Naive optics: Understanding the geometry of mirror reflections.

Abstract

Paper-and-pencil tasks showed that many university students believed that when laterally approaching a mirror, they would see a reflection in the mirror before it was geometrically possible. Participants failed to adequately factor in the observer's location in the room. However, when asked about the behavior of a ray of light, participants knew about the law of reflection. No differences between psychology and physics students were detected, suggesting that the phenomenon is widespread and refractory to training. The findings were replicated with observers making judgments about image locations in a real room using a pretend mirror. Possible heuristics about mirror reflection that might explain the data are discussed. Naive optics is a promising venue to further knowledge of how observers understand basic laws of physics.

The Venus effect in real life and in photographs

“…We take this as evidence that these proportions are not specific to one procedure; instead, they reflect the fact that for many of the participants, Vince did not need to be in front of a mirror to see himself. This may be surprising but is entirely consistent with the documented early error in the literature (Bertamini, Latto, & Spooner, 2003;Croucher et al, 2002). For instance, in Croucher et al, there were three groups of responses that appeared across all of the experiments: Few people thought that a person can see herself in a mirror as soon as the mirror is visible to her; 40%-50% correctly expected that the person had to reach the near edge of the mirror, and 30%-50% placed their responses too (n 35) saw the vertical stimuli, and the other (n 31) saw the horizontal stimuli.…”

“…The answers given by the participants were classified on the basis of what they claimed that the mannequin (Bertamini, Latto, & Spooner, 2003;Croucher et al, 2002).…”

“…We can distinguish three types of mistakes. (1) The early error occurs when people predict that they will be able to see themselves in a mirror before they arrive in front of it (Bertamini, Spooner, & Hecht, 2003;Croucher, Bertamini, & Hecht, 2002). That is, people overestimate what is visible in a mirror, and this applies to questions about where they could see themselves or where they could see other objects.…”

On the Legibility of Mirror-Reflected and Rotated Text

“…Familiarity with certain frames of reference over others may account for why the recognition of one's own face is better when it is shown mirrored, while the faces of others are better recognized when shown in the manner in which we are used to seeing them (i.e., not mirrored) [188][189][190][191][192]. In general, however, naïve understanding of how reflections work and appear is quite poor [193][194][195][196][197]. It is possible that given an appropriate frame of reference with many cues to text direction, such as seeing a mirrored image of a person holding a sheet of text, may facilitate the maintenance of a consistent frame of reference during reading.…”

Mirror image arm used in monocular, binocular, and blindfolded pointing

“…Also, vision allows self-perception of most of the body, and mirrors substantially provide the same kind of optic information about one's body that is gained in direct inspection. Nevertheless, people make mistakes when asked what can be seen in a mirror (Croucher, Bertamini, & Hecht, 2002), when they predict the location of the object reflected (Hecht, Bertamini, & Gamer, 2005), in judging the size of the image on the mirror (Lawson, Bertamini, & Liu, 2007) and stating how mirror images move as an object moves (Savardi, Bianchi, & Bertamini, 2010).…”