Desempeño ante condiciones críticas de ruido

It may be, however, that such cues are supplied by the allocentric coordinates of the visual percept. The reason for this is that, if this format encodes information about the relative positions of two or more objects, it may stipulate the rules about where to site picture primitives so that a consistent space is mapped

between distinct elements in the pictorial field. Furthermore, these rules would not be determined ex post facto by monitoring the look of a picture as it develops. Nor would they necessarily require that the artist was drawing from life so that the transient information of views was constantly available for reference. Since visual percepts facilitate recognition, presumably their output can be stored in and accessed through long-term memory, thus allaying (but not supplanting) the need for outwardly directed visual attention, whether this is of the picture itself, of other pictures, or of the look of real scenes. In short,

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This idea – and similarly Willats‟s discussion of the way a view is worked out from the emerging look of the picture – both owe a debt to Wollheim‟s argument about the dual role of the artist as both the producer and the initial beholder of the work. See „What the Spectator Sees‟, especially pp. 101 – 104.

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While Paul Smith argues that there is such a thing as a naturally generated pictorial „grammar‟ insofar as this relates to vision for perception, he claims that there is no such grammar relating to vision for action as it would be too fragmentary and too piecemeal to warrant this name. Personal correspondence, 24th August 2010.

allocentric coordinates might have an equivalent role to object-centred descriptions – they might allow the representation to develop in a non-arbitrary fashion according to rules which are innately supplied. However, while the latter would underpin the mapping of primitives with respect to a discrete shape or object, the former would give consistency to the intervening space. 193

But this also generates another set of questions, for if object-centred descriptions are identified with one frame of reference and allocentric coordinates are identified with another, then how should we say that they relate to one another? If children have not mastered the more „advanced‟ drawing

systems such as linear perspective – that is, if they have not yet learnt how to adjust their pictures to views and thus are mainly relying on formats which are more easily encoded in visual memory – will they abide by rules which transform object-centred descriptions or those which transform allocentric coordinates? Should we hypothesise that object-centred descriptions are more likely to underpin the mapping rules employed by younger children since, on the one hand, theirs tends to be a less globally coherent space and, on the other, these rules relate to a less developed phase of vision?194 Or should we simply say that

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Of course, it is difficult to say what counts as a discrete object either in a real view or in a represented scene. For Marr‟s comments on this subject see Vision, p. 270. Jacob and Jeannerod claim that for something to be considered a visual object it will necessarily be subject to both perceptual individuation (parsing and attribute binding) and conceptual classification (assigning to a stimulus class). Ways of Seeing, pp. 139 – 40.

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On the face of it, this might seem like a fairly tenuous suggestion for even if there were a correlation between the age of a child and the complexity of the transformational algorithms used in vision, then it would still seem likely that these capacities are developed well in advance of the ability to draw (given, for example, the relatively slow development of the motor skills required to produce meaningful pictures). And even then it might be argued that the computation of object-centred descriptions actually supervenes on the computation of locational coordinates. For instance, developmental studies indicate that the child‟s ability to track and individuate multiple objects by location (and thus, as Jacob and Jeannerod suggest, by coding in allocentric

coordinates) precedes its ability to do so by using featural information such as shape (and so potentially by coding in object-centred descriptions). See Fei Xu and Susan Carey, „Infants‟ metaphysics: the case of numerical identity‟, Cognitive Psychology, 30, no. 2 (April 1996), pp.

these two frames of reference are collapsed together in pictures as they are in normal seeing? In other words, if it is not possible to see a shape without seeing its location in a field, should we say that the material these coordinate systems proffer for transformation cannot be distinct and that, as a consequence, it cannot differently affect the appearance of pictures?

I pose these questions, not because I intend to answer them exhaustively – for this would warrant a thesis in its own right – but rather because I wish to make some brief suggestions which, while they are rather speculative in nature, at least have the merit of hinting at the work that is left to be done in this field. First, it is worth pointing out that since there is evidence for attention at multiple levels of spatial description,195 it may be that we are aware of these different frames of reference as they modulate perception. For instance, this tension in seeing might relate to the „object-horizon structure‟ that Merleau-Ponty describes. According to the philosopher:

It is necessary to put the surroundings in abeyance the better to see the object, and to lose in background what one gains in focal figure, because to look at an object is to plunge oneself into it…it comes to life and is

111 – 53 and Jacob and Jeannerod Ways of Seeing, pp. 191 – 94. However, as I intend to show later, there are still grounds for thinking that younger children‟s drawings are mapped from object-centred descriptions while only later do they use systems which derive from allocentric coordinates.

