Influence of typical size of objects in a categorization task]

This study explores the influence of typical size during a categorization task. The specificity of this experimental work is based on the homogeneity of the graphic stimuli size. We have created a typical size standard of our stimuli, that concerns the real size of the objects represented by the drawings of homogeneous sizes. Then, a priming experiment was performed in which the prime and target drawings had two types of relations: a typical size, and a categorial. The participants are na?ve as to the typical size relation between prime and target. The results show a positive priming effect of the typical size but not of the category. The results are discussed in term of theoretical approach developed by Barsalou and his colleagues (1999, 2003). In this theoretical framework, the typical size can be considered as a perceptual knowledge. In that way, we propose that participants could automatically simulate the typical size as soon as they perceived the drawings of objects with homegenous sizes.     

Visual statistical decisions

To identify variables that underlie intuitive judgments about the sizes of groups of similar objects, we asked people to judge the relative heights of vertical bars briefly shown, two groups at a time, on a computer display. Randomly selected normal deviates determined individual bar height. Average differences in height and group sizes were also randomly varied. Twenty-eight participants judged 250 differences each, which were then submitted to multiple regression analysis and psychophysical inspection. The total number of bars sharpened discrimination, whereas variance dulled it. Critical ratio (CR), the forerunner to the modern t test, emerged as the most important predictor, little additional variance was explained by other factors. The difference in the number of bars was a reliable factor, favoring the greater number of bars. Confidence limits around thresholds, defined as CRs needed to say "possibly greater" surrounded 1.65; as a z value, this corresponded to a one-tailed probability of .05. Judgments about noisy stimuli thus seem to be based on a statistical process and to employ a probability criterion similar to that used in the formal statistical evaluation of experimental findings--namely, p < .05.     

Visual statistical decisions

To identify variables that underlie intuitive judgments about the sizes of groups of similar objects, we asked people to judge the relative heights of vertical bars briefly shown, two groups at a time, on a computer display. Randomly selected normal deviates determined individual bar height. Average differences in height and group sizes were also randomly varied. Twenty-eight participants judged 250 differences each, which were then submitted to multiple regression analysis and psychophysical inspection. The total number of bars sharpened discrimination, whereas variance dulled it. Critical ratio (CR), the forerunner to the modern t test, emerged as the most important predictor; little additional variance was explained by other factors. The difference in the number of bars was a reliable factor, favoring the greater number of bars. Confidence limits around thresholds, defined as CRs needed to say “possibly greater,” surrounded 1.65; as a z value, this corresponded to a one-tailed probability of .05. Judgments about noisy stimuli thus seem to be based on a statistical process and to employ a probability criterion similar to that used in the formal statistical evaluation of experimental findings—namely, p<.05.     

记忆重构和信心评估:商标属性与使用经验的影响

记忆是重现,还是重构?已有理论存在争论。本研究以商标信息为实验材料,应用任务分离范式、元记忆检测范式等方法,探讨了商标属性和用户使用经验对记忆重构的影响。结果发现:(1)商标信息的正确回忆频数及成绩显著低于错误回忆的频数和成绩。(2)简单商标的记忆成绩高于复杂商标的记忆成绩;同时,忠实用户对商标信息的记忆成绩显著高于非忠实用户;(3)在回忆任务之前,人们对商标信息的回忆及其信心评估存在分离;但在回忆任务后二者的变化趋于一致。这表明,复杂程度对商标信息的记忆重构存在显著影响,而且存在用户类型差异;商标信息的记忆重构过程中元认知判断及信心评估会发生变化。     

Vague Objects with Sharp Boundaries

In this article I shall consider two seemingly contradictory claims: first, the claim that everybody who thinks that there are ordinary objects has to accept that they are vague, and second, the claim that everybody has to accept the existence of sharp boundaries to ordinary objects. The purpose of this article is of course not to defend a contradiction. Indeed, there is no contradiction because the two claims do not concern the same ‘everybody’. The first claim, that all ordinary objects are vague, is a claim that stems both from common sense intuitions as well as from various types of ontologies of ordinary objects. This puts then pressure on theories of vagueness to account for the vague nature of ordinary objects – but, as we shall see, all theories of vagueness have to accept the existence of sharp thresholds. This is obvious in the case of epistemicism, and it is a well‐known defect of supervaluationism, but as we will see friends of metaphysical vagueness do have to endorse the existence of sharp thresholds in their theory as well. Consequently, there are reasons for dissatisfaction with these accounts, since they do not seem to be able to do the job we asked them to do. 1     

