Concurrent session II

Saturday June 21, 2:00PM-4:00PM

  • CS 2.1. Decision-Making
  • CS 2.2. New Methods for Studying Consciousness
  • CS 2.3. Modeling Consciousness

 

CS 2.1. Decision-Making

Chair: Nicholas Georgalis

Choice Blindness and Consumer Decision Making

Petter Johansson, RCAST, University of Tokyo; JSPS, Japan
Lars Hall, Psychology, Harvard University, USA
Yuko Yamaguchi, Cognitive and Behavioral Science, University of Tokyo, Japan
Hirokazu Ogawa, RCAST, University of Tokyo, Japan
Katsumi Watanabe, RCAST, University of Tokyo; ERATO-JST; AIST, Japan

There is a great tension in current research on consumer choice. Convincing evidence can be mustered that people are either largely unaware of the factors influencing their choices, or that they know both what they want and why they want it. The psychologists focus on the non conscious influences, both as a general framework and with new discoveries of various implicit effects. The world of marketing and consumer behavior relies to a large extent on explicit measures of consumer attitudes and post-choice explanations, collected through questionnaires and surveys. We introduce the choice blindness methodology as a new kind of dissociation that cuts across the explicit/implicit divide.

In a recent study, we let participants choose which of two consumer goods they would rather buy. The alternatives were presented two at a time on a single slide, each represented by a simple drawing and 12 attributes, six of which were positive and six negative (e.g. for laptops: low price, short battery-life, etc ). If an attribute was positive for the first alternative (i.e. low price), it was negative for the second alternative (high price). The pairs were presented for 50s, and after the participants had indicated their choice the original slide was immediately presented again. The participants now had to rate how important they thought each attribute had been for their decision.

On some of the trials, a manipulation was introduced. When the choice slide was presented the second time, two of the most important attributes were switched between the alternatives: if the first laptop originally had low price and short battery-life it now had high price and long battery-life. The great majority of these manipulations remained undetected. The post-choice rating was also affected by the manipulation, as the originally negative attributes were rated as being significantly more influential when they were turned positive, with a reversed pattern for the attributes changed from positive to negative. In fact, this response pattern was so strong it mirrored the result from the non-manipulated trials.

The overall conclusion from this data is that the post-choice rating of the influence of an attribute was determined by the perceived positive or negative value of that attribute after the choice, rather than an accurate introspective awareness of the actual importance of the attribute when the decision was made.

  • Keywords: choice blindness, consumer psychology, introspection
  • Support: JSPS & ERATO-JST
  • Corresponding Email: petter.johansson@lucs.lu.se
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Socrates Hall

 

Gambling on the Unconscious

Zoltan Dienes, Psychology, University of Sussex, UK
Anil Seth, Informatics, University of Sussex, UK

Three experiments employing an implicit learning paradigm provide evidence against the current way wagering is sometimes used to measure conscious awareness. The most straightforward method of determining whether a person is aware of knowing is to ask the person after a judgment whether they knew the answer (to some degree) or were guessing. Another approach involves gambling, determining the degree to which a person is willing to put their money where their mouth is. There are several ways gambling can be used. Persaud et al (2006) used wagering, where a person bets a low or high wager on each judgment and either gains or loses that amount depending on whether they were correct. For a person maximizing expected profit, a low wager indicates no confidence whatsoever in the judgment, and a high wager some confidence. But can the amount of a wager be taken as such a direct reflection of awareness of knowledge? Gambling behaviour may also be affected by other factors, such as risk aversion, or simply a poor understanding of what is required to maximize profit. The accuracy of judgments for different types of wagers and for simple verbal confidence ratings was compared. We found that high rather than low verbal confidence was related to greater accuracy, indicating some awareness of knowing. Even so, when people claimed they were quite literally guessing, their accuracy was above baseline, indicating some unconscious knowledge. By contrast, with high-low wagering, there was no detectable difference in accuracy between a low wager and a high wager; in fact, wagering was significantly less able to predict accuracy than simple verbal confidence. These results suggest that wagering is not a good indicator of awareness of knowing. However, when we removed the element of risk aversion by only using wagers that might lead to gain but never loss, gambling was as sensitive as verbal report in predicting accuracy. If results are in, I may also report a study using other gambling measures theoretically superior to wagering for assessing the conscious status of knowledge.

