With the development of mobile Internet technology, firms need to complete the entire process of consumer targeting, ad content generation, and ad display in a very short time window. Therefore, computational advertising, such as native ads on social media platforms, has become the mainstream of online advertising with its automation and personalization features. However, computational advertising faces some problems when using artificial intelligence technology to generate content. First, the images should have a significant enough impact on consumers and be easy (...) to adjust to save computational power at the same time; second, the iteration of the computational advertising system relies on consumer behaviors or advertising effectiveness, and firms need to learn the relationship between ad design and consumer behaviors. Under the above two problems, this paper selects visual distance as the main variable, and images can be adjusted by cropping to save computational power. This paper incorporates image design and ad effectiveness metrics into the construal level theory framework, under which the effectiveness metrics can be quickly determined. Following previous studies, we use click-through rate to represent the early stage of the sales funnel and a higher construal level and CVR to represent the later stage of the sales funnel and a lower construal level. Therefore, visually distant images bring distant psychological distance or higher construal level, which can get higher CTR; visually proximate images bring near psychological distance or lower construal level, which can bring higher CVR. These findings suggest that firms can improve the efficiency of their advertising systems and gain more revenue by understanding consumer psychological states. (shrink)

In two experiments, we investigate to what extent various visual saliency cues in realistic visual scenes cause speakers to overspecify their definite object descriptions with a redundant color attribute. The results of the first experiment demonstrate that speakers are more likely to redundantly mention color when visual clutter is present in a scene as compared to when this is not the case. In the second experiment, we found that distractor type and distractor color affect redundant color use: (...) Speakers are most likely to overspecify if there is at least one distractor object present that has the same type, but a different color than the target referent. Reliable effects of distractor distance were not found. Taken together, our results suggest that certain visual saliency cues guide speakers in determining which objects in a visual scene are relevant distractors, and which not. We argue that this is problematic for algorithms that aim to generate human-like descriptions of objects, since these generally select properties that help to distinguish a target from all objects that are present in a scene. (shrink)

Journal Name: Semiotica Issue: Ahead of print.

PurposeTo evaluate the relationship between intraocular straylight perception and: (i) contrast sensitivity (CS), (ii) halo size, and (iii) hazard recognition distance, in the presence and absence of glare.Subjects and methodsParticipants were 15 (5 female) ophthalmologically healthy adults, aged 54.6–80.6 (median: 67.2) years. Intraocular straylight (log s) was measured using a straylight meter (C-Quant; Oculus GmbH, Wetzlar, Germany). CS with glare was measured clinically using the Optovist I device (Vistec Inc., Olching, Germany) and also within a driving simulator using Landolt (...) Cs. These were presented under both static or dynamic viewing conditions, and either with or without glare. Hazard detection distance was measured for simulated obstacles of varying contrast. For this, the participant was required to maintain a speed of 60 km/h within a custom-built nighttime driving simulator. Glare was simulated by LED arrays, moved by cable robots to mimic an oncoming car’s headlights. Halo size (“halometry”) was measured by moving Landolt Cs outward originating from the center of a static glare source. The outcome measure from “halometry” was the radius of the halo (angular extent, in degrees visual angle).ResultsThe correlation between intraocular straylight perception, log s, and hazard recognition distance under glare was poor for the low contrast obstacles (leading/subdominant eye: r = 0.27/r = 0.34). Conversely, log CS measured with glare strongly predicted hazard recognition distances under glare. This was true both when log CS was measured using a clinical device (Optovist I: r = 0.93) and within the driving simulator, under static (r = 0.69) and dynamic (r = 0.61) conditions, and also with “halometry” (r = 0.70). Glare reduced log CS and hazard recognition distance for almost all visual function parameters.ConclusionIntraocular straylight was a poor predictor of visual function and driving performance within this experiment. Conversely, CS was a strong predictor of both hazard recognition and halo extent. The presence of glare and motion lead to a degradation of CS in a driving simulator. Future studies are necessary to evaluate the effectiveness of all above-mentioned vision-related parameters for predicting fitness to drive under real-life conditions. (shrink)

