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Norbert Furstenau - One of the best experts on this subject based on the ideXlab platform.

  • Simulating bistable perception with interrupted Ambiguous Stimulus using self-oscillator dynamics with percept choice bifurcation
    Cognitive Processing, 2014
    Co-Authors: Norbert Furstenau
    Abstract:

    A behavioral stochastic self-oscillator model is used for simulating interrupted Ambiguous Stimulus-induced percept reversals. The results provide further support for a dynamical systems foundation of cognitive and psychological problems as discussed in detail within the context of Gestalt psychology by Wagemans et al. (Concept Theor Found Psychol Bull 138(6):1218–1252, 2012 ), and for coordination dynamics of the brain (Kelso in Philos Trans R Soc B 367:906–918, 2012 ). Statistical evaluation of simulated reversal time series predicts a maximum of the percept reversal rate that conforms with a number of results in the literature. The macroscopic model is based on two inhibitorily coupled sets of three coupled nonlinear equations, one triplet for each percept. The derivation of our specific dynamics equations is based on a drastically simplified field theoretical approach using well-known phase synchronization for explaining brain dynamics on the macroscopic EEG level. The degree of coherence (contrast μ , 0 ≤  μ  ≤ 1) of the superimposed fields required for onset of bistable dynamics is related to a phase synchronization index of EEG fields, and it is used in the present context as ambiguity control parameter. For quantitative agreement with the experimental data, the addition of a stochastic Langevin force term in the attention equation proved essential. Formal analysis leads to a quantification of well-known “cognitive inertia” and supports the interplay between percept choice (bifurcation) dynamics during Stimulus onset and adaptive gain (attention fatigue) driven quasiperiodic percept reversals.

  • simulating bistable perception with periodically interrupted Ambiguous Stimulus using percept choice bifurcation with stochastic self oscillator dynamics
    2013
    Co-Authors: Norbert Furstenau, Monika Mittendorf
    Abstract:

    Formal modeling of cognitive bistability (e.g.[1][2]) is an interesting problem because a constant Stimulus (e.g. the Necker cube) excites quasi periodic alternations between only two well defined perception states. Periodic Stimulus–off switching (toff < 1 s, ton = 300 ms) was introduced by Orbach et al. [3] as experimental paradigm to get more insight into the underlying perceptual dynamics. Their Necker cube experiments showed a maximum of the percept reversal rate R at Rmax  36 min-1 and toff  200 ms which was confirmed by recent experiments [4]. Noest et al. [5] demonstrated with a low level neural activation model [6] that a bifurcation of the percept choice dynamics during the Ambiguous-Stimulus on-off switching dominates the statistics of the reversal time series. Our simulations based on a macroscopic (behavioral) dynamics model [7][8] (similar to [1]) support this finding and show that the measured R vs. toff-time characteristics can be fitted with only few model parameters: attention (= adaptive feedback gain) fatigue time constant = 1 – 2 s, feedback delay T = 40 ms, gain-noise power J. Synchronisation of attention fatigue induced self-oscillations (yielding inter-Stimulus transition time TTr  4 – 5 T) with Stimulus-onset induced percept bifurcation appears to determine the reversal rates and the toff-value at Rmax. A linear approximation allows for an estimate of the cognitive damping time constant (v ≈ 1 s) which by use of the Fluctuation-Dissipation theorem via Jdefines an index of cognitive inertia (suggested in [8]) as crucial parameter of the simulated dynamics. [1] Ditzinger, T., Haken, H. (1989). Oscillations in the Perception of Ambiguous Patterns. Biol. Cybern. ( 61) 279-287 [2] Huys, R,, Jirsa, V.K. (2010): Nonlinear Dynamics in Human Behavior. Springer Verlag, Berlin, Heidelber. [3] Orbach. J., Zucker, E., Olson, R. (1966). Reversibility of the Necker Cube: VII. Reversal rate as a function of figure-on and figure-off durations. Percept. Motor Skills (22), 615-618 [4] Kornmeier, J., Ehm, W. Bigalke, H., Bach, M. (2007): Discontinuous presentation of Ambiguous figures: How interStimulus-interval durations affect reversal dynamics and ERP’s. Psychophysiology, 44, 552-560 [5] Noest, A.J., van Ee, R., Nijs, M.M., van Wezel, R.J.A. (2007) Percept-choice sequences driven by interrupted Ambiguous stimuli: A low-level neural model. J of Vision 7, 1-14 [6] Amari, S. (1977): Dynamics of pattern formation in lateral-inhibition type neural fields. Biological Cybernetics vol. 27, 77-87 [7] Furstenau, Norbert (2010). A nonlinear dynamics model for simulating long range correlations of cognitive multistability. Biol. Cybern., vol. 103. (3) 175-198 [8] Gao, J.B., Merk, I., Tung W. W., Billok V., White, K.D., Harris J G, Roychowdhury V P. (2006). Inertia and memory in visual perception. Cogn. Processing vol. 7 105-112