* Keywords:conscious vs unconscious knowledge, artificial grammar learning, gambling, subjective measures
* Corresponding Email:dienes@sussex.ac.uk
* Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Socrates Hall

 

Reexamining the Effect of Long-Term Outcome and Gain-Loss Frequency: From Unconsciousness to Consciousness

Ching-Hung Lin, Institute of Neuroscience, National Yang-Ming University, Taiwan
Yao-Chu Chiu, Department of Psychology, Soochow University, Taiwan
Jong-Tsun Huang, Institute of Neural and Cognitive Sciences, China Medical University & Hospital, Taiwan

A large body of research on the well-known Iowa gambling task (IGT) tend to suggest that normal decision-makers can acquire a hunch of the long-term outcome (or, expected value, EV) through the help of somatic markers or the implicitly induced emotional indicators like GSR under the uncertainty decision context. In the original IGT, bad decks A and B resulted with a negative EV ($ -250) and good decks C and D the positive EV ($ +250) across every ten trials. Internal game structure was not revealed to the subjects through the end of the play. Subjects were supposed to be unknown to the probability structure that is designed in the IGT. Somatic markers would then be induced unconsciously to facilitate the decision process. However, the Soochow gambling task (SGT) demonstrated a very different observation from IGT (Chiu et al. 2005). The results of SGT found no indications that decision makers can really acquire a hunch of the EV in these uncertain situations with the help of unconscious somatic markers. Even by providing the gain-loss structure (probability and value of gain and loss in the game) of each deck in the second run, most subjects can not acquire the EV hunch immediately (Chiu et al. 2006; Peterson 2007). In this study, we directly provided the gain-loss structure and EV (decks A, B $ -250; decks C, D $ +250) together to subjects in the second stage to verify the possible effect of rule consciousness. The study enrolled 18 adults to perform the two-stage SGT. Each subject played the first stage (the first 100 trials) without knowledge of EV and then the second stage (the next 100 trials) by providing the gain-loss structure and EV together. The result showed that subjects still preferred the bad EV decks (A, B) to the good EV decks (C, D) in the first stage as shown in the previous studies. While in the second stage, the behavioral profile is basically the same as in the first stage. Subjects did manifest a small shift of their preference by the end of the second stage to the good EV decks (C, D), however, the barely noticeable shift is still around the chance level. This study reinforces the original finding of SGT, namely, normal decision makers can not be benefited even by providing consciously-clear game structure information, not to mention the possible effect of unconscious facilitators.

  • Keywords: Iowa gambling task, Soochow gambling task, Decision making, Rule consciousness
  • Corresponding Email: yaochu@mail2000.com.tw
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Socrates Hall

 

Unconscious Formation of Free Intentions: Functional Dissociation of Different Regions in Prefrontal Cortex

Chun Siong Soon, Attention & Awareness, MPI CBS Leipzig, Germany
Anna He, Attention & Awareness, MPI CBS Leipzig, Germany
John-Dylan Haynes, Global Computation - Systemic Synthesis, BCCN Berlin, Germany

Rather than just passive reactions to external stimulation, much of human behavior is self-initiated, often involving free choice between alternative possibilities. However, the functional neuroanatomy underlying the formation of intentions for self-initiated behavior is still poorly understood. Here, we present two studies showing that different prefrontal regions contain predictive information about the content and timing of such an intention long before it reaches awareness.

Experiment 1:
In a novel variant of Libet’s clock task (Libet et al., 1983), subjects freely chose to make a button press with either left or right index finger immediately when they felt the spontaneous “urge” to do so. Concurrently, they monitored a letter stream, noting the letter presented when the choice first became conscious. Previously, we showed that this choice was already encoded in the spatial pattern of activation in frontopolar cortex up to ten seconds before the decision reached awareness. In a new decoding analysis, we show that preSMA and SMA contained early predictive information about when the conscious decision will be formed, but not what the decision outcome will be. In contrast, the timing of the decision could not be predicted from frontopolar cortex.

Experiment 2
To verify whether the findings in Experiment 1 related to covert intentions per se, or unconscious preparation of motor output, a second experiment was conducted involving abstract intentions rather than motor intentions. Subjects monitored a letter stream, and remembered the letter presented when they first felt the spontaneous urge to perform either addition or subtraction. A number stream was presented concurrently above the letter stream, and the chosen arithmetic operation was performed on the two subsequent numbers presented after the conscious decision was made.

