Intuitive Physics

Herein we describe CRAMM, a framework for Causal Reasoning via Attention and Mental Models. CRAMM develops and extends assumptions made by a previously developed counterfactual simulation model of human causal judgment. We implement CRAMM computationally and demonstrate how it robustly captures human causal judgments about simple twoobject interactions at the level of underlying cognitive and perceptual processes, including data on eye-movements that serve as direct evidence for the role of counterfactuals in causal judgment.

This text finds the intimate affinity between dance and philosophy in the concept of problem and invites the reader to perceive dance and philosophy as a form of ballistics: the art of throwing. On one hand, this text is an invitation to look at dance not necessarily as an artistic practice but rather as an affirmative force that manifests itself as an expression of the power to turn any domain into a dance floor. On the other hand, this text also understands philosophy as an invitation to dance a problem, or, in other words, philosophy is a practice of choreographing the trajectories of problems.

This article presents a detailed examination of projectile motion, exploring its various types and their fundamental role within the broader framework of classical mechanics. Projectile motion, characterized by the curved trajectories of objects under the influence of gravity, is a fundamental concept in classical mechanics and objects in free flight. This study delves into both human-propelled and mechanically-launched projectiles—such as thrown objects, arrows, bullets, and artillery shells—exploring how kinematic equations, air resistance, and gravitational forces govern their behavior. By integrating the analysis of motion with key theoretical physics principles, including energy conservation, Newton’s laws, and the influence of external forces, this article highlights the interdependence of projectile motion with notable physics problems. The discussion extends to the applications of these principles in diverse fields such as engineering, military technology, and sports, offering a holistic view of how the theoretical framework of physics guides real-world problem-solving. This comprehensive examination illustrates the broad relevance of projectile motion in both academic and practical contexts, positioning it as a cornerstone for understanding complex systems in physics.

Prior work suggests that our understanding of how things work ("intuitive physics") and how people work ("intuitive psychology") are distinct domains of human cognition. Here we directly test the dissociability of these two domains by investigating knowledge of intuitive physics and intuitive psychology in adults with Williams syndrome (WS)-a genetic developmental disorder characterized by severely impaired spatial cognition, but relatively spared social cognition. WS adults and mental-age matched (MA) controls completed an intuitive physics task and an intuitive psychology task. If intuitive physics is a distinct domain (from intuitive psychology), then we should observe differential impairment on the physics task for individuals with WS compared to MA controls. Indeed, adults with WS performed significantly worse on the intuitive physics than the intuitive psychology task, relative to controls. These results support the hypothesis that knowledge of the physical world can be disrupted independently from knowledge of the social world.

We studied adults' understanding of the relationship between objects and their reflections. Two studies investigated whether adults performed in a similar way when asked to predict the movement of a reflection in a flat mirror based on the movement of the corresponding object or, vice versa, predict the movement of the material object based on the movement of its reflection. We used simple movements in the experiments: movements in a straight line at various angles with respect to the mirror. Despite the simplicity of the task, some of the participants made incorrect predictions in a percentage of cases ranging from 0% to 54%, depending on the angle. Asymmetries between the two directions of prediction emerged, in particular in terms of types of error. Results confirmed a cognitive difference between deriving the reflected (virtual) world from the "real" (material) world and vice versa. In particular the expectation that something will be opposite in a mirror is more salient when people imagine how a reflection will be with respect to the material world rather than when they imagine how the material world will be with respect to a reflection.

Many adults hold mistaken beliefs concerning the behavior of mechanical motion and reflections. In the field of psychology this has been investigated in the areas of naïve physics and naïve optics. The interesting question regards where these false beliefs come from. Particularly thought-provoking is the case of errors which are at odds not only with (presumably or even actually) known physical/optical concepts, but also with what people would actually perceive. Some errors are in fact consistent with what people see in ecological conditions while others apparently are not. This has led to the former being referred to as perceptual errors and the latter as conceptual errors (Lawson & Bertamini 2006). We propose that many of these 'conceptual errors' are generalizations of what can be actually perceived under some conditions that are then incorrectly applied under others. In this sense, they can be thought of as a second way in which perception shapes naïve beliefs.

