Riemer’s recent paper on the perception of time discusses a neglected yet important topic in the psychological literature: the consequences for psychology (and psychophysics) from the ‘anisotropy’ of time. The paper presents an argument that there are unique kinds of challenges for psychophysics from such temporal anisotropy: (a) Challenges because the psychological experience of time has temporal anisotropy and the physical concept of time does not have temporal anisotropy. (b) Challenges for experimental research which are unique to temporal anisotropy. -/- (...) Although it is important to consider temporal anisotropy, I think there are reasons to deny the force of both kinds of challenges. (shrink)

In his 1935 book Principles of Gestalt Psychology, Kurt Koffka stated that empirical research in perceptual psychology should begin with “a phenomenological analysis,” which in turn would put constraints on the “true theory.” In this paper, I take this statement as a point of departure to investigate in what sense Gestalt psychologists practiced a phenomenological analysis and how they saw it related to theory construction. I will contextualize the perceptual research in Gestalt psychology vis-a-vis Husserlian phenomenology on the one hand (...) and mainstream psychophysics on the other, and I will argue that Gestalt psychologists practiced a form of “frontloading” phenomenology: Instead of requiring experimental subjects to engage in experiential reflections, such reflections were—in a sense—already engrained in the experimental designs used by researchers. This type of phenomenology was decidedly anti-“introspectionist” and as such was compatible with some of Husserl’s basic commitments, while at the same time bearing a surprising resemblance with the methods employed by psychophysicists like E. Boring and S.S. Stevens. This latter point will prompt me to explore what the difference between Gestalt-psychology and psychophysics amounted to. My analysis will reveal some disagreements and misunderstandings, especially with regard to the notions of isomorphism and introspection. (shrink)

In 1947, Hardy, Wolff, and Goodell achieved a psychophysics milestone: they built a putative sensation-growth scale, for skin pain, from pain-difference limens. Limens were found using the “dolorimeter”, a device first made by Hardy & co. to evoke pain for pain-threshold measurements. Scant years later, though, H.K. Beecher (MD) discredited the pain scale – according to Paterson (2019), citing the historian Tousignant. Yet Hardy & co. receive approval in the literature. Intrigued, we scrutinized their methods, then Beecher’s critiques, and Tousignant’s (...) history of threshold dolorimetry. Beecher decried dolorimetry as irrelevant, favoring clinical trials of pain relief. But he failed to discredit dolorimetry. (shrink)

Friedrich Nietzsche’s criticism towards the substance-concept „I“ plays an important role in his late thought, and can be properly understood by making reference to the 19th century debate on the scientific psychology. Friedrich Lange and Ernst Mach gave an important contribution to that debate. Both of them developed the ideas of Gustav Fechner, and thought about a „psychology without soul“, i.e. an investigation that gives up with the old metaphysics of substance in dealing with the mind-body problem. In this paper (...) I shall deal with both Lange and Mach (whose writings has been read by Nietzsche), in order to shed some light on Nietzsche’s rejection of the „I“ in philosophy. (shrink)

Advances in neuroscience implicate reentrant signaling as the predominant form of communication between brain areas. This principle was used in a series of masking experiments that defy explanation by feed-forward theories. The masking occurs when a brief display of target plus mask is continued with the mask alone. Two masking processes were found: an early process affected by physical factors such as adapting luminance and a later process affected by attentional factors such as set size. This later process is called (...) masking by object substitution, because it occurs whenever there is a mismatch between the reentrant visual representation and the ongoing lower level activity. Iterative reentrant processing was formalized in a computational model that provides an excellent fit to the data. The model provides a more comprehensive account of all forms of visual masking than do the long-held feed-forward views based on inhibitory contour interactions. (shrink)

