Visual similarity is greater for line drawings of nonliving than living things: the importance of musical instruments and body parts

It has been argued that greater intra-category structural similarity for living things, and the subsequent "visual crowding," makes them more difficult to recognize and name for neurologically damaged individuals and normal subjects (Humphreys et al., 1988). Nevertheless, the precise meaning and quantification of structural similarity remains unclear, as does the rationale for why it necessarily should be greater for living things. We derived a new measure of visual overlap from the Snodgrass and Vanderwart corpus of line drawings: the degree of pixel overlap within subcategories (Euclidean distance: ED). Contrary to existing notions of visual crowding and extant measures of contour overlap, within-category ED indicated less within-category visual overlap for living things. Furthermore, musical instruments clustered with living things (having low overlap), while body parts clustered with nonliving things (having high overlap). These counter-intuitive findings accord with patient data and thus, provide evidence for the psychological reality and utility of ED.     

Seeing ghosts: Negative body evaluation predicts overestimation of negative social feedback

The current study investigated whether negative body evaluation predicts women's overestimation of negative social feedback related to their own body (i.e., covariation bias). Sixty-five female university students completed a computer task where photos of their own body, of a control woman's body, and of a neutral object, were followed by nonverbal social feedback (i.e., facial crowds with equal numbers of negative, positive, and neutral faces). Afterward, women estimated the percentage of negative, positive, and neutral social feedback that followed their own body, the control woman's body, and the neutral object. The findings provided evidence for a covariation bias: negative body evaluation predicted higher estimates of negative social feedback for women's own body, but not for the other stimuli. Additionally, the covariation bias was not explained by differences in how women interpreted the social feedback (the facial stimuli). Clinical implications of the covariation bias to body image are discussed.     

Recognition thresholds for plane-rotated pictures of familiar objects

We investigated picture plane rotation effects on the minimum stimulus duration required to recognise pictures of familiar objects in a picture-word verification task. Participants made unspeeded responses, selecting from 126 written alternatives. Longer stimulus durations were needed to identify plane-misoriented views. These orientation effects were non-linear, arguing against a simple mental rotation account of compensation for plane misorientation in identification tasks. Orientation effects were found for almost all items, in particular including those labelled at the basic level (cf. Hamm, McMullen, 1998, Journal of Experimental Psychology: Human Perception and Performance 24, 413-426). We suggest that plane misorientation increases the difficulty of basic level as well as subordinate level identification unless only a small, visually dissimilar set of stimuli are presented. Errors in the task were analysed to provide an alternative, objective measure of perceived visual similarity, by assessing the number and nature of mistaken identifications made to a given target object. We propose that misorientation effects are best understood in terms of the effects of the perceived visual similarity of a target to its set of response alternatives rather than in terms of the level (basic or subordinate) at which the target is to be identified.     

Biased processing of stereotype-incongruency is greater for low than high status groups

Two studies assessed whether a stereotypic explanatory bias emerges primarily when members of low (compared to high) social status groups engage in behaviors inconsistent with group stereotypes. A preliminary study showed that male and female participants spontaneously showed more stereotypically biased explanatory processing of female stereotype-inconsistency (i.e., explanation of male-stereotypic behaviors performed by female compared to male actors) than male stereotype-inconsistency (i.e., explanation of female-stereotypic behaviors performed by male compared to female actors). The main experiment provided a manipulation of social status of target groups, and both external (i.e., situational) and internal (i.e., dispositional) explanations for stereotype-inconsistent behaviors were assessed. Results showed that external explanations for female stereotype-inconsistency were greater for targets described as low, not high in socioeconomic status. This research suggests that information processing is biased when members of a low status group engage in stereotype-inconsistent behaviors, whereas members of high status groups can engage in either stereotypic or counter-stereotypic behaviors without instigating biases in information processing.     

Visual search for arbitrary objects in real scenes

How efficient is visual search in real scenes? In searches for targets among arrays of randomly placed distractors, efficiency is often indexed by the slope of the reaction time (RT) × Set Size function. However, it may be impossible to define set size for real scenes. As an approximation, we hand-labeled 100 indoor scenes and used the number of labeled regions as a surrogate for set size. In Experiment 1, observers searched for named objects (a chair, bowl, etc.). With set size defined as the number of labeled regions, search was very efficient (~5 ms/item). When we controlled for a possible guessing strategy in Experiment 2, slopes increased somewhat (~15 ms/item), but they were much shallower than search for a random object among other distinctive objects outside of a scene setting (Exp. 3: ~40 ms/item). In Experiments 4–6, observers searched repeatedly through the same scene for different objects. Increased familiarity with scenes had modest effects on RTs, while repetition of target items had large effects (>500 ms). We propose that visual search in scenes is efficient because scene-specific forms of attentional guidance can eliminate most regions from the “functional set size” of items that could possibly be the target.     

