical demand is attributable to the recursive and automatable character of valid deductions, suggesting a physical indicator of computational deductive properties. It is hypothesized that all valid deductions are recursive and hypoactive. (shrink)

The importance of electrical signalling in bacteria is an emerging paradigm. Bacillus subtilis biofilms exhibit electrical communication that regulates metabolic activity and biofilm growth. Starving cells initiate oscillatory extracellular potassium signals that help even the distribution of nutrients within the biofilm and thus help regulate biofilm development. Quorum sensing also regulates biofilm growth and crucially there is convergence between electrical and quorum sensing signalling axes. This makes B. subtilis an interesting model for cell signalling research. SpoOF is (...) predicted to act as a logic gate for signalling pathway convergence, raising interesting questions about the functional nature of this gate and the relative importance of these disparate signals on biofilm behaviour. How is an oscillating signal integrated with a quorum signal? The model presented offers rich opportunities for future experimental and theoretical modelling research. The importance of direct cell‐to‐cell electrical signalling in prokaryotes, so characteristic of multicellular eukaryotes, is also discussed. (shrink)

The potential of a static electric charge located in a Schwarzschild gravitational field is given by Linet. The expressions for the field lines derived from this potential are calculated by numerical integration and drawn for different locations of the static charge in the gravitational field. The field lines calculated for a charge located very close to the central mass can be compared to those calculated by Hanni–Ruffini. Maxwell equations are used to analyze the dynamics of the falling electric field in (...) a gravitational field. (shrink)

The evolutionary origin of synapses and neurons is an enigmatic subject that inspires much debate. Non-bilaterian metazoans, both with and without neurons and their closest relatives already contain many components of the molecular toolkits for synapse functions. The origin of these components and their assembly into ancient synaptic signaling machineries are particularly important in light of recent findings on the phylogeny of non-bilaterian metazoans. The evolution of synapses and neurons are often discussed only from a metazoan perspective leaving a (...) considerable gap in our understanding. By taking an integrative approach we highlight the need to consider different, but extremely relevant phyla and to include the closest unicellular relatives of metazoans, the ichthyosporeans, filastereans and choanoflagellates, to fully understand the evolutionary origin of synapses and neurons. This approach allows for a detailed understanding of when and how the first pre- and postsynaptic signaling machineries evolved. The evolutionary origin of synapses and neurons is an enigmatic subject that inspires much debate. Most of our knowledge and recent discussions are biased towards a metazoan perspective, leaving a considerable gap in our understanding. Recent work has now revealed important insights into the emergence and co-regulation of complex synaptic signaling machineries from studies in the closest unicellular relatives of metazoans. (shrink)

Recent experiments have begun to decipher the molecular dialog that mediates differentiation at sites of synaptic between neurons and their targets. It had been hypothesized that the protein agrin is released by axon terminals at embryonic neuromuscular junctions and binds to a receptor on the myofiber surface to trigger postsynaptic differentiation. Now a genetic ‘Knockout’ experiment has confirmed the essential role of agrin in signaling between developing nerve and muscle(1). A second ‘knockout’ has shown that the muscle‐specific receptor tyrosine kinase (...) MuSK is a critical element in the agrin‐induced signaling cascade(2). Additional results suggest that MuSK may comprise a portion of the agrin receptor(3). (shrink)

Déjà vu and involuntary autobiographical memories (IAM) can be induced by intracranial electric brain stimulation in epileptic patients, sometimes in the same individual. We suggest that there may be different types of IAM which should be taken into account and provide several ideas to test the hypothesis of a continuity between IAM and déjà vu phenomena.

This article analyses the contested adoption of electric lights by the Spanish Catholic church during the Bourbon Restoration era. Through a careful reading of primary sources, namely Catholic popular magazines, and official documents, it will show how Catholic authorities and practitioners resisted, negotiated and, ultimately, engaged with electricity in religious spaces. The article argues that electric light contributed to wider exchanges in a non-monolithic Spanish Catholicism on the observance of traditional values or the possibilities of the church’s modernization. However, amid (...) a particularly tense moment regarding the secular–clerical relations, the systematic use of electric lights in churches at the turn of the twentieth century—but also in other public ceremonies—contributed to the making of religious sensations aimed at attracting new believers and reasserting the presence of the institution in a disputed public space. (shrink)

Wind turbines have been used by many groups of humans for many centuries. Wind turbines have allowed groups of humans to perform many different tasks in the past. However, only a century and a half ago, they began to be used to convert the energy captured from wind into electric energy. Moreover, only approximately twenty-five years ago, we started to introduce on a massive scale the energy generated from wind turbines into the electric networks of most developed countries in the (...) world for regular consumption. According to 2017 statistics, approximately 12 percent of the electric energy consumed in the EU is produced by wind turbines. Despite the fact that wind turbines generally appear quite similar externally—i.e., a three-blade structure, a nacelle, a tower, etc.—if we carefully examine the electric technology used within them, we find quite a wide range of technologies for energy conversion, which is a key issue in wind turbine technology. Hence, this paper adopts a dialectic perspective towards analyzing and understanding why several electric technologies coexist in wind turbine technology. We explain the specific factors that have influenced different wind turbine manufacturers to adopt different electric technologies across the last twenty-five years. We show how their actions and the technological directions that have followed have been mutually codetermined, resulting in a technological evolution that has produced today’s wind turbine variety. (shrink)

