Something Overlooked? How experts in change detection use visual saliency

How does expertise in the analysis of particular images influence the effects of visual saliency upon attention? Expert analysts of aerial photographs and untrained viewers undertook change‐detection and location memory tasks using aerial photographs with eye movements recorded throughout. Experts were more accurate in both tasks. Significant differences were also seen in the scanpaths: Untrained viewers fixated preferentially upon salient features throughout stimulus presentation whereas experts did not. However, both groups showed a strong influence of saliency in change detection and memory tasks. We interpret this apparent contradiction by: (i) assuming that the use of saliency in visual search is discretionary, and experts can use semantic information to prioritise where to fixate next; whereas, (ii) in tasks requiring spatial memory, analysis of visual saliency delivers easily acquired landmarks to reference the location of items in an image; a previously overlooked function used by expert and untrained viewers alike. Copyright © 2009 John Wiley & Sons, Ltd.     

Converging operations revisited: Assessing what infants perceive using discrimination measures

In four experiments, we explored the perception of facial distortions seen in pictures viewed from the side or from above or below. In all four, however, we disguised the slant of the picture surface by using a double-projection technique that removed binocular and monocular cues: Faces were digitized, distorted to mimic a particular slant behind the image plane, cropped to a frame, and presented to viewers for their judgments. In the first experiment, we found that simulated rotations around a horizontal axis (pictures seen as if from above or below) created more noticeable distortions in faces than did simulated rotations around a vertical axis (pictures seen as if from the left or right). In the second experiment, pursuing a result from the first but with a between-subjects design, we found that pictured faces with a slant around a vertical axis of 22° were seen as having no more distortion than unslanted faces. In the third experiment, we placed each image within a frame slanted either in the same way as or differently from the picture, and found no effect of frame. In the fourth experiment, we determined that viewers had little ability to match appropriately slanted frames with slanted pictures. Thus, we claim that part of the reason why one can look at moderately slanted pictures without perceptual interference is that the distortions in the image are subthreshold, or perhaps within the bounds of acceptability. These results contrast with the generally accepted theory that viewers mentally compensate for distortions in moderately slanted pictures.     

Suffering by comparison: Twitter users’ reactions to the Victoria's Secret Fashion Show

Social comparison theory suggests that evaluating the self in comparison with others (e.g., peers, celebrities, models) can influence body image. Experimental studies that have tested effects of viewing idealized images in the media often show that women feel worse about themselves after seeing images that illustrate the beauty ideal. Twitter presents a naturally occurring opportunity to study viewers’ reactions. An analysis was conducted of 977 tweets sent immediately before and during the 2011 Victoria's Secret Fashion Show that reference the show. Although the majority were idiosyncratic remarks, many tweets contain evidence of upward social comparisons to the fashion models. There were tweets about body image, eating disorders, weight, desires for food or alcohol, and thoughts about self-harm. The results support social comparison theory, and suggest that vulnerable viewers could experience negative affect, or even engage in harmful behaviors, during or after viewing the show or others like it.     

Why cast shadows are expendable: insensitivity of human observers and the inherent ambiguity of cast shadows in pictorial art

The kinds of visual cues artists choose to use or not use in their work can offer insight into perceptual processes. On the basis of the observed paucity of the use of cast shadow in pictorial art, we hypothesized that cast shadows might be relatively expendable as pictorial cues. In this study, we investigated two potential reasons for this expendability: first, viewers might be insensitive to much of the information that cast shadows provide; and, second, ambiguities about what is shadow and what is pigment can often be resolved only through motion-something that static media are ill-equipped to deal with. In experiment 1, we used a visual-search paradigm in which viewers had to determine if there were odd cast shadows in sets of 4, 8, 16, and 32 objects. In experiment 2, viewers had to discriminate between shadow/pigment ambiguities in both still and moving images. Our results demonstrate that viewers are neither particularly sensitive to static cast-shadow incongruities, nor are they able to disambiguate cast shadow from pigment without continuous motion information. Taken together, these results may help explain why cast shadows are relatively rare in static pictorial work.     