Distinct processing for pictures of animals and objects: evidence from eye movements

Many studies have suggested that emotional stimuli orient and engage attention. There is also evidence that animate stimuli, such as those from humans and animals, cause attentional bias. However, categorical and emotional factors are usually mixed, and it is unclear to what extent human context influences attentional allocation. To address this issue, we tracked participants' eye movements while they viewed pictures with animals and inanimate images (i.e., category) as focal objects. These pictures had either negative or neutral emotional valence, and either human body parts or nonhuman parts were near the focal objects (i.e., context). The picture's valence, arousal, position, size, and most of the low-level visual features were matched across categories. The results showed that nonhuman animals were more likely to be attended to and to be attended to for longer times than inanimate objects. The same pattern held for the human contexts (vs. nonhuman contexts). The effects of emotional valence, category, and context interacted. Specifically, in images with a negative valence, focal animals and objects with human context had comparable numbers of gaze fixations and gaze duration. These results highlighted the attentional bias to animate parts of a picture and clarified that the effects of category, valence, and picture context interacted to influence attentional allocation.     

"Seeing things in my head": a synesthete's images for music and notes

We explored synesthetic experiences (photisms) elicited by music and notes for GS, a 22-year-old female college student, who is a genuine digit synesthete (Mills et al 1999 Cognitive Neuropsychology 16 181-191). After extensive interviews, we conducted five studies using synthesizer notes in different octaves and in different instrument sounds. GS described, drew, or selected her photisms from alternatives. The results were: (a) her photisms had shape, color, movement, and texture: (b) different instruments had photisms with different shapes and families of instruments had similar shapes; (c) low-pitched notes were darker and larger than high notes; (d) instrument and pitch affected each other; (e) a given note was perceived as darker after a high note than after a low note; and (f) GS's drawings of notes became more consistent with repeated trials. Theoretical observations are discussed on the basis of these results.     

Memory for objects in real scenes: The development of recognition and recall

Subjects examined crowded semirealistic layouts of toy objects, or photographs of these layouts, and then tried to identify added, moved or deleted items. The main study, involving 1st-, 3rd, 6th-graders, and adults, showed that although successful recognition of added items was superior to both recall of deleted items and recognition of moved ones, all three scores improved with age. In addition, false reports of “new” items decreased markedly in the older groups. The results argue against the widely held view that recognition memory undergoes little or no developmental improvement. No significant difference between real layouts and photographs appeared either in the main experiment or in replications involving shorter exposure (Experiment 2) or retarded subjects (Experiment 3).     

Using eye height in different postures to scale the heights of objects

Four experiments examined eye height (EH) scaling of object height across different postures. In Experiment 1, participants viewed rectangular targets while they were standing, seated, and prone. Standing and seated judgments were similar, possibly due to EH scaling. Prone judgments were significantly lower, a result not attributable to the unfamiliarity of that posture (Experiment 2). In Experiment 3, shifts of seated EH produced height overestimations equivalent to those of standing viewers. Experiment 4 examined the visual salience of size information in the seated and prone judgments by holding EH constant and manipulating another source: linear perspective. Participants viewed targets placed on true- and false-perspective (FP) gradients. The FP gradient affected prone judgments but not seated judgments, which presumably relied on EH. It appears that the human visual system weights size information differentially depending on its utility.     

Infants' comprehension of toy replicas as symbols for real objects

Infants' understanding of toy model-real exemplar relations was assessed through preferential looking and habituation tasks. Results from the preferential looking task suggest that 18-month toddlers are just beginning to demonstrate comprehension of symbolic relations between iconic models and their real object counterparts. Performance of 10- and 14-month-old infants in the preferential looking task did not improve when across-domain pairs of videos were used in place of within-domain pairs. Habituation task results indicated that 10-month-olds do not comprehend symbolic relations between miniature toy replicas and their "real" counterparts, but that such understanding begins to emerge by age 14 months. Interactions between symbolic processing and early lexical development are considered, as are methodological implications for the study of infant categorization.     