Most of the research done with spatial demonstratives have focused on the production, not the interpretation, of these words. In addition, emphasis has been largely on demonstrative pronouns, leaving demonstrative adverbs with relatively little research attention. The present study explores the interpretation of both demonstrative pronouns and demonstrative adverbs in Estonian—a Finno-Ugric language with two dialectal-specific demonstrative pronoun systems. In the South-Estonian dialectal region, two demonstrative pronouns, see—“this” and too—“that”, are used. In the North-Estonian region, only one, see—“this/that”, is used. (...) The aim of this study is twofold. First, we test if the distance and the visual salience of a referent have an effect on the interpretation of demonstratives. Second, we explore if there is a difference in the interpretation of demonstratives between native speakers from SE and NE. We used an interpretation experiment with 30 participants per group and compared the SE and NE group responses. The results clearly show that the distance of the referent has an effect on how demonstratives are interpreted across the two groups, while the effect of visual salience is inconclusive. There is also a difference in the interpretation of demonstratives between the two dialectal groups. When using the Estonian with an influence of the SE dialect, the NE speakers rely on demonstrative adverbs in interpreting the referential utterance that includes demonstrative pronoun and adverb combinations, whereas the SE speakers also take into account the semantics of demonstrative pronouns. We show that, in addition to an already known difference in the production, there is also a difference in the interpretation of demonstratives between the two groups. In addition, our findings support the recognition that languages that have distance neutral demonstrative pronouns enforce the spatial meaning of a referring utterance by adding demonstrative adverbs. Not only is the interpretation of demonstrative pronouns affected, but the interpretation of demonstrative adverbs as well. The latter shows the importance of studying adverbs also, not just pronouns, and contributes to further knowledge of how demonstratives function. (shrink)

Visual Perception of Shape, Space and Appearance Liliana Albertazzi. the sort I have in mind. What I am speaking of is the mandatory correlations between attributes of visual space (those of, e.g., surfaces, shape, distance, direction) and  ...

Two theses appear to be central to Reid’s view of the visual field. By sight, we do not originally perceive depth or linear distance from the eye. By sight, we originally perceive the position that points on the surface of objects have with regard to the centre of the eye. In different terms, by sight, we originally perceive the compass direction and degree of elevation of points on the surface of objects with reference to the centre of the (...) eye. I consider various problems about distance perception and perception of position with regard to the centre of the eye raised by Reid’s texts. These questions are relevant to Reid’s description of the geometry of visibles as the “intrinsic” geometry of the surface of the sphere. (shrink)

When referring to a target object in a visual scene, speakers are assumed to consider certain distractor objects to be more relevant than others. The current research predicts that the way in which speakers come to a set of relevant distractors depends on how they perceive the distance between the objects in the scene. It reports on the results of two language production experiments, in which participants referred to target objects in photo-realistic visual scenes. Experiment 1 manipulated (...) three factors that were expected to affect perceived distractor distance: two manipulations of perceptual grouping (region of space and type similarity), and one of presentation mode (2D vs. 3D). In line with most previous research on visually-grounded reference production, an offline measure of visual attention was taken here: the occurrence of overspecification with color. The results showed effects of region of space and type similarity on overspecification, suggesting that distractors that are perceived as being in the same group as the target are more often considered relevant distractors than distractors in a different group. Experiment 2 verified this suggestion with a direct measure of visual attention, eye tracking, and added a third manipulation of grouping: color similarity. For region of space in particular, the eye movements data indeed showed patterns in the expected direction: distractors within the same region as the target were fixated more often, and longer, than distractors in a different region. Color similarity was found to affect overspecification with color, but not gaze duration or the number of distractor fixations. Also the expected effects of presentation mode (2D vs. 3D) were not convincingly borne out by the data. Taken together, these results provide direct evidence for the close link between scene perception and language production, and indicate that perceptual grouping principles can guide speakers in determining the distractor set during reference production. (shrink)