Expert – Non-expert differences in visual behaviour during alpine slalom skiing

The aim of this study was to investigate visual behaviour of expert and non-expert ski athletes during an alpine slalom. Fourteen non-experts and five expert slalom skiers completed an alpine slalom course in an indoor ski slope while wearing a head-mounted eye tracking device. Experts completed the slalom clearly faster than non-experts, but no significant difference was found in timing and position of the turn initiation. Although both groups already looked at future obstacles approximately 0,5 s before passing the upcoming pole, the higher speed of experts implied that they shifted gaze spatially earlier in the bend than non-experts. Furthermore, experts focussed more on the second next pole while non-expert slalom skiers looked more to the snow surface immediately in front of their body. No difference was found in the fixation frequency, average fixation duration, and quiet eye duration between both groups. These results suggest that experts focus on the timing of their actions while non-experts still need to pay attention to the execution of these actions. These results also might suggest that ski trainers should instruct non-experts and experts to focus on the next pole and, shift their gaze to the second next pole shortly before reaching it. Based on the current study it seems unadvisable to instruct slalom skiers to look several poles ahead during the actual slalom. However, future research should test if these results still hold on a real outdoor slope, including multiple vertical gates.     

Categorizing moving objects into film genres: The effect of animacy attribution,emotional response,and the deviation from non-fiction

The reported study follows the footsteps of Heider, and Simmel (1944) [Heider, F., & Simmel, M. (1944). An experimental study of apparent behavior. American Journal of Psychology, 57, 243–249] and Michotte (1946/1963) [Michotte, A. (1963). The perception of causality (T.R. Miles & E. Miles, Trans.). London: Methuen (Original work published 1946)] who demonstrated the role of object movement in attributions of life-likeness to figures. It goes one step further in studying the categorization of film scenes as to genre as a function of object movements.In an animated film scene portraying a chase, movements of the chasing object were systematically varied as to parameters: velocity, efficiency, fluency, detail, and deformation.The object movements were categorized by viewers into genres: non-fiction, comedy, drama, and action. Besides this categorization, viewers rated their animacy attribution and emotional response. Results showed that non-expert viewers were consistent in categorizing the genres according to object movement parameters. The size of its deviation from the unmanipulated movement scene determined the assignment of any target scene to one of the fiction genres: small and moderate deviations resulted in categorization as drama and action, and large deviations as comedy. The results suggest that genre classification is achieved by, at least, three distinct cognitive processes: (a) animacy attribution, which influences the fiction versus non-fiction classification; (b) emotional responses, which influences the classification of a specific fiction genre; and (c) the amount of deviation from reality, at least with regard to movements.     

Presence and Image Quality: The Case of High-Definition Television

Previous research has demonstrated that form variables can increase television viewers' sense of presence. The current broadcasting of high-definition television (HDTV) programming makes testing this relation between form and presence possible in a new context, image quality. In this experiment, television viewers watched either HDTV or standard-definition television images and then rated their viewing experience on a pencil-and-paper questionnaire. The results demonstrate that HDTV provided viewers with a greater sense of presence than the current standard, thus providing empirical evidence for the claim that improved image quality will lead to television viewers' experiencing presence. Additionally, the results suggest that with the coming of HDTV, sensations of presence will be both stronger and more common.     

Perception of Mooney faces by young infants: the role of local feature visibility, contrast polarity, and motion

We examined the ability of young infants (3- and 4-month-olds) to detect faces in the two-tone images often referred to as Mooney faces. In Experiment 1, this performance was examined in conditions of high and low visibility of local features and with either the presence or absence of the outer head contour. We found that regardless of the presence of the outer head contour, infants preferred upright over inverted two-tone face images only when local features were highly visible (Experiment 1a). We showed that this upright preference disappeared when the contrast polarity of two-tone images was reversed (Experiment 1b), reflecting operation of face-specific mechanisms. In Experiment 2, we investigated whether motion affects infants' perception of faces in Mooney faces. We found that when the faces appeared to be rigidly moving, infants did show an upright preference in conditions of low visibility of local features (Experiment 2a). Again the preference disappeared when the contrast polarity of the image was reversed (Experiment 2b). Together, these results suggest that young infants have the ability to integrate fragmented image features to perceive faces from two-tone face images, especially if they are moving. This suggests that an interaction between motion and form rather than a purely motion-based process (e.g., structure from motion) facilitates infants' perception of faces in ambiguous two-tone images.     

Not looking yourself: The cost of self‐selecting photographs for identity verification

Photo‐identification is based on the premise that photographs are representative of facial appearance. However, previous studies show that ratings of likeness vary across different photographs of the same face, suggesting that some images capture identity better than others. Two experiments were designed to examine the relationship between likeness judgments and face matching accuracy. In Experiment 1, we compared unfamiliar face matching accuracy for self‐selected and other‐selected high‐likeness images. Surprisingly, images selected by previously unfamiliar viewers – after very limited exposure to a target face – were more accurately matched than self‐selected images chosen by the target identity themselves. Results also revealed extremely low inter‐rater agreement in ratings of likeness across participants, suggesting that perceptions of image resemblance are inherently unstable. In Experiment 2, we test whether the cost of self‐selection can be explained by this general disagreement in likeness judgments between individual raters. We find that averaging across rankings by multiple raters produces image selections that provide superior identification accuracy. However, benefit of other‐selection persisted for single raters, suggesting that inaccurate representations of self interfere with our ability to judge which images faithfully represent our current appearance.     