The validity of psychological measurement is crucially connected to a peculiar form of epistemic circularity. This circularity can be a threat when there are no independent ways to assess whether a certain procedure is actually measuring the intended target of measurement. This paper focuses on how Gustav Theodor Fechner addressed the measurement circularity that emerged in his psychophysical research. First, I show that Fechner's approach to the problem of circular measurement involved a core idealizing assumption of a shared human physiology. (...) Second, I assess Fechner's approach to this issue against the backdrop of his own epistemology of measurement and the measurement context of his time. Third, I claim that, from a coherentist and historicallysituated perspective, Fechner's quantification can be regarded as a first successful step of a longer-term quantification process. To conclude, I draw from these insights some general epistemological reflections that are relevant to current quantitative psychology. (shrink)

Purpose – This study aims to examine the observer’s role in “infant psychophysics”. Infant psychophysics was developed because the diagnosis of perceptual deficits should be done as early in a patient’s life as possible, to provide efficacious treatment and thereby reduce potential long-term costs. Infants, however, cannot report their perceptions. Hence, the intensity of a stimulus at which the infant can detect it, the “threshold”, must be inferred from the infant’s behavior, as judged by observers (watchers). But whose abilities are (...) actually being inferred? The answer affects all behavior-based conclusions about infants’ perceptions, including the well-proselytized notion that auditory stimulus-detection thresholds improve rapidly during infancy. Design/methodology/approach – In total, 55 years of infant psychophysics is scrutinized, starting with seminal studies in infant vision, followed by the studies that they inspired in infant hearing. Findings – The inferred stimulus-detection thresholds are those of the infant-plus-watcher and, more broadly, the entire laboratory. The thresholds are therefore tenuous, because infants’ actions may differ with stimulus intensity; expressiveness may differ between infants; different watchers may judge infants differently; etc. Particularly, the watcher’s ability to “read” the infant may improve with the infant’s age, confounding any interpretation of perceptual maturation. Further, the infant’s gaze duration, an assumed cue to stimulus detection, may lengthen or shorten nonlinearly with infant age. Research limitations/implications – Infant psychophysics investigators have neglected the role of the observer, resulting in an accumulation of data that requires substantial re-interpretation. Altogether, infant psychophysics has proven far too resilient for its own good. Originality/value – Infant psychophysics is examined for the first time through second-order cybernetics. The approach reveals serious unresolved issues. (shrink)

Full applicability of physics to human biology does not necessarily imply that one can uncover a comprehensive, algorithmic correlation between physical brain states and corresponding mental states. The argument takes into account that information processing is finite in principle in a finite world. Presumbly the brain-mind-relation cannot be resolved in all essential aspects, particularly when high degrees of abstraction or self-analytical processes are involved. Our conjecture plausibly unifies the universal validity of physics and a logical limitation of human thought, and (...) it does not regard consciousness -the most basic human experience - as a marginal phenomenon. (shrink)

Pictures are 2D surfaces designed to elicit 3D-scene-representing experiences from their viewers. In this essay, I argue that philosophers have tended to underestimate the relevance of research in vision science to understanding the nature of pictorial experience. Both the deeply entrenched methodology of virtual psychophysics as well as empirical studies of pictorial space perception provide compelling support for the view that pictorial experience and seeing face-to-face are experiences of the same psychological, explanatory kind. I also show that an empirically informed (...) account of pictorial experience provides resources to develop a novel, resemblance-based account of depiction. According to what I call the deep resemblance theory, pictures work by presenting virtual models of objects and scenes in phenomenally 3D, pictorial space. (shrink)

Due to the wide array of phenomena that are of interest to them, psychologists offer highly diverse and heterogeneous types of explanations. Initially, this suggests that the question "What is psychological explanation?" has no single answer. To provide appreciation of this diversity, we begin by noting some of the more common types of explanations that psychologists provide, with particular focus on classical examples of explanations advanced in three different areas of psychology: psychophysics, physiological psychology, and information-processing psychology. To analyze what (...) is involved in these types of explanations, we consider the ways in which law-like representations of regularities and representations of mechanisms factor in psychological explanations. This consideration directs us to certain fundamental questions, e.g., "To what extent are laws necessary for psychological explanations?" and "What do psychologists have in mind when they appeal to mechanisms in explanation?" In answering such questions, it appears that laws do play important roles in psychological explanations, although most explanations in psychology appeal to accounts of mechanisms. Consequently, we provide a unifying account of what psychological explanation is. (shrink)