Global warming and other climate issues seriously threaten global sustainable development. As citizen environmental behavior can have a positive impact on the environment, it is of great theoretical significance and practical reference value to study the impact of psychological distance theory on citizen environmental behavior. This study obtained 2,633 related studies from 1980 to 2020 from the Web of Science as research objects, and used CiteSpace, VOSviewer, Netdraw, and other software programs to perform a bibliometric analysis, which can show (...) the complex relationship implied in the citation, intuitively grasp the development context and hot frontier in this field, and help scholars better study citizen environmental behavior. The results and conclusions are as follows. The related research covered three periods: infancy, growth, and outbreak. Chronologically, the relevant research evolved from building models to analyze the impact of environmental enrichment on human environmental behavior, to studying the motivation behind citizen environmental behavior, and finally to paying attention to sustainable development. A cluster analysis of high-frequency keywords identified three research hotspots: “drivers of psychological distance of environmental change perception on citizen environmental behavior,” “impact of social distance on adolescents’ behavior,” and “construal level theory and citizen green behavior.” Based on these findings, possible future research directions were identified, including changing from a single theory to a combination of multiple theories to comprehensively study citizen environmental protection behavior; analyzing the motivation of citizen environmental behavior and summarizing the general motivation of environmental behavior according to its internal relationship; and determining how to narrow the global psychological distance, strengthen the awareness of the community of human destiny, and explore the establishment of an efficient global climate cooperation mechanism. (shrink)

When viewed from a distance, visual hallucinations fall into one of two symptom patterns, a dichotomy which poses a problem for theoretical models treating them as a single entity. Such models should be broadened to allow for two distinct but overlapping syndromes – one likely to relate to visual de-afferentation, the other to Perception and Attention Deficit (PAD) cholinergic pathology.

This article is an exploration of Apple’s iPhone 4 as both a technology and an object of marketing. This analysis looks at the FaceTime app and how its marketing created a visual hand-phone-face Deleuzian assemblage while playing on affective connections of parenthood and long-distance caring labor. This is connected to the ways in which mobile telephony creates divided attention between home and labor and the mobile phone and car while driving. This analysis is especially concerned with technological transparency (...) and how it creates divided attention in the home and in the car. (shrink)

The visual world of adults consists of objects at various distances, partly occluding one another, substantial and stable across space and time. The visual world of young infants, in contrast, is often fragmented and unstable, consisting not of coherent objects but rather surfaces that move in unpredictable ways. Evidence from computational modeling and from experiments with human infants highlights three kinds of learning that contribute to infants’ knowledge of the visual world: learning via association, learning via active (...) assembly, and learning via visual-manual exploration. Infants acquire knowledge by observing objects move in and out of sight, forming associations of these different views. In addition, the infant’s own self-produced behavior—oculomotor patterns and manual experience, in particular—is an important means by which infants discover and construct their visual world. (shrink)

As the word “optics” was understood from antiquity into and beyond the early modern period, it did not mean simply the physics and geometry of light, but meant the “theory of vision” and included what we should now call physiological and psychological aspects. From antiquity, these aspects were subject to geometrical analysis. Accordingly, the geometry of visual experience has long been an object of investigation. This chapter examines accounts of size and distance perception in antiquity (Euclid and Ptolemy) (...) and the Middle Ages (Ibn al-Haytham), before turning to "natural geometry" in Kepler and Descartes. It finds a purely mechanical realization of natural geometry in Descartes (primarily in his L'Homme, 1664), in which he conceives states of the visual system as varying in accordance with distance, much as his geometrical compasses vary their spatial relations in accordance with geometrical proportions. This reading challenges the notion that a two-dimensional sensation (without three-dimensional phenomenality) was universally accepted prior to the nineteenth century by positing a direct psychophysiological account of the experience of distance in Descartes. It thereby challenges the interpretations of Descartes on natural geometry of George Berkeley, Nancy Maull, Margaret Wilson, Erwin Panofsky, and Jonathan Crary. (shrink)

Four experiments investigated the extent to which abstract quantitative information can be conveyed by basic visual features. This was done by asking observers to estimate and discriminate Pearson correlation in graphical representations where the first data dimension of each element was encoded by its horizontal position, and the second by the value of one of its visual features; perceiving correlation then requires combining the information in the two encodings via a common abstract representation. Four visual features were (...) examined: luminance, color, orientation, and size. All were able to support the perception of correlation. Indeed, despite the strikingly different appearances of the associated stimuli, all gave rise to performance that was much the same: just noticeable difference was a linear function of distance from complete correlation, and estimated correlation a logarithmic function of this distance. Performance differed only in regards to the level of noise in the feature, with these values compatible with estimates of channel capacity encountered in classic experiments on absolute perceptual magnitudes. These results suggest that quantitative information can be conveyed by visual features that are abstracted at relatively low levels of visual processing, with little representation of the original sensory property. It is proposed that this is achieved via an abstract parameter space in which the values in each perceptual dimension are normalized to have the same means and variances, with perceived correlation based on the shape of the joint probability density function of the resultant elements. (shrink)