Preliminary findings similarly suggest a double dissociation: early cortical activity patterns in frontopolar cortex encoded decision content, addition or subtraction, while preSMA encoded the decision timing, but not vice versa. This suggests that our earlier findings related to covert intentions rather than motor preparation.

Taken together, our results reveal a functional dichotomy between different prefrontal regions in the pre-conscious formation of intentions for self-initiated behavior.

  • Keywords: decoding, unconscious, intention, covert, fMRI
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Socrates Hall

 

 

CS 2.2. New Methods for Studying Consciousness

Chair: Keng-Chen Liang

Novel Paradigms for Studying Subjective Experience in Motion and Object Perception

Chia-Huei Tseng, Psychology, National Taiwan University, Taiwan
George Sperling, Department of Cognitive Sciences, University of California Irvine, USA

To investigate the connection between perceptual experiences and consciousness, researchers have successfully created scenarios in which observers are not aware of existing physical stimuli by reducing the physical strength of stimuli below their detection threshold (sub-threshold stimuli) or by presenting a different stimulus occupying the same spatial location (binocular rivalry or flash suppression) from the other eye. Here we introduce two novel paradigms, one which presents identical motion images well above threshold level to both eyes, yet observers fail to construct a reliable motion perception and therefore the physically moving object seems to be standing still, another in which a motion is experienced but all the visible objects appear to be standing still.
(1) The novel phenomenon of motion standstill occurs when an object exceeds the limits of the motion systems but remains within the capacity of shape extraction systems. It illustrates that consciousness of shape and consciousness of motion are separable. The shape computation can extract a stable shape from a moving stimulus, but it cannot convey the sense of motion, which arises only from the output of motion systems. (2) In a complementary paradigm, pedestalled motion, a moving sinewave grating is superimposed on a stationary grating of larger amplitude (the pedestal). At low temporal frequencies of the moving sine wave, the pedestal grating seems to wobble back and forth. At high temporal frequencies, the wobble disappears, and only a stationary grating is perceived with an objectless "wind" that seems to move in the direction of the physically moving grating. This shows that the sensation of motion can occur without being attached to an object, the only visible object appears to be stationary. These demonstrations illustrate that consciousness is composed of elements that are joined in normal perception but which can be separated experimentally.

  • Keywords: stereo motion, motion standstill, pedestal motion, shape perception
  • Support: This research was supported by NSC 95-2413-H-006-019-MY2 to CT, and AFOSR, Life Science Directorate, Visual Information Processing Program to GS
  • Corresponding Email: CH_Tseng@alumni.uci.edu
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Plato Hall

 

Global Encoding of Affective Space in Large-Scale Patterns of Human Brain Activity

Silke Anders, Neuroimage Nord and Department of Neurology, University of Luebeck, Germany
John-Dylan Haynes, Bernstein Center for Computational Neuroscience, Charite-Universitatsmedizin, Germany

When people experience emotions, a distributed network of brain regions is activated. Different emotions activate the nodes of this network to different degrees, suggesting that the large-scale pattern of brain activity carries information about a person’s emotional state. However, it is currently unclear how specific emotions relate to global activity in this distributed network. Here we investigated whether the similarity between different emotional feelings is related to similarities in corresponding patterns of brain activity. We used functional magnetic resonance imaging (fMRI) and correlation analysis to compare patterns of brain activity associated with five different emotions (joy, anger, disgust, fear, sadness). We show that correlation analysis can be used to decode an individual’s emotional state from his brain activity, both in individuals recalling emotional events and in individuals observing other people’s facial expressions. Emotional states could be successfully decoded even when the brain activity of another individual was used as reference. Moreover, the brain activity of an individual observing another individual’s facial expression could be correctly classified based on the sender’s brain activity alone. This indicates that the global pattern of brain activity for each emotion is very similar across individuals and induction methods. Importantly, the similarity of patterns of brain activity associated with different types of emotion reflected the similarity between emotional experiences in psychological models of affective space. These findings show that different types of emotions evoke distinct large-scale patterns of brain activity that (1) are reproducible across individuals, (2) can be communicated between individuals, and (3) reflect similarity of emotional experience.