Are widely used measurements in the human sciences (say happiness surveys or depression scales) quantitative or merely ordinal? If they are merely ordinal, could they be developed into quantitative measurements, just like in the progression from thermoscopes to thermometers? Taking inspiration from recent philosophy of measurement, some practitioners express optimism about future human science measurements. The so-called quantity objection stands out for having the only chance of settling the debate in favour of the pessimists. It claims that the problem lies (...) not with current, or likely future, measurement practices in the human sciences, but with human science attributes themselves—they just are not quantitative, but merely ordinal. Hence, they cannot not (thus will not) be measured quantitatively. The argument has a long and distinguished pedigree. This paper assesses old and recent versions of it, namely: the objection made originally to Fechner’s psychophysics by von Kries (among others) and Michell’s recent version of this objection. To do so, the paper first draws important distinctions between different versions of the argument that have been overlooked. Then, it argues that none of the versions of the quantity objection provide a good reason for the optimists to give up their optimism. In particular, Michell’s argument characterizes the measurand (that is, the attribute to be measured) in a way that optimists do not and need not accept. Yet the optimists’ defence articulated here brings with it serious burdens to discharge. The ball is in their court. (shrink)

Hermann von Helmholtz allows for not only physiological facts and psychological inferences, but also perspectival reasoning, to influence perceptual experience and knowledge gained from perception. But Helmholtz also defends a version of the view according to which there can be a kind of “perspectival truth” revealed in scientific research and investigation. Helmholtz argues that the relationships between subjective and objective, real and actual, actual and illusory, must be analyzed scientifically, within experience. There is no standpoint outside experience from which we (...) can reason, no extra-sensory knowledge of the constitution of the “ideal subject” or of the properties of “real objects.” In the tradition of psychophysics inherited by Helmholtz, we can arrive at a kind of perspectival analysis of perceptual experience, which embeds an account of that experience within the context of the history and situation of the perceiving subject. That analysis is relative to the perceiving subject, but the perspectival explanations Helmholtz constructs are not thereby relativist: in fact, for Helmholtz, the more squarely the perceiving subject is placed in a scientific, perspectival context, the more facts we are able to learn about her experience and the objects with which she interacts. (shrink)

In general, visual experiences represent determinately. And visual experiences, generally, represent properties of distal objects like their colour, shape, and size, but they do not, generally, represent properties of proximal states like that of incoming light or the retina. By making perceptual constancies central to perceptual representation, Peter Schulte extends Karen Neander’s Causal-Informational Teleosemantic theory in order to accommodate these facts. However, by appealing to the psychophysics and chemistry of how light-related properties interact to produce stimulation to the visual system (...) and how the visual system processes such input to produce experiences, I argue that Schulte’s theory fails to accommodate the facts of distality and determinacy. (shrink)

Traditionally, the investigation of truth has been anchored in a priori reasoning. Cognitive science deviates from this tradition by adding empirical data on how people understand and use concepts. Building on psychophysics and machine learning methods, we introduce conceptual scaling, an approach to map people's understanding of abstract concepts. This approach, allows computing participant-specific conceptual maps from obtained ordinal comparison data, thereby quantifying perceived similarities among abstract concepts. Using this approach, we investigated individual's alignment with philosophical theories on truth and (...) the predictive capacity of conceptual maps. The obtained results indicated that, while people's understanding of truth is multifaceted and encapsulates notions of coherence and authenticity, alignment is best for the correspondence theory of truth. Furthermore, conceptual maps allowed predicting individual outcomes with an accuracy of roughly 70%. This research demonstrates that conceptual scaling offers accurate descriptions of individual's understanding of abstract concepts, behavioral predictions, and quantification of alignment with theoretical perspectives. (shrink)

