kinds of Memory Storage
1. Sensory information store - very short term, fractions of
a second (afterimage), information held is not processed or interpreted
(its not needed)
sensory = visual representation, touch,
2. Short term memory = identifies
object features such as colour
3. Long term memory = generated
The three systems are not localised or isolated but
they do have
- different systems of operation
- different representations
identifies a series of factors which influence this connection between
eye and brain.
- Seeing - the processes by which
we see the world and the connections, through the neural net, that we
use to make sense of it
- Light - we need light to see,
and we see in colour! The eye is sensitive to light.
- The eyes - two eyes work in co-operation
(stereo vision) and as range finders.
- The brain (the only lump of matter
we know from the inside) processes the information gathered through
our eyes and is complex and mysterious. Concerned with thinking, memory,
and sensation (not only visual stimulus but all five senses).
- Seeing brightness - the effects
of intensity (measurable physical energy) and brightness (an experience).
Linked with seeing colour, brightness is associated with hue and thus
with the emotional experience of colour.
- Seeing movement - on the edge
of the retina only movement is registered so we see things moving peripherally,
without being able to identify them as an object. Without being able
to identify movement, we would be unable to detect either danger or
food! Our perception of movement is enhanced as not only does the world
move but our eyes can also move. The two movements work in conjunction
with each other.
- Seeing colour - an off shoot
of visual perception, colour affects our emotions and our visual aesthetics.
With an extraordinary variety of theories, the study of colour began
with Newton’s Opticks written in 1692, destroyed in a
fire and not published until 1704, his last book instead of his first.
Theory of Illusions
When perception ‘goes
wrong’ we have an illusion of reality. This can happen in many ways,
and very sometimes very dramatically! Illusions happen in four main ways:
- drug induced states (altered
states of reality)
- mental illness (hallucinations)
- Hallucinations and Dreams
- very similar - visual or auditory (but can involve other senses: touch,
socially determined (witnesses of events which never occur)
Two ways of viewing hallucinations:
people who have insights into another world of reality and truth (supra
physical reality) where the brain gets in the way of understanding (see
Aldous Huxley Doors of Perception - the complete text is
- Empirical Philosophers:
people who consider hallucinations as abnormal outputs of the brain
(not to be trusted)
Definition of hallucination:
Spontaneous activity of the nervous system when unchecked by
What we know about
the brain's auto stimulation (situations where hallucinations
may take place):
Premise: The brain is continually active (as it is in
sleep and dreaming).
- Brain Tumours
and Epileptic seizures may cause hallucinations of
- SENSORY DEPRIVATION
- the active brain runs wild and hallucinates (terrifying and dangerous
or irritating and amusing)
- Possibly in SCHIZOPHRENIA
when the outside world makes little contact with the individual
- In normal life,
when isolation and lack of stimulation, such as when operating automatic
- In outer space
(don’t go there alone!)
(Gregory clearly stated that
he has no evidence to support the mystic viewpoint but does recognise
that uncontrolled brain activity could indicate something of hidden motives
which Disturb (Distortions)
forms can disturb
suggests that the visual system is upset by redundancy of patterns
(when there is nothing apparently there).
at the pictures above for a while and wavy lines appear (similar
to when you look at a blank wall where an imprint appears). It may
be that the eye movements searching over the image create massive
on/off signals, rather like a flickering light.
thing happens with parallel lines [on the right]
and ‘fields’ of dots (striped or spotted wallpaper to
it has a purpose.......(See Marr's
Almost everyone sees these distortions, including animals.
Muller-Lyer’s arrow illusion where
a part of the figure appears longer/shorter, and of a different
size even though when measured, the lines are identical in length
Ponzo, or railway line illusion where one circle looks
larger than the other
Horizontal/Vertical Illusion the upright line looks longer
than the base line it stands one, even though they are the same
Illusion - The centre circles look different sizes
Lyer arrows still work, even without the vertical bars.
do these illusions work then?
- Our eyes move -
neat theory but rejected, you just have to watch someone looking to
see their eyes don't move.
theory - not reliable enough
- Empathy theory
- viewer is emotionally involved by associating with the figure, thus
causing distortion, much as emotions confuse thinking e.g. the arrows
suggest expansion, which is what we see. Not true, because we experience
the distortions whatever our mood, and we all see the distortions, and
can have many moods.
(the gestalt of the figure) similar to the idea of a ‘pregnant
silence’ the figures are loaded with meaning.
- Perspective (a
strong history to this one). Flatten versions of the experience of the
three dimensional world. It about distance: the parts of the figure
which represent distant objects are enlarged, those representing nearer
objects are reduced (it’s the corner of a building, or the corner
of a room).
Plausible, but not completely water tight as if you change the view
(ie the arrows become a steeple jack’s view of a roof) the illusion
- Why should distance
(and depth) change size?
- Why should distance
make things appear bigger when we know that things further away
Perspective is the best theory we have to date, and is worth following
up (as Gregory does in detail)
SIZE CONSTANCY - A TENDENCY
TO CHANGE VIEWING DISTANCES.
AN IMAGE DOUBLES IN SIZE WHENEVER
ITS DISTANCE IS HALVED. The brain compensates for this.
A test - look
at your hands, placed at arms length, draw one hand closer to you by bending
your elbow - the hands continue to look the same size, even though the
furthest away hand is half the linear size.
Now let the nearer hand overlap the other and you will see the difference
in size - the hand nearest to you covers the other hand........ even though
you know they haven't change size, just their position.
(This was first identified by DESCARTES)
But this is ok in reality,
but we are looking at a piece of paper or a book (or in your case we are
looking at wall, at projected image which could be a canvas or a image
on a screen - the cinema or TV. A flat image.
Many of the tests carried
out by psychologists involved darkened rooms with phlorescent strings
or wires, which converge to given perceptual rules of change. Since the
Rennaisance, experiments with measurements, string grids, and marking
out perceptual space have taken place. Details of these empricial science
experiements are multiple and deserve further exploration, but not here
Theory of Size Constancy
Living in a Western ‘squared’
world, full of rooms with corners, and railway lines. We 'read'
reality, with perspective.
In other cultures, the
world is often experienced as rounded or circular, in houses (huts),
with land ploughed in curves. (East/Western perspectives) diamorphic
perspective and a series of cultural traditions.
Near and far
can be perceived differently: aborigines, forest dwellers, ice snow,
Perspectival clues are important
only after considerable experience of perspective clues in photographs,
and the flattened world of the visual image. So much so, that it could
be claimed that our world is more clearly perceived through the flat experience
- through illusion, not reality. Hardly surprising then that the children’s
drawings create a world of imagination, of play, on paper that is
real, until the age of logic and visual reality, of perspective and illusion
takes over as representing the real.
It could be said that it is
the role of the artist to begin re-entry into the area of play between
the real world and the reality of representation of the real.
Its worth remembering that
it is not until the age of the Renaissance (and the birth of Science)
did the artist/scientist discover the laws and rules of perspective. Previously,
much older systems of representation gave very different views of the
world. (See Dubery, Fred
and Willats, John (1972) Drawing Systems Studio Vista
(Margaret Street Library 741.2/Dub)
List - Gestalt -