Powered by Imagination: Nanobots at the Science Photo Library

Nanobots have been a key image deployed in nanoscience and nanofiction. At present nanobots are still largely ‘imaginary’. But what do ‘imaginary’ nanobots look like, how are they visually and imaginatively constructed and what functions are they envisioned to have? And what can such images tell us about the aesthetic and cultural conventions and metaphors that are employed, and expectations and visions created or engineered, in the process of ‘visualizing’ nanoscience and nanotechnology for science and society? To answer these questions images of nanobots available at the Science Photo Library were studied. Nanobots were envisioned as ‘working’ mostly in futuristic domains of health and medicine. Most nanobots were artistically rendered as familiar objects or animals, as fulfilling useful functions in healthcare, rather than as running wild and causing harm. Such images were displayed mostly to engage lay publics with biotechnology and nanotechnology. By selectively using metaphors, images of nanobots tended to assimilate the unknown into the known and the unfamiliar into the familiar. This assimilation invites viewers to react to these images as if nanobots already existed and as if they were normal. Thus the images open up a space for ‘normalizing’ this new, rather speculative technology; it is framed in such a way as to invite public acceptance and even excitement.     

Face learning with multiple images leads to fast acquisition of familiarity for specific individuals

Matching unfamiliar faces is a difficult task. Here we ask whether it is possible to improve performance by providing multiple images to support matching. In two experiments we observe that accuracy improves as viewers are provided with additional images on which to base their match. This technique leads to fast learning of an individual, but the effect is identity-specific: Despite large improvements in viewers’ ability to match a particular person's face, these improvements do not generalize to other faces. Experiment 2 demonstrated that trial-by-trial feedback provided no additional benefits over the provision of multiple images. We discuss these results in terms of familiar and unfamiliar face processing and draw out some implications for training regimes.     

The contribution of memory to differences in situation awareness in expert and non-expert drivers

Situation awareness (SA) is knowing what is going on in the environment: identifying objects, understanding how they interact and predicting future events. It is important in the context of driving as it is related to hazard perception. Driving-related SA may help explain expert drivers’ superior driving skill, but it is important to understand whether this is because expert drivers have better memory for driving-related tasks, whether superior memory performance is task specific, and the degree to which any effect is attributable to experience vs. expertise. On-road paramedics were compared with non-expert drivers. The participants engaged in an SA driving task where they were required to describe a vide taped driving situation after the screen cut to black. We measured their SA, memory and demographic driving variables. The starting SA of World, Action and Schema was re-developed to better reflect driving SA, into World, Action, Other-Agent Action, Projection, and Rationale. Driving expertise predicted each category of SA, except the Action category, independently of other experience variables. Similarly, expertise also predicted SA categories independently of any of the memory tasks. We concluded that expert drivers have better driving-SA than non-expert drivers and this is not due to better memory for driving tasks, or ‘time-on-road’. This finding is important in driver training because if we can harness the SA skills that expert drivers demonstrate, we could potentially implement them in better driver training programs.     

Mediated Identity in the Parasocial Interaction of TV

Electronic media contributes toward modifying the self as they shape it as a multivoiced construction. Television talk shows function as a space of parasocial interaction where ordinary people represented on the screen offer involving images of subjectivity for the home viewers. Through interpretative procedures, viewers integrate screen suggestions in the positions' repertoire of their self. This study hypothesized that viewers co-construct identities through involvement in what they are watching and employed focus group discussions and content analysis to investigate this hypothesis. The results demonstrate recurrent comparisons contrasting the screen "other" and the real self. This categorization marks a strong involvement of participants and an interpretative reconstruction of television images. As such, identity is constructed in the dialogical relation between others and selves in a mediated relation whose only result is a self traveling through different repositionings.     

Deconstructing Ally: Explaining Viewers' Interpretations of Popular Television

Two hundred fifty one Israeli students, viewers of the series Ally McBeal, were asked to choose among preformulated interpretations of the program. Discriminant analysis was used to explore why some viewers endorsed an interpretation of the program as favorable to women, others as sexist, and others preferred a humorous interpretation. Results show that relationship status, feminist attitudes, identification with the lead character and perceptions of her, as well as liking of the program, were important determinants of the interpretation of the program adopted by viewers. The results are discussed in terms of contributions to reception theory and media psychology in general.     

