Visual perception and rhythm
Produced by: Marcela Romero. In collaboration with: Inés Puparelli
Artículo en proceso de traducción
In order to make a good design work we must understand how the physical and cultural mechanisms that are put into play work when we visualize a graphic message. The word «rhythm» comes from the Greek term that means «to flow». Applied to typography, it can contribute to optimizing reading or to the good form (prägnanz) of the page.
When we visualize something it is because «our eyes have been spoken to», they have caused something to become visible within a certain environment, where there are many other things. In the environment there are two large areas that coexist in an indivisible manner, but which have different origins. One is the real world of things, objects and phenomena. There is no intention whatsoever in these things. The other is the area of messages and it is intention what makes it visible. This area is a cultural, not a natural construction.
Messages are organized, put together on the basis of an intangible structure, they relate to each other with a specific intention. The messages produced are information prepared to be understood by those to whom it is addressed.
How reality is perceived is based on an empirical substrate, on experience, while how messages are perceived is based on the cultural substrate and as such, it varies with age and with belonging to different cultures.
The signs in the real environment are indicators (signifiers) which can be «read» depending on the experience, there is no information in them, though they might be used to deduce things. These real signs are not images but representations of themselves. Images, instead, are representations, symbolic constructions, more or less real, more or less abstract, more or less codified.
Perceiving is actively seeing. It is an activity that can originate in two different ways. One is that in which the eye searches for something, in which the recipient acts as radar and it implies an intention in the person who watches. The other is that in which the eye is surprised by the message and the recipient is a target for that message. It does not look for but is looked by the message. Perception is the result of a combination of innate skills, maturation of the nervous system, and learning. The last one is more decisive in men that in other animals, as other animals are better equipped with innate skills and depend less on learning.
The difference in perception between a baby and an adult lies not in the visual system nor in the amount of information received, but in the ability to process visual information. This ability improves with practice and experience.
The development of perception begins with visualizing big differences until the differentiation of small subtleties is achieved. It is more of an intellectual problem than a strictly sensory, physical or neurological matter.
How do we see?
The eye is like a photographic camera with a sensitive surface, the retina, located at the back of a rounded ball and all the anterior part of the eye is an optic device that allows focusing the image on the retina.
Between the moment when the light beam impacts the retina and that when the image forms in the brain many milliseconds go by during which the light information received by the eye undergoes several successive treatments. The image formed at the back of each eye is nothing but the starting point of visual perception. Then it is codified in electrical impulses, which, when transmitted through the visual areas of the brain, are analyzed in terms of knowledge of forms, colors, movements, proportions, etc.
Visual exploration of space
The eye perceives by integration, suddenly and simultaneously, the complex shape of an object as a unitary whole.
The Gestalt theory maintains that shape is perceived by the subject immediately as wholes or collections, with a result that is greater than the sum of the parts. The relations, association, ordering or organization, are established in such a way so as to make the minimum possible perceptive effort.
This process is ruled by a law of prägnanz (German for good form) of the forms, where the «good forms» prevail as units (see the law of unitary perception).
Nature of Visual Perception
It is at the higher brain centers that reception and elaboration of sensations supplied by the senses take place.
These data, which are sometimes kept in our memory, are called images. Only the human being (thanks to its conceptual and abstract intelligence) is capable of relating them with an external object or stimuli. These are the psychic processes that constitute the essence of perception. Such operations transform sensory impression into cognitive image (which may be used). When the eye sees a group of letters, it is the brain that perceives words. Those words will make sense to the person who knows the language in which they are written. In turn, somebody trained, with experience, will «see» certain formal features in those letters and the acquired knowledge will let him place them within a certain style or historic period.
We may conclude that we «see» with the brain, the eye only transmits nervous impulses. In the process of perception, the subject, guided by his experience and expectations, values certain features, especially significant ones, ignoring others which he considers irrelevant. Thus, visual perception looks for the meaning of stimuli by attaching recognition to «unchangeable patterns» (i.e. genre or model, for instance: P letters), from which they may then recognize their «circumstantial variables» (or, to put it in other words, peculiarities, for instance: a “P” form the Rosario family —first one from the left—).
As a conclusion, the phenomena that define perception are:
- Identification, or perceptual recognition of the stimuli: the observer assimilates the stimuli by associating it to other known types, produced in his prior experience.
- Differentiation: the subject discovers in the stimuli those peculiarities that make it similar or different from others.
Optic, geometric and organic aspects
Our sensory perception, both optic and aesthetic is much more complex than the geometric construction, and it is to it that we must resort when looking for balance between what’s white and what’s black and between forms.
A task that seems «right» to the eye, can not be geometrically constructed, instead perception requires that certain «corrections» be made to the geometry so as to avoid optic illusions, as the saying goes «it has to be built by rough estimate».
In order for us to perform this task we have to train our perception and become sensible. For this, we must consider that:
- A geometric square is perceived as wider than higher. Likewise, a geometric circle is perceived as wider than higher. An «optic square and an optic circle» should be built slightly higher than wider so that they may «look» square and circular.