The appearance of Priestley's electrical work as a brief and irrelevant prelude to his more substantial chemical enquiries may explain why it has been strangely overlooked by historians of science. It was only fairly recently that Sir Philip Hartog sought to rectify this situation with the affirmation that ‘Priestley's electrical work offers the key to Priestley's scientific mind’. Attacking traditional chemical historiography for tracing Priestley's opposition to Lavoisier's theory to a deficiency in his scientific sensibilities, Hartog insisted that (...) Priestley's natural philosophy can properly be understood only in relation to his ‘profound convictions on scientific method’ as fully expressed in the History of electricity. Only thus would Priestley's scientific thought be related correctly to his ‘work as a whole’. (shrink)

This article examines in detail a remarkable but short-lived cosmological theory of 1959. The theory depended crucially on a hypothesis that could be, and was, tested in the laboratory. I use the case to discuss the nature of testing in cosmology and to argue against ideas about astronomy suggested by Ian Hacking. The case of the electrical universe exemplifies how disagreements can be settled by good experiments and also how experiments of wide-ranging theoretical significance need not be biased by (...) either theory or the experimentalists’ predisposed ideas. I argue that the episode supports Allan Franklins “evidence model” and disputes accounts based on the sociology of scientific knowledge. (shrink)

A formalism is introduced to represent the connective organization of an evolving neuronal network and the effects of environment on this organization by stabilization or degeneration of labile synapses associated with functioning. Learning, or the acquisition of an associative property, is related to a characteristic variability of the connective organization: the interaction of the environment with the genetic program is printed as a particular pattern of such organization through neuronal functioning. An application of the theory to the development of the (...) neuromuscular junction is proposed and the basic selective aspect of learning emphasized. (shrink)

A dualistic approach to consciousness is presented that employs Hebbian synaptic dynamics and the basic notion of measurement in science to bridge the so-called explanatory gap between first-person consciousness and third-person science. Unconscious processing by neural circuitry characterizes (i) the neuron as a measuring instrument and (ii) the neural signal as the quantity to be measured. Hebbian synaptic dynamics, effectuating the storage of information, implements the role of an observer of a measurement outcome. The approach extends physical renormalization techniques, as (...) applied to phase changes, to biology. This leads to the proposal of a ramification process in neural systems (brains) from a primitive form of sensation associated with the Hebbian synapse toward more elaborate experiential forms of consciousness (feelings, qualia) associated with hierarchies of neuronal assemblies. Characterizing sensation as a form of mutual information at the synaptic level motivates a relation between consciousness and phase changes of information. (shrink)

The developing neuromuscular junction has provided an important paradigm for studying synapse formation. An outstanding feature of neuromuscular differentiation is the aggregation of acetylcholine receptors (AChRs) at high density in the postsynaptic membrane. While AChR aggregation is generally believed to be induced by the nerve, the mechanisms underlying aggregation remain to be clarified. A 43‐kD protein (43k) normally associated with the cytoplasmic aspect of AChR clusters has long been suspected of immobilizing AChRs by linking them to the cytoskeleton. In (...) recent studies, the AChR clustering activity of 43k has, at last, been demonstrated by expressing recombinant AChR and 43k in non‐muscle cells. Mutagenesis of 43k has revealed distinct domains within the primary structure which may be responsible for plasma membrane targeting and AChR binding. Other lines of study have provided clues as to how nerve‐derived (extracellular) AChR‐cluster inducing factors such as agrin might activate 43k‐driven postsynaptic membrane specialization. (shrink)

Price is a central analytic concept in both neoclassical and old institutional economics. Combining the social network perspective with old and new institutionalist approaches to price formation, this article examines technological, economic, institutional, and political factors that shaped the earliest pricing systems for electricity used in the United States, between 1882 and 1910. We show that certain characteristics of electricity supply led to ambiguities in how the product should be priced, which created a politics of pricing among electricity producers. In (...) particular, we investigate why the “Wright system,” arguably inferior in productive efficiency to other alternatives, was widely adopted by 1900. We argue that this outcome resulted in part from the political and organizational clout of its supporters, as well as from their particular conceptions of the boundaries and future of the industry itself. The Wright system best suited the “growth dynamic” strategy promoted by the managers of large central stations in their fierce competition with smaller and more decentralized installations. Thus, even in this apparently highly technical and mainly economic issue of how to price the product, there was ample room for social construction and political manipulation. The outcome reached was by no means inevitable and had a highly significant impact on the shape of the American industrial infrastructure. (shrink)