Attention to Television: Alpha Power and Its Relationship to Image Motion and Emotional Content

A laboratory experiment investigated the impact of image motion and emotional content in brief television clips on attention. Using an electroencephalogram (EEG) as a measure of attention, cortical activity in 25 participants was measured while they viewed either still or moving emotion-provoking images. Spectral analysis of the EEG was done to gauge changes in alpha-wave (8-13 Hz) power because reductions in alpha power are thought to indicate greater attention. The analysis revealed that subjective reports of emotional arousal were directly related to cortical activation (i.e., reduced alpha power), and this was particularly true at the parietal recording site. The relationship between alpha power and ratings of valence was curvilinear; cortical activation was associated with both positive and negative images relative to neutral images. Alpha power was also reduced during the viewing of moving compared with still images, and this effect occurred independent of stimulus valence. The association of greater cortical activation with moving than with still images is consistent with previous research using autonomic measures and suggests that image motion modulates emotional responding-and sustains attention-primarily through increasing "gain" in the arousal dimension.     

Sex,skull length,breed, and age predict how dogs look at faces of humans and conspecifics

The gaze of other dogs and humans is informative for dogs, but it has not been explored which factors predict face-directed attention. We used image presentations of unfamiliar human and dog heads, facing the observer (portrait) or facing away (profile), and measured looking time responses. We expected dog portraits to be aversive, human portraits to attract interest, and tested dogs of different sex, skull length and breed function, which in previous work had predicted human-directed attention. Dog portraits attracted longer looking times than human profiles. Mesocephalic dogs looked at portraits longer than at profiles, independent of the species in the image. Overall, brachycephalic dogs and dogs of unspecified breed function (such as mixed breeds) displayed the longest looking times. Among the latter, females observed the images for longer than males, which is in line with human findings on sex differences in processing faces. In a subsequent experiment, we tested whether dog portraits functioned as threatening stimuli. We hypothesized that dogs will avoid food rewards or approach them more slowly in the presence of a dog portrait, but found no effect of image type. In general, older dogs took longer to approach food placed in front of the images and mesocephalic dogs were faster than dogs of other skull length types. The results suggest that short-headed dogs are more attentive to faces, while sex and breed function predict looking times through complex interactions.     

Surreptitiously projecting different movies to two subsets of viewers

A new technique (manipulation of overlapping rivalrous images by polarizing filters, or MORI) has been invented for presenting on the same screen two different images that can be seen separately by two groups of viewers without their noticing the overlap. It can easily create desired artificial conflicts among viewers. Two perpendicular polarizing filters provide separate invisible channels from dual video projectors to two groups of viewers on a single screen. The basic principle of the presentation technique, details of the apparatus, and limitations are introduced. As an example of the application of this technique, an eyewitness experiment is briefly reported. The results of experiments conducted by the author and colleagues provide evidence of the effectiveness of this technique with various projectors, video materials, group sizes, and ages of participants.     

Dogs do look at images: eye tracking in canine cognition research

Despite intense research on the visual communication of domestic dogs, their cognitive capacities have not yet been explored by eye tracking. The aim of the current study was to expand knowledge on the visual cognition of dogs using contact-free eye movement tracking under conditions where social cueing and associative learning were ruled out. We examined whether dogs spontaneously look at actual objects within pictures and can differentiate between pictures according to their novelty or categorical information content. Eye movements of six domestic dogs were tracked during presentation of digital color images of human faces, dog faces, toys, and alphabetic characters. We found that dogs focused their attention on the informative regions of the images without any task-specific pre-training and their gazing behavior depended on the image category. Dogs preferred the facial images of conspecifics over other categories and fixated on a familiar image longer than on novel stimuli regardless of the category. Dogs’ attraction to conspecifics over human faces and inanimate objects might reflect their natural interest, but further studies are needed to establish whether dogs possess picture object recognition. Contact-free eye movement tracking is a promising method for the broader exploration of processes underlying special socio-cognitive skills in dogs previously found in behavioral studies.     

Preferences for female body size in Britain and the South Pacific

To assess current attitudes to body weight and shape in the South Pacific, a region characterised by relatively high levels of obesity and traditionally positive views of large bodies, 38 high socio-economic status (SES) adolescent males and 38 low SES adolescent males in Independent Samoa were asked to rate a set of images of real women for physical attractiveness. Participants in both SES settings preferred women with a slender figure, as did a comparison group in Britain, suggesting that the traditional veneration of large bodies is no longer apparent in Samoa. However, the results also showed that low SES adolescents were more likely to view overweight figures as attractive, which suggests that the veneration of slim figures may be associated with increasing SES. Implications of this finding are discussed in conclusion.