  • percept choice dynamics of stochastic self oscillator model dominates percept reversal rate characteristics under periodically interrupted Ambiguous Stimulus
    2012
    Co-Authors: Norbert Furstenau
    Abstract:

    A stochastic nonlinear dynamics model is presented which explains published experimental results with periodically interrupted Ambiguous Stimulus [1][2]. The model is related to the synergetic order parameter approach of Ditzinger & Haken [4] and was recently used for explaining long range correlations of the percept reversal time series [3]. Delayed perception state feedback via an attention control parameter (adaptive gain) is used, which in turn is modulated through a slowly varying bias (memory). A mapping of the perception, attention, memory (PAM) equations to basic Thalamo-Cortical reentrant loops was suggested. Experiments with the Necker cube with Stimulus-off times toff 200 ms the percept is stabilized with increasing toff due to recovery from neural fatigue. Within the present model the percept choice or Stimulus-onset dynamics during the Ambiguous Stimulus off-on switching turns out to dominate over fatigue with increasing toff in agreement with Noest et al.[5]. This onset dynamics is induced by the off-on switching of the Stimulus ambiguity parameter which correspondingly modulates the feedback. Onset-bifurcation of the perception state at the critical ambiguity parameter value (percept choice) adds to the phase oscillator self-oscillations and to the effects of stochastic attention noise (a fluctuating Langevin force). Numerical simulations are based on the dynamical coupling of the behavioral PAM-variables with delayed feedback. The toff-value at Rmax and the absolute reversal rate values are determined by the time constants (fatigue, recovery, feedback delay = 40 ms) and by the attention noise power as parameters of the nonlinear PAM-state space equations. A linear approximation in the form of a second order Langevin equation allows for an analytic estimate of the percept reversal rate (Rmax = 30 – 40 min-1) and of the perceptual damping time constant (tauv ≈ 1 s). Within a thermodynamic equilibrium approximation the Fluctuation-Dissipation theorem (or Einstein diffusion coefficient of Brownian motion) relates the noise power spectral density and damping to an index of cognitive inertia and a cognitive perceptual energy value of at least 16 orders of magnitude above the thermal noise level at body temperature.

  • self oscillator model of cognitive bistability explains percept reversal rate characteristics with periodically interrupted Ambiguous Stimulus
    2012
    Co-Authors: Norbert Furstenau
    Abstract:

    A stochastic nonlinear dynamics model is presented which explains published experimental results with periodically interrupted Ambiguous stimuli [1][2]. Experiments with the Necker cube with Stimulus-off times toff 200 ms the percept is stabilized with increasing toff due to recovery from neural fatigue. Within the present model these results are quantitatively explained by dynamical coupling of behavioral perception, attention, and memory (PAM) variables with delayed feedback. The model is related to the synergetic order parameter approach of Ditzinger & Haken [5] and was recently used for explaining long range correlations of the percept reversal time series [3][4]. A mapping of the PAM equations to basic Thalamo-Cortical reentrant loops was suggested. In the present work the the percept choice dynamics [6] during the Ambiguous Stimulus on-off switching is the focus of data analysis of the numerically simulated reversal time series. The deterministic bifurcation of the perception state at the critical Stimulus ambiguity parameter value (percept choice) adds to the phase oscillator self-oscillations and to stochastic attention noise (a fluctuating Langevin force). Delayed perception state feedback via an attention control parameter (adaptive gain) is used, which in turn is modulated through a slowly varying bias (memory). The toff value at Rmax and the absolute reversal rate values are determined by the time constants (fatigue, recovery, feedback delay = 40 ms) and by the attention noise power as parameters of the nonlinear PAM-state space equations. A linear approximation in the form of a Langevin equation allows for an analytic estimate of the percept reversal rate (Rmax = 30 – 40 1/min) and of the deterministic damping time constant (tauv ≈ 1 s). Within a free energy (thermodynamic equilibrium) approximation the Fluctuation-Dissipation theorem relates the noise power spectral density and damping to an index of cognitive inertia and a cognitive perceptual energy value of at least 16 orders of magnitude above the thermal noise level at body temperature.