Strong claims have been made about the importance of orientation in visual art. Although there have been a few studies whether left or right oriented pictures are more aesthetically pleasing, there have been no empirical studies whether the meaning and expressiveness of pictures depend on orientation. Thomas Bewick (1753^1828) made explicit decisions about whether the main protagonist in his pictures should face left or right and did so to express particular meaning. In three experiments we examined whether orientation changes the expressiveness of an image. In experiment 1 participants viewed eight of Bewick's animal wood engravings facing either in their original orientation or reversed, in a between-subjects design. They rated each print on ten characteristics, for example: docile^wild, clumsy^agile, and weak^strong. The original received more extreme ratings, across characteristics, than the reversal. Experiment 2 confirmed this result with participants from Italy. In experiment 3, using a within-subjects design, participants viewed ten wood engravings of dogs and rated them on characteristics specifically identified by Bewick. Again, the ratings of the original orientation were more extreme. Thus, in agreement with Bewick, we conclude that orientation affects expressiveness.

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While it is a well known fact that the initial and final velocity vectors of an ideal projectile, for a launching angle of 45° to the horizontal, are mutually perpendicular for maximum range; this fact is not that well known in case of other launching angles. In this article we provide three simple methods that show why the two velocities must be orthogonal. The first is based on the fact that the ranges of two projectiles launched from the same point with any speed but complimentary angles of projection have the same value of maximum range. The second deals with the total angle of rotation of the initial velocity vector. The third takes advantage of the similarity between reflection of light at parabolic mirror surfaces and the initial and final tangential velocities of the projectile path.

It is already known that an ellipse passes through the apexes of a family of the parabolic paths of projectiles shot from a point with constant speed but different angles of projection. In this article we describe a method to show that a circle passes through the focii of such a family of projectile paths whose center is the point of projection. In this method, we don't use vectors, or calculus or Newton's laws of motion.

The visual system uses the physical laws of nature as constraints for perceiving objects and events. Images violating natural laws would therefore tend to be perceived as unnatural. To understand vision's implicit knowledge of natural speed in the real world, we examined visual tolerance to artificial speed deviations in 22 natural movies. For most movies, perception could tolerate deviations from original speed by as much as a factor 2Â. However, for movies including human body movements or falling objects, perception only tolerated a significantly narrower range of speed deviations. In general, human observers are poor at judging the naturalness of speed in natural scenes except for events involving gravitational or biological motions.

While some learning scientists have begun to explore ensemble learning, the organization of shared activity across people and through time (Ma & Hall, 2018), little is still known about how groups develop the embodied instincts necessary to achieve such coordinated performances. This work explores the patterns and tools of social interaction that emerge in a group of university students learning advanced theatre movement techniques. Through the generative practice of increasingly difficult coordinated tasks (in this case, the act of throwing a sock full of beans in rhythm with each other), students begin to develop an instinct for and awareness of their body in relation to others in time and space. This study has implications for how individuals in groups achieve the embodied intersubjectivity necessary to learn as an ensemble.

Although many cognitive functions require information about the orientations of objects, little is known about representation or processing of object orientation. Mirror-image confusion provides a potential clue. This phenomenon is typically characterized as a tendency to confuse images related by left-right reflection (reflection across an extrinsic vertical axis). However, in most previous studies the stimuli were inadequate for identifying a specific mirror-image (or other) relationship as the cause of the observed confusions. Using stimuli constructed to resolve this problem, Gregory and McCloskey (2010) found that adults' errors were primarily reflections across an object axis, and not left-right reflections. The present study demonstrates that young children's orientation errors include both object-axis reflections and left-right reflections. We argue that children and adults represent object orientation in the same coordinate-system format (McCloskey, 2009), with orientation errors resulting from difficulty encoding or retaining one (adults) or two (children) specific components of the posited representations.