  • Keywords: emotion, feelings, affective space, fMRI, decoding
  • Corresponding Email: silkeanders@gmx.net
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Plato Hall

 

Decoding Monkey’s Conscious Experience during Ambiguous and Unambiguous Motion Percept Reveals Initial Non-conscious Spike Activity and Later Neuronal Correlates of Consciousness in Area MT

Naotsugu Tsuchiya, Humanities and Social Sciences, California Institute of Technology, USA
Alexander Maier, National Institute of Health, USA
Nikos K. Logothetis, Max Plank Institute, Germany
David A. Leopold, National Institute of Health, USA

The class of ambiguous stimuli is a powerful tool to study the neuronal correlates of consciousness; under the constant physical stimulation, the conscious experience of the stimulus spontaneously flips back and forth over time. Previous electrophysiological studies with concurrent behavioral measurements during ambiguous percepts concentrated on the trial-by-trial relationship between the activity of isolated single neurons and monkeys’ reports. In these studies, either the stimulus or the recorded neuron was carefully selected so that the two alternative conscious experiences maximally differentiate the spike counts of the recorded neurons. Focusing on single neurons ignores a potentially information-rich signal: the temporal correlation in the spikes of neighboring neurons. We were interested to learn how and when the firing of many neurons began to reflect the conscious perception of an ambiguous stimulus over time. Specifically, we wanted to learn the extent to which we could track the development over time of a neural correlate of consciousness. To address this issue, we trained two monkeys to report their percepts while they were seeing an ambiguous structure-from-motion stimulus. We recorded neuronal activity from the motion sensitive area MT, with 8-10 microelectrodes. We used a decoding approach to quantify how monkeys’ reports are correlated with the activity of the simultaneously recorded multiple neurons over time. The time resolved decoding performance was compared between ambiguous and unambiguous conditions. The ambiguity was manipulated via binocular disparity. The decoding performance attained with many neurons in both conditions was very accurate, although a significant difference emerged between the ambiguous and unambiguous conditions over time. For the unambiguous condition the decoding performance was very accurate from shortly after the stimulus onset and remained high throughout the stimulus presentation. In a stark contrast, the decoding performance for the ambiguous condition built up gradually (almost linearly) over time, and reached at the peak at around.4-.8 sec after the stimulus onset. Our results show that the initial neuronal activity evoked by the onset of a stimulus reflects the physical properties of the input and thus is less correlated with conscious percept, while the later activity is increasingly reflective of the conscious percept of the animal.

  • Keywords:neuron MT ambiguous structure-from-motion decoding bistable
  • Support:Japan Society for Promotion of Science
  • Corresponding Email:naotsu@gmail.com
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Plato Hall

 

Gradual Change and Implicit Detection: A New Methodological Approach

Bruno Berberian, Psychology, Cognitive Science Research Unit (ULB), Belgium
Axel Cleeremans, Psychology, Cognitive Science Research Unit (ULB), Belgium

Recent findings have revealed our surprising inability to detect large changes to scenes from one view to the next ('change blindness'). Similarly, extremely gradual changes generally do not draw attention even if we might subsequently notice that a change has occurred. At the same time, recent evidence suggests that explicit change detection measures may underestimate our ability to process and represent changes in our visual system and that the brain can represent and process some information outside the focus of attention or below the level of awareness—phenomena well known as implicit change detection.

In this context, the goal of this study was to characterize observers' abilities to detect gradual changes and to explore putative dissociations between the conscious experience of change and behavioral adaptation to the changing stimulus. In this perspective, we developed a new experimental paradigm to study change detection based on an original conception of variability as an index of memory stability. On each trial, participants were first shown a dot pattern on the screen. Next, the pattern disappeared and participants had to reproduce it. We assume that an increase in the variability (response variation across trials) is an index of visual change detection. To investigate gradual change detection, the target configuration was gradually rotated of 2 degrees per trial, with a global change of 30 degrees. Verbal reports and a choice task were used to evaluate the level of awareness of the change.

