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2 - Scanning and collection of information from the environment

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«We cannot live or think
except in fragments of time
each of which goes off along its own trajectory
and immediately disappears» 1.

  The first act of reading is connected to the perception of the text, something similar, from some points of view, to the perception of an object. The difference, one could argue, lies in the fact that the perception of a physical table is more immediate than that of the word "table", for example. In the former case, the perceived object is not interpreted, but simply assimilated, because an object is what it is; in the latter case, on the contrary, to the word "table" can be linked, in each of us, different mental materials, different interpretants, consequently the perception of a word is an interpretive act.
  But in semiotics a table is a sign as well, not simply an object: the perception of a given table by a given person produces an interpretive chain of mental events, there is an analogous perception of the word "table". Also to the table, as an object, and to its image, are linked meanings of cultural and subjective types, as happens with verbal signs. The table is a sign then, though a non-verbal sign: it belongs to another code or, better, to many other codes, and it has a different meaning according to the cultural background in which it is inserted.
  Or - we might express the same notion in other terms - we could also say that when we perceive objects, or persons, we read. Calvino writes:

Ludmilla, now you are being read. Your body is being subjected to a systematic reading, through channels of tactile information, visual, olfactory, and not without some intervention of the taste buds. Hearing also has its role, alert to your gasps and your trills [...] and all the signs that are on the frontier between you and usage and habits and memory and prehistory and fashion, all codes, all the poor alphabets by which one human being believes at certain moments that he is reading [...] 2.

The perception of any object - in the broad sense of the word - is just an inference we make, completing sensorial data with our knowledge and expectations.
  We will take a closer look at the question of text perception starting from generic perception, particularly from an activity called scanning, which interests us as a tool for the collection of surrounding information. We are used to connecting the verb "scan" to the electronic scanner, but in its other, perceptive meaning, the verb was used for many years before the existence of scanning devices. The two notions share many common points: we scan our environment and receive perceptions about objects and about words. But the scanner connected to our PC also works this way - although it is much less specialized - and, if you wish, it can recognize characters as well as it reproduces images.
  Scanning activity consists in observing parts of a sequence in succession, i.e. not simultaneously. As J. J. Gibson states in The Senses Considered as Perceptual Systems, even in the case of non-verbal signs a person is nonetheless looking for a meaning:

[...] the human individual can visually scan a picture for its design, but what he is generally in search of is meaning. The esthete may practice discrimination and enjoy the structure of a painting or the composition of music, but this is a sort of perceptual luxury 3.

In fact, man looks for a meaning in the objects that surround him, and this is the main function of perception, from a pragmatic point of view. The "perceptual luxury", or perceptual hypersensitivity, of the esthete, of the literary critic, of the translator will be the subject of other parts of the course, when dealing with the question of the interpretation of literary texts. Now we are interested in pure perception. Perception is characterized by economicity and efficiency as are the other functions that have been selected on the basis of the Darwinian principle of the survival of the fittest over the course of biological history.
  When we read, apparently we get a series of successive optical stimuli, not a simultaneous view: such is the ingenuous sensation we get when, more generally, we look around the world 4. Since the minimal meaningful result of having read is to get a whole view (of a word or of an utterance), and not a mere succession of graphic signs, intuitively one could infer the existence of a sort of buffer memory or short-term memory allowing to create a sort of mental synchronic "picture" of the single perceptions dispersed along time. Not an absurd hypothesis: many perception psychologists thought this way before 1966.
  But some experiments reported by Gibson lean toward thinking of perception as spanning both kinds of order, spatial and temporal; through it, one can single out not only little fragments, but complete invariant elements. The initial perception provides an approximate distinction between "same" and "different". Perceived sequences already contain the whole scene, so that it is not necessary to use notions such as buffer memory or short-term memory - like they did before Gibson - because the sequences are converted within the perception of the whole (word, utterance, text, in our case) 5.
  We can, in fact, perceive a written utterance, recognize it, even if we have never seen it in the given graphic form, or even if the utterance is not complete, if there is a coffee stain on the page or printing is not perfect. This is because the whole of our retino-neuro-muscular system is attuned on invariant information and can perceive it, thanks to the locomotion of sense organs (i.e., in our case, above all to the repeated movements of the eye), which determines an overlapping stimulation.
  In other words, we perceive the same objects more than once - the same words or sentences - because our eye runs up and down, right and left, without our being aware of these "replays", until we get a perceptual view we consider complete and satisfying. If perception were a series of successive stimuli, as the theory before Gibson went, we would perceive the words or sentences more than once that our eye scans repeatedly, but this is not true. Simple perception already provides us with the complete view of the utterance, without having to explain it with a buffer memory made of engrams or mnemonic traces.
  The memory notion has a role, though, not as far as single perceptual acts are concerned, but in perception repeated over time. The invariants an individual can make out on a first encounter are more approximate than the invariants she can isolate after repeated readings:

[...] an observer learns with practice to isolate more subtle invariants during transformation and to establish more exactly the permanent features of an array 6.

This leads us to say that the perceptual system distinguishes the known objects from new objects. Thanks to memory, the individual can create a diachronic series of the perceptions of objects (or utterances) that are apparently the same and, after a while, learn to make subtler, more refined distinctions.
  In the next unit, we will face these problems, passing from the question of scanning of our environs to the question of information collection.

  

Bibliographical references

CALVINO I. If on a Winter's Night a Traveller, translated by William Weaver, London, Vintage, 1998, ISBN 0-7493-9923-6.

GIBSON J. J. The Senses Considered as Perceptual Systems, Westport (Connecticut), Greenwood Press, 1983, ISBN 0-313-23961-4. First edition: 1966.


1 Calvino 1998, p. 8.
2 Calvino 1998, p. 155.
3 Gibson 1983, p. 250.
4 Gibson 1983, p. 251.
5 Gibson 1983, p. 262.
6 Gibson 1983, p. 265.
 



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