In this paper, I develop a solution to the puzzle of mirror perception: why do mirrors appear to reverse the image of an object along a left/right axis and not around other axes, such as the top/bottom axis? I set out the different forms the puzzle takes and argue that one form of itarguably the key form-has not been satisfactorily solved. I offer a solution in three parts: setting out the conditions in which an apparent left/right reversal of mirror images is generated; explaining why these conditions are so often met; explaining why we are cognitively biased towards the perception of left/right reversal when these conditions are met.

Our aim is to develop a better understanding of how the Point of Release (PoR) of a ball affects the perception of animated throwing motions. We present the results of a perceptual study where participants viewed animations of a virtual human throwing a ball, in which the point of release was modified to be early or late. We found that errors in overarm throws with a late PoR are detected more easily than an early PoR, while the opposite is true for underarm throws. The viewpoint and the distance the ball travels also have an effect on perceived realism. The results of this research can help improve the plausibility of throwing animations in interactive applications such as games or VR.

Our aim is to develop a better understanding of how the Point of Release (PoR) of a ball affects the perception of animated throwing motions. We present the results of a perceptual study where participants viewed animations of a virtual human throwing a ball, in which the point of release was modified to be early or late. We found that errors in overarm throws with a late PoR are detected more easily than an early PoR, while the opposite is true for underarm throws. The viewpoint and the distance the ball travels also have an effect on perceived realism. The results of this research can help improve the plausibility of throwing animations in interactive applications such as games or VR.

Previous research has found that people frequently provide incorrect predictions about the path of moving objects when given an idealised physics problem to solve. The aim of this research was to explore whether these incorrect predictions are due to the application of an incorrect naïve physics theory, whether incorrect perceptions generated from past experiences lead to misconceptions of how moving objects behave, or whether it is a combination of both. Thirty-one participants volunteered to take part in the experiment which followed a two (experience congruent/incongruent with naïve physics theory) by two (carried versus free-moving object) within-subject design. The dependent variable was participant response (straight down or curved forwards). Results of the study revealed that participants provided answers both consistent and inconsistent with the naïve physics theory. This suggests that responses were primarily elicited through the retrieval of associatively-mediated memories...

Titian is usually credited with reintroducing the theme of the toilet of Venus into Renaissance art, a theme that was popular in late Hellenistic and Roman art (Poglayen-Neuwall, 1934). From then onward, a small mirror is often part of the composition, either in the hands of Venus or held for her by someone next to her. Let us take as an example the famous Toilet of Venus by Velázquez (1599-1660). This is also known as the Rokeby Venus, and the image can be seen on the National Gallery Web site (www.nationalgallery.org.uk/; Baker & Henry, 2001). A woman, Venus, is lying on a bed and her son, Cupid, holds up a mirror for her. Her face is seen centered in the small mirror. Most people describe the scene by saying that she is looking at herself (Bertamini, Latto, & Spooner, 2003). Note, however, that the viewpoint of the observer is different from the viewpoint of Venus; that is, the observer is not behind Venus with respect to the mirror. Therefore, what can be seen in the mirror differs for the observer and for Venus. A reasonable implication for a small mirror is that if the observer sees Venus's face nicely framed in the mirror, Venus should see the observer's face. Each layout is unique, but in many famous paintings, the scene is not compatible with Venus looking at her own reflection. A striking example is the Venetian Venus at Her Toilette, c. 1582, by Veronese (1528-1588), which can be seen on the Joslyn Museum Web site (www.joslyn.org/). The Lady and the Unicorn (15th century), which can be seen on the Cluny Museum Web site (www.musee-moyenage.fr/), is an example in which an animal, rather than a person, is shown in the mirror. Many more examples exist in movies and television productions where an actor is seen reflected in a mirror but is standing to the side of the mirror. The fact that observers claim that Venus is seeing herself (when she cannot, given the layout) has been named the Venus effect (Bertamini, Latto, & Spooner, 2003). Consistent with naive observers' statements, art historians also tend to describe the scene as showing Venus looking at herself (e.g., Poglayen-Neuwall, 1934, p. 363, with reference to Titian's painting in the Hermitage collection). Bertamini, Latto, & Spooner (2003), in the original article, made clear that the Venus effect has no direct implications for what Velázquez or any other painter intended to depict. The Venus effect is about how observers describe the scene. The effect does not imply that anything is wrong with the image. For instance, a scene could easily be arranged to match the layout in the Rokeby Venus. What would be the case, however, is that the woman would not see her own face in the mirror. What artists do is to produce an image that tells a certain story, exploiting, consciously or not, how observers tend to interpret images.