Results showed that 70% of subjects had no conscious experience of change. However, we observed that the reproductions were characterized by a high level of variability for all the subjects. Moreover, we observed a behavioral adaptation to the gradual rotation of the target configuration, marked by a gradual rotation of the subject’s reproductions. The above result tends to confirm the idea of implicit detection and suggests that some changes may produce a change signal that is large enough to be seen but not large enough to draw attention. These results argue for different level of detection and for a flexibility of these levels and are considered in a more global theory of change detection.

  • Keywords: Gradual change, change detection, variability, memory
  • Corresponding Email: bruno.berberian@ulb.ac.be
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Plato Hall

 

CS 2.3. Modeling Consciousness

Chair: Thomas Metzinger

Consciousness and Metarepresentation: A Computational Sketch

Axel Cleeremans, Psychology, Universite Libre de Bruxelles, Belgium
Bert Timmermans, Psychology, Universite Libre de Bruxelles, Belgium
Antoine Pasquali, Psychology, Universite Libre de Bruxelles, Belgium

When one is conscious of something, one is also conscious that one is conscious. Higher-Order Thought Theory (Rosenthal, 1997) takes it that it is in virtue of the fact that one is conscious that one is conscious that one is conscious! Here, we ask what the computational mechanisms may be that implement this intuition. Our starting point is Clark and Karmiloff-Smith (1993)’s point that knowledge acquired by a connectionist network always remains “knowledge in the network rather than knowledge for the network”: While such networks may become exquisitely sensitive to regularities contained in their input-output environment, they never exhibit the ability to access and manipulate this knowledge as knowledge. Instead, knowledge can only be expressed through performing the trained tasks and remains forever embedded in the causal pathways that developed as a result of learning. To address this issue, we present simulations in which two networks interact. The states of a first-order network trained to perform a simple categorization task become input to a second-order network trained either as an encoder or on another categorization task. Thus, the second-order network “observes” the states of the first-order network and has, in the first case, to reproduce these states on its output units, and in the second case, to use the states as cues in order to solve the secondary task.. This implements a limited form of metarepresentation, to the extent that the second-order network’s internal representations become re-representations of the first-order network’s internal states. We explore how well this mechanism accounts for observed dissociations between performance and report in the different situations recently explored by Persaud et al. (2007). We conclude that this mechanism forms the basis of mental attitudes, that is, a cognitive system’s understanding of the manner in which its first-order knowledge is held (belief, hope, fear, etc.). Consciousness, in this light, involves knowledge of the geography of one own’s internal representations — a geography that is itself learned over time as the results of an agent’s attributing value to the various experiences it enjoys through interaction with itself, the world, and others.

  • Keywords: consciousness, metarepresentation, neural networks
  • Corresponding Email: axcleer@ulb.ac.be
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Locke Hall

 

Nonlinear Functional Connectivity in Visual Awareness: A Small-World Study

Hung-Wei Lee, Applied Psychology, Hsuan-Chuang University, Taiwan
Shwu-Lih Huang, Psychology, National Chengchi University, Taiwan
Yu-Chieh Chang, Psychology, National Chengchi University, Taiwan

In this electroencephalogram study, we modified the "Mooney face" recognition experiment of Rodriguez et al. (1999) to differentiate patterns of functional connectivity which correlated to the participant's states of visual awareness. We first used an index of generalized synchrony proposed by Arnhold et al. (1999) to define the strength of connections between pairs of EEG channels. Then we followed Watts and Strogatz (1998) to calculate several parameters of small-world theory to reveal different network structures of the moments on which the participant perceived a stable face or not. The results showed that a small-world topology of brain network did correlate to visual awareness. That is, when the participant recognized a face, the functional connectivity was characterized by a decreased number of connections, an increased density of local clustering and shortened path lengths between pairs of connecting channels. In addition, we also divided the whole brain network into either left/right hemispheres or front/hind parts. And we found that only left/right sub-networks could represent the states of visual awareness, but they were not as reliable as the whole brain network.

  • Keywords: visual awareness,functional connectivity,nonlinearity,small-world
  • Corresponding Email: spoon@hcu.edu.tw
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Locke Hall

 

Does the Brain Implement Some Form of Delay Coordinate Embedding?