- In a figure transversally divided in two halves, the lower part looks smaller than the upper one. In order to make them equal it is necessary to move the division slightly upwards.
3 If two stripes of the same width are taken and one is set in horizontal position and the other in vertical position, the first one will look wider than the second. For them to look the same one of them should be corrected.
4 The eye tends to simplify the data that really exists in a figure, it selects those that will be perceived. Thus, for instance, it tends to round sharp points, angles, eliminating its apexes.
5 A circle and an equilateral triangle built with equal diameter and height will look smaller than a square when put next to it.
These optic corrections have to be used to adjust figures so that they can be perceived as «correctly built or equal in size or weight».
From now on the right thing to do is to train the eye, the brain and the hand so that they may serve as measurement tools, making a sensible construction of figures and spaces, trusting what we perceive, and not measurements or geometric forms.
Notion of good form (prägnanz): Good form (Wertheimer) is the strength of the form. It is the dictatorship that the form exerts over ocular movement, as well as its ability to impose itself as a mental image and in memory.
Principle of topological invariance: A form resists the deformation to which it is submitted. This resistance exists as long as the form is a good form.
Principle of masking: A form resists the different disturbances to which it is submitted. The better the form, the more resistant it will be.
Birkhoff’s principle: The more symmetric axis a figure has (regularity, stability) the better the figure will be.
Principle of proximity: The elements in the perceptual field which are isolated, but are neighbors, tend to be considered as collective or totality.
Principle of similarity: In a field of equidistant elements, those that are more similar in form, size or direction, are perceived as related to each other to form a chain or homogenous group.
Principle of memory: Forms are much better perceived when they are more frequently presented.
Principle of hierarchy: A complex form will be a better one when the perception is better oriented by the designer, taking the eye of the recipient from main to accessory. That is to say, when its parts are better hierarchically organized.
Laws that govern unitary or synthetic perception
Principle of totality: The whole is different and greater than the sum of the parts.
Principle of structure: A form is perceived as a whole, regardless of the nature of the parts that constitute it.
Law of dialectics: Every form takes a prominent role over the background on which it is placed. The gaze decides which element of the visual field belongs alternatively to the form or to the background.
Principle of contrast: A form is better perceived as long as a greater contrast is established between it and its background. (It is the principle of «the good form»).
Law of complementation: If a contour is not completely closed, the mind tends to continue or to complete it with the elements that are easier to fit in the form or that are somehow induced by it.
Law of simplicity: In a given graphics field the less complex figures have better form. A simple figure is that which needs less graphemes to create it: less straight line segments, less curves, less angles, less intersections, less changes in direction.
Law of closure: A form will be better as long as its contour is better closed. In effect a form should go back to itself, otherwise it lets the potential form escape through that provoked opening.
Law of continuity: Elements which develop along an axis become good forms.
Law of symmetry: (called of symmetry, of balance, and of inclusion): Elements which organize themselves around a central point, their nucleus, become a good form.
Principle of contour: Those figures with a form that has a greater contrast over the ground are grouped and associated by perception, and are good forms.
Principle of coordinated movement: The different elements that take part in a same movement constitute a good form.
Principle of common fate: A curved lined is conceived as a fragment of a circumference and as a fragment of a line. This principle is related to the stroboscopic effect on which «closure» is based. If visual stimuli follow one another quickly but separately, the image seems to be moving.
«It is worth mentioning once again that in the joint origin of writing and art there was rhythm, the regular stroke, the simple punctuation of non-significant and repeated incisions. the signs (empty) were rhythms and not forms. What is abstract in its origin is a graphism, writing in its origin is art.» Barthes, Roland. Ensayo en La escritura y la etimología del mundo / R. Campa, Editorial Sudamericana.
There is rhythm in heartbeat and in the way we walk, in how living beings grow and in every form in which nature manifests itself. Then it is not surprising that it is a constant in every human activity.
Rhythm is essentially repetition and structure, (separates order from chaos). In order to define it we need more than one element, at least one repeated pulse and pause. It may be a simple pulse, where all the elements are equal and uniformly distributed, or complex, with intervals of different duration and elements of different characteristics, but which also repeats itself.
Though «rhythm» is a word usually related to auditory perception, it is also a determinant within visual perception. Rhythm as regards visual has its most elementary manifestation in the repetition at constant intervals of a same design, thus conforming a texture or «pattern».
Typography as a visual discipline is also closely related to it. In a simple line of text we find that the interletter space constitutes regular «blanks» which, at the same time, interact with larger spaces (or silences) that obey to the interword space. Lines of words, separated from each other, are also rhythmically related. The result of the whole depends on the harmony of this set. If this rhythm is constant, relatively regular, the block of text will be of a homogenous grey.
The rhythm may become more complex without loosing the structure that makes it distinguishable. The use of signs of different morphological characteristics and sizes also modifies it. In typographic work it constitutes an element which is essential to master, because it is the net that contains the layout of the page, the design of a sign, or as we said, the composition of text.
This entry is also available in: Spanish
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