In three experiments, a bias to inflate in drawing the proportion of an image on a mirror over the mirror itself is demonstrated in a sample ( N = 146) of undergraduate students taking introductory psychology classes. The inflation is not confined to the image of one’s own head but is likely to occur in depictions of any object from a mirror with the mirror frame included. Having to include in the drawing background objects visible in the mirror is found to reduce the inflation. The inflation also diminishes with a smaller mirror and at a longer viewing distance. An account for the inflation in terms of a mechanism of size constancy contingent on selective attention is offered. The size of the inflation suggests a conflation of the perceived mirror image size with the size of the distal object it signals rather than a complete take-over by the latter. The reduction of the size inflation when participants are asked draw both a target and background objects is more likely a result of ...

One of the most compelling phenomena in visual memory is the Boundary Extension (BE) which is the tendency to remember close-up scenes as if they include more information than that was seen. Intraub and Richardson (1989; JEP:LMC), suggested that this phenomenon is due to a filling in process: we fill the scene with information around the boundaries based on our knowledge. For the BE to occur, the scene must be perceived as part of a continuous environment. This project investigated whether the BE can be implicitly affected by the directional information provided by a camera. In the learning phase of a recognition experiment, participants were presented with an image on a computer screen that could have been cropped either to the left or to the right whilst a camera could have been positioned either to their left or right. In the testing phase, the image was then presented again, and participants were asked to judge if it was the same. Results showed that the BE magnitude reduces whe...

Understanding whether observers are sensitive to physical distor-tions in dynamic events is important in order to develop plausible simulations while saving time on details that observers cannot per-ceive [Barzel et al. 1996]. In this experiment, we evaluated ob-

People have a powerful “physical intelligence”–an ability to infer physical properties of objects and predict future states in complex, dynamic scenes–which they use to interpret their surroundings, plan safe and effective actions, build and understand devices and machines, and communicate efficiently. For instance, you can choose where to place your coffee to prevent it from spilling, arrange books in a stable stack, judge the relative weights of objects after watching them collide, and construct systems of levers and pulleys to ...

The effect of height in the picture plane on the remembered location of ascending or descending targets was examined. Consistent with previous research, memory was displaced forward in the direction of motion. The magnitude of forward displacement was larger for targets low in the picture plane than for targets high in the picture plane, and this was observed with ascending motion and with descending motion. This pattern is consistent with the hypothesis that memo1T for the location of ascending or descending targets is biased by the effects of implied gravitational attraction on the velocity of those targets, and some implications of such a bias for issues in mental representation are noted.

American pastime, has been played in some manner since 1744. While the rules, names, and uniforms have changed and evolved, the basic physical principles of balls in flight have not. By examining the forces on a baseball, we calculated and studied the trajectory of batted balls based on models by Adair, Watts and Bahill, and Sawicki et. al.. We calculated several possible trajectories from these models for one very impressive homerun. On June 9, 1934, Ted Williams hit a homerun at Fenway Park that was said to go 502.5 feet before it landed on the head of Joseph Boucher seated in Section 42, Row 37, Seat 21. How far would the ball have gone if its path was not impeded by Mr. Boucher's straw hat? The answer depends on several parameters including ball rotation, velocity, launch angle, and prevailing winds. A key feature of this homerun was that it was hit on a day of 20 mph tail winds and low humidity. According to our calculations, Ted Williams or another of the greatest players of all-time, could have hit homerun this far. The most probable case, in our opinion, seems to occur at an initial velocity of 118 mph, with a launch angle of 28 degrees, and a rotation rate of 1800 rpm. However, this is at the extreme of what appears to be humanly possible.