  • self oscillator model of bistable perception with interrupted Ambiguous Stimulus explains percept stabilization and reversal rate characteristics
    2011
    Co-Authors: Norbert Furstenau
    Abstract:

    Experiments with periodically interrupted Ambiguous Stimulus (e.g. the Necker cube) with short off-times (< 1 s) exhibit a maximum of the percept reversal rate of R ca. 36 min-1 at Stimulus-off time toff ca. 200 – 300 ms (with ton = const = 300 ms (Orbach et.al.1966)(Kornmeier & Bach 2007). The subjective percept is stabilized with increasing toff-time due to recovery from fatigue. In this contribution it is shown that these results can be explained by a simple nonlinear dynamics attention fatigue model with delayed feedback (adaptive gain) which was recently used for explaining long range correlations of the reversal time series (Gao et.al. 2006)(Furstenau 2010). The present model is related to the Synergetic order parameter approach of Ditzinger & Haken (1989). A reentrant phase oscillator equation (circle map) describes the dynamics of the perception state (order parameter) with feedback through the attention (gain) control parameter. It was shown earlier that the present model correctly predicts a number of features of multistable percept dynamics, e.g. the the hysteresis behavior between stationary perception states and theGamma-distribution of the percept dwell time statistics Here we demonstrate that also the Stimulus - off induced percept stabilization and reversal rate maximum of interrupted Stimulus experiments is correctly predicted. The maximum separates the nonstationary regime with toff < percept transition time ca. 200 ms from the stationary percept stabilization regime (toff ca. 200 ms). The absolute toff - value is determined by the time constants (fatigue, recovery, feedback delay) and noise power as parameters of the three coupled perception-attention-memory (PAM-) equations. A mapping of the PAM equations to basic Thalamo-Cortical reentrant loops is suggested. References Furstenau, Norbert (2010). A nonlinear dynamics model for simulating long range correlations of cognitive multistability. Biol. Cybern., vol. 103. (3) 175-198 Gao, J.B., Merk, I., Tung W W, Billok V, White, K.D., Harris J G, Roychowdhury V P. (2006a) Inertia and memory in visual perception. Cogn. Process 7 105-112 Ditzinger, T., Haken, H. (1989). Oscillations in the Perception of Ambiguous Patterns. Biol. Cybern. ( 61) 279-287 Orbach. J., Zucker, E., Olson, R. (1966). Reversibility of the Necker Cube: VII. Reversal rate as a function of figure-on and figure-off durations. Percept. and Motor Skills (22), 615-618 Kornmeier, J., Ehm, W. Bigalke, H., Bach, M. (2007): Discontinuous presentation of Ambiguous figures: How interStimulus-interval durations affect reversal dynamics and ERP’s. Psychophysiology, 44, 552-560

Franz Josef Van Der Staay - One of the best experts on this subject based on the ideXlab platform.

  • Discrimination learning and judgment bias in low birth weight pigs.
    Animal cognition, 2019
    Co-Authors: Sanne Roelofs, Franz Josef Van Der Staay, Floor A. C. Alferink, Allyson F. Ipema, Tessa Van De Pas, Rebecca E. Nordquist
    Abstract:

    Low birth weight (LBW) is a risk factor for cognitive and emotional impairments in humans. In pigs, LBW is a common occurrence, but its effects on cognition and emotion have received only limited scientific attention. To assess whether LBW pigs suffer from impaired cognitive and emotional development, we trained and tested 21 LBW and 21 normal birth weight (NBW) pigs in a judgment bias task. Judgment bias is a measure of emotional state which reflects the influence of emotion on an animal’s interpretation of Ambiguous stimuli. Pigs were trained to perform a specific behavioral response to two auditory stimuli, predicting either a positive or negative outcome. Once pigs successfully discriminated between these stimuli, they were presented with intermediate, Ambiguous stimuli. The pigs’ responses to Ambiguous stimuli were scored as optimistic (performance of ‘positive’ response) or pessimistic (performance of ‘negative’ response). Optimistic or pessimistic interpretation of an Ambiguous Stimulus is indicative of a positive or negative emotional state, respectively. We found LBW pigs to require more discrimination training sessions than NBW pigs to reach criterion performance, suggesting that LBW causes a mild cognitive impairment in pigs. No effects of LBW on judgment bias were found, suggesting a similar emotional state for LBW and NBW pigs. This was supported by comparable salivary and hair cortisol concentrations for both groups. It is possible the enriched housing conditions and social grouping applied during our study influenced these results.

  • making decisions under ambiguity judgment bias tasks for assessing emotional state in animals
    Frontiers in Behavioral Neuroscience, 2016
    Co-Authors: Sanne Roelofs, Rebecca E. Nordquist, Hetty Boleij, Franz Josef Van Der Staay
    Abstract:

    Judgment bias tasks (JBTs) are considered as a family of promising tools in the assessment of emotional states of animals. JBTs provide a cognitive measure of optimism and/or pessimism by recording behavioral responses to Ambiguous stimuli. For instance, a negative emotional state is expected to produce a negative or pessimistic judgment of an Ambiguous Stimulus, whereas a positive emotional state produces a positive or optimistic judgment of the same Ambiguous Stimulus. Measuring an animal's emotional state or mood is relevant in both animal welfare research and biomedical research. This is reflected in the increasing use of JBTs in both research areas. We discuss the different implementations of JBTs with animals, with a focus on their potential as an accurate measure of emotional state. JBTs have been successfully applied to a very broad range of species, using many different types of testing equipment and experimental protocols. However, further validation of this test is deemed necessary. For example, the often extensive training period required for successful judgment bias testing remains a possible factor confounding results. Also, the issue of Ambiguous stimuli losing their ambiguity with repeated testing requires additional attention. Possible improvements are suggested to further develop the JBTs in both animal welfare and biomedical research.

Mounya Elhilali - One of the best experts on this subject based on the ideXlab platform.

  • ensemble modeling of auditory streaming reveals potential sources of bistability across the perceptual hierarchy
    PLOS Computational Biology, 2020
    Co-Authors: David F Little, Joel S Snyder, Mounya Elhilali
    Abstract:

    Perceptual bistability—the spontaneous, irregular fluctuation of perception between two interpretations of a Stimulus—occurs when observing a large variety of Ambiguous Stimulus configurations. This phenomenon has the potential to serve as a tool for, among other things, understanding how function varies across individuals due to the large individual differences that manifest during perceptual bistability. Yet it remains difficult to interpret the functional processes at work, without knowing where bistability arises during perception. In this study we explore the hypothesis that bistability originates from multiple sources distributed across the perceptual hierarchy. We develop a hierarchical model of auditory processing comprised of three distinct levels: a Peripheral, tonotopic analysis, a Central analysis computing features found more centrally in the auditory system, and an Object analysis, where sounds are segmented into different streams. We model bistable perception within this system by applying adaptation, inhibition and noise into one or all of the three levels of the hierarchy. We evaluate a large ensemble of variations of this hierarchical model, where each model has a different configuration of adaptation, inhibition and noise. This approach avoids the assumption that a single configuration must be invoked to explain the data. Each model is evaluated based on its ability to replicate two hallmarks of bistability during auditory streaming: the selectivity of bistability to specific Stimulus configurations, and the characteristic log-normal pattern of perceptual switches. Consistent with a distributed origin, a broad range of model parameters across this hierarchy lead to a plausible form of perceptual bistability.

