The sensing and perceptive spirit: which developments took place in this area in the period between Kant and the Gestalt psychologists? - Chapter 4

The German philosopher Immanuel Kant (1724-1804) became known because of what he called 'my dogmatic slumbers'. He was trained in the Leibnizian tradition and had written before on subjects such as the origin of God and the difference between absolute and relative space. He was stimulated by one of John Locke's successors to start thinking about 'critical philosophy’, which ultimately led to subtle but crucial changes in how Germany, until then, thought about humanity and nature.

What is Kant's background?

It was the Scotsman David Hume who caused Kant to become inspired to bring empiricism and associationism to an extreme. In addition, he started the logical status of the causal connection (the intuitive belief that certain events are directly 'caused' by certain other prior events).

They started from a cause, which implied a necessary consecutive relationship between certain preconditions and subsequent events. It also suggests that when we observe events, we immediately attribute causality to them. Hume brought this assumption, however, in doubt. He states that 'causality' is nothing more than that we expect events that took place in a certain way in the past, will occur in the same way in the future. The supposed connection between the events is never directly observed, so causality only has a probable rather than an absolute base. 

From a practical point of view, these considerations make no difference. People thrive best in the real world by anticipating regularities in nature, whether or not this causality is genuine or assumed. For a philosopher like Kant, who dealt with the essential nature of human knowledge, this matter was crucial. Kant responded to this challenge with a simple but revolutionary variant of the nativist argument. He argued that even though causality could not be proven to exist in the external world, it nevertheless seemed to be an inevitable part of our experience. Therefore, according to him, it will be an innate quality in our minds. 

He assumed two separate domains of reality, one complete within the human mind and one complete out there. The external or noumenal world consists of things-in-itself: objects in a pure state of independence of human experience. Despite that assuming that a certain object exists and that it interacts with the human mind, the noumenal world can never directly being seen. When this object encounters the human spirit, said spirit transforms the object into the inner or phenomenal world. The term phenomenal comes from the Greek phainomenon, meaning 'appearance', and reflects Kant’s argument that people never directly experience the true reality of things-in-themselves. Instead they experience a number of 'apparitions' or 'phenomena', which are the creation of an active mind who experiences the noumenal world.

To create this phenomenal world, the Kantian spirit inevitably follows a certain amount of own rules. In this way, the mind localizes the phenomenon in space and time,  dimensions which Kant called intuitions. In addition, Kant stated that the mind automatically organizes phenomena into twelve categories, based on their quality, quantity, relationships and manner. Among these categories of relationships, there is also the concept of causality. Thus, human beings inevitably experience the world as organized in time and space, and as active according to causal laws. This does not happen because the noumenal world is necessary or 'real', but because the mind can do nothing else than to structure the phenomenal experience in this way. The consequences of his critical philosophy, Kant described in a series of books between 1781 and 1798, starting with the 'Critique of Pure Reason' and concluding with 'Anthropology from a Pragmatic Point of View'

Ironically, Kant emphasized the importance of studying the organization of the mind, but at the same time he also claimed that this study could never be a real science like for instance physics is. Kant assumed that mental phenomena, in contrast to the physical objects that are examined by physiological scientists, (1) have no spatial dimension, (2) are too fleeting to hold onto for persistent observation, (3) cannot be experimentally manipulated and, possibly most important of all, (4) cannot be arithmetically described or analysed. For these reasons, Kant always thought that psychology was a philosophical rather than a scientific discipline.

In the century after Kant, there were still a number of scientists who did seriously study the human sensory processes, focusing on many situations where conscious experience clearly differs from the objective external stimuli that lead to the experience. In the footsteps of Kant's philosophy, these changes seemed to be interpretable as the effects of an active, creative mediator. The simplest and most natural of these situations are optical illusions, in which one's conscious impression of a visual stimulus is clearly different from the 'objective' characteristics of the stimulus. Discovered in a similar line of research, neurophysiologists demanded a law of specific nervous energies early in the nineteenth century. This law states that every sensory nerve in the body transmits only one kind of sensation. This was first proposed by Charles Bell (1774-1842), and further elaborated in 1830 by John Müller (1801-1858). 

A simple experiment shows the visual specificity of the optic nerve, which is led to the brain from the retina in the back of the eye. With normal vision, the optic nerve is stimulated by photochemical reactions of light on the retina and brings signals to the brain that result in conscious visual sensations of light. If you, however, have your eyes turn to the right, as far as you can, close your eyes, and gently push on the left side of you left eye ball, you see a coloured light on the right side of your visual field. You have your retina stimulated and thus the optic nerve with tactile pressure instead of the normal light rays, but the effect is still visual. You have literally seen the pressure on your eyeball because the optical nerve can only transmit visual sensations. The same specificity also applies to the other sensory nerves. Furthermore, scientists increasingly see the usefulness of conceptualising of the physical world as consisting of different forces, waves, and energies. These are, just like Kant's things-an-sich, not perceptible with the senses.