Vikas Shah, Department of Internal Medicine, Banner Good Samaritan Medical Center, United States

A fundamental question about how the brain works is how it is able to perform a wide variety of tasks with high degrees of accuracy, reproducibility, adaptability, and plasticity. Apart from characterization of how some fairly simple visual processing tasks are implemented, very little is known about how neuronal firing translates into the processing of information. I develop here a hypothesis that neuronal circuitry implements some form of delay coordinate embedding (DCE) to process information. DCE is a relatively recent mathematical advancement that allows prediction of the behavior of chaotic systems. Though there is no hard evidence supporting this hypothesis, there are several reasons to pursue it. First, predictions based on DCE are essentially heuristic in nature, and increasing amounts of previously collected data about the behavior of a chaotic system allows progressively better prediction of the future behavior of the system; such tasks are performed commonly and easily by the brain. Second, DCE based predictions only require that DCE be performed in an appropriately high number of dimensions and may be performed with data from a single state variable. Thus, for relatively simple systems such an approach provides a highly efficient method for developing accurate predictions about the behavior of a system based only on limited information. One possible advantage of neuronal modules performing DCE is that the approach is generic and reproducible; such modules could be copied across several different systems to provide analysis of sound, motion, arithmetic/mathematics, language, proprioception, muscular movement and coordination, possibly even psychological analysis/prediction of the behavior of other actors. Additionally, such a approach would allow (teleologically speaking) neuronal systems to quickly learn "the rules of reality" without positing the need for centrally hardwired rules and the accompanying difficulties in positing a mechanism for genetic specification of the ontogenetic configuration required to implement these rules. Finally, re-entrant processing has recently become a focus of attention as an important mechanism underlying information processing and possibly consciousness itself; it is possible to envision that re-entrant firing could represent information transfer necessary for DCE analysis as implemented by the brain.

  • Keywords: consciousness; information processing; neuronal mechanisms; nonlinear dynamics; delay coordinate embedding; taken's theorem
  • Corresponding Email: vikas.shah.1976@gmail.com
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Locke Hall

 

Simulation of Bistable Perception with Long Range Correlations Using Reentrant Nonlinear Perception-Attention-Memory Coupling

Norbert Fuerstenau, Institute of Flight Guidance, German Aerospace Center, Germany

Simulation results of bistable perception due to ambiguous visual stimuli are presented which are obtained with a behavioral nonlinear dynamics (phase oscillator) model using perception–attention–memory coupling. As a kind of minimum architecture representing the Thalamo-Cortical and ventral ("what") V4–InferoTemporal–PraeFrontal–V4 loops the basic model couples the nonlinear dynamics of a macroscopic perception state order parameter with an adaptive attention (feedback gain) control parameter with reentrant delay T and additive band limited white noise (Furstenau 2006, 2007). Quasiperiodic perceptual switching is induced by attention fatigue coupled to the perception state, with a perception bias which balances the relative duration of the alternative percepts, corresponding to the well known Synergetics model of Ditzinger and Haken (1989). As a new feature memory effects are introduced by allowing for the slow adaptation of the perception bias parameter via coupling to the perception state. The simulations exhibit long range correlations of the perceptual duration times in agreement with recent experimental results of Gao et al. (2006). They are determined by calculation of the self similarity (Hurst) parameter H of the reversal time series (H > 0.5). Deviations of the simulated reversal time statistics from the Gamma-distribution as typically observed in experiments, increase with decreasing memory time constant and attention noise. Mean perceptual duration times of 2 – 5 s are predicted in agreement with experimental results reported in the literature, if a feedback delay T of 40 ms is assumed which is typical for cortical reentrant loops and the stimulus-V1 latency (Lamme 2003). Numerically determined perceptual transition times of 3 – 5 T are in reasonable agreement with stimulus–conscious perception delay of 150 – 200 ms. The symmetrized absolute value of the attention parameter exhibits qualitative agreement with the dynamics of the eye blink rate and saccade frequency as reported by Ito et.al. (2003). Initial periodic stimulus simulations yields the reversal rate variation as a function of stimulus off-time in surprisingly good quantitative agreement with experimental results of Orbach et.al.(1966) when selecting adaptation and recovery time constants of 1 – 2 s.

  • Keywords: cognitive bistability, nonlinear dynamics model, simulation, perception, attention, memory, coupling, long range correlations
  • Corresponding Email: norbert.fuerstenau@dlr.de
  • Presentation: Talk, Saturday June 21, 2:00PM-4:00PM at Locke Hall