  • ensemble modeling of auditory streaming reveals potential sources of bistability across the perceptual hierarchy
    bioRxiv, 2019
    Co-Authors: David F Little, Joel S Snyder, Mounya Elhilali
    Abstract:

    Abstract Perceptual bistability—the spontaneous fluctuation of perception between two interpretations of a Stimulus—occurs when observing a large variety of Ambiguous Stimulus configurations. This phenomenon has the potential to serve as a tool for, among other things, understanding how function varies across individuals due to the large individual differences that manifest during perceptual bistability. Yet it remains difficult to interpret the functional processes at work, without knowing where bistability arises during perception. In this study we explore the hypothesis that bistability originates from multiple sources distributed across the perceptual hierarchy. We develop a hierarchical model of auditory processing comprised of three distinct levels: a Peripheral, tonotopic analysis, a Central analysis computing features found more centrally in the auditory system, and an Object analysis, where sounds are segmented into different streams. We model bistable perception within this system by injecting adaptation, inhibition and noise into one or all of the three levels of the hierarchy. We evaluate a large ensemble of variations of this hierarchical model, where each model has a different configuration of adaptation, inhibition and noise. This approach avoids the assumption that a single configuration must be invoked to explain the data. Each model is evaluated based on its ability to replicate two hallmarks of bistability during auditory streaming: the selectivity of bistability to specific Stimulus configurations, and the characteristic log-normal pattern of perceptual switches. Consistent with a distributed origin, a broad range of model parameters across this hierarchy lead to a plausible form of perceptual bistability. The ensemble also appears to predict that greater individual variation in adaptation and inhibition occurs in later stages of perceptual processing. Author summary Our ability to experience the everyday world through our senses requires that we resolve numerous ambiguities present in the physical evidence available. This is accomplished, in part, through a series of hierarchical computations, in which Stimulus interpretations grow increasingly abstract. Our ability to resolve ambiguity does not always succeed, such as during optical illusions. In this study, we examine a form of perceptual ambiguity called bistability—cases in which a single individual’s perception spontaneously switches back and forth between two interpretations of a single Stimulus. A challenge in understanding bistability is that we don’t know where along the perceptual hierarchy it is generated. Here we test the idea that there are multiple origins by building a simulation of the auditory system. Consistent with a multi-source account of bistability, this simulation accurately predicts perception of a simple auditory Stimulus when bistability originates from a number of different sources within the model. The data also indicate that individual differences during Ambiguous perception may primarily originate from higher levels of the perceptual hierarchy. This result provides a clue for future work aiming to determine how auditory function differs across individual brains.

Sanne Roelofs - One of the best experts on this subject based on the ideXlab platform.

  • Discrimination learning and judgment bias in low birth weight pigs.
    Animal cognition, 2019
    Co-Authors: Sanne Roelofs, Franz Josef Van Der Staay, Floor A. C. Alferink, Allyson F. Ipema, Tessa Van De Pas, Rebecca E. Nordquist
    Abstract:

    Low birth weight (LBW) is a risk factor for cognitive and emotional impairments in humans. In pigs, LBW is a common occurrence, but its effects on cognition and emotion have received only limited scientific attention. To assess whether LBW pigs suffer from impaired cognitive and emotional development, we trained and tested 21 LBW and 21 normal birth weight (NBW) pigs in a judgment bias task. Judgment bias is a measure of emotional state which reflects the influence of emotion on an animal’s interpretation of Ambiguous stimuli. Pigs were trained to perform a specific behavioral response to two auditory stimuli, predicting either a positive or negative outcome. Once pigs successfully discriminated between these stimuli, they were presented with intermediate, Ambiguous stimuli. The pigs’ responses to Ambiguous stimuli were scored as optimistic (performance of ‘positive’ response) or pessimistic (performance of ‘negative’ response). Optimistic or pessimistic interpretation of an Ambiguous Stimulus is indicative of a positive or negative emotional state, respectively. We found LBW pigs to require more discrimination training sessions than NBW pigs to reach criterion performance, suggesting that LBW causes a mild cognitive impairment in pigs. No effects of LBW on judgment bias were found, suggesting a similar emotional state for LBW and NBW pigs. This was supported by comparable salivary and hair cortisol concentrations for both groups. It is possible the enriched housing conditions and social grouping applied during our study influenced these results.