Who was Hermann Helmholtz (1821-1894)?

Hermann Helmholtz (1821-1894) and Gustav Theodor Fechner (1801-1887) studied and discovered the relationships between new measurable aspects of the physical world and the way in which it is consciously experienced. Fechner laid the foundation for an arithmetic-based experimental psychology by examining how differences in the physical intensities of stimulation can be observed psychologically. The law of Fechner means that an increase in physical intensity of a stimulus leads to a greater increase in psychological intensity of the sensation. In the early twentieth century, a group of emerged that were called the Gestalt psychologists. They showed other ways in which an active and creative mind forms the important aspects of a conscious perceptual experience.

Helmholtz was born near Berlin. He was accepted into  a medical education at the age of seventeen, despite the fact that he was more interested in physics. During the second year of his studies, he began studying physiology with Johannes Müller. He also became friends with a brilliant group of fellow students, including Emil du Bois-Reymond, who would later work with Helmholtz in discovering the physical nature of the nerve impulse. Even with his respect for physics, Müller still insisted on vitalism. Vitalism assumes that all living organisms are infused with an indescribable 'life force'. This life force gives them their vitality, which is not analysable by scientific methods. Believing in vitalism suggests that there is a limitation in the possible scientific understanding of physiological processes, because it is plausible that the life force itself is beyond the reach of the scientific analyses. Helmholtz and his friends respected their teacher but refused to accept his implicit limitation of science. For them, the use of the physical principles in physiology provided so much, that it seemed stupid to them to bring any limitations to this approach. They rejected vitalism and adopted it physiologically mechanism.

What is the physiological mechanism?

The physiological mechanism states that it is possible to understand all physiological processes in terms of everyday physical and chemical principles. Müller only disagreed with his students in his assumption that at one point, there would be a limit to the mechanism, when the life force comes into view. At the age of 21, Helmholtz got his medical title and began his military obligation. He became a surgeon in the army, but he had enough time for himself to build a small laboratory in the barracks, where he studied metabolic processes in frogs. On the basis of this research, Helmholtz showed that everyday chemical reactions are capable of producing (though not necessarily actually doing it) all physical activities and heat generations within a living organism. 

In 1847 the idea of ​​conserving energy came into being, which means that all kinds of forces that exist in the universe, are possibly interchangeable forms of a single large, reservoir of energy that is not variable in quantity. Energy can be transformed from one form into another, but it can never be created or destroyed by a physical process. 

The total amount of energy in the universe is constant. The government saw how brilliant Helmholtz was, and shortened his military obligation. In 1849, he was appointed professor of physiology at the university in Königsberg. Here he performed a study on the speed of a nerve signal. His friend Bois-Reymond had already speculated that the nerve signal could be an electrochemical signal that travels through the nerve on a slower pace than anyone had ever imagined. Helmholtz then thought it was slow enough to observe in the laboratory. To test this idea, he designed an ingenious one device with the needle of a galvanometer to measure smaller time units than before possible. He examined this in the leg of a frog, with an electrode that ran electricity through the paw. The bending of the leg would then turn off the electrical current. This was measured by his device. He discovered that the elapsed time was measurably longer when the electricity was applied to points of the leg that were further away from the foot: extra time because the nerve impulse had to travel further. He then also investigated this people. He did one of the first studies on variations in reaction time: the measured time between the presentation of a stimulus and a specific reaction. At first, many scientists did not see the value of Helmholtz's work because of his dense literary style, making it difficult to understand. In addition, some things were too surprising to be easily believed, so that scientists from that time did not believe it quickly. However, Helmholtz's ideas became gradually more and more accepted.

Helmholtz tries to describe all available knowledge about the senses of sight and hearing in the Handbook of Physiological Optics (1856-1866) and The Theory of the Sensation of Tone as a Physiological Basis for the Theory of Music (1863). He approached both senses with one similar strategy, which is explained with his dissertation of vision. He started with dividing his general subject into primary physical, physiological and psychological categories, while keeping in mind that they are related. The physical studies saw the eye as an optical instrument. These studies examined the process by which light from the external world is transformed into an image on the retina. The physiological analyses were mainly the problem of how an image of the retina is converted into signals in the brain, what results in conscious sensations of light. The psychological analyses went a lot further and wondered how sensations of light are converted into meaningful perceptions of discrete objects and events. There is a difference between sensation and perception, according to Helmholtz. Sensations are the 'raw elements' of conscious experiences, with no previous experiences whether learning processes are needed. Perceptions, on the other hand, are the meaningful interpretations of sensations.

