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Concept: Reversal


Every day, thousands of polls, surveys, and rating scales are employed to elicit the attitudes of humankind. Given the ubiquitous use of these instruments, it seems we ought to have firm answers to what is measured by them, but unfortunately we do not. To help remedy this situation, we present a novel approach to investigate the nature of attitudes. We created a self-transforming paper survey of moral opinions, covering both foundational principles, and current dilemmas hotly debated in the media. This survey used a magic trick to expose participants to a reversal of their previously stated attitudes, allowing us to record whether they were prepared to endorse and argue for the opposite view of what they had stated only moments ago. The result showed that the majority of the reversals remained undetected, and a full 69% of the participants failed to detect at least one of two changes. In addition, participants often constructed coherent and unequivocal arguments supporting the opposite of their original position. These results suggest a dramatic potential for flexibility in our moral attitudes, and indicates a clear role for self-attribution and post-hoc rationalization in attitude formation and change.

Concepts: Arguments, Addition, Change, Reversal, Argument, Magic, Morality, Social psychology


Up to 6% of men who have undergone vasectomy will ultimately elect for reversal in the form of vasovasostomy or vasoepididymostomy for various reasons. Vasovasostomy performed to regain fertility is a technique that has undergone numerous advances during the last century, including the use of microsurgical equipment and principles to construct a meticulous anastomosis. It is important during vasovasostomy to ensure good blood supply to the anastomosis as well as to build as a tension-free anastomosis. Visual inspection to ensure healthy mucosa and inner muscularis as well as atraumatic handling of tissues is helpful. With vasovasostomy, it is essential create a watertight anastomosis to prevent secondary scar formation. The microdot technique of vasovasostomy allows for markedly discrepant lumens to be brought together more precisely. Thereby, the planning is separated from suture placement, which prevents dog-ears and avoids subsequent leaks. In the age of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI), it becomes even more important to clarify outcomes after vasectomy reversals, as patients now have a choice between surgical sperm retrieval coupled with IVF/ICSI versus vasectomy reversal. Little data on long-term outcomes for vasectomy reversals exist. Therefore, further research in this field needs to evaluate the rate of late failures and the predictors of late failures.Asian Journal of Andrology advance online publication, 12 November 2012; doi:10.1038/aja.2012.79.

Concepts: Reversal, Infertility, Andrology, Urology, Vasovasostomy, Vasectomy, Fertility, In vitro fertilisation


Contextual preference reversals occur when a preference for one option over another is reversed by the addition of further options. It has been argued that the occurrence of preference reversals in human behavior shows that people violate the axioms of rational choice and that people are not, therefore, expected value maximizers. In contrast, we demonstrate that if a person is only able to make noisy calculations of expected value and noisy observations of the ordinal relations among option features, then the expected value maximizing choice is influenced by the addition of new options and does give rise to apparent preference reversals. We explore the implications of expected value maximizing choice, conditioned on noisy observations, for a range of contextual preference reversal types-including attraction, compromise, similarity, and phantom effects. These preference reversal types have played a key role in the development of models of human choice. We conclude that experiments demonstrating contextual preference reversals are not evidence for irrationality. They are, however, a consequence of expected value maximization given noisy observations. (PsycINFO Database Record

Concepts: Game theory, Bounded rationality, Behavior, Utility, Motivation, Rationality, Human behavior, Reversal


Fear-relevant stimuli such as snakes and spiders are thought to capture attention due to evolutionary significance. Classical conditioning experiments indicate that these stimuli accelerate learning, while instructed extinction experiments suggest they may be less responsive to instructions. We manipulated stimulus type during instructed aversive reversal learning and used quantitative modeling to simultaneously test both hypotheses. Skin conductance reversed immediately upon instruction in both groups. However, fear-relevant stimuli enhanced dynamic learning, as measured by higher learning rates in participants conditioned with images of snakes and spiders. Results are consistent with findings that dissociable neural pathways underlie feedback-driven and instructed aversive learning.