O presente trabalho pretende delinear a noção de Panpsiquismo no projeto filosófico de Gustav Theodor Fechner, especialmente a partir da análise do livro Über die Seelenfrage, de 1861. Para isso, o artigo repõe em linhas gerais a questão das relações entre seu projeto filosófico e a Psicofísica, uma vez que as interpretações clássicas sobre Fechner geralmente enxergam essas duas competências como separadas. Em segundo lugar, o artigo situa questões históricas sobre Fechner e a Psicologia (e sobre filosofia e ciência), bem (...) como a importância da Naturphilosophie em seu projeto. Finalmente, passa-se à análise dos argumentos de Fechner em defesa do Panpsiquismo e analisam-se novamente as relações entre essa visão e a Psicofísica. *** *** *** *** *** *** *** The present work analyses the concept of Panpsychism considering Gustav Theodor Fechner's philosophical project, especially fo- cusing on his 1861 book Über die Seelenfrage. To accomplish this purpose, the article firstly out- lines the links between his philosophical project and Psychophysics, considering that several classic interpretations of Fechner’s writings often considers these two subjects as separate. Secondly, the article situates some historical questions on Fechner and Psychol- ogy, as well as his perspectives on philosophy and science, and including his interpretation of Naturphilosophie. Finally, the article analyses Fechner’s arguments defending Panpsychism and looks again at the relationships between this view and Psychophysics. (shrink)

This essay addresses the attitude of some leading Neo-Kantian philosophers toward scientific psychology and psychophysics. Early influential figures like Friedrich A. Lange counted Gustav T. Fechner’s psychophysical law among their allies in the rehabilitation of the Kantian standpoint. Later on, however, Neo-Kantian philosophers firmly rejected psychological measurement as a whole and harshly criticized the methods adopted by several psychologists of their time. For example, the Marburg mathematician and philosopher August Stadler reduced the validity of Fechner’s law to the mere physiological (...) sphere, and Hermann Cohen conceived the application of mathematical integration to human sensations as an inane enterprise. (shrink)

The topic of the human face is addressed from a biocultural perspective, focusing on the empirical investigation of how the face is represented, perceived, and evaluated in artistic portraits and self-portraits from the XVth to the XVIIth century. To do so, the crucial role played by the human face in social cognition is introduced, starting from development, showing that neonatal facial imitation and face-to-face dyadic interactions provide the grounding elements for the construction of intersubjective bonds. The neuroscience of face perception (...) is concisely presented and discussed, together with the psychophysics of face perception and gaze exploration, introducing the notions of the left visual field advantage and the left gaze bias. The results of experiments on the perception and the emotional and aesthetic rating of artistic portraits and self-portraits are reported, showing that despite participants’ inability to tell self-portraits and portraits apart, greater emotional, communicative-social, and aesthetic ratings were attributed to self-portraits. It is concluded that neuroscience and experimental aesthetics can contribute to better understand the human face, hence to better understand ourselves. (shrink)

A preview of my book *Perception*. Discusses the relationship between perception and the physical world and the issue of whether reality is as it appears. Useful examples are included throughout the book to illustrate the puzzles of perception, including hallucinations, illusions, the laws of appearance, blindsight, and neuroscientific explanations of our experience of pain, smell and color. The book covers both traditional philosophical arguments and more recent empirical arguments deriving from research in psychophysics and neuroscience. The addition of chapter summaries, (...) suggestions for further reading and a glossary of terms make Perception essential reading for anyone studying the topic in detail, as well as for students of philosophy of mind, philosophy of psychology and metaphysics. (shrink)

Friedrich Nietzsche's criticism towards the substance-concept «I» plays an important role in his late thought, and can be properly understood by making reference to the 19th century debate on the scientific psychology. Friedrich Lange and Ernst Mach gave an important contribution to that debate. Both of them developed the ideas of Gustav Fechner, and thought about a «psychology without a soul», i.e. an investigation that gives up with the old metaphysics of substance in dealing with the mind-body problem. In this (...) paper I shall deal with Lange's and Mach's view of the I/soul, in order to shed some light on Nietzsche's rejection of the «I» in philosophy. (shrink)