The present experiment investigated children and adults’ knowledge of the pendulum law under different task conditions. The question asked was whether adults and fourth-graders knew that the period of a pendulum is a function of pendulum length but is independent of its mass. The task was to judge the period on a rating scale (judgment task), to imagine the swinging pendulum and indicate the corresponding time interval (imagery task), or to adjust the period of a dynamically presented pendulum (perception task). Normative consideration of pendulum length as the only relevant factor was primarily found in the perception task and, for adults, in the imagery task, whereas in the judgment task, children and adults frequently considered the irrelevant dimension of mass. Most children showed poor imagery performance. Preceding adjustment (perception task) and rating (judgment task) had no differential influence on subsequent imagery performance.

Distributions of anthropogenic signatures (impacts and activities) are mathematically analysed. The aim is to understand the Anthropocene and to see whether anthropogenic signatures could be used to determine its beginning. A total of 23 signatures were analysed and results are presented in 31 diagrams. Some of these signatures contain undistinguishable natural components but most of them are of purely anthropogenic origin. Great care was taken to identify abrupt accelerations, which could be used to determine the beginning of the Anthropocene. Results of the analysis can be summarised in three conclusions. 1. Anthropogenic signatures cannot be used to determine the beginning of the Anthropocene. 2. There was no abrupt Great Acceleration around 1950 or around any other time. 3. Anthropogenic signatures are characterised by the Great Deceleration in the second half of the 20th century. The second half of the 20th century does not mark the beginning of the Anthropocene but most likely...

for their comments and suggestions, especially to Jason, who also patiently edited my manuscript; Friends, who provided encouragement and joyful company; and Most of all, my family-Sam, for the love, and assistance in putting together my data; my kids Schuyler James and Shirlene Joyce, for the inspiration which kept me going during those tough times; and, my parents and sisters, for the words of encouragement amidst the distance that separate us. iii TABLE OF CONTENTS Acknowledgements ………………………………………………………………….

Prior work suggests that our understanding of how things work (''intuitive physics") and how people work (''intuitive psychology") are distinct domains of human cognition. Here we directly test the dissociability of these two domains by investigating knowledge of intuitive physics and intuitive psychology in adults with Williams syndrome (WS)-a genetic developmental disorder characterized by severely impaired spatial cognition, but relatively spared social cognition. WS adults and mental-age matched (MA) controls completed an intuitive physics task and an intuitive psychology task. If intuitive physics is a distinct domain (from intuitive psychology), then we should observe differential impairment on the physics task for individuals with WS compared to MA controls. Indeed, adults with WS performed significantly worse on the intuitive physics than the intuitive psychology task, relative to controls. These results support the hypothesis that knowledge of the physical world can be disrupted independently from knowledge of the social world.

Naïve conceptions and associated misconceptions about object motion arise in part from limitations on perceptual experience. Certain commercial video games, such as Enigmo, provide interactive experience with realistic trajectories and practice at purposefully manipulating those trajectories. We tested the possibility that this experience could modify naïve intuitions about object motion, bringing them into closer alignment with Newtonian principles of mechanics. Fifty-one middle-school children were randomly assigned to play either Enigmo or a strategy game for six sessions. Only the Enigmo group improved their ability to generate realistic trajectories, but this improvement was limited to learning about the general parabolic shape of trajectories. After training, both groups received a 30-minute tutorial on Newtonian principles which generated a much larger improvement in producing realistic trajectories than did game play. This improvement was of similar magnitude in both training groups, indicating that gaming experience provided no advantage in deriving benefits from direct instruction.

