Two envelope problems and the roles of ignorance

Four variations on Two Envelope Paradox are stated and compared. The variations are employed to provide a diagnosis and an explanation of what has gone awry in the paradoxical modeling of the decision problem that the paradox poses. The canonical formulation of the paradox underdescribes the ways in which one envelope can have twice the amount that is in the other. Some ways one envelope can have twice the amount that is in the other make it rational to prefer the envelope that was originally rejected. Some do not, and it is a mistake to treat them alike. The nature of the mistake is diagnosed by the different roles that rigid designators and definite descriptions play in unproblematic and in untoward formulations of decision tables that are employed in setting out the decision problem that gives rise to the paradox. The decision maker’s knowledge or ignorance of how one envelope came to have twice the amount that is in the other determines which of the different ways of modeling his decision problem is correct. Under this diagnosis, the paradoxical modeling of the Two Envelope problem is incoherent.

The projected hand illusion: component structure in a community sample, and association with demographics, cognition and psychotic-like experiences

The projected hand illusion (PHI) is a variant of the rubber hand illusion (RHI), and both are commonly used to study mechanisms of self-perception. A questionnaire was developed by Longo et al. (2008) to measure qualitative changes in the RHI. Such psychometric analyses have not yet been conducted on the questionnaire for the PHI. The present study is an attempt to validate minor modifications of the questionnaire of Longo et al. to assess the PHI in a community sample (n = 48) and to determine the association with selected demographic (age, sex, years of education), cognitive (Digit Span), and clinical (psychotic-like experiences) variables. Principal components analysis on the questionnaire data extracted four components: Embodiment of “Other” Hand, Disembodiment of Own Hand, Deafference, and Agency—in both synchronous and asynchronous PHI conditions. Questions assessing “Embodiment” and “Agency” loaded onto orthogonal components. Greater illusion ratings were positively associated with being female, being younger, and having higher scores on psychotic-like experiences. There was no association with cognitive performance. Overall, this study confirmed that self-perception as measured with PHI is a multicomponent construct, similar in many respects to the RHI. The main difference lies in the separation of Embodiment and Agency into separate constructs, and this likely reflects the fact that the “live” image of the PHI presents a more realistic picture of the hand and of the stroking movements of the experimenter compared with the RHI.

A `Rubber-hand` illusion reveals a relationship between perceptual body image and unhealthy body change

The ‘rubber-hand’ illusion, in which individuals misattribute tactile sensations felt by their hand to a rubber prosthetic hand that they see being stimulated, was employed to examine the relationship between perceptual body image and unhealthy body change in 128 volunteers. Variance in unhealthy body development in males (22%) and in bulimic symptomatology in both females and males (10%), was explained by susceptibility to the illusion. The illusion, which is relatively free from cognitive and emotional ‘contamination’, could be used to identify individuals most responsive to therapies designed to correct inaccurate body perceptions–individuals whose perceptual body image is malleable.

Safety illusion and error trap in a collectively-operated machine accident

Workplace accidents involving machines are relevant for their magnitude and their impacts on worker health. Despite consolidated critical statements, explanation centered on errors of operators remains predominant with industry professionals, hampering preventive measures and the improvement of production-system reliability. Several initiatives were adopted by enforcement agencies in partnership with universities to stimulate production and diffusion of analysis methodologies with a systemic approach. Starting from one accident case that occurred with a worker who operated a brake-clutch type mechanical press, the article explores cognitive aspects and the existence of traps in the operation of this machine. It deals with a large-sized press that, despite being endowed with a light curtain in areas of access to the pressing zone, did not meet legal requirements. The safety devices gave rise to an illusion of safety, permitting activation of the machine when a worker was still found within the operational zone. Preventive interventions must stimulate the tailoring of systems to the characteristics of workers, minimizing the creation of traps and encouraging safety policies and practices that replace judgments of behaviors that participate in accidents by analyses of reasons that lead workers to act in that manner.

Safety illusion and error trap in a collectively-operated machine accident

Workplace accidents involving machines are relevant for their magnitude and their impacts on worker health. Despite consolidated critical statements, explanation centered on errors of operators remains predominant with industry professionals, hampering preventive measures and the improvement of production-system reliability. Several initiatives were adopted by enforcement agencies in partnership with universities to stimulate production and diffusion of analysis methodologies with a systemic approach. Starting from one accident case that occurred with a worker who operated a brake-clutch type mechanical press, the article explores cognitive aspects and the existence of traps in the operation of this machine. It deals with a large-sized press that, despite being endowed with a light curtain in areas of access to the pressing zone, did not meet legal requirements. The safety devices gave rise to an illusion of safety, permitting activation of the machine when a worker was still found within the operational zone. Preventive interventions must stimulate the tailoring of systems to the characteristics of workers, minimizing the creation of traps and encouraging safety policies and practices that replace judgments of behaviors that participate in accidents by analyses of reasons that lead workers to act in that manner.