On page 146 of this book, an image explains how the eye works. The field of the eye with maximum sharpness is very narrow, namely only that part of the image that falls inside a small section of the retina. This section is known as the fovea. Everything outside this area is vague. However, we do not notice this because the eye has the possibility to 'scan' the environment, whereby the focus is fast and flexible and shifts between one part of the visual field to another part. Helmholtz observed even more 'defects' in the optical properties of the eye. For example, colours are not perfectly reproduced on the retina, because the liquid in the eyeball is not perfectly colourless and because the lens breaks has the relatively longer wavelength of the red light less than the shorter wavelength of blue-violet at the end of the spectrum.

An imperfect tuning of refractive surfaces, known as astigmatism, distorts images in the eyes, but this happens to a very different degree. Possibly the most dramatic defect of all is the blind spot, which arises because a small portion of the retina, where the optic nerves leave the eye, does not have photosensitive cells. Helmholtz stated that the registered image of the external 'reality' on the retina is not perfect reproduction of the external stimulus. The above-mentioned changes and disruptions have one inevitable influence and on a psychological level transformations and disturbances are still further enlarged. Helmholtz illustrates this fact on the basis of his influential treatment to see the subject of colours.

How does seeing colors work?

Isaac Newton discovered through a solar spectrum that the 'white' light of the sun is more complicated than it seems. He stated that the different colours of the spectrum represent light of different wavelengths and that the white light of the sun consists of all these wavelengths mixed. When sunlight passes through a prism, shorter waves become more broken than longer ones. Something similar happens when sunlight comes alongside water and produces a rainbow. Experiments with mixing colours which show that the true situation is more complex, also show that the visual sense sometimes responds to mixes of wavelengths. This happens exactly the same way as with individual spectrum colours. So, very different physical stimuli can produce identical conscious sensations of colour.

Several scientists have studied the mixing of colours, which in 1855 has been described  the most extensively by Scot James Clerk Maxwell (1831-1879). Multiple pairs of complementary colours were identified. These are pairs of spectrum colours that, when mixed properly, can create a sensation of white light that cannot be distinguished from sunlight. The colours red, green and blue-violet are therefore called primary colours. This phenomenon is explainable because the retina contains three different types of recipient cells, each of which is strong reacts to light waves from one of these three primary colours. When it comes to sensory signals sent through the nerves, Müller assumed a specific type (visual, auditory, tangible etc.) and of a specific quality (red, green or blue-violet). Because the English scientist Thomas Young (1773-1829) had proposed a similar idea, it was named as the Young-Helmholtz trichromatic theory.

According to the theory, one type of receptor is strongly stimulated when there is a spectrum of red, green or blue-violet that falls on the retina, resulting in a sensation of a 'pure' primary colour. When, for example, red and green are stimulated, orange or yellow is created. All three together leads to white. Colours are therefore now more seen as products of the human sensory systems than as properties of physical reality.

How does visual perception work?

Helmholtz did not entirely agree with Kant about perception. Sensations that are interpreted during the perceptual process undergo further transformations in the Kantian 'spirit'. Sometimes the mind causes the perception to contradict reality, such as with optical illusions. The mind then makes a false interpretation of the visual sensation. The discussion deals with the origin of the perceptual processes (including those involved in illusions). It is a discussion of the nativist versus empiricist. According to Kant, spatial perception is mainly determined by innate intuitions. Helmholtz stated that experience and learning are more important perception. He demonstrated perceptual adaptation in his experiments, which he believed to be the result was a process that he called unconscious inference. A classical series of experiments showed how spatial perception can be changed by experience. Helmholtz set up a pair of glasses with participants, so that the visual field was systematically disturbed by moving the images of objects a few degrees to the right of their normal location. When subjects were asked to look at an object, then close their eyes and reach for the object to touch it, their first reactions were far too much to the right - towards the apparent rather than the real location. However, if they got a few minutes touching objects while looking through the glasses, perceptual adaptation took place. First, the participants had to give themselves the order to consciously move their hands to the left of the apparent objects they saw, but this action quickly became natural, automatic and unconscious. When the glasses were removed, they made mistakes again, but now to the left of right side. Perceptual adaptation had become so complete and automatic that it a minute or two before it was restored again. A visual experience, such as the manipulation of objects while wearing glasses that distort vision can lead to the unconscious use of certain rules that operate according to the main assumptions in logical syllogisms. For example, the main position can be: The size of the image of an object varies conversely with his distance to the eye. The second proposition is then: The size of the image of a ball is getting smaller at the moment. The conclusion is then that the ball moves away. The difference between perception and syllogistic reasoning lies in the fact that perception is immediate and effortless, while working out a syllogism can be laborious and time-consuming. This difference is possible because the main starting point of a perception is as good as automatic and unconsciously learned. Syllogisms can lead to wrong conclusions, so can unconscious inferences sometimes also lead to erroneous perceptions, such as optical illusions.