Using a paper-and-pencil task, undergraduate students predicted when a character would be able to see her reflection in a planar mirror. Experiment 1 showed that participants expected the character to be able to see her reflection earlier than she actually would when moving horizontally, but not when moving vertically, confirming previous findings (Croucher, Bertamini & Hecht, 2002; Bertamini, Hecht, Spooner, 2003), but unlike previous studies the vantage-point from which the character was depicted was identical for both conditions. In Experiment 2 and 3 we tested for the role of body orientation, and relation between the eyes and the mirror surface in explaining these results. We conclude that the early error can be avoided only when the eyes define an axis parallel to the near edge of the mirror. We call this the eye-plane heuristics. Experiment 4 did not reveal a significant increase in the early error with distance from the mirror, and Experiment 5 demonstrated a weak effect of ...

Human observers make errors when predicting what is visible in a mirror. This is true for perception with real mirrors as well as for reasoning about mirrors shown in diagrams. We created an illustration of a room, a top-down view, with a mirror on a wall and objects (nails) on the opposite wall. The task was to select which nails were visible in the mirror from a given position (viewpoint). To study the importance of the social nature of the viewpoint, we divided the sample ( N = 108) in two groups. One group ( n = 54) were tested with a scene in which there was the image of a person. The other group ( n = 54) were tested with the same scene but with a camera replacing the person. Participants were instructed to think about what would be captured by a camera on a tripod. This manipulation tests the effect of social perspective-taking in reasoning about mirrors. As predicted, performance on the task shows an overestimation of what can be seen in a mirror and a bias to underestimate ...

The mirror reversal of an image is subtly different from the original. Often such change goes unnoticed in pictures, although it can affect preference. For the first time we studied the effect of mirror reversal of feature films. People watched Yojimbo or Sanjuro in a cinema, both classic films by Akira Kurosawa. They knew that this was a study and filled out a questionnaire. On one day Yojimbo was shown in its original orientation, and on another day the film was mirror reversed. Sanjuro was shown reversed on one day and non-reversed on another day. Viewers did not notice the reversal, even when they had seen the film before and considered themselves fans of Kurosawa. We compared this with estimates from a survey. In addition, the question about the use of space (scenography) revealed that although people who had seen the film before gave higher ratings compared with those who had not, this was only true when the film was not reversed.

It is already known that an ellipse passes through the apexes of a family of the parabolic paths of projectiles shot from a point with constant speed but different angles of projection. In this article we describe a method to show that a circle passes through the focii of such a family of projectile paths whose center is the point of projection. In this method, we don’t use vectors, or calculus or Newton’s laws of motion.

While it is a well known fact that the initial and final velocity vectors of an ideal projectile, for a launching angle of 45° to the horizontal, are mutually perpendicular for maximum range; this fact is not that well known in case of other launching angles. In this article we provide three simple methods that show why the two velocities must be orthogonal. The first is based on the fact that the ranges of two projectiles launched from the same point with any speed but complimentary angles of projection have the same value of maximum range. The second deals with the total angle of rotation of the initial velocity vector. The third takes advantage of the similarity between reflection of light at parabolic mirror surfaces and the initial and final tangential velocities of the projectile path.

Newton's cradle, a device consisting of a chain of steel balls suspended in alignment, has been used extensively in physics teaching to demonstrate the principles of conservation of momentum and kinetic energy in elastic collisions. The apparent simplicity of the device allows one to test commonly hold views regarding the intuitive understanding of physics by lay people. We present and discuss the results of two experiments wherein the extension of the chain, the height of release (experiment 1) and the material of the balls (experiment 2) were systematically varied in graphical depictions of the Newton's cradle. Participants had to estimate the height that the last ball in the chain would reach if a collision took place. The outcomes revealed a sophisticated cognitive model wherein the magnitude of the displacement of the target ball increased in direct proportion with the acceleration of the launcher and in inverse proportion with the number of balls in the chain. The results closely mimicked the predicted behavior of a Newton's cradle if the collisions were not perfectly elastic. This isomorphism shows that judgments of physical events are not detached from the environment, as one seldom sees a perfectly elastic collision, and it speaks unfavorably to the hypothesis that, in such tasks, people rely on simple heuristics.