The process of continuing education of paramedics is based on gaining educational credits during five-year educational periods. One of the forms of self-improvement are Internet-based educational programs. The lack of regulations concerning the organizational and technical aspects of e-learning made the authors attempt to analyze the phenomenon. The aim of the article is to present an initial analysis of the role of online educational programs in comparison with other forms of professional training of paramedics. One in three respondents has recently (...) used one of the methods of distance learning. Despite the low awareness of the effectiveness of e-learning, almost 70% of the interviewees expressed a positive opinion about it and over 50% were willing to use such forms in the future. The respondents preferred online trainings in the asynchronous version, containing audio-visual materials and providing the possibility to obtain a certificate issued to the participant after completing the course. The demand for topics in the area of professional training included mainly the fields of Drug Therapy, electrotherapy, electrocardiogram evaluation, medical segregation, and help in delivery in pre-hospital conditions. Modern forms of distance learning do not make it possible to acquire practical skills, yet their role in professional training of paramedics is still significant. According to the authors, online educational programs constitute an effective complement to traditional training through the performance of tasks in a mixed form, known as blended-learning. (shrink)

This article identifies the structural and conceptual aspects of a visual construction often used in advertisements to establish a metaphoric or associative relation, that is, symmetric object alignment (SOA). It offers an account of the formal ingredients of SOA, which fall into two groups: object-constitutive factors (like size, shape, and color) and object-depictment factors (like perspective, orientation, and distance from viewing point). Both factors allow us to treat SOA as a visual rhetorical scheme. We also discuss how (...) SOA relates to conceptual structure, metaphoric or otherwise. Four types of relations are distinguished, based on the way in which perceptual and conceptual characteristics interact. Finally, we discuss the way in which these characteristics relate to the processing of such visual messages. One depictment factor will be focused on in particular: one-to-one versus one-to-many alignments. An attempt is made to connect these 2 patterns to the much-discussed topic in verbal metaphor theory, object comparison versus categorization. (shrink)

Sensation is the reflection of the brain on the individual attributes of objective things that directly act on the sense organs. Feeling is the most elementary cognitive process and the simplest psychological phenomenon. Vision is a kind of sense, and sense is produced by objective things acting on the sense organs. But at present, it is rare to analyze interior design exhibition from the perspective of visual psychology, an emerging science, as an interdisciplinary attempt, only in interior design research. (...) Therefore, the study of sensory process should start from its external stimuli, in order to first understand how it acts on the sensory organs to produce sensory phenomena. This paper mainly studies the visual performance of psychological factors in interior design under the background of artificial intelligence. This paper proposes a K-means clustering algorithm and a localization algorithm fused with visual and inertial navigation. The distance thresholds corresponding to the SIFT feature descriptors of threshold T1, 128D, 96D, 64D, and 32D are 170, 160, 150, and 90, respectively. This verifies that the candidate image with the highest number of matching points is considered the best matching image. (shrink)

This chapter focuses on a 1914 photograph by Stefano Bricarelli that can be considered a visual representation of the concerns of landscape. It explores the concept of the sublime in terms of the interplay between distance, immediacy, and representation. Before considering the concept of sublimity, the question regarding entry into the scene must first be addressed. The possibility that landscape may only exist because of such an entry plays a vital role in any analysis of the photographic image. (...) This possibility also allows a conception of human presence that is not mere construction but a form of production. While there may be a process in which a form of presence comes into consideration, what is present brings with it a transformational quality. The logic of addition also suggests that human presence creates an original form of distancing. (shrink)

Pupillary responses and associated vergence eye movements were monitored during imagery of objects of differing sizes (“large” or “small”) from varying distances (“near” or “far”). Objects’ imagined size and distance affected oculomotor behavior. Objects visualized as “far” resulted in the larger pupil dilations and smaller visual angle, while small objects imagined “near” were associated with smaller pupils in contrast to relatively larger pupils when imagined as “far” away. Furthermore, near objects resulted in larger visual angle, and particularly, (...) vergence adjustments were observed that were dependent on imagined size and distance of the small objects. The findings are consistent with the idea that imagery emulates perception, also at the embodied level of oculomotor behaviors. (shrink)