Seeing things from a different angle: the pigeon's recognition of single geons rotated in depth

In 2 experiments involving computer-rendered versions of single shapes or "geons," the extent to which depth rotation affects the visual discrimination performance of pigeons in both go/no-go and forced-choice tasks was documented. The pigeons were able to recognize geons at most rotations in depth; however, the pigeons' recognition performance was better at the training view than at most other views. Aspects of these results are both consistent with and problematic for object-centered and viewer-centered theories of object recognition.     

Seeing the big picture: map use and the development of spatial cognition

This paper considers the relation between the development of spatial cognition and children’s use of maps and models. A new theoretical perspective is presented that takes into account the influences of maps on the development of spatial cognition. Maps provide a perspective on spatial information that differs in important ways from the perspective gained from direct experience navigating in the world. Using and thinking about maps may help children to acquire abstract concepts of space and the ability to think systematically about spatial relations that they have not experienced directly. In addition, exposure to maps may help children to think about multiple spatial relations among multiple locations. The results of previous studies that have demonstrated developmental differences in children’s cognition of large‐scale environments are examined from this theoretical perspective. This review suggests that the development of spatial cognition consists partly of the acquisition of models of large‐scale space, and that maps influence the development of the modern Western model.     

The effect of prior experience on recognition thresholds for plane-disoriented pictures of familiar objects

We investigated plane rotation effects on the minimum presentation duration that is required in order to recognize pictures of familiar objects, using the method of ascending limits. Subjects made unspeeded verification responses, selecting from 126 written alternatives. Replicating similar identification studies in which brief, masked pictures (Lawson & Jolicoeur, 1998) were presented, disorientation reduced the efficiency of recognition. Mirroring the findings in speeded picture naming studies (e.g., Jolicoeur, 1985; Jolicoeur & Milliken, 1989), but in contrast to those of Lawson and Jolicoeur (1998), orientation effects were found over a wide range of views and were attenuated but not eliminated with experience with a given object. The results bridge the findings from unspeeded verification and speeded naming tasks. They suggest that the same orientation-sensitive processes are tapped in both cases, and that practice effects on these processes are object specific.     

Rotation of objects in pictures viewed at an angle: evidence for different properties of two types of pictorial space

As an observer views a picture from different viewing angles, objects in the picture appear to change orientation relative to the observer, but some objects change orientation more than others. This difference in rotation for different objects is called the differential rotation effect. The differential rotation is not, however, accompanied by corresponding changes in the perception of the spatial layout of objects in the picture. This lack of correspondence between the perception of rotation and the perception of spatial layout is a result of the fact that the information on a picture's surface defines two kinds of pictorial space with different properties. Rotation is perceived in terms of the pictorial space outside the picture, and spatial layout is perceived in terms of the pictorial space inside the picture.     

Age differences in implicit memory: More apparent than real

Elderly subjects and a group of young subjects identified fragmented picture sequences under conditions of focused attention. Two other groups of young subjects carried out this task under divided-attention conditions. Implicit memory, as measured by item-specific savings, was found in all groups, but this effect was smaller in the elderly group. The young subjects, but not elderly subjects, performed better on new items. The divided-attention conditions equated recall and recognition by the young and the elderly, but only the young subjects showed greater savings for recalled items. The elderly subjects’ reduced implicit memory therefore stemmed from their inability to facilitate implicit memory with explicit memory. A second experiment, involving only young subjects tested after delay, produced findings similar to those for the young divided-attention subjects. Implicit memory, as measured by savings in picture completion, does not show an age-related change when the role of explicit memory is considered. Age does, however, reduce skill learning.     

Seeing is believing: the reality of hypnotic hallucinations

Two experiments investigated the reality attributed to hypnotic suggestion through subtle projection of a visual image during simultaneous suggestion for a visual hallucination that resembled the projected image. In Experiment 1, high and low hypnotizable participants were administered either a hypnotic induction or wake instructions, given a suggestion to hallucinate a shape, and then the projected image was subsequently introduced. Although highs in both conditions rated the projected image more vividly than lows, highs in the hypnosis (but not wake) condition made comparable reality ratings when the projected image was absent and present. In Experiment 2, high hypnotizable participants were administered a suggestion to see a shape on a wall. For half the participants the suggested image was projected on the wall and then removed, and for half the projection was initially absent and then introduced. Participants who had the projection absent and then present reported comparable reality and vividness ratings when the projection was absent and present. These findings indicate that elevated hypnotizability and hypnosis are associated with attributions of external reality to suggested experiences.