Feature inference with uncertain categorization: Re-assessing Anderson’s rational model

A key function of categories is to help predictions about unobserved features of objects. At the same time, humans are often in situations where the categories of the objects they perceive are uncertain. In an influential paper, Anderson (Psychological Review, 98(3), 409–429, 1991) proposed a rational model for feature inferences with uncertain categorization. A crucial feature of this model is the conditional independence assumption—it assumes that the within category feature correlation is zero. In prior research, this model has been found to provide a poor fit to participants’ inferences. This evidence is restricted to task environments inconsistent with the conditional independence assumption. Currently available evidence thus provides little information about how this model would fit participants’ inferences in a setting with conditional independence. In four experiments based on a novel paradigm and one experiment based on an existing paradigm, we assess the performance of Anderson’s model under conditional independence. We find that this model predicts participants’ inferences better than competing models. One model assumes that inferences are based on just the most likely category. The second model is insensitive to categories but sensitive to overall feature correlation. The performance of Anderson’s model is evidence that inferences were influenced not only by the more likely category but also by the other candidate category. Our findings suggest that a version of Anderson’s model which relaxes the conditional independence assumption will likely perform well in environments characterized by within-category feature correlation.     

Encoding strategies in self-initiated visual working memory

During a typical day, visual working memory (VWM) is recruited to temporarily maintain visual information. Although individuals often memorize external visual information provided to them, on many other occasions they memorize information they have constructed themselves. The latter aspect of memory, which we term self-initiated WM, is prevalent in everyday behavior but has largely been overlooked in the research literature. In the present study we employed a modified change detection task in which participants constructed the displays they memorized, by selecting three or four abstract shapes or real-world objects and placing them at three or four locations in a circular display of eight locations. Half of the trials included identical targets that participants could select. The results demonstrated consistent strategies across participants. To enhance memory performance, participants reported selecting abstract shapes they could verbalize, but they preferred real-world objects with distinct visual features. Furthermore, participants constructed structured memory displays, most frequently based on the Gestalt organization cue of symmetry, and to a lesser extent on cues of proximity and similarity. When identical items were selected, participants mostly placed them in close proximity, demonstrating the construction of configurations based on the interaction between several Gestalt cues. The present results are consistent with recent findings in VWM, showing that memory for visual displays based on Gestalt organization cues can benefit VWM, suggesting that individuals have access to metacognitive knowledge on the benefit of structure in VWM. More generally, this study demonstrates how individuals interact with the world by actively structuring their surroundings to enhance performance.     

Universal intuitions of spatial relations in elementary geometry

Spatial relations are central to geometrical thinking. With respect to the classical elementary geometry of Euclid’s Elements, a distinction between co-exact, or qualitative, and exact, or metric, spatial relations has recently been advanced as fundamental. We tested the universality of intuitions of these relations in a group of Senegalese and Dutch participants. Participants performed an odd-one-out task with stimuli that in all but one case display a particular spatial relation between geometric objects. As the exact/co-exact distinction is closely related to Kosslyn’s categorical/coordinate distinction, a set of stimuli for testing all four types was used. Results suggest that intuitions of all spatial relations tested are universal. Yet, culture has an important effect on performance: Dutch participants outperformed Senegalese participants and stimulus layouts affect the categorical and coordinate processing in different ways for the two groups. Differences in level of education within the Senegalese participants did not affect performance.     

Sexualized and Athletic: Viewers’ Attitudes toward Sexualized Performance Images of Female Athletes

Using an experimental methodology, the present study investigated college students’ attitudes toward media images of female athletes. We are particularly focused on how viewers perceive media images of female athletes that have both an appearance and athleticism focus, such as those found in ESPN’s The Body Issue. An aim of our study was to assess viewers’ attitudes toward these images that are not purely objectified, thereby contributing to the objectification literature and providing empirical data relevant to theorizing on the social impact of these images. U.S. college students (n?=?563) viewed one of four types of images of the same athletes including: (a) sexualized athletes, (b) sexualized performance athletes (in which both athleticism and sexualization are present), (c) sport performance athletes (in which athletes are depicted playing their sport), or (d) non-sexualized athletes. They then rated the athletes’ competence, esteem, and sexual appeal. Overall, sexualized performance athletes were rated more positively than sexualized athletes, but less positively than sport performance athletes. These results have implications for advocacy efforts calling for more media coverage in which women are depicted as athletes rather than as sexual objects.