The form of an action has a strong influence on the interaction between humans. According to their mood, people may perform the same gesture in different ways, such as gently or rudely. These aspects of social communication are named vitality forms by Daniel Stern, represent a mean to establish a direct and immediate connection with others. Indeed, the expression of different vitality forms enables us to communicate our affective states and at the same time the perception of these vitality forms (...) enables people around us to understand how we feel in that moment. In the last years of research, different fMRI studies have been carried out to investigate the neural correlates of vitality forms recognition and execution. Moreover, recent psychophysics studies conducted from our research group have demonstrated the presence of an affective contagion effect, during which vitality forms expressed by an agent affect the action perception and the motor response of the receiver. This means that vitality forms expressed by others can influence our mood positively or negatively, modulating as consequence our behavior. Note that vitality forms pervade our lives in a continuous manner and thus they are not expressed and perceived only during social interactions. For example, when we observe an artistic representation at the theatre, the dynamic postures of dancers, together with an alternation of acceleration and deceleration in their movements, communicate to us different affective states. Also when we are in a museum in front of a painting, lines, colors and shapes used by the artist can elicit in us different sensations and modify our attitude. In this view, with the aim to extend the concept of vitality forms from neuroscience and psychology to other disciplines of study, we dedicate part of this review to discuss how art, in all its forms, can be considered a pure expression of vitality forms. (shrink)

Do sensory measurements deserve the label of “measurement”? We argue that they do. They fit with an epistemological view of measurement held in current philosophy of science, and they face the same kinds of epistemological challenges as physical measurements do: the problem of coordination and the problem of standardization. These problems are addressed through the process of “epistemic iteration,” for all measurements. We also argue for distinguishing the problem of standardization from the problem of coordination. To exemplify our claims, we (...) draw on olfactory performance tests, especially studies linking olfactory decline to neurodegenerative disorders. (shrink)

The paper seeks to refute the idea that physiology can explain at best an organism’s behaviour, outward and inner, but not the conscious experiences that accompany that behaviour. To do so, the paper clarifies the idea by confrontation with an actual example of psychophysical explanation of perceptual experience. This reveals that the idea relies on a prejudice about physiological practice. Then the paper explores some peculiar ways in which this prejudice may survive its refutation. This is to bring out that (...) such explanations of experience as are actually offered by contemporary psychophysics explain nothing less than what they purport to explain; and that these achievements are not, in some peculiar way, more remarkable than equally clever physical explanations of other phenomena. (shrink)

Panpsychism has many sides in common with Jung and Pauli's thinking, and analytical psychology is also a form of panpsychism. In this article we want to lay the foundations for a psychophysics that has an adequate onto-epistemology for the complex phenomenology of the relationship between quantum physics and consciousness. This onto-epistemology is a monism in which an informational-spiritual atemporal dimension, completely entangled in itself and teleologically anthropic, precedes and “informs” instantaneously and constantly matter-energy, space-time and consciousness.

Some experiments in perceptual psychology measure perceivers’ phenomenal experiences of objects versus their cognitive assessments of object properties. Analyzing such experiments, this article responds to Pizlo’s claim that much work on shape constancy before 1985 confused problems of shape ambiguity with problems of shape constancy. Pizlo fails to grasp the logic of experimental designs directed toward phenomenal aspects of shape constancy. In the domain of size perception, Granrud’s studies of size constancy in children and adults distinguish phenomenal from cognitive factors.

In recent literature, it has been suggested that Lange’s social and political philosophy is separate from his neo-Kantian program. Prima facie, this interpretation makes sense given that Lange argues for an account of social norms that builds on Darwin and Smith rather than on Kant. Still, this paper argues that elements of psychophysiological transcendentalism can be found in Lange’s social and political philosophy. A detailed examination of the second edition of the History of Materialism, Schiller’s Poems, and the second edition (...) of The Worker’s Question reveals that Lange sought to develop a systematic foundation of psychophysiological transcendentalism that is presupposed in his social and political philosophy. This allows for a more detailed understanding of Lange’s practical philosophy and assures him a position in the tradition of neo-Kantian socialism. (shrink)

