Surprising Events Research Articles

Trial-by-Trial Fluctuations in the Event-Related Electroencephalogram Reflect Dynamic Changes in the Degree of Surprise

The P300 component of the human event-related brain potential has often been linked to the processing of rare, surprising events. However, the formal computational processes underlying the generation of the P300 are not well known. Here, we formulate a simple model of trial-by-trial learning of stimulus probabilities based on Information Theory. Specifically, we modeled the surprise associated with the occurrence of a visual stimulus to provide a formal quantification of the "subjective probability" associated with an event. Subjects performed a choice reaction time task, while we recorded their brain responses using electroencephalography (EEG). In each of 12 blocks, the probabilities of stimulus occurrence were changed, thereby creating sequences of trials with low, medium, and high predictability. Trial-by-trial variations in the P300 component were best explained by a model of stimulus-bound surprise. This model accounted for the data better than a categorical model that parametrically encoded the stimulus identity, or an alternative model of surprise based on the Kullback-Leibler divergence. The present data demonstrate that trial-by-trial changes in P300 can be explained by predictions made by an ideal observer keeping track of the probabilities of possible events. This provides evidence for theories proposing a direct link between the P300 component and the processing of surprising events. Furthermore, this study demonstrates how model-based analyses can be used to explain significant proportions of the trial-by-trial changes in human event-related EEG responses.

AFTERWORDS

AFTERWORDS

Bayesian surprise attracts human attention

We propose a formal Bayesian definition of surprise to capture subjective aspects of sensory information. Surprise measures how data affects an observer, in terms of differences between posterior and prior beliefs about the world. Only data observations which substantially affect the observer’s beliefs yield surprise, irrespectively of how rare or informative in Shannon’s sense these observations are. We test the framework by quantifying the extent to which humans may orient attention and gaze towards surprising events or items while watching television. To this end, we implement a simple computational model where a low-level, sensory form of surprise is computed by simple simulated early visual neurons. Bayesian surprise is a strong attractor of human attention, with 72% of all gaze shifts directed towards locations more surprising than the average, a figure rising to 84% when focusing the analysis onto regions simultaneously selected by all observers. The proposed theory of surprise is applicable across different spatio-temporal scales, modalities, and levels of abstraction.

Folk Theories of Happiness: A Cross-Cultural Comparison of Conceptions of Happiness in Germany and South Africa

Although happiness as a state of mind may be universal, its meaning takes culture-specific forms. Drawing on the concept of folk theories, this study attempted to uncover lay beliefs about the nature of happiness in Germany and South Africa. To that end, 57 German and 44 black South African students wrote free-format essays in response to the question: “What is happiness to you?” Using thematic analysis the following themes were found: (1) satisfaction; (2) contentment; (3) positive affect; (4) social relationships; (5) freedom; and (6) the opposite of unhappiness. In addition, German respondents defined happiness in terms of (7) surprising events. The exact meaning content of the above-mentioned dimensions showed clear influences of individualism/collectivism. However, strong culture-specific factors, such as the influence of philosophical traditions, material living circumstances and linguistic influences, were also found.

Surprising Twist on Auditory Representation. Focus on: “What's That Sound? Auditory Area CLM Encodes Stimulus Surprise, Not Intensity or Intensity Changes”

The concept of sensory representation is central to psychological theories of perception and cognition and to neurobiological models of sensory coding. Understanding exactly what a neural response “represents,” however, turns out to be a difficult question to answer fully—particularly for neurons many synapses away from the point of sensory transduction. A recent paper by Gill and colleagues (2007) takes a large step forward in understanding stimulus representation in the auditory system. To appreciate the contribution this paper makes, it’s helpful to have a little background. To a first approximation, sensory systems and the receptive fields they comprise are organized hierarchically. The concept of a “receptive field” was first applied to the visual system (Hartline 1938) to describe the sensitivity of optic nerve fibers to light shined on spatially restricted portions of the retina. While neurons in primary visual cortex inherit the spatial receptive fields of the retinal projections, they respond to oriented bars or edges rather than spots of light. At higher levels in the visual pathway, cells respond best to complex

Désillusions des donateurs ?

Cet article esquisse un etat des lieux des relations entre Occident et Asie centrale post-sovietique. En 1991, la disparition du systeme politique et economique sovietique a ete une experience traumatique tant pour les gouvernements que pour les populations. Le contact direct avec les gouvernements occidentaux entrainait une modification des cles de lecture generalement utilisees a l’Ouest pour apprehender ces societes. Les relations entre Occident et Asie centrale sont passees en quinze ans par differentes phases : decouverte et illusions, puis relative desillusion et partiel desengagement de l’Occident. Depuis 2005, la cooperation internationale occidentale semble etre de plus en plus marginalisee, Russie, Chine et Inde devenant des acteurs incontournables du developpement economique et politique de la region.