Concepts: Quantitative research, Instruction, Higher Learning, Reversal, Experiment, Test method, Psychology, Classical conditioning


Research suggests that implicit evaluations are relatively insensitive to single instances of new, countervailing information that contradicts prior learning. In 6 experiments, however, we identify the critical role of the perceived diagnosticity of that new information: Counterattitudinal information that is deemed highly diagnostic of the target’s true nature leads to a complete reversal of the previous implicit evaluation. Experiments 1a and 1b establish this effect by showing that newly formed implicit evaluations are reversed minutes later with exposure to a single piece of highly diagnostic information. Experiment 2 demonstrates a valence asymmetry in participants' likelihood of exhibiting rapid reversals of newly formed positive versus negative implicit evaluations. Experiment 3 provides evidence that a target must be personally responsible for the counterattitudinal behavior and not merely incidentally associated with a negative act. Experiment 4 shows that participants exhibit revision only when they judge the target’s counterattitudinal behavior as offensive and thus diagnostic of his character. Experiment 5 demonstrates the behavioral implications of newly revised implicit evaluations. These studies show that newly formed implicit evaluations can be completely overturned through deliberative considerations about a single piece of counterattitudinal information. (PsycINFO Database Record © 2014 APA, all rights reserved).

Concepts: Science, Behavior, Experiment, The Target, Psychology, All rights reserved, Revision, Reversal


Early social housing is known to benefit cognitive development in laboratory animals. Pre-weaned dairy calves are typically separated from their dam immediately after birth and housed alone, but no work to date has addressed the effect of individual housing on cognitive performance of these animals. The aim of this study was to determine the effects of individual versus social housing on two measures of cognitive performance: reversal learning and novel object recognition. Holstein calves were either housed individually in a standard calf pen (n = 8) or kept in pairs using a double pen (n = 10). Calves were tested twice daily in a Y-maze starting at 3 weeks of age. Calves were initially trained to discriminate two colours (black and white) until they reached a learning criterion of 80% correct over three consecutive sessions. Training stimuli were then reversed (i.e. the previously rewarded colour was now unrewarded, and vice-versa). Calves from the two treatments showed similar rates of learning in the initial discrimination task, but the individually housed calves showed poorer performance in the reversal task. At 7 weeks of age, calves were tested for their response to a novel object in eight tests over a two-day period. Pair-housed calves showed declining exploration with repeated testing but individually reared calves did not. The results of these experiments provide the first direct evidence that individual housing impairs cognitive performance in dairy calves.

Concepts: Reversal, Veal, Knowledge, Dairy farming, Cognitive psychology, Color, Cattle, Calf


When two sequential video frames extracted from a single video clip are followed by the negative of the two frames, a viewer often experiences a visual illusion whereby a scene in the frames continuously moves in a single direction (four-stroke apparent motion). To create a four-stroke apparent motion display, the image intensities of the whole of the second pair of images are reversed. However, this intensity reversal creates a strong impression of flicker that can be undesirable for comfortable viewing. This study reports that four-stroke apparent motion can be induced by only reversing the luminance intensities in those spatial areas which contain motion signals in high-pass filtered images. This use of only a partial reversal of image intensities greatly reduces the apparent flicker in the display while retaining motion perception.

Concepts: Reversal, Visual perception, Computer graphics, Vision, Illusion, Reverse, Optics, Photography


To describe characteristics of participants and overdose reversals associated with a community-based naloxone distribution program and identify predictors of obtaining naloxone refills and using naloxone for overdose reversal.

Concepts: E-participation, Naloxone, Drug overdose, Reversal, Participation


Naloxone is commonly administered in emergency department (ED) to reverse opioid intoxication. Several naloxone dose recommendations exist for acute management of opioid intoxication based on limited published clinical data. A case series of ED patients with opioid-induced ventilatory depression that was reversed using a low-dose naloxone (0.04 mg with titration) is presented.

Concepts: Morphine, Psychology, Opioid, Evaluation methods, Hospital, Reversal, Reverse, Naloxone


Understanding what leads people to reverse their choices is important in many domains. We introduce a contrast paradigm for studying reversals in choices-here between pairs of abstract paintings-implemented in both within-subject (Experiment 1; N = 320) and between-subject (Experiment 2; N = 384) designs. On each trial, participants chose between a pair of paintings. A critical pair of average-beauty paintings was presented before and after either a reversal or control block. In the reversal block, we made efforts to bias preference away from the chosen average-beauty painting (by pairing it with more-beautiful paintings) and toward the non-chosen average-beauty painting (by pairing it with less-beautiful paintings). Meta-analysis revealed more reversals after reversal blocks than after control blocks, though only when the biasing manipulations succeeded. A second meta-analysis revealed that reversals were generally more likely for participants who later misidentified their initial choice, demonstrating that memory for initial choices influences later choices. Thus, the contrast paradigm has utility both for inducing choice reversals and identifying their causes.

Concepts: Wassily Kandinsky, Cryptography, Free will, Reversal, Western painting, History of painting, Choice, Preference