The recent emergence of machine-manipulated media raises an important societal question: How can we know whether a video that we watch is real or fake? In two online studies with 15,016 participants, we present authentic videos and deepfakes and ask participants to identify which is which. We compare the performance of ordinary human observers with the leading computer vision deepfake detection model and find them similarly accurate, while making different kinds of mistakes. Together, participants with access to the model’s prediction (...) are more accurate than either alone, but inaccurate model predictions often decrease participants’ accuracy. To probe the relative strengths and weaknesses of humans and machines as detectors of deepfakes, we examine human and machine performance across video-level features, and we evaluate the impact of preregistered randomized interventions on deepfake detection. We find that manipulations designed to disrupt visual processing of faces hinder human participants’ performance while mostly not affecting the model’s performance, suggesting a role for specialized cognitive capacities in explaining human deepfake detection performance. -/- . (shrink)

Friedrich Nietzsche’s criticism towards the substance-concept “I” plays an important role in his thought, and can be properly understood by making reference to the 19th century debate on the scientific psychology. Friedrich Lange and Ernst Mach gave an important contribution to that debate. Both of them thought about a “psychology without soul”, that is, an investigation that gives up with the old metaphysics of substance in dealing with the mind-body problem. In this paper I shall deal with Lange’s and Mach’s (...) views, in order to shed some light on Nietzsche’s rejection of the I in philosophy. (shrink)

Cognitive Science, Volume 46, Issue 10, October 2022.

Contemporary discussions about operational definition often hark back to Stanley Smith Stevens’ classic papers on psychological operationism (1935ab). Still, he was far from the only psychologist to call for conceptual hygiene. Some of Stevens’ direct colleagues at Harvard---most notably B. F. Skinner and E. G. Boring---were also actively applying Bridgman’s conceptual strictures to the study of mind and behavior. In this paper, I shed new light on the history of operationism by reconstructing the Harvard debates about operational definition in the (...) years before Stevens published his seminal articles. Building on a large set of archival evidence from the Harvard University Archives, I argue that we can get a more complete understanding of Stevens’ contributions if we better grasp the operationisms of his former teachers and direct colleagues at Harvard’s Department of Philosophy and Psychology. (shrink)

An ongoing mystery in sensory science is how sensation magnitude F(I), such as loudness, increases with increasing stimulus intensity I. No credible, direct experimental measures exist. Nonetheless, F(I) can be inferred algebraically. Differences in sensation have empirical (but non-quantifiable) minimum sizes called just-noticeable sensation differences, ∆F, which correspond to empirically-measurable just-noticeable intensity differences, ∆I. The ∆Is presumably cumulate from an empirical stimulus-detection threshold I_th up to the intensity of interest, I. Likewise, corresponding ∆Fs cumulate from the sensation at the stimulus-detection (...) threshold, F(I_th ), up to F(I). Regarding the ∆Is, however, it is unlikely that all of them will be known experimentally; the procedures are too lengthy. The customary approach, then, is to find ∆I at a few widely-spaced intensities, and then use those ∆Is to interpolate all ∆Is using some smooth continuous function. The most popular of those functions is Weber’s Law, ∆I⁄I=K. But that is often not even a credible approximation to the data. However, there are other equations for ∆I⁄I. Any such equation for ∆I⁄I can be combined with any equation for ∆F, through calculus, to altogether obtain F(I). Here, two assumptions for ∆F are considered: ∆F=B (Fechner’s Law) and (∆F⁄F)=g (Ekman’s Law). The respective integrals involve lower bounds I_th and F(I_th ). This stands in broad contrast to the literature, which heavily favors non-bounded integrals. We, hence, obtain 24 new, alternative equations for sensation magnitude F(I) (12 equations for (∆I⁄I) × 2 equations for ∆F). (shrink)