Understanding the dynamics of strategic risks and resources in innovative ventures

This paper presents a model of the evolution of activities, risks, and required resources for innovative ventures. A key implication of the model is the importance of surprising events in the life of ventures. Such events happen in most innovative ventures and appear to be a major source of preventable failures. Reacting to these events requires significant inflows of new resources into the venture. However, inflows are usually prevented by the disconcerting effect of surprising events on venture participants and by the centrifugal reactions they trigger among participants. The model is used to provide recommendations for developing business plans elements that can diminish the impact of unexpected events on innovative ventures and can reduce the number of preventable failures.

Models in search of a brain

Mental localization efforts tend to stress the where more than the what. We argue that the proper targets for localization are well-specified cognitive models. We make this case by relating an existing cognitive model of category learning to a learning circuit involving the hippocampus, perirhinal, and prefrontal cortices. Results from groups varying in function along this circuit (e.g., infants, amnesics, and older adults) are successfully simulated by reducing the model's ability to form new clusters in response to surprising events, such as an error in supervised learning or an unfamiliar stimulus in unsupervised learning. Clusters in the model are akin to conjunctive codes that are rooted in an episodic experience (the surprising event) yet can develop to resemble abstract codes as they are updated by subsequent experiences. Thus, the model holds that the line separating episodic and semantic information can become blurred. Dissociations (categorization vs. recognition) are explained in terms of cluster recruitment demands.

Asymmetric Nash Bargaining with Surprised Players

This paper introduces two-player bargaining problems allowing for asymmetric subjective uncertainty about factors that determine whether agreement is achieved, focusing on surprising events, i.e. events believed possible by only one player. A `subjective Nash' solution is proposed, in which a bargaining outcome is defined as immune to all possible appeals given the subjective uncertainty of disagreement. In addition to Pareto optimality and independence of irrelevant alternatives, the main axiom in the solution characterization is `subjective symmetry'. The solution is shown to be equivalent to a specific, non-symmetric, Nash solution, with preference dependent weights that equal the subjective probability players assign to the intersection of their belief supports.

Bayesian theories of conditioning in a changing world

The recent flowering of Bayesian approaches invites the re-examination of classic issues in behavior, even in areas as venerable as Pavlovian conditioning. A statistical account can offer a new, principled interpretation of behavior, and previous experiments and theories can inform many unexplored aspects of the Bayesian enterprise. Here we consider one such issue: the finding that surprising events provoke animals to learn faster. We suggest that, in a statistical account of conditioning, surprise signals change and therefore uncertainty and the need for new learning. We discuss inference in a world that changes and show how experimental results involving surprise can be interpreted from this perspective, and also how, thus understood, these phenomena help constrain statistical theories of animal and human learning.

Clues, Cues and Complexity: Unpackuing the Concept of Organizational Surprise

We discuss why surprises, defined as events that happen unexpectedly or expected events that take unexpected shapes, are important to organizations and should be considered in the organizational literature. The concept of organizational surprises is unpacked on the basis of a typology built around the(un)expectedeness of issue and process. This typology uncovers the several types of surprising events that organizations may face, and contributes to the literature by suggesting that different surprises require distinct approaches.

Latency and duration of the action interruption in surprise

Cognitive and biological theories of emotion consider surprise as an emotional response to unexpected events. Four experiments examined the latency and the duration of one behavioural component of surprise: The interruption of ongoing action. Participants were presented with an unannounced visual event—the appearance of new perceptual objects—during the execution of a continuous action—a rapid alternate finger tapping—which allowed a precise measurement of the latency, and the duration of an action interruption induced by the surprising event. Of the participants, 78% interrupted the tapping with a mean latency of 214 ms and a mean duration of 995 ms. Variations of the number and perceptual heterogeneity of the new objects revealed that the perceptual analysis of the surprising event contributes significantly to the interruption duration.

In the Blink of an Eye: How Vision Sparked the Big Bang of Evolution

An accomplished young scientist solves one of the greatest mysteries of evolution: What caused the dramatic explosion of life half a billion years ago?. About 550 million years ago, there was literally an explosion of life forms, as all the major animal groups suddenly and dramatically appeared. Although several books have been written about this surprising event, known as the Cambrian explosion, none has explained why it occurred. Indeed, none was able to. Here, for the first time, Oxford zoologist Andrew Parker reveals his theory of this great flourishing of life. Parker's controversial but increasingly accepted Light Switch Theory holds that it was the development of vision in primitive animals that caused the explosion. Drawing on evidence not just from biology, but also from geology, physics, chemistry, history, and art, In the Blink of an Eye is the fascinating account of a young scientist's intellectual journey, and a celebration of the scientific method.

Evidence for strong dissociation between emotion and facial displays: The case of surprise.

Eight experiments examined facial expressions of surprise in adults. Surprise was induced by disconfirming a previously established schema or expectancy. Self-reports and behavioral measures indicated the presence of surprise in most participants, but surprise expressions were observed only in 4%-25%, and most displays consisted of eyebrow raising only; the full, 3-component display was never seen. Experimental variations of surprise intensity, sociality, and duration/complexity of the surprising event did not change these results. Electromyographic measurement failed to detect notably more brow raisings and, in one study, revealed a decrease of frontalis muscle activity in the majority of the participants. Nonetheless, most participants believed that they had shown a strong surprise expression.