     

Monitoring the capacity of working memory: Executive control and effects of listening effort

In two experiments, we used an interruption-and-recall (IAR) task to explore listeners’ ability to monitor the capacity of working memory as new information arrived in real time. In this task, listeners heard recorded word lists with instructions to interrupt the input at the maximum point that would still allow for perfect recall. Experiment 1 demonstrated that the most commonly selected segment size closely matched participants’ memory span, as measured in a baseline span test. Experiment 2 showed that reducing the sound level of presented word lists to a suprathreshold but effortful listening level disrupted the accuracy of matching selected segment sizes with participants’ memory spans. The results are discussed in terms of whether online capacity monitoring may be subsumed under other, already enumerated working memory executive functions (inhibition, set shifting, and memory updating).     

Body ownership affects visual perception of object size by rescaling the visual representation of external space

Size perception is most often explained by a combination of cues derived from the visual system. However, this traditional cue approach neglects the role of the observer’s body beyond mere visual comparison. In a previous study, we used a full-body illusion to show that objects appear larger and farther away when participants experience a small artificial body as their own and that objects appear smaller and closer when they assume ownership of a large artificial body (“Barbie-doll illusion”; van der Hoort, Guterstam, & Ehrsson, PLoS ONE, 6(5), e20195, 2011). The first aim of the present study was to test the hypothesis that this own-body-size effect is distinct from the role of the seen body as a direct familiar-size cue. To this end, we developed a novel setup that allowed for occlusion of the artificial body during the presentation of test objects. Our results demonstrate that the feeling of ownership of an artificial body can alter the perceived sizes of objects without the need for a visible body. Second, we demonstrate that fixation shifts do not contribute to the own-body-size effect. Third, we show that the effect exists in both peri-personal space and distant extra-personal space. Finally, through a meta-analysis, we demonstrate that the own-body-size effect is independent of and adds to the classical visual familiar-size cue effect. Our results suggest that, by changing body size, the entire spatial layout rescales and new objects are now perceived according to this rescaling, without the need to see the body.     

Widgets: A new set of parametrically defined 3D objects for use in haptic and visual categorization tasks

IntroductionMost research to date on human categorization ability has concentrated on the visual and auditory domains. However, a limited – but non-negligible – range of studies has also examined the categorization of familiar or unfamiliar (i.e., novel) objects in the haptic (i.e., tactile-kinesthetic) modality.ObjectiveIn this paper, we describe how we developed a new set of parametrically defined objects, called widgets, that can be used as 3D (or 2D) materials for haptic (or visual) categorization purposes.MethodWidgets are unfamiliar complex 3D shapes with an ovoid body and four types of elements attached to it (eyes, tail, crest, and legs). The stimulus set comprises 24 objects divided into four categories of six exemplars each (the files used for 3D printing are provided as Supplementary Material).ResultsWe also assessed and demonstrated the validity of our stimulus set by conducting two separate studies of haptic and visual categorization, involving participants of different ages: young adults (Study 1), and children and adolescents (Study 2). Results showed that humans can categorize our 3D complex shapes on the basis of both haptically and visually perceived similarities in shape attributes.ConclusionWidgets are very useful new experimental stimuli for categorization studies using 3D printing technology.     

Out of Mind, Out of Sight: Unexpected Scene Elements Frequently Go Unnoticed Until Primed

The human visual system employs a sophisticated set of strategies for scanning the environment and directing attention to stimuli that can be expected given the context and a person’s past experience. Although these strategies enable us to navigate a very complex physical and social environment, they can also cause highly salient, but unexpected stimuli to go completely unnoticed. To examine the generality of this phenomenon, we conducted eight studies that included 15 different experimental conditions and 1,577 participants in all. These studies revealed that a large majority of participants do not report having seen a woman in the center of an urban scene who was photographed in midair as she was committing suicide. Despite seeing the scene repeatedly, 46 % of all participants failed to report seeing a central figure and only 4.8 % reported seeing a falling person. Frequency of noticing the suicidal woman was highest for participants who read a narrative priming story that increased the extent to which she was schematically congruent with the scene. In contrast to this robust effect of inattentional blindness, a majority of participants reported seeing other peripheral objects in the visual scene that were equally difficult to detect, yet more consistent with the scene. Follow-up qualitative analyses revealed that participants reported seeing many elements that were not actually present, but which could have been expected given the overall context of the scene. Together, these findings demonstrate the robustness of inattentional blindness and highlight the specificity with which different visual primes may increase noticing behavior.     