In a series of three experiments, we probed the accessibility of action knowledge in different versions of a virtual environment (VE) with 7-year-old children and adults. Using a PHANToM haptic interface, participants performed a virtual throwing task in which they tried to propel a ball from a table to hit a target on the ground. In Experiments 1 and 2, the virtual scene was presented on a computer monitor, and, in Experiment 3, it was projected by using a video projector so that the vertical and horizontal dimensions and the spatial location of the VE corresponded to the real-world dimensions. Results indicate that action knowledge is accessible even in a nonimmersive VE, but also suggest that the need to recalibrate perceptual-motor mappings constrains the accessibility of this kind of intuitive knowledge.

While it has long been known that time is a cue to causation, recent work with adults has demonstrated that causality can also influence the experience of time. In causal reordering (Bechlivanidis & Lagnado, 2013, 2016) adults tend to report the causally consistent order of events, rather than the correct temporal order. Across four experiments, 4- to 10-year-old children (N=813) and adults (N=178) watched a 3-object Michotte-style ‘pseudocollision’. While the canonical version of the clip would have object A colliding with B, which would then collide with object C (order: ABC), the pseudocollision involved the same spatial array of objects but featured object C moving before object B (order: ACB), with no collision between B and C. Participants were asked to judge the temporal order of events and whether object B collided with C. Across all age groups, participants were significantly more likely to judge that B collided with C in the 3-object pseudocollision than in a 2-object cont...

In this paper, I develop a solution to the puzzle of mirror perception: why do mirrors appear to reverse the image of an object along a left/right axis and not around other axes, such as the top/bottom axis? I set out the different forms the puzzle takes and argue that one form of itarguably the key form-has not been satisfactorily solved. I offer a solution in three parts: setting out the conditions in which an apparent left/right reversal of mirror images is generated; explaining why these conditions are so often met; explaining why we are cognitively biased towards the perception of left/right reversal when these conditions are met.

Human observers make errors when predicting what is visible in a mirror. This is true for perception with real mirrors as well as for reasoning about mirrors shown in diagrams. We created an illustration of a room, a top-down view, with a mirror on a wall and objects (nails) on the opposite wall. The task was to select which nails were visible in the mirror from a given position (viewpoint). To study the importance of the social nature of the viewpoint, we divided the sample ( N = 108) in two groups. One group ( n = 54) were tested with a scene in which there was the image of a person. The other group ( n = 54) were tested with the same scene but with a camera replacing the person. Participants were instructed to think about what would be captured by a camera on a tripod. This manipulation tests the effect of social perspective-taking in reasoning about mirrors. As predicted, performance on the task shows an overestimation of what can be seen in a mirror and a bias to underestimate ...

Symmetry is a salient aspect of biological and man-made objects, and has a central role in perceptual organization. Two studies investigate the role of opposition and identicalness in shaping adults' naïve idea of "symmetry". In study 1, both verbal descriptions of symmetry (either provided by the participants or selected from among alternatives presented by the experimenter) and configurations drawn as exemplars of symmetry were studied. In study 2, a pair comparison task was used. Both studies focus on configurations formed by two symmetrical shapes (i.e., between-objects symmetry). Three main results emerged. The explicit description of symmetry provided by participants generally referred to features relating to the relationship perceived between the two shapes and not to geometrical point-by-point transformations. Despite the fact that people tended to avoid references to opposition in their verbal definition of symmetry in study 1, the drawings that they did to represent their prototypical idea of symmetry manifested opposition as a basic component. This latter result was confirmed when the participants were asked to select the definition (in study 1) or the configuration (in study 2) that best fitted with their idea of symmetry. In conclusion, identicalness is an important component in people's naïve idea of symmetry, but it does not suffice: opposition complements it.