What did Helmholtz leave behind?

In 1871 he was appointed professor of physics at the University of Berlin. From that moment on, his research was mainly about thermodynamics, meteorology and electromagnetism. After his death in 1894, he was seen as one of the most respected scientist. Helmholtz was also one of the pioneers in psychology because of two reasons. First, he showed how neurological processes that underlie mental functions could be studied in the laboratory. Second, he helped with the development of the scientific concept of the 'Kantian spirit', with his integrated physical, physiological and psychological study of seeing and hearing. Many of his ideas are still accepted as true today. However, it is nowadays also accepted that processing of colour does not end on the retina. His fellow scientist Ewald Hering emphasized the importance of colour after images. For example, if you look at a red stimulus and then turn your gaze to a neutral coloured background, you see an afterimage of the same stimulus, only then in the complementary colour blue-green. The extreme empiricism of Helmholtz was challenged by Eleanor Jack Gibson (1910-2002) and her colleague Walk. Babies are born with the innate ability to stand upright and walk, and not to fall over on steep slopes. In this way, human babies systematically avoid walking or crawling over platforms without visible undergrounds to avoid complications.

What did Fechner write about psychophysics?

Gustav Theodor Fechner (1801-1887), like Helmholtz, started with a broad interest in physics and physiology, and then in psychology through the relationship between external physical reality and someone's conscious phenomenal experience of that reality. Both men worked on the same problem but did this in a different way and with a different reason. 

Fechner was born in Germany. His father and grandfather were both religious pastors and when his father died, he went to live with an uncle. His father appreciated both science and religion. Fechner grew up with strong philosophical and religious interests but did not want to follow the family tradition. He started his medical training in Leipzig when he was sixteen, but never started a practice when he was finished. He started to translate French textbooks on physics and chemistry. He learned a lot, and went to conduct his own research un electricity, making him a teacher of physics at the University of Leipzig in 1824. In 1833 he was a professor of physics. Fechner also studied the philosophy of nature, a bit of a mystical, semi-scientific movement that was popular at the time Germany. This movement saw the entire universe as an organic entity with consciousness and others animal functions. When someone died, his individual consciousness became one with consciousness of the entire universe. 

Fechner saw this movement as an antidote to materialism. He appreciated the scientific power of mechanistic analyses, but also felt suppressed by its implications. He found it a depressing doctrine. Fechner was obsessed with whether nature or the world had a soul. He had two different answers for this question. Fechner spoke of Tagesansicht and Nachtansicht. "Night-time" the mechanical version of the world view, with the universe as a dead machine and where life and consciousness were only side effects of this. The 'Tagesansicht' was the animated version of the world view, describing the universe as a place where consciousness plays a major role. The mechanical laws described in this perspective only a part of the whole. 

For years, Fechner fought a mental war between his day and night image. In 1839 he got a serious eye condition, and emotional and philosophical factors worsened the situation. He became complete disabled, and often could not speak or eat. He withdrew from his professorship. He solved his eating problem slowly, after a mystical advice to to consume only fruit, ham and wine. In 1850 he suddenly got an idea while he was meditating in bed, through which he returned to the scientific world, and gained a position as one of the fathers of modern experimental psychology. He reflected on the relationship between the material and mental worlds, just like Helmholtz. But while Helmholtz has the differences between these worlds emphasized and wrote about the imperfections of the eye as an optical instrument and the incongruences imposed by the colour sensation device, Fechner saw the harmony between the physical and mental world.