Manipulation and mitigation

Manipulation arguments are commonly deployed to raise problems for compatibilist theories of responsibility. These arguments proceed by asking us to reflect on an agent who has been manipulated to perform some (typically bad) action but who still meets the compatibilist conditions of responsibility. The incompatibilist argues that it is intuitive that the agent in such a case is not responsible even though she met the compatibilist conditions. Thus, it is argued, the compatibilist has not provided conditions sufficient for responsibility. Patrick Todd has recently argued that incompatibilists have taken on a heavier dialectical burden than is necessary. Todd argues that incompatibilists need not argue that an agent in a manipulation case is not at all responsible, but only that her responsibility is mitigated in order to refute compatibilism. Hannah Tierney has responded to Todd’s argument by arguing that a compatibilist can admit that manipulation mitigates responsibility without eliminating it. I argue that Tierney’s response is unsuccessful on its own terms. But, I argue, Todd’s argument can be resisted by way of a parallel counter-argument for compatibilism. I argue that Todd’s argument for incompatibilism is no more powerful than my argument for compatibilism. And since Todd’s manipulation argument is offered as an objection to compatibilism, this amounts to a victory for the compatibilist; the objection is defused.     

Rapid recalibration to audiovisual asynchrony follows the physical—not the perceived—temporal order

In natural scenes, audiovisual events deriving from the same source are synchronized at their origin. However, from the perspective of the observer, there are likely to be significant multisensory delays due to physical and neural latencies. Fortunately, our brain appears to compensate for the resulting latency differences by rapidly adapting to asynchronous audiovisual events by shifting the point of subjective synchrony (PSS) in the direction of the leading modality of the most recent event. Here we examined whether it is the perceived modality order of this prior lag or its physical order that determines the direction of the subsequent rapid recalibration. On each experimental trial, a brief tone pip and flash were presented across a range of stimulus onset asynchronies (SOAs). The participants’ task alternated over trials: On adaptor trials, audition either led or lagged vision with fixed SOAs, and participants judged the order of the audiovisual event; on test trials, the SOA as well as the modality order varied randomly, and participants judged whether or not the event was synchronized. For test trials, we showed that the PSS shifted in the direction of the physical rather than the perceived (reported) modality order of the preceding adaptor trial. These results suggest that rapid temporal recalibration is determined by the physical timing of the preceding events, not by one’s prior perceptual decisions.     

Confinement has no effect on visual space perception: The results of the Mars-500 experiment

People confined to a closed space live in a visual environment that differs from a natural open-space environment in several respects. The view is restricted to no more than a few meters, and nearby objects cannot be perceived relative to the position of a horizon. Thus, one might expect to find changes in visual space perception as a consequence of the prolonged experience of confinement. The subjects in our experimental study were participants of the Mars-500 project and spent nearly a year and a half isolated from the outside world during a simulated mission to Mars. The participants were presented with a battery of computer-based psychophysical tests examining their performance on various 3-D perception tasks, and we monitored changes in their perceptual performance throughout their confinement. Contrary to our expectations, no serious effect of the confinement on the crewmembers’ 3-D perception was observed in any experiment. Several interpretations of these findings are discussed, including the possibilities that (1) the crewmembers’ 3-D perception really did not change significantly, (2) changes in 3-D perception were manifested in the precision rather than the accuracy of perceptual judgments, and/or (3) the experimental conditions and the group sample were problematic.     

The privileged role of location in visual working memory

Reports have conflicted about the possible special role of location in visual working memory (WM). One important question is: Do we maintain the locations of objects in WM even when they are irrelevant to the task at hand? Here we used a continuous response scale to study the types of reporting errors that participants make when objects are presented at the same or at different locations in space. When several objects successively shared the same location, participants exhibited a higher tendency to report features of the wrong object in memory; that is, they responded with features that belonged to objects retained in memory but not probed at retrieval. On the other hand, a similar effect was not observed when objects shared a nonspatial feature, such as color. Furthermore, the effect of location on reporting errors was present even when its manipulation was orthogonal to the task at hand. These findings are consistent with the view that binding together different nonspatial features of an object in memory might be mediated through an object’s location. Hence, spatial location may have a privileged role in WM. The relevance of these findings to conceptual models, as well as to neural accounts of visual WM, is discussed.     

