Silent gesture is not considered to be linguistic, on par with spoken and sign languages. It is claimed that silent gestures, unlike language, represent events holistically, without compositional structure. However, recent research has demonstrated that gesturers use consistent strategies when representing objects and events, and that there are behavioral and clinically relevant limits on what form a gesture may take to effect a particular meaning. This systematicity challenges a holistic interpretation of silent gesture, which predicts that there should be no (...) stable form‐meaning correspondence across event representations. Here, we demonstrate to the contrary that untrained gesturers systematically manipulate the form of their gestures when representing events with and without a theme (e.g., Someone popped the balloon vs. Someone walked), that is, transitive and intransitive events. We elicited silent gestures and annotated them for manual features active in coding transitivity distinctions in sign languages. We trained linear support vector machines to make item‐by‐item transitivity predictions based on these features. Prediction accuracy was good across the entire dataset, thus demonstrating that systematicity in silent gesture can be explained with recourse to subunits. We argue that handshape features are constructs co‐opted from cognitive systems subserving manual action production and comprehension for communicative purposes, which may integrate into the linguistic system of emerging sign languages. We further suggest that nonsigners tend to map event participants to each hand, a strategy found across genetically and geographically distinct sign languages, suggesting the strategy's cognitive foundation. (shrink)

In The Society of the Spectacle, Debord describes the spectacle as a capitalist social formation that is at the same time reflective of the privileging of vision in the history of Western philosophy. This article highlights Debord’s appeal to the Hegelian-Marxist notion of reciprocal alienation in his discussion of how the spectacle invents the visual form. Reciprocal alienation produces a dialectical relation between concrete social activity and the spectacle, which I argue is key for understanding how the political subject (...) is represented in the hyper-spectacularized societies of the 21st century. (shrink)

This somewhat odd paper argues against a representational view of visual experience using an intricate "inversion" type thought experiment involving double vision: two subjects could represent external space in the same way while differing phenomenally due to different "spread" in their double images. The spatial structure of the visual field is explained not by representation of external space but functionally, in terms of the possible locations of an attentional spotlight. -/- I'm fond of the ideas in this paper (...) but doubt I'll be returning to it soon. (shrink)

The cortical visual mechanisms involved in processing spatial relationships remain subject to debate. According to one current view, the ''dorsal stream'' of visual areas, emanating from primary visual cortex and culminating in the posterior parietal cortex, mediates this aspect of visual processing. More recently, others have argued that while the dorsal stream provides egocentric coding of visual location for motor control, the separate ''ventral'' stream is needed for allocentric spatial coding. We have assessed the (...) class='Hi'>visual form agnosic patient DF, whose lesion mainly affects the ventral stream, on a prehension task requiring allocentric spatial coding. She was presented with transparent circular disks. Each disk had circular holes cut in it. DF was asked to reach out and grasp the disk by placing her fingers through the holes. The disks either had three holes (for forefinger, middle finger, and thumb) or two holes (for forefinger and thumb). The distance between the forefinger and thumb holes, and the orientation of the line formed by them, were independently varied. DF was quite unable to adjust her grip aperture or her hand orientation in the three-hole task. Although she was able to orient her hand appropriately for the two-hole disks, she still remained unable to adjust her grip aperture to the distance between the holes. These findings are consistent with the idea that allocentric processing of spatial information requires a functioning ventral stream, even when the information is being used to guide a motor response. (shrink)

Previous studies have identified the critical role of the left fusiform cortex in visual word form processing, learning, and memory. However, this so-called visual word form area's other functions are not clear. In this study, we used fMRI and the subsequent memory paradigm to examine whether the putative VWFA was involved in the processing and successful memory encoding of faces as well as words. Twenty-two native Chinese speakers were recruited to memorize the visual forms of faces (...) and Chinese words. Episodic memory for the studied material was tested 3. h after the scan with a recognition test. The fusiform face area and the VWFA were functionally defined using separate localizer tasks. We found that, both within and across subjects, stronger activity in the VWFA was associated with better recognition memory of both words and faces. Furthermore, activation in the VWFA did not differ significantly during the encoding of faces and words. Our results revealed the important role of the so-called VWFA in face processing and memory and supported the view that the left mid-fusiform cortex plays a general role in the successful processing and memory of different types of visual objects. © 2010 Elsevier Inc. (shrink)