Symmetry is a salient aspect of biological and man-made objects, and has a central role in perceptual organization. Two studies investigate the role of opposition and identicalness in shaping adults' naïve idea of "symmetry". In study 1, both verbal descriptions of symmetry (either provided by the participants or selected from among alternatives presented by the experimenter) and configurations drawn as exemplars of symmetry were studied. In study 2, a pair comparison task was used. Both studies focus on configurations formed by two symmetrical shapes (i.e., between-objects symmetry). Three main results emerged. The explicit description of symmetry provided by participants generally referred to features relating to the relationship perceived between the two shapes and not to geometrical point-by-point transformations. Despite the fact that people tended to avoid references to opposition in their verbal definition of symmetry in study 1, the drawings that they did to represent their prototypical idea of symmetry manifested opposition as a basic component. This latter result was confirmed when the participants were asked to select the definition (in study 1) or the configuration (in study 2) that best fitted with their idea of symmetry. In conclusion, identicalness is an important component in people's naïve idea of symmetry, but it does not suffice: opposition complements it.

His main research interests are on theoretical and methodological foundations of experimental phenomenology, on direct perception of relationships (identity, sameness, opposition, diversity), on space perception and representation and on the psychology of art.

We studied adults' understanding of the relationship between objects and their reflections. Two studies investigated whether adults performed in a similar way when asked to predict the movement of a reflection in a flat mirror based on the movement of the corresponding object or, vice versa, predict the movement of the material object based on the movement of its reflection. We used simple movements in the experiments: movements in a straight line at various angles with respect to the mirror. Despite the simplicity of the task, some of the participants made incorrect predictions in a percentage of cases ranging from 0% to 54%, depending on the angle. Asymmetries between the two directions of prediction emerged, in particular in terms of types of error. Results confirmed a cognitive difference between deriving the reflected (virtual) world from the "real" (material) world and vice versa. In particular the expectation that something will be opposite in a mirror is more salient when people imagine how a reflection will be with respect to the material world rather than when they imagine how the material world will be with respect to a reflection.

Many adults hold mistaken beliefs concerning the behavior of mechanical motion and reflections. In the field of psychology this has been investigated in the areas of naïve physics and naïve optics. The interesting question regards where these false beliefs come from. Particularly thought-provoking is the case of errors which are at odds not only with (presumably or even actually) known physical/optical concepts, but also with what people would actually perceive. Some errors are in fact consistent with what people see in ecological conditions while others apparently are not. This has led to the former being referred to as perceptual errors and the latter as conceptual errors (Lawson & Bertamini 2006). We propose that many of these 'conceptual errors' are generalizations of what can be actually perceived under some conditions that are then incorrectly applied under others. In this sense, they can be thought of as a second way in which perception shapes naïve beliefs.

His main research interests are on theoretical and methodological foundations of experimental phenomenology, on direct perception of relationships (identity, sameness, opposition, diversity), on space perception and representation and on the psychology of art.

Strong claims have been made about the importance of orientation in visual art. Although there have been a few studies whether left or right oriented pictures are more aesthetically pleasing, there have been no empirical studies whether the meaning and expressiveness of pictures depend on orientation. Thomas Bewick (1753^1828) made explicit decisions about whether the main protagonist in his pictures should face left or right and did so to express particular meaning. In three experiments we examined whether orientation changes the expressiveness of an image. In experiment 1 participants viewed eight of Bewick's animal wood engravings facing either in their original orientation or reversed, in a between-subjects design. They rated each print on ten characteristics, for example: docile^wild, clumsy^agile, and weak^strong. The original received more extreme ratings, across characteristics, than the reversal. Experiment 2 confirmed this result with participants from Italy. In experiment 3, using a within-subjects design, participants viewed ten wood engravings of dogs and rated them on characteristics specifically identified by Bewick. Again, the ratings of the original orientation were more extreme. Thus, in agreement with Bewick, we conclude that orientation affects expressiveness.