Online usage of theory of mind continues to develop in late adolescence

The development of theory of mind use was investigated by giving a computerized task to 177 female participants divided into five age groups: Child I (7.3–9.7 years); Child II (9.8–11.4); Adolescent I (11.5–13.9); Adolescent II (14.0–17.7); Adults (19.1–27.5). Participants viewed a set of shelves containing objects, which they were instructed to move by a ‘director’ who could see some but not all of the objects. Correct interpretation of critical instructions required participants to use the director’s perspective and only move objects that the director could see. In a control condition, participants were asked to ignore objects in slots with a grey background. Accuracy improved similarly in both conditions between Child I and Adolescent II. However, while performance of the Adolescent II and Adult groups did not differ in the control condition, the Adolescent II group made more errors than the adults in the experimental condition. These results suggest that theory of mind use improves between late adolescence and adulthood. Thus, while theory of mind tasks are passed by age 4, these data indicate that the interaction between theory of mind and executive functions continues to develop in late adolescence.     

Human Participants in Engineering Research: Notes from a Fledgling Ethics Committee

For the past half-century, issues relating to the ethical conduct of human research have focused largely on the domain of medical, and more recently social–psychological research. The modern regime of applied ethics, emerging as it has from the Nuremberg trials and certain other historical antecedents, applies the key principles of: autonomy, respect for persons, beneficence, non-maleficence, and justice to human beings who enter trials of experimental drugs and devices (Martensen in J Hist Med Allied Sci 56(2):168–175, 2001). Institutions such as Institutional Review Boards (in the U.S.) and Ethics Committees (in Europe and elsewhere) oversee most governmentally-funded medical research around the world, in more than a hundred nations that are signers of the Declaration of Helsinki (World Medical Association 2008). Increasingly, research outside of medicine has been recognized to pose potential risks to human subjects of experiments. Ethics committees now operate in the US, Canada, the U.K. and Australia to oversee all governmental-funded research, and in other jurisdictions, the range of research covered by such committees is expanding. Social science, anthropology, and other fields are falling under more clear directives to conduct a formal ethical review for basic research involving human participants (Federman et al. in Responsible research: a systems approach to protecting research participants. National Academies Press, Washington, 2003, p. 36). The legal and institutional response for protecting human subjects in the course of developing non-medical technologies, engineering, and design is currently vague, but some universities are establishing ethics committees to oversee their human subjects research even where the experiments involved are non-medical and not technically covered by the Declaration of Helsinki. In The Netherlands, as in most of Europe, Asia, Latin America, or Africa, no laws mandate an ethical review of non-medical research. Yet, nearly 2 years ago we launched a pilot ethics committee at our technical university and began soliciting our colleagues to submit their studies for review. In the past year, we have become officially recognized as a human subjects ethics committee for our university and we are beginning the process of requiring all studies using human subjects to apply for our approval. In this article, we consider some of the special problems relating to protecting human participants in a technology context, and discuss some of our experiences and insights about reviewing human subjects research at a technical university, concluding: that not less than in medical studies, human participants used in technology research benefit from ethical committees’ reviews, practical requirements for publications, grants, and avoiding legal liability are also served by such committees, and ethics committees in such contexts have many similarities to, but certain other special foci than medical ethics committees. We believe that this experience, and these observations, are helpful for those seeking to establish such committees in technology research contexts, and for framing the particular issues that may arise in such contexts for the benefit of researchers, and nascent committees seeking to establish their own procedures.     

Reference frames in spatial updating when body-based cues are absent

The current study investigated the reference frame used in spatial updating when idiothetic cues to self-motion were minimized (desktop virtual reality). In Experiment 1, participants learned a layout of eight objects from a single perspective (learning heading) in a virtual environment. After learning, they were placed in the same virtual environment and used a keyboard to navigate to two of the learned objects (visible) before pointing to a third object (invisible). We manipulated participants’ starting orientation (initial heading) and final orientation (final heading) before pointing, to examine the reference frame used in this task. We found that participants used the initial heading and the learning heading to establish reference directions. In Experiment 2, the procedure was almost the same as in Experiment 1 except that participants pointed to objects relative to an imagined heading that differed from their final heading in the virtual environment. In this case, pointing performance was only affected by alignment with the learning heading. We concluded that the initial heading played an important role in spatial updating without idiothetic cues, but the representation established at this heading was transient and affected by the interruption of spatial updating; the learning heading, on the other hand, corresponded to an enduring representation which was used consistently.