A detection task was performed using different pictographic representations of objects in order to test the hypothesis that high-level information (familiarity) may influence detection thresholds. The stimuli were five versions of forms: outline drawings of objects, silhouettes, and three fragmented versions of forms derived from the outlines. The stimuli varied on two parameters: their nameability (easily nameable, hardly nameable, and not nameable) as assessed by a naming task, and their energy content as assessed by a two-dimensional fast-Fourier transform. (...) The greatest amount of energy was observed for silhouettes, and the amount of energy contained in the vertical and horizontal spatial frequency components was equivalent for outlines and the three versions of fragmented forms. Luminance thresholds for the detection of the forms were measured by means of an adaptive method. The results show that thresholds were determined only by the energy content of the stimuli. High-level semantic or name information had no influence on the detectability of the visual signal. The results are discussed in terms of the visibility of spatial frequency components at detection threshold. (shrink)

People unfamiliar with Chinese characters show poorer visual working memory (VWM) performance for Chinese characters than do literates in Chinese. In a series of experiments, we investigated the reasons for this expertise advantage. Experiments 1 and 2 showed that the advantage of Chinese literates does not transfer to novel material. Experts had similar resolution as novices for material outside of their field of expertise, and the memory of novices and experts did not differ when detecting a big change, e.g., (...) when a character’s color was changed. Memorizing appears to function as a rather abstract representation of word forms because memory for characters’ fonts was poor independently of expertise (Experiment 3), though still visual. Distractors that were highly similar conceptually did not increase memory errors, but visually similar distractors impaired memory (Experiment 4). We hypothesized that literates in Chinese represent characters in VWM as tokens of visual word forms made available by long-term memory. In Experiment 5, we provided novices with visual word form knowledge. Participants subsequently performed a change detection task with trained and novel characters in a functional magnetic resonance experiment. We analyzed set size- and training-dependent effects in the intraparietal sulcus (IPS) and the visual word form area. VWM for trained characters was better than for novel characters. Neural activity increased with set size and at a slower rate for trained than for novel characters. All conditions approached the same maximum, but novel characters reached the maximum at a smaller set size than trained characters. The time course of the bold response depended on set size and knowledge status. Starting from the same initial maximum, neural activity at small set sizes returned to baseline more quickly for trained characters than for novel characters. Additionally, high performers showed generally more neural activity in the IPS than low performers. We conclude that experts’ better performance in working memory (WM) is caused by the availability of visual long-term representations (word form types) that allow a sparse representation of the perceived stimuli and make even small changes big because they cause a type change that is easily detected. (shrink)

En 1928 la théorie des form constants par Klüver catégorisait les hallucinations visuelles en quatre grandes catégories. Alors que la notion de form constants venait à s’appliquer virtuellement à toutes les figures entoptiques, comme l’avait prévu son auteur, dont les photismes synesthésiques, Cytowic a décrit et Carol Steen représenté ce que voient réellement des synesthètes visuels. L’une des caractéristiques d’œuvres de peintres synesthètes serait justement la présence de ces formes classées par Klüver. L’anthropologie avec la thèse de l’externalisation a montré (...) que certaines cultures ont repris les form constants perçues dans le premier stade de l’intoxication pour en faire les patterns de leur art. Les modèles physiologico-mathématiques permettent de localiser en V1 l’origine de production des photismes et d’expliquer leur morphogénèse. Mais une explication des circuits neuraux empruntés pour passer des différents types de déclencheur sensoriel à l’apparition de photismes synesthésiques reste aujourd’hui au stade de l’hypothèse. La synesthésie est l’objet de recherches alliant les sciences les plus contemporaines dont la génomique. Il est possible que les études sur la synesthésie transforment son statut de phénomène marginal en un élément essentiel dans la compréhension du système physiologique sous-jacent à l’esprit humain. In 1928, Klüver’s theory of form constants placed visual hallucinations into four broad categories. Whereas, as predicted by its author, the notion of form constants was virtually applicable to all entoptic figures, including synesthetic photisms, the very notion of entoptics was definitively extended. Cytowic has described and Carol Steen has represented what visual synesthetes actually see. The presence of these forms, as they have been classified by Klüver, is precisely one of the characteristics of the works of synesthetic painters. With the thesis of externalization, the field of Anthropology has shown that some cultures have adopted the constant forms perceived in the first stage of intoxication as patterns for their art. Physiological-mathematical models allow us to locate the origin of photism production in V1, and to explain these photisms’ morphogenesis. But, even today, an explanation of the neural pathways used to pass from different types of sensory triggers to the appearance of synesthetic photisms remains at the hypothesis stage. Synesthesia is a research topic that combines some of the most contemporary sciences, including genomics. Studies on synesthesia may just transform its status as that of a marginal phenomenon into that of an essential element in understanding the physiological system underlying the human mind. (shrink)