SPACE PERCEPTION -through seeing, hearing and touching

Post 630 –by Gautam Shah

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Space perception is realization based on three faculties of Perceptions, namely seeing, hearing and touching. First two of these are bi-nodal, and allow us to perceive an extra dimension of the space, whereas touch is multi-focal, but operates as local sense. The information is received through spatially separated sensors, but complex neural integration allows the three to be perceived in mutually balancing experience. Absence or deficiencies of one or few are substantially overcome through such assimilation. These sensorial experiences (seeing, hearing and touch) persist in a space for a while, and so prolong and reinforce the experience. The experience persists, when the main happening is active, through the fading period, and after the expiry of the original causation.

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Earth Sphere, Science city, Kolkata > Wikipedia image by Biswarup Ganguly

Space perception is a process of becoming aware of the relative positions of the own-self, surrounding objects, and environmental effects. Sense of near-far, distance, orientation, datum, are part of space perception. Space perception of objects in movement and changes in the environment offer cues to direction and rate of change. Space perception occurs naturally and virtually. It occurs substantially through making-up by the past remembrances. And so though it is substantially predictive, surprises, deviations and deceptions do occur.

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Rainy Day Boston > Visual depth and dimensions of perception > Wikipedia > ART by Childe Hassam (1859-1935)

Space perception offers dimension, orientation and direction to the space. The dimensions are perceived in terms of body sizes and capacities. Orientation suggests the position of the causation in front, back, up, below, or sideways. “The horizontal, vertical, and sagittal planes divide space into various sectors: something is perceived as ‘above’ or ‘below’ (the horizontal plane), as ‘in front of’ or ‘behind’ (the vertical plane), or as ‘to the right’ or ‘to the left’ (of the sagittal plane). The Horizontal and Vertical have universal justification of the gravity, reinforced by the fluid levels. But it is the sagittal plane or the sense of left and right, which is self centred.

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Elgin Cathedral ruins Scotland > Pixabay image by misterfarmer Deutschland

The depth in space is a perceived notion. Visually it is sensed by the stereophonic vision and fading over (only larger) the distance. Depth is perceived by scaling in scenic perspective. Visual depth perception is also a process of learning. Seafarers, aircraft pilots, mountaineers, desert travelers have extraordinary sense of space distances. Similarly architects, embroiders, watch repairers have coordinated visual and touch depth perception.

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Woman carrying head load looks as big as the tree due to absence of foreground-backgroud clues > Wikipedia image

Aural perception of space dimension, orientation and direction operate differently. The two ears create stereophonic effect for richness of sound, but unlike vision do not lead to distinct direction or orientation of the space perception. The sense of the dimension, though is more accurate, as sound fades remarkably strongly even in the shorter depth. Aural perception has more deviations and deceptions. Depth or distance perception is due to the loudness and pitch, both affect little late (sound of lightening), but reinforce the information offered through the visual perception. Changes in pitch ( Doppler effect) of a moving object, defines the depth.

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Pipe organs are conceived in terms of the space, sound and visual placement > Taiwan National concert hall at Taipei > Wikipedia image by : Alton Thompson

Touch perception of objects is governed by recognition of the edges or remarkable intermittent features. Touch perception is texture recognition combined with energy transmission (temperature, electrical, magnetic, vibrations etc.). These operate at touching or very close distance, but are highly variable. The perceiver and the perceived (object or an organism) both exchange the energies to form the perception. The touch perception plays very little role in perception of spatial dimensions in spite of transiting between edge to edge, or other features of the surface.

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Streograms are stereophonic image or animations that combine Left and Right frames showing slightly different visual angles to form 3D perception

Clarity and Consistency of visual perception are very important features of experience. It is accepted that visual clarity depends on the distance, quality (angle, strength, contrast, colour) of illumination and physiological condition of the perceiver. Beyond these obvious parameters other factors are foreground-background, glare, framing of the view, other distractions. Consistency of visual sensation derives from field size, movement of the perceiver and within the scene, distractions, aberrations. Clarity and consistency, together depend on subjective aspects, such as the intent and duration of the perception.

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Audio perception (and expression) when accompanied by Visual perception, mutually reinforce each other > Wikipedia image

Clarity and Consistency of aural perception occur in terms of the echoes, reverberation, presence-absence of background noise. It also depends on the dominant range of operative frequencies. Clarity is affected when one cannot decode a scrambled or garbled noise. This happens in large halls and open layout offices, where one subconsciously cannot decipher the message, and tries to interpret it. To reduce such irritations, ‘white-sounds’ -a background or masking noise are added to the space. Hospital rooms and commercial spaces with round the clock operations pose different aural profiles at different times of the day-night, ‘white sounds’ reduce such variations. Consistency of level and quality of sounds allows one to ‘fathom’ a space more effectively.

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Tactile Floors for Nagoya-daigaku Subway platform > Wikipedia image by LERK

Clarity and Consistency in touch perception are important in space perception, so far these are demarcations of space zones. For persons with imperfect perceptive capacities (blind, deaf, old age, infants, sick) touch becomes an important faculty to reinforce the space extent. The consistency of touch is governed by duration and use of limbs that show better reception to touch.

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Polyphemus, the one eyed mythological character was supposed to be an Iron Smith and used the one-eye vision for work accuracy > art by Johann Heinrich Wilhelm Tischbein 1802

 Peter Zumthor outlines (Atmospheres, p. 29) that, ‘Interiors are like large instruments, collecting sound, amplifying it, transmitting it elsewhere. That has to do with the shape peculiar to each room and with the surface of materials they contain, and the way those materials have been applied.’