Marx Illusion

With “Marx Illusion”, Claudiu Coman recalls sociology - this science of analytic and methodological strictness - to its uncorrupted philosophical dignity. Not only the theorization - that is the seduction of quality essay, Claudiu Coman demonstrating here a single ability - but the philosophy itself: a science, if we want, but as a way of cognitive enclosure of the beings of the world, firstly of those who make the world possible, but of the transcendent world that transcends them making possible - as a 20th century scientist would say - the man’s connection to an existence that is not his own, but that identifies itself with the difference. Being in the world - M. Heidegger writes (in 1928, after the apparition of the work “The Being and Time”) - it is specific only to the man - and here within the Territory of Existence I have the impression that philosophy and sociology responded together. However, working together with philosophy, the sociology extends enveloping the “world less” beings, too. These things would already been in the world as “direct” things (“handy”) being caught by the man by referring to them in the world itself.

Reduced perception of the motion-induced blindness illusion in schizophrenia

Motion-induced blindness (MIB) occurs when target stimuli are presented together with a moving distractor pattern. Most observers experience the targets disappearing and reappearing repeatedly for periods of up to several seconds. MIB can be viewed as a striking marker for the organization of cognitive functioning. In the present study, MIB rates and durations were assessed in 34 schizophrenia-spectrum disorder patients and matched controls. The results showed that positive symptoms and excitement enhanced MIB, whereas depression and negative symptoms attenuated the illusion. MIB was more frequently found in normal subjects. The results remained consistent after adjusting for reaction time and error rates. Hence, MIB may provide a valid and reliable measure of cognitive organization in schizophrenia.

Do expert drivers have a reduced illusion of superiority?

It is well established that people tend to rate themselves as better than average across many domains. To maintain these illusions, it is suggested that people distort feedback about their own and others' performance. This study examined expert/novice differences in self-ratings when people compared themselves with others of the same level of expertise and background as themselves. Given that a key expert characteristic is increased self-monitoring, we predicted that experts in a domain may have a reduced illusion of superiority because they are more aware of their actual ability. We compared expert police drivers with novice police drivers and found that this prediction was not supported. Expert police drivers rated themselves as superior to equally qualified drivers, to the same degree as novices, Cohen's d = .03 ns. Despite their extensive additional training and experience, experts still appear to be as susceptible to illusions of superiority Lis everyone else. (C) 2004 Elsevier Ltd. All rights reserved.

Drivers' ratings of different components of their own driving skill: A greater illusion of superiority for skills that relate to accident involvement

Different components of driving skill relate to accident involvement in different ways. For instance, while hazard-perception skill has been found to predict accident involvement, vehicle-control skill has not. We found that drivers rated themselves superior to both their peers and the average driver on 18 components of driving skill (N = 181 respondents). These biases were greater for hazard-perception skills than for either vehicle-control skills or driving skill in general. Also, ratings of hazard-perception skill related to self-perceived safety after overall skill was controlled for. We suggest that although drivers appear to appreciate the role of hazard perception in safe driving, any safety benefit to be derived from this appreciation may be undermined by drivers' inflated opinions of their own hazard-perception skill. We also tested the relationship between illusory beliefs about driving skill and risk taking and looked at ways of manipulating drivers' illusory beliefs.

The functional subdivision of the visual brain : Is there a real illusion effect on action? A multi-lab replication study

Acknowledgements We thank Brian Roberts and Mike Harris for responding to our questions regarding their paper; Zoltan Dienes for advice on Bayes factors; Denise Fischer, Melanie Römer, Ioana Stanciu, Aleksandra Romanczuk, Stefano Uccelli, Nuria Martos Sánchez, and Rosa María Beño Ruiz de la Sierra for help collecting data; Eva Viviani for managing data collection in Parma. We thank Maurizio Gentilucci for letting us use his lab, and the Centro Intradipartimentale Mente e Cervello (CIMeC), University of Trento, and especially Francesco Pavani for lending us his motion tracking equipment. We thank Rachel Foster for proofreading. KKK was supported by a Ph.D. scholarship as part of a grant to VHF within the International Graduate Research Training Group on Cross-Modal Interaction in Natural and Artificial Cognitive Systems (CINACS; DFG IKG-1247) and TS by a grant (DFG – SCHE 735/3-1); both from the German Research Council.