In psychophysical experiments, the use of a psychophysical procedure of brightness/darkness cancellation shed light on interactions between spatial arrangement and figure–ground contrast in the perceptual filling in of achromatic and colored surfaces.Achromatic and chromatic Kanizsa squares with varying contrast, contrast polarity, and inducer spacingwere used to test how these factors interact in the perceptual filling in of surface brightness or darkness. The results suggest that the neuronal processing of surfaces with apparent contrast, leading to figure–ground segregation (i.e., perceptual organization), is (...) governed by mechanisms that integrate both luminance contrast and spatial information carried by the inducing stimuli, while discarding information on contrast polarity or color. The findings are discussed in relation to earlier observations on brightness assimilation and contrast. They support theories of nonantagonistic neural mechanisms suppressing local contrast or color signs in brightnessbased figure–ground percepts. Such mechanismsmight be necessary to cancel potentially conflicting polarities in geometricallycomplex visual stimuli so that perceptual filling in resulting in the most plausible representation of figure and ground can be achieved. (shrink)

Humans coordinate their focus of attention with others, either by gaze following or prior agreement. Though the effects of joint attention on perceptual and cognitive processing tend to be examined in purely visual environments, they should also show in multisensory settings. According to a prevalent hypothesis, joint attention enhances visual information encoding and processing, over and above individual attention. If two individuals jointly attend to the visual components of an audiovisual event, this should affect the weighing of visual information during (...) multisensory integration. We tested this prediction in this preregistered study, using the well-documented sound-induced flash illusions, where the integration of an incongruent number of visual flashes and auditory beeps results in a single flash being seen as two (fission illusion) and two flashes as one (fusion illusion). Participants were asked to count flashes either alone or together, and expected to be less prone to both fission and fusion illusions when they jointly attended to the visual targets. However, illusions were as frequent when people attended to the flashes alone or with someone else, even though they responded faster during joint attention. Our results reveal the limitations of the theory that joint attention enhances visual processing as it does not affect temporal audiovisual integration. (shrink)

East Asians and Westerners differ in various aspects of perception and cognition. For example, visual memory for East Asians is believed to be more influenced by the contextual aspects of a scene than is the case for Westerners (Masuda & Nisbett, 2001). There are also differences in visual search: for Westerners, search for a long line among short is faster than for short among long, whereas this difference does not appear to hold for East Asians (Ueda et al., submitted). However, (...) it is unclear how these group-level differences originate. To investigate the extent to which they depend upon environment, we tested visual search and visual memory in East Asian immigrants who had lived in Canada for different amounts of time. Recent immigrants were found to exhibit no search asymmetry, unlike Westerners who had spent their lives in Canada. However, immigrants who had lived in Canada for more than two years showed performance comparable to that of Westerners. These differences could not be explained by the general analytic/holistic processing distinction believed to differentiate Westerners and East Asians, since all observers showed a strong holistic tendency for visual recognition. Results instead support the suggestion that exposure to a new environment can significantly affect the particular processes used to perceive a given stimulus. (shrink)

The perception of brightness differences in Ehrenstein figures and of illusory contours in phase-shifted line gratings was investigated as a function of the contrast polarity of the inducing elements. We presented either continuous lines or line-like arrangements composed of aligned dashes or dots whose spacing was varied. A yes/no procedure was used in which naive observers had to decide whether or not they perceived a brightness difference in a given Ehrenstein figure or an illusory contour in a phase-shifted line grating. (...) The results show that brightness differences are perceived to some extent in Ehrenstein figures with inducers of opposite polarity of contrast; however, the percentage of yes response was systematically lower and response times were longer than for figures with inducers of the same polarity. Phase-shifted line gratings with lines of opposite polarity of contrast yielded stronger illusory contours and shorter response times than those with lines of the same polarity. When the sign of contrast was not the same within a given line of induction, neither differences in brightness nor illusory contours were perceived. The results suggest that the mechanisms that lead to apparent differences in brightness are more sensitive to input of the same contrast polarity, the mechanisms generating illusory contours more sensitive to input of opposite polarity. The data are discussed in the light of a multistage approach to illusory form perception and some implications for cortical models of illusory contour integration are discussed. (shrink)

