183 research outputs found

    Spectral convergence in tapping and physiological fluctuations: coupling and independence of 1/f noise in the central and autonomic nervous systems.

    Get PDF
    When humans perform a response task or timing task repeatedly, fluctuations in measures of timing from one action to the next exhibit long-range correlations known as 1/f noise. The origins of 1/f noise in timing have been debated for over 20 years, with one common explanation serving as a default: humans are composed of physiological processes throughout the brain and body that operate over a wide range of timescales, and these processes combine to be expressed as a general source of 1/f noise. To test this explanation, the present study investigated the coupling vs. independence of 1/f noise in timing deviations, key-press durations, pupil dilations, and heartbeat intervals while tapping to an audiovisual metronome. All four dependent measures exhibited clear 1/f noise, regardless of whether tapping was synchronized or syncopated. 1/f spectra for timing deviations were found to match those for key-press durations on an individual basis, and 1/f spectra for pupil dilations matched those in heartbeat intervals. Results indicate a complex, multiscale relationship among 1/f noises arising from common sources, such as those arising from timing functions vs. those arising from autonomic nervous system (ANS) functions. Results also provide further evidence against the default hypothesis that 1/f noise in human timing is just the additive combination of processes throughout the brain and body. Our findings are better accommodated by theories of complexity matching that begin to formalize multiscale coordination as a foundation of human behavior

    Economic Value Added (EVA) and the Valuation of Small Businesses

    Get PDF
    This article presents an overview of the standard asset, market, and income valuation methods generally used to estimate the value of small businesses

    Value Creation and the Entrepreneurial Business

    Get PDF
    The need to finance high growth and manage the interests and needs of investors makes value creation a critical concern for entrepreneurial businesses. Almost any financial endeavor, such as attracting new investors or making investment decisions, necessitates the consideration of the equity value created by the endeavor. The perceived value creation, for example, has a direct effect on the percentage of the firm outside investors will require if they are to invest in the business. Measuring the value created by publicly traded businesses, depending on the assumptions made, is relatively straightforward. If public markets are at least semi-strong form efficient (i.e., equity prices reflect all publicly available information regarding a business’s true underlying value), then the closing price on a large, publicly-traded company should accurately reflect that enterprise’s value. In other words, public markets take individual investors’ beliefs of the magnitude, timing and riskiness of the business’s expected future cash flows and incorporate them into the actual equity value reported at closing. Like the managers of large companies, the entrepreneur should think market value, rather than just accounting profits, when making economic decisions. Unfortunately, the major problem of measuring the value of an entrepreneurial business is that many are either privately-owned or are publicly-traded in very thin secondary markets, subsequently market assessment of the true value of the business’s equity is not readily available. This unavailability of market information makes the value creation assessment process more difficult for entrepreneurial companies, but certainly not any less important. Thus, information about the correlation of readily available performance measures with a true market value creation measure is worthwhile. This study statistically examines the relationship of non-market measures of value creation with a true market value creation measure for a sample of small publicly-traded companies (i.e., less than $100 million). We restricted the size of the companies we examined to make our sample more representative of entrepreneurial businesses, which are more likely to be either privately-held or traded very thinly in public markets. For the purposes of this study the market value creation measure utilized was shareholder return. Each company’s shareholder return was estimated using stock price and dividend information. Three different dimensions of non-market value creation measures were utilized. These three dimensions were accounting profitability, cash flow performance, and growth. Our investigation revealed that relationships between certain non-market measures of value and small entrepreneurial types of businesses existed. Statistically significant positive correlations were found between shareholder return and the earnings profitability measures of return on equity, return on assets and return on invested capital. These relationships were found to exist only for companies that reported positive earnings. Stronger relationships were found to exist between shareholder return and the cash flow performance measures of earnings growth and sales growth. Furthermore, the sales growth measure was found to be correlated for companies that had positive earnings and companies that reported negative earnings

    An Improved Algorithm for Generating Database Transactions from Relational Algebra Specifications

    Full text link
    Alloy is a lightweight modeling formalism based on relational algebra. In prior work with Fisler, Giannakopoulos, Krishnamurthi, and Yoo, we have presented a tool, Alchemy, that compiles Alloy specifications into implementations that execute against persistent databases. The foundation of Alchemy is an algorithm for rewriting relational algebra formulas into code for database transactions. In this paper we report on recent progress in improving the robustness and efficiency of this transformation

    The TEC as a theory of embodied cognition

    Full text link

    Computational Grounded Cognition: A New Alliance between Grounded Cognition and Computational Modeling

    Get PDF
    Grounded theories assume that there is no central module for cognition. According to this view, all cognitive phenomena, including those considered the province of amodal cognition such as reasoning, numeric, and language processing, are ultimately grounded in (and emerge from) a variety of bodily, affective, perceptual, and motor processes. The development and expression of cognition is constrained by the embodiment of cognitive agents and various contextual factors (physical and social) in which they are immersed. The grounded framework has received numerous empirical confirmations. Still, there are very few explicit computational models that implement grounding in sensory, motor and affective processes as intrinsic to cognition, and demonstrate that grounded theories can mechanistically implement higher cognitive abilities. We propose a new alliance between grounded cognition and computational modeling toward a novel multidisciplinary enterprise: Computational Grounded Cognition. We clarify the defining features of this novel approach and emphasize the importance of using the methodology of Cognitive Robotics, which permits simultaneous consideration of multiple aspects of grounding, embodiment, and situatedness, showing how they constrain the development and expression of cognition

    Making the Invisible Visible: Verbal but Not Visual Cues Enhance Visual Detection

    Get PDF
    Background: Can hearing a word change what one sees? Although visual sensitivity is known to be enhanced by attending to the location of the target, perceptual enhancements of following cues to the identity of an object have been difficult to find. Here, we show that perceptual sensitivity is enhanced by verbal, but not visual cues. Methodology/Principal Findings: Participants completed an object detection task in which they made an object-presence or-absence decision to briefly-presented letters. Hearing the letter name prior to the detection task increased perceptual sensitivity (d9). A visual cue in the form of a preview of the to-be-detected letter did not. Follow-up experiments found that the auditory cuing effect was specific to validly cued stimuli. The magnitude of the cuing effect positively correlated with an individual measure of vividness of mental imagery; introducing uncertainty into the position of the stimulus did not reduce the magnitude of the cuing effect, but eliminated the correlation with mental imagery. Conclusions/Significance: Hearing a word made otherwise invisible objects visible. Interestingly, seeing a preview of the target stimulus did not similarly enhance detection of the target. These results are compatible with an account in which auditory verbal labels modulate lower-level visual processing. The findings show that a verbal cue in the form of hearing a word can influence even the most elementary visual processing and inform our understanding of how language affect

    The Embodiment of Success and Failure as Forward versus Backward Movements

    Get PDF
    People often speak of success (e.g., “advance”) and failure (e.g., “setback”) as if they were forward versus backward movements through space. Two experiments sought to examine whether grounded associations of this type influence motor behavior. In Experiment 1, participants categorized success versus failure words by moving a joystick forward or backward. Failure categorizations were faster when moving backward, whereas success categorizations were faster when moving forward. Experiment 2 removed the requirement to categorize stimuli and used a word rehearsal task instead. Even without Experiment 1’s response procedures, a similar cross-over interaction was obtained (e.g., failure memorizations sped backward movements relative to forward ones). The findings are novel yet consistent with theories of embodied cognition and self-regulation
    corecore