Surprises in Management and Organization: Concept, Sources and A Typology*

We discuss why surprises, defined as events that happen unexpectedly or expected events that take unexpected shapes, are important to organizations and should be considered in the organization and management literature as an umbrella concept, encompassing a variety of related phenomena. The concept of organizational surprises is unpacked and a typology is built around the (un)expectedness of the issue and the (un)expectedness of the process. This typology uncovers the several types of surprising events that organizations may face, and contributes to the literature by identifying how different types of surprises require distinct managerial approaches.

The Kaliningrad, West Russia earthquakes on the 21st of September 2004—Surprise events in a very low-seismicity area

The earthquakes in Kaliningrad, West Russia on the 21st of September 2004 were unexpected in a seismically quiet area. The main shock of magnitude m b = 5 was widely felt around the Baltic Sea. A comparison with some historic earthquakes in Northern Europe shows that its perceptibility area is smaller than that of the 1904 Oslo Graben earthquake of an estimated magnitude ( M L) 5.4 but larger than those of the 1759 Kattegat and 1819 Lurøy earthquakes. The latter are claimed to have had magnitudes ( M S) in the range of 5.7–6.0. An analysis of the Lg phase of the Kaliningrad earthquakes as recorded at a number of European stations accords only weakly with the macroseismic intensity pattern that shows fast attenuation towards west–northwest and southeast. The strike–slip focal mechanism of the main shock is discussed in the context of remnant glacial rebound stresses in generating present-day seismicity in N. Europe.

The processing of affectively valenced stimuli: The role of surprise

Two experiments tested the hypothesis that the surprise mechanism activates a threat detection system that prioritises the processing of threat-related stimuli. In Experiment 1, participants responded to a dot that appeared during the presentation of two words. In the critical trial, one of the two words was either pleasant or unpleasant. In Experiment 2, depending on the condition, the participants had to decide whether at least one of two simultaneously presented pictures depicted either a pleasant or an unpleasant stimulus. In the critical trial, both a pleasant and an unpleasant picture appeared. In both experiments, the stimuli in the critical trial were presented either during routine behaviour or in the context of a surprising event. The results showed that during routine behaviour unpleasant stimuli received more attentive resources than pleasant stimuli only if the affective valence of the stimuli was action-relevant (Experiment 2). In contrast, in the context of surprise, unpleasant words engaged more attentive resources than pleasant words although they were action-irrelevant (Experiment 1). In addition, in the context of surprise, the decision time increase was more pronounced in the pleasant than in the unpleasant experimental group. This finding was interpreted as evidence that the threat detection system of the surprise mechanism initially searches for a threat-related stimulus.

Design and Evaluation of a Prototype Rear Obstacle Detection and Driver Warning System

This study, concerned with the development of driver interface criteria for a rear obstacle detection system, assessed the appropriateness of alternative warning timing algorithms and evaluated various interface approaches for presenting warning information to drivers. Interface testing used a minivan and a passenger sedan equipped with a prototype rear obstacle detection system. Two different warning timing algorithms and four different interface conditions were examined. The appropriateness of the warning timing algorithms was tested using an alerted backing procedure wherein drivers backed to known obstacles and braked in response to the warning. A surprise event scenario was also included in order to examine driver reaction to the warning under unexpected conditions. Alerted backing results suggest that although both timing algorithms led to few target strikes, one algorithm led to more acceptable ratings, fewer target strikes and close calls, and less urgent braking. None of the interface warning conditions reliably induced avoidance braking under the surprise event condition. Actual or potential applications of this work include the appropriate design of effective backing warning systems.

INEVITABLE HUMANS: SIMON CONWAY MORRIS'S EVOLUTIONARY PALEONTOLOGY

Abstract. Simon Conway Morris, noted Cambridge University paleontologist, argues that in evolutionary natural history humans (or beings rather like humans) are an inevitable outcome of the developing speciating processes over millennia; humans are “inherent” in the system. This claim, in marked contrast to claims about contingency made by other prominent paleontologists, is based on numerous remarkable convergences—similar trends found repeatedly in evolutionary history. Conway Morris concludes approaching a natural theology. His argument is powerful and informed. But does it face adequately the surprising events in such history, particularly notable in unexpected co‐options that redirect the course of life? The challenge to understand how humans are both on a continuum with other species and also utterly different remains a central puzzle in paleontology.

The Jeffords Effect

Abstract In May 2001, Senator James Jeffords left the Republican Party and tipped control of the U.S. Senate to the Democrats. This paper uses the surprise event to demonstrate what I term the “Jeffords effect”: changes in the political landscape have large effects on the market value of firms. I use a firm’s soft‐money donations to the national parties as the measure of how the firm aligns itself politically. In this event study, a firm lost .8 percent of market capitalization the week of Jeffords’s switch for every $250,000 it gave to the Republicans in the previous election cycle. On the basis of the point estimates, the stock price gain associated with Democratic donations is smaller than the loss associated with Republican donations, but the estimates are consistent with the effects being equal and opposite. The results withstand several robustness checks, and the effects appear to persist over time.