There are remarkable behavioral, neural, and genetic similarities between the way songbirds learn to sing and human infants learn to speak. Furthermore, the brain regions involved in birdsong learning, perception, and production have been identified and characterized in detail. In particular, the caudal medial nidopallium (the avian analog of the mammalian auditory‐association cortex) has been found to contain the neural substrate of auditory memory, paving the way for analyses of the underlying molecular mechanisms. Recently, the zebra finch genome was sequenced, (...) and annotated cDNA databases representing over 15,000 unique brain‐expressed genes are available, enabling high‐throughput gene expression analyses. Here we review the involvement of immediate early genes (e.g. zenk and arc), their downstream targets (e.g. synapsins), and their regulatory signaling pathways (e.g. MAPK/ERK) in songbird memory. We propose that in‐depth investigations of zenk‐ and ERK‐dependent cascades will help to further unravel the molecular basis of auditory memory. (shrink)

Improving the reliability of electricity supply is closely related to the national industrial economy and people’s livelihood. When procuring electricity, the large consumer faces the risk of insufficient electricity supply. Such insufficiency may be caused by the supply disruption of the upstream electricity generator and the fluctuation of electricity prices in the electricity pool. We establish an expected cost model for the large consumer and a revenue model for the electricity generator by introducing robustness and opportunity functions to analyse the (...) impact of supply disruption and price fluctuation on both members. Then, we obtain the optimal reliability level and subsidy rate. Our analytical results reveal the following points: During an electricity price fluctuation, the sufficient and necessary condition for the large consumer to expect high robustness of his own decision-making is to pay a high cost. The high uncertainty of electricity price leads to less revenue for the electricity generator; thus, the electricity generator should perform well in price forecasting. Without disruption risk, the electricity generator is reliable. Furthermore, the electricity pool is unreliable from the perspective of price. However, the electricity supply of the electricity generator is no longer reliable when considering disruption risk, whereas the electricity pool is reliable because the large consumer is tolerant of price fluctuation under this circumstance. Moreover, the impacts of market uncertainty and players’ attributes on the optimal strategies are explored. (shrink)

It may be seen, then, that if one was prepared to accept the existence of insulating sheaths on the nerves, all the arguments raised against the proposed identification of the nervous and electrical fluids, except one, could be answered satisfactorily. The single exception involved the question of how an electrical disturbance in the brain could be confined to a single nerve, and, as was indicated earlier, it was scarcely fair to hold this sort of objection against the (...) class='Hi'>electrical theory alone. In that case, there remained no convincing argument to show why one should not accept the identification of the two fluids. On the other hand, of course, it remained an open question as to whether there was any convincing argument to show why one should accept the identification either. Galvani thought that his experiments provided just such an argument. (shrink)

Non‐invasive brain stimulation is used to modulate brain excitation and inhibition and to improve cognitive functioning. The effectiveness of the enhancement due to transcranial direct current stimulation (tDCS) is still controversial, but the technique seems to have large potential for improvement and more specific applications. In particular, it has recently been used by athletes, both beginners and professionals. This paper analyses the ethical issues related to tDCS enhancement, which depend on its specific features: ease of use, immediate effect, non‐detectability and (...) great variability of effects. If tDCS were to become widespread, there could be some potential side effects, especially the rise of inequality in many selective competitive contexts. I discuss two possible scenarios to counter this effect: that of prohibition and that of compensation, each supported by reasons and arguments that seem plausible and worthy of consideration. In conclusion, I show why I think the scenario of compensation is the preferable one. (shrink)

Investigations with electrometers in the 1770s led Volta to envision mobile charge in electrical conductors as a compressible fluid. A pressure-like condition in this fluid, which Volta described as the fluid’s “effort to push itself out” of its conducting container, was the causal agent that makes the fluid move. In this paper I discuss Volta’s use of analogy and imagery in model building, and compare with a successful contemporary conceptual approach to introducing ideas about electric potential in instruction. The (...) concept that today is called “electric potential” was defined mathematically by Poisson in 1811. It was understood after about 1850 to predict the same results in conducting matter as Volta’s pressure-like concept—and to predict electrostatic effects in the exterior space where Volta’s concept had nothing to say. Complete quantification in addition to greater generality made the mathematical concept a superior research tool for scientists. However, its spreading use in instruction has marginalized approaches to model building based on the analogy and imagery resources that students bring into the classroom. Data from pre and post testing in high schools show greater conceptual and confidence gains using the new conceptual approach than using conventional instruction. This provides evidence for reviving Volta’s compressible fluid model as an intuitive foundation which can then be modified to include electrostatic distant action. Volta tried to modify his compressible fluid model to include distant action, using imagery borrowed from distant heating by a flame. This project remained incomplete, because he did not envision an external field mediating the heating. However, pursuing Volta’s strategy of model modification to completion now enables students taught with the new conceptual approach to add distant action to an initial compressible fluid model. I suggest that a partial correspondence to the evolving model sequence that works for beginning students can help illuminate Volta’s use of intermediate explanatory models. (shrink)