This paper demonstrates an empirical analysis of the visual order of membership categories in a way consistent with both an early ethnomethodological research interest and recent arguments in membership categorization analysis. Early ethnomethodological studies have highlighted that we can infer and understand the membership categories of observed people about whom we have no information in advance, even without talking to them. Recent membership categorization analysts have argued the methodological importance of using video data. Given this, fictional films serve as (...) video data to advance the investigation into the visual order of membership categories since audiences do not know the fictional characters’ information in advance and cannot talk to them. We analyze how potential audiences understand fictional characters’ membership categories and how production crew members organize the visual and conversational order of membership categories. The analysis illustrates that our practical inferences of fictional characters’ membership categories are based on conversations among characters and visually available information. Such visually available information includes environments and lighting, as well as characters’ clothes, body orientations, facial expressions, and physical distance from each other. In other words, production crew members of fictional films design the visual and conversational order for remote audiences by arranging visually available information and fictional characters’ conversations. The findings provide insights into the “possible correctness” and “defeasibility” of membership categorization practices. Particularly regarding fictional characters’ membership categories, production crew members can employ the “possible correctness” and “defeasibility” of categorization practices to mislead audiences. (shrink)

The empirical study of visual space has centered on determining its geometry, whether it is a perspective projection, flat or curved, Euclidean or non-Euclidean, whereas the topology of space consists of those properties that remain invariant under stretching but not tearing. For that reason distance is a property not preserved in topological space whereas the property of spatial order is preserved. Specifically the topological properties of dimensionality, orientability, continuity, and connectivity define “real” space as studied by physics and (...) are the spatial properties that characterize the physical universe as being an integral whole. By contrast the geometrical analysis of VS has taken little cognizance of its topology. Instead such properties have been presupposed a priori rather than being established a posteriori by empirical means, perhaps because these properties are self-evident. Applying the method of coordinative definition expounded by Hans Reichenbach for determining geometrical and topological properties of physical space, it can be shown that VS fulfills the topological criteria of being a “real” space sui generis. Though theorized to be produced by the brain, the topology of VS is not topologically equivalent with the structure and activity of the brain because, as will be shown, the topology of VS cannot be formed from the topology of the brain without tearing and/or cutting and pasting. (shrink)

Visual space can be distinguished from physical space. The first is found in visual experience, while the second is defined independently of perception. Theorists have wondered about the relation between the two. Some investigators have concluded that visual space is non-Euclidean, and that it does not have a single metric structure. Here it is argued that visual space exhibits contraction in all three dimensions with increasing distance from the observer, that experienced features of this contraction (...) are not the same as would be the experience of a perspective projection onto a fronto-parallel plane, and that such contraction is consistent with size constancy. These properties of visual space are different from those that would be predicted if spatial perception resulted from the successful solution of the inverse problem. They are consistent with the notion that optical constraints have been internalized. More generally, they are also consistent with the notion that visual spatial structures bear a resemblance relation to physical spatial structures. This notion supports a type of representational relation that is distinct from mere causal correspondence. The reticence of some philosophers and psychologists to discuss the structure of phenomenal space is diagnosed in terms of the simple materialism and the functionalism of the 1970s and 1980s. (shrink)

In this paper, an in-depth study of interactive visual communication of network topology through non-line-of-sight congestion control algorithms is conducted to address the real-time routing problem of adapting to dynamic topologies, and a delay-constrained stochastic routing algorithm is proposed to enable packets to reach GB within the delay threshold in the absence of end-to-end delay information while improving network throughput and reducing network resource consumption. The algorithm requires each sending node to select an available relay set based on the (...) location of its neighbor nodes and channel state and computes transfer probabilities for each node in the relay set combining the remaining delay of the packet with the distance from the relay node to GB. Based on the obtained transfer probability and local channel state, the sending node passes the packet to the relay node. The convergence of the algorithm is proved and its performance is verified by simulation. The first part of the algorithm is based on the greedy algorithm to deploy and locate the network flying platform nodes with the goal of efficient coverage of the network flying platform nodes, considering the ground base station services. As the delay on each link varies due to the change of channel state, the source and relay nodes asynchronously update the data generation rate and the pairwise parameters based on the received local information and use the obtained optimal values to pass the packets to GB. (shrink)