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VISUAL PERCEPTION of MOVEMENTS

Post 395 — by Gautam Shah 

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visual movement

There are many other conditions where movement is perceived to have occurred, but in reality no change may have happened.

1. When there are changes in the object itself.

The process of apparent visual motion was realized when several pages with slight and progressive alterations were flapped, to experience the movement. Later a devices called zoetrope provided animated images ( zoetrope, -from Greek words, where zoe =life and tropos =turning). The Phenakistoscope (or phenakistiscope or phenakitiscope) was an image animation device that used a spinning disk of sequential images. The visual motion was also realized when two images shot at slightly distanced points, and seen through a ‘view master (1940). It created a stereoscopic 3-D image. A stereoscopic range finder uses two eyepieces and relies on the operator’s visual cortex to merge the two images into a single picture.

The horse in motion

Phenakistoscope Dance sequence

St George St St Augustine Florida stereoscopic view

coincidence rangefinder US Army

2. When the environment causes changes over an object.

Environmental factors such as light, air, etc. affect the visual perception of movements. Changes in illumination level, angle and colour are important aids for perception of motion. People do not perceive very slow movements such as shadows of sunlight or increasing-decreasing of brightness through a day. Such movements are however, inferred by remembering the previous condition. At a very high rate of change in illumination, the perception of an object becomes difficult. On a performance stage illumination level, angle and colour are continuously varied to reinforce the movement in dances. In a cinema the movement is enhanced by showing the moving object along with the moving shadows.

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Decorative series of lights are stationary or fixed to buildings, but due to their going off in a sequence for few seconds, creates an impression of movement. This movement is more enhanced when same series of lighting are fixed on merry-go-rounds like entertainment rides. In Indian cinema songs, and night clubs at other places, enhance the dancers’ movement by strobe lights.

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3. When the context such as background and foreground change one begins to perceive the change or movement. We register changes in things in some context. The context is provided by the familiar objects on the scene, by objects that remain consistent within the nominal field of vision, and by the object in the background that usually show lesser changes. A thing that is receding steadily and slowly, along a visual axial seems less changing, compared with a thing moving at slightly an angular axis. A luminous and stationary object, shrinking in size, seems receding.

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Foreground Background contrast Gustave Caillebotte Paris Street Rainy Day 1877

Background and foreground perception is a not a major problem for human eyes, as these can continuously and rapidly shift from one to another. But the same process in a Camera takes time for resetting by manual or automatic process. A far object can become dulled while attending a foreground entity. The differences, of visual and camera perception of foreground and background objects, are being solved on several fronts. In one process a camera lens is simulated as multiple eyes entity, that individual captures the scene, which ultimately are merged or morphed to form a composite image. In another feature the lens is endowed with scanning capacity of the eye that creates a composite image.

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421 BALANCE and MOVEMENT

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PERCEPTION of MOVEMENTS

 

Post 298 –by Gautam Shah

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We perceive movements in many different conditions and context. By perception of movements we understand the direction and speed of elements in a situation. Perception of movement is basically a visual process but other sensory faculties aid it. We use our eyes to perceive things aided by movement of eyeballs, eyes, facial and body movement and shift. We also use flickering -fast closing-opening of eyelids to perceive the movement. We use mental process of recollection to judge, if there was any change in comparison to a past event. Movements are perceived in reference to something, a context.

Perception of different speeds of movement in back and foreground

We perceive movements of physical objects, metaphysical entities or effects, and of our own body. Perception of movement is also accompanied by other responses, such as facial and body realignment or orientation, heightened perception of the same happening by other sensorial faculties, and movement of the self towards or away from the object in motion.

Wagon wheel effect -referential movement perception

The perceptions of movement modalities are different in various beings. The eyes of lower animals respond selectively to what is of important for survival. The retina does not carry out much processing. The condition with higher animals is more complex, the brain responds with sets of movement-detector cells for each direction across the field of view. Human visual experience is constructed by movement detectors that exist in the brain. Each of the retinas has a central zone for perceiving colour and pattern, and a peripheral zone for catching general characteristics of the adjunct visual field. The outer section, on sensing a motion activates (by slight shifting) the core part to take cognizance of it.

Zones of perception in Retina

There are many different conditions where we observe motion. Simplest perception is of moving object within nominal field of view against static field. A slightly more composite scene is where several objects are moving, each at different speed and direction, and one is able to deduce a general flow and its speed.

Billboards and other electronic signs use apparent motion to simulate moving text by flashing lights on and off as if the text is moving.

When a person in a stationary train observes, through a window (a field that cuts off surroundings) another train, start moving, one feels own train in motion. The observer and the object both moving in same direction (e.g. two trains) may seem to be a non or very slow moving, whereas when moving in opposite directions the apparent speed is enhanced.

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People often report that an isolated point of light in a dark room is moving, when it is not. Similar situations arise when we observe movement without a static frame reference, such as watching a star through a telescope, where a star seems to be moving. When a rotating electric fan is illuminated by a flashing light source (called a stroboscope) At certain speed the fan blades seem to be non-moving. An illuminated size reducing object in a dark background seems receding.

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A movement effect is created by serially blinking lights (of decoration) that give manifestation of movement. When we watch a movie, we are perceiving motion instead of static images due to blinking of eye or image refreshing rates.

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While walking up a curved street in spite of very keen observation, one may not find it familiar, when walking down the same street, because the convex and concave curvilinear natures give different sense of direction and apparent sense of speed.

Curvilinear road -convex – concave movements and perception

Camera capturing a street view at faster speed, creates a visual abhorrence or anomaly. Similarly motion can be captured by moving a camera closer to the object, moving the object closer to the camera, and by varying the focus of the lense. In each case the perception as projected is different.

Movement blurring in camera -unlikely with eyes

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