  • making decisions under ambiguity judgment bias tasks for assessing emotional state in animals
    Frontiers in Behavioral Neuroscience, 2016
    Co-Authors: Sanne Roelofs, Rebecca E. Nordquist, Hetty Boleij, Franz Josef Van Der Staay
    Abstract:

    Judgment bias tasks (JBTs) are considered as a family of promising tools in the assessment of emotional states of animals. JBTs provide a cognitive measure of optimism and/or pessimism by recording behavioral responses to Ambiguous stimuli. For instance, a negative emotional state is expected to produce a negative or pessimistic judgment of an Ambiguous Stimulus, whereas a positive emotional state produces a positive or optimistic judgment of the same Ambiguous Stimulus. Measuring an animal's emotional state or mood is relevant in both animal welfare research and biomedical research. This is reflected in the increasing use of JBTs in both research areas. We discuss the different implementations of JBTs with animals, with a focus on their potential as an accurate measure of emotional state. JBTs have been successfully applied to a very broad range of species, using many different types of testing equipment and experimental protocols. However, further validation of this test is deemed necessary. For example, the often extensive training period required for successful judgment bias testing remains a possible factor confounding results. Also, the issue of Ambiguous stimuli losing their ambiguity with repeated testing requires additional attention. Possible improvements are suggested to further develop the JBTs in both animal welfare and biomedical research.

Rebecca E. Nordquist - One of the best experts on this subject based on the ideXlab platform.

  • Discrimination learning and judgment bias in low birth weight pigs.
    Animal cognition, 2019
    Co-Authors: Sanne Roelofs, Franz Josef Van Der Staay, Floor A. C. Alferink, Allyson F. Ipema, Tessa Van De Pas, Rebecca E. Nordquist
    Abstract:

    Low birth weight (LBW) is a risk factor for cognitive and emotional impairments in humans. In pigs, LBW is a common occurrence, but its effects on cognition and emotion have received only limited scientific attention. To assess whether LBW pigs suffer from impaired cognitive and emotional development, we trained and tested 21 LBW and 21 normal birth weight (NBW) pigs in a judgment bias task. Judgment bias is a measure of emotional state which reflects the influence of emotion on an animal’s interpretation of Ambiguous stimuli. Pigs were trained to perform a specific behavioral response to two auditory stimuli, predicting either a positive or negative outcome. Once pigs successfully discriminated between these stimuli, they were presented with intermediate, Ambiguous stimuli. The pigs’ responses to Ambiguous stimuli were scored as optimistic (performance of ‘positive’ response) or pessimistic (performance of ‘negative’ response). Optimistic or pessimistic interpretation of an Ambiguous Stimulus is indicative of a positive or negative emotional state, respectively. We found LBW pigs to require more discrimination training sessions than NBW pigs to reach criterion performance, suggesting that LBW causes a mild cognitive impairment in pigs. No effects of LBW on judgment bias were found, suggesting a similar emotional state for LBW and NBW pigs. This was supported by comparable salivary and hair cortisol concentrations for both groups. It is possible the enriched housing conditions and social grouping applied during our study influenced these results.

  • making decisions under ambiguity judgment bias tasks for assessing emotional state in animals
    Frontiers in Behavioral Neuroscience, 2016
    Co-Authors: Sanne Roelofs, Rebecca E. Nordquist, Hetty Boleij, Franz Josef Van Der Staay
    Abstract:

    Judgment bias tasks (JBTs) are considered as a family of promising tools in the assessment of emotional states of animals. JBTs provide a cognitive measure of optimism and/or pessimism by recording behavioral responses to Ambiguous stimuli. For instance, a negative emotional state is expected to produce a negative or pessimistic judgment of an Ambiguous Stimulus, whereas a positive emotional state produces a positive or optimistic judgment of the same Ambiguous Stimulus. Measuring an animal's emotional state or mood is relevant in both animal welfare research and biomedical research. This is reflected in the increasing use of JBTs in both research areas. We discuss the different implementations of JBTs with animals, with a focus on their potential as an accurate measure of emotional state. JBTs have been successfully applied to a very broad range of species, using many different types of testing equipment and experimental protocols. However, further validation of this test is deemed necessary. For example, the often extensive training period required for successful judgment bias testing remains a possible factor confounding results. Also, the issue of Ambiguous stimuli losing their ambiguity with repeated testing requires additional attention. Possible improvements are suggested to further develop the JBTs in both animal welfare and biomedical research.