Our visual system not only mediates information about the visual environment but is capable of generating pictures of nonexistent worlds: afterimages, illusions, phosphenes, etc. We are ''aware'' of these pictures just as we are aware of the images of natural, physical objects. This raises the question: is the neural correlate of consciousness (NCC) of such images the same as that of images of physical objects? Images of natural objects have some properties in common with afterimages (e.g., stability of (...) verticality) but there are also obvious differences (e.g., images maintain size constancy, whereas afterimages follow Emmert's Law: when seen while screens at different distances are observed, an afterimage looks larger, the greater the distance of the screen). The differences can be explained by differences in the retinal extent of images and afterimages, which favors the view that both have the same NCC. It seems reasonable to assume that before neural activity can produce awareness, all the computations necessary for a veridical representation of, e.g., an object, must be completed within the neural substrate and that information characteristic of a particular object must be available within the NCC. Given these assumptions, it can be shown that no retinotopic (in a strict sense) cortical areas can serve as the NCC, although some type of topographic representation is necessary. It seems also to be unlikely that neurons classified as cardinal cells alone can serve as NCC. (shrink)

TheConceptual Feature framework predicts that word meaning is represented within a high-dimensional semantic space bounded by weighted contributions of perceptual, affective, and encyclopedic information. The ACF, like latent semantic analysis, is amenable to distance metrics between any two words. We applied predictions of the ACF framework to abstract words using eyetracking via an adaptation of the classical “visual word paradigm”. Healthy adults selected the lexical item most related to a probe word in a 4-item written word array comprising (...) the target and three distractors. The relation between the probe and each of the four words was determined using the semantic distance metrics derived from ACF ratings. Eye movement data indicated that the word that was most semantically related to the probe received more and longer fixations relative to distractors. Importantly, in sets where participants did not provide an overt behavioral response, the fixation rates were nonetheless significantly higher for targets than distractors, closely resembling trials where an expected response was given. Furthermore, ACF ratings which are based on individual words predicted eye fixation metrics of probe-target similarity at least as well as latent semantic analysis ratings which are based on word co-occurrence. The results provide further validation of Euclidean distance metrics derived from ACF ratings as a measure of one facet of the semantic relatedness of abstract words and suggest that they represent a reasonable approximation of the organization of abstract conceptual space. The data are also compatible with the broad notion that multiple sources of information shape the organization of abstract concepts. While the adapted “VWP” is potentially a more metacognitive task than the classical visual world paradigm, we argue that it offers potential utility for studying abstract word comprehension. (shrink)

How does art – literature, visual art, or music – endure over time? What special power does it possess that enables it to “transcend” time – to overcome temporal distance and speak to us not just as evidence of times gone by, but as a living presence? The Renaissance, which discovered this transcendent power of art in the classical sculpture and literature it admired so strongly, concluded that great art is impervious to time – “timeless”, “immortal”, “eternal” – (...) a belief that left a profound impression on Renaissance culture and often found expression in its poetry. Subsequently the same belief exerted a powerful influence on Enlightenment aesthetics and, in various forms, it still lingers on today. The nineteenth century, however, saw a major challenge to this thinking. Hegel, Marx and Taine stressed the historical embeddedness of art and for these three thinkers, as for a series of more recent theorists such as Sartre, Benjamin, and Adorno, art belongs within the world of historical change. To locate its essential qualities in a “timeless” realm removed from the flow of history would be an idealist illusion. The conflict between these two positions has resulted in an impasse, and today we appear to lack any viable account of one of art’s key features – its capacity to transcend time. André Malraux proposes an entirely new account of this unique power of art. For Malraux, as this article explains, art is neither exempt from history (timeless) nor wholly inseparable from it. Art overcomes temporal distance – transcends time – through metamorphosis, a process of continual transformation in significance in which history plays an essential, but not exclusive, part. “La métamorphose,” Malraux writes, “est la vie même de l’œuvre d’art dans le temps, l’un de ses caractères spécifiques.” This proposition, to which contemporary aesthetics has so far paid very little attention, is a revolutionary step in our thinking about art. -/- . (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)