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For instance, Steven Tipper and Marlene Behrmann write that, „Increasing evidence…suggests that attention can operate on object- as well as on location-based

representations and that accessing one representation rather than another may be a function of the task demands‟ „Object-Centred Not Scene-Based Visual Neglect, Journal of Experimental Psychology, 22, no. 5 (1996), pp. 1261 – 1278. Presumably, „location based coordinates‟ can either refer to allocentric or egocentric frames of reference.

disclosed, while the other objects recede into the periphery and become dormant, while, however, not ceasing to be there.196

It may therefore be that things appear to gain volume (or shape constancy) when we focus upon them because, in narrowing our gaze, we reduce the range of allocentric coding – that is, the number of items that can be individuated concurrently – and allow object-centred descriptions to be retrieved more effectively. But this will also imply the reverse situation: if we attend to a wider segment of the visual field, then more objects will retain their identity while simultaneously appearing much flatter. In short, the power of allocentricity will be gained at the expense of volume perception and vice versa. Therefore if this idea has any purchase, then these two opposing pulls – the tension between single-object focus and panoramic sight – may account for the elastic phenomenology of visual attention. And indeed, if Merleau-Ponty is right in suggesting that the object-horizon structure is precisely „what guarantees the identity of the object‟197

then this play of forces may characterise the process of perception before it is rendered determinate by conceptual thought.

It is therefore plausible that the extraction of object-centred descriptions in semantic vision acts as a constancy mechanism which adjusts the appearance of objects in the direction of their true dimensions. And so, if seeing were wholly dependent on allocentric coordinates, then presumably space would be a pure function of the respective locations of objects and would not seem to come into definition under the attentions of our gaze. Of course, it is difficult (and perhaps

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Merleau-Ponty, Phenomenology of Perception, p. 78.

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futile) to imagine what this would actually look like, and yet it is interesting to consider pictures in precisely these terms, for these evidently do structure different kinds of visual space.

It might be, for instance, that images which generalise viewpoint while still being effective for the recognition of shape – such as this drawing of a locomotive in orthogonal projection (fig. L) or this Japanese illustration of the Genji Monogatar (The Perfumed Prince) in oblique projection (fig. 33) – form a loose correspondence to the allocentric frame of reference. The reason I suggest this is that each drawing system produces an arrangement that extends uniformly across the representational field without this being afforded its stability by a vanishing point. Therefore, on the one hand it would seem that the problems presented by mapping from object-centred descriptions have been avoided since there is no evidence of the disjunctures which might potentially arise from trying to make discretely perceived volumes agree. But equally, the integrity of these pictures cannot only be a function of their reliance on views, for space is isotropic between objects and their parts rather than radiating out from a particular point. In other words, the space is recursive and eo ipso cohesive.

Figure L. Drawing of a locomotive in orthogonal projection

Of course, if we say that the artist is positioned far enough away from the scene that the projection rays reaching the eye are parallel, it is possible for each picture to be derived from a view. However, this seems a fairly contrived way of looking at things, particularly in the case of The Perfumed Prince since, given its raised vantage point, the artist would have to be stationed somewhere high in the air. Evidently, this is not suggested by the size of the figures unless they had somehow been seen through a telephoto lens.

Furthermore, if we consider the relationship of these pictures to their contexts of reception and use, we may gain an insight into the kinds of function this scene-based arrangement can serve. As Willats notes, for instance, orthogonal projection offers a particular advantage to engineers and architects. This is because, by phasing out the distortions of viewpoint and depth, such pictures can give us accurate information about the shape of an object and (as Willats fails to acknowledge) about the relationship between its parts (or between it and other objects) insofar as they occupy the same plane in space.198 In contrast, the space constituted by oblique projection, while still arguably based on allocentric coordinates, structures a very different kind of viewing experience. As can be seen by looking at The Perfumed Prince, a sense of depth is preserved but unlike the convergence of linear perspective, it runs diagonally across the scene without diminution of scale. In this way, the artist creates a kind of self- contained world, which seems to carry on endlessly, irrespective of the beholder. Thus, as Rudolf Arnheim notes, this kind of „centreless continuum‟ is well suited

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to the Taoist and Zen philosophies of the East which stress, among other things, the equality and unity of man with nature.199

However, it might be more accurate to say that the drawing systems this coordinate system underpins are suitable for the purposes of religious depiction more broadly. This is because, by implying a station point which we know we cannot occupy, they effect a departure from realism which may at once safeguard against idolatry while also indicating the juncture between our world and a spiritual realm.200 For instance, the oblique projection implied by the table in Duccio‟s Last Supper (fig. 34) may help to emphasise the religious significance of the Eucharist by tipping the food up so that it is readily seen and by forging an unlikely, or otherworldly space. And moreover, since Christ occupies the crucial interstice between this system and the converging orthogonals which define the depth of the room, this may further underline his divinity by locating him at the most nodal and anomalous place.