Twenty-two experienced action video-game players (AVGPs) and 18 non-VGPs were tested on a pen-and-paper line bisection task that was untimed. Typically, right-handers bisect lines 2 % to the left of true centre, a bias thought to reflect the dominance of the right-hemisphere for visuospatial attention. Expertise may affect this bias, with expert musicians showing no bias in line bisection performance. Our results show that experienced-AVGPs also bisect lines with no bias with their right hand and a significantly reduced bias with (...) their left hand compared to non-AVGPs. Bisections by experienced-AVGPs were also more precise than those of non-AVGPs. These findings show the cognitive proficiencies of experienced-AVGPs can generalize beyond computer based tasks, which resemble their training environment. (shrink)

When visual attention is directed away from a stimulus, neural processing is weak and strength and precision of sensory data decreases. From a computational perspective, in such situations observers should give more weight to prior expectations in order to behave optimally during a discrimination task. Here we test a signal detection theoretic model that counter-intuitively predicts subjects will do just the opposite in a discrimination task with two stimuli, one attended and one unattended: when subjects are probed to discriminate the (...) unattended stimulus, they rely less on prior information about the probed stimulus’ identity. The model is in part inspired by recent findings that attention reduces trial-by-trial variability of the neuronal population response and that they use a common criterion for attended and unattended trials. In five different visual discrimination experiments, when attention was directed away from the target stimulus, subjects did not adjust their response bias in reaction to a change in stimulus presentation frequency despite being fully informed and despite the presence of performance feedback and monetary and social incentives. This indicates that subjects did not rely more on the priors under conditions of inattention as would be predicted by a Bayes-optimal observer model. These results inform and constrain future models of Bayesian inference in the human brain. (shrink)

Naive observers viewed a sequence of colored Mondrian patterns, simulated on a color monitor. Each pattern was presented twice in succession, first under one daylight illuminant with a correlated color temperature of either 16,000 or 4,000 K and then under the other, to test for color constancy. The observers compared the central square of the pattern across illuminants, either rating it for sameness of material appearance or sameness of hue and saturation or judging an objective property—that is, whether its change (...) of color originated from a change in material or only from a change in illumination. Average color constancy indices were high for material appearance ratings and binary judgments of origin and low for hue–saturation ratings. Individuals’ performance varied, but judgments of material and of hue and saturation remained demarcated. Observers seem able to separate phenomenal percepts from their ontological projections of mental appearance onto physical phenomena; thus, even when a chromatic change alters perceived hue and saturation, observers can reliably infer the cause, the constancy of the underlying surface spectral reflectance. (shrink)

Ormerod and Chronicle reported that optimal solutions to traveling salesperson problems were judged to be aesthetically more pleasing than poorer solutions and that solutions with more convex hull nodes were rated as better figures. To test these conclusions, solution regularity and the number of potential intersections were held constant, whereas solution optimality, the number of internal nodes, and the number of nearest neighbors in each solution were varied factorially. The results did not support the view that the convex hull is (...) an important determinant of figural attractiveness. Also, in contrast to the findings of Ormerod and Chronicle, there were consistent individual differences. Participants appeared to be divided as to whether the most attractive figure enclosed a given area within a perimeter of minimum or maximum length. It is concluded that future research in this area cannot afford to focus exclusively on group performance measures. (shrink)

The visual system adapts to a wide range of visual features, from lower-level features like color and motion to higher-level features like causality and, perhaps, number. According to some, adaptation is a strictly perceptual phenomenon, such that the presence of adaptation licenses the claim that a feature is truly perceptual in nature. Given the theoretical importance of claims about adaptation, then, it is important to understand exactly when the visual system does and does not exhibit adaptation. Here, we take as (...) a case study one specific kind of adaptation: visual adaptation to size. Supported by evidence from four experiments, we argue that, despite robust effects of size adaptation in the lab, (1) size adaptation effects are phenomenologically underwhelming (in some cases, hardly appreciable at all), (2) some effects of size adaptation appear contradictory, and difficult to explain given current theories of size adaptation, and (3) prior studies on size adaptation may have failed to isolate size as the adapted dimension. Ultimately, we argue that while there is evidence to license the claim that size adaptation is genuine, size adaptation is a puzzling and poorly understood phenomenon. (shrink)