Some simple, everyday observations about hearing and seeing can illustrate Fechner's idea. If we hear, we take it for granted that little noise is filtered from a lot of background noise. As with vision, when a small light can be clearly visible in a dark room, but not in a brightly lit room. These facts indicate that conscious sensations of stimulus intensity are not perfectly reflect the physical reality, because the same stimuli create different impressions of their strength under different circumstances. These are examples of Kant's point, namely that the sensory system presses and transforms them before they become conscious brought. Fechner thought it would be possible to see both the observed and the physical to measure intensities of sensory stimuli, and the mathematical relationship between the two measurements determine. His intuition told him that this relationship would be harmonious. This was the inspiring of the idea of ​​what Fechner called psychophysics, the study of the relationships between the objectively measurable intensities of different stimuli and the subjective impressions of these intensities. Fechner's practical problem was how he could measure subjective intensities of stimulation. Several years rather, Weber had researched the ability of people to distinguish between objects that exist look the same but have different weights. He found that accurate judgement depended on the relative difference in weight. Weber concluded that it is just noticeable difference '(jnd) for this specific discrimination task - the minimum weight difference to distinguish them - always about 0.03. Weber found this kind regularities also for other types of sensory discrimination. Fechner discovered that the observed relation between the physical and subjective stimulus intensities for many different ones senses can be expressed by one general mathematical formula, which claims that the subjective intensity (S) of a stimulus measured in jnd units is always equal to the logarithm of his physical intensity (P) times a constant (k), which varies for every senses can be determined experimentally. This is called the law of Fechner. In 1860 this law was published in his book 'elements of psychophysics'. Critics pointed to studies that showed that his law was only about right and did not work for the extremes of high and low sensory intensities. They found that absolute limits differed from person to person, or even within the same person from time to time. Another criticism came from Stevens (1906- 1973), who found that for some types of stimulation, subjective intensities increased more rapidly than the physical intensities - the opposite of what Weber and Fechner emphasized. He came with the law of Stevens. However, this law was only good for the middle range of physical stimulation and also differed per individual and situation.

What is Gestalt Psychology?

The name Gestalt psychology comes from the German word Gestalt and means 'form'. The Gestalt psychology focuses on the ways in which the mind organizes experiences and perceptions in organized units that are more than the sum of the separated parts. Austrian Christian von Ehrenfelds (1859-1932) wrote about certain perceptual 'form qualities' that could not be introspectively broken down into separate sensory elements. Instead, these form qualities resided in the overall composition of objects or ideas. Only around 1910 these Gestalt qualities were explored. Wertheimer (1880-1943), Koffka (1886-1941) and Köhler(1887-1967) set it to motion.

Wertheimer studied the optical illusion of apparent movement: the perception of continuous movement that arises when a succession of still slightly different still images being observed. Wertheimer showed, on the basis of different time intervals and still images, that a minimum interval is needed to see that it is two separate, still images. This apparent movement (a simplified form of a film) he called the phi phenomenon. Wertheimer showed that an observer (when they are random is faced with both apparent movement and real movement) could not tell the one that was different. Both the real and the apparent movement could be identical negative afterimages: a tendency to see static objects in motion in the opposite direction of the moving object that was observed immediately before. When we are observing actual movement, the light literally sweeps past the retina and it falls on all receiving cells that are in this path. With the phi phenomenon only the receiving cells that are located at the beginning and at the end of this path are physically illuminated. Movement is therefore one property that is possibly assigned to static images by the higher brain processes.

The mind seems to organize the elements of an experience in wholes. Unlike a lot other scientists, Gestalt psychologists do not start with the simplest 'elements' of their subject, but with these integers. Then they try to describe the functions of the parts, that together form the wholes. Gestalt psychologists state that perception always takes place within one 'field' in which there is a distinction between the figure and the background. The background is necessary for the figure because it is contrasts with it. A figure cannot exist without a background to exist on. For example, the words on this paper cannot be seen (as a figure) without the lighter background of the page. The figure on page 176 shows that you can never see the background and the figure at the same time, making the figure (or shape) in your perceptual field constantly changing. 

Wertheimer, Koffka and Köhler emphasize that the mind tries to simplify and organize perceptual fields in which observed figures occur. This happens with more complex combinations of stimuli. These are perceived by consciousness as several small groups of stimuli. For example, the figure on page 163 suggests that there are three circles there, with which we can simplify and organize the figure. The same applies to auditory information, here too something must be heard against a relatively neutral background. This happens according to the principles of contiguity and resemblance.

What are implications of Gestalt psychology?

In 1920-1930, the three pioneers of Gestalt psychology fled to America, what benefited the American psychology greatly. Koffka promoted the general Gestalt perspective as a counterpart to atomistic behaviourism that then dominated in the US. His book called 'Principles of Gestalt Psychology' remains the most comprehensive and systematic book on the Gestalt psychology in history. Köhler and Wertheimer expanded Gestalt principles from sensation and perception towards learning and thinking. Köhler saw that learning often includes insight. New and adaptive reactions often arise suddenly, after another organization of the perceptual field. Wertheimer analysed creative human thinking. He was in favour of free discovery and encouraged flexibility and understanding. His book was called 'Productive thinking'. He befriended the psychologist Maslow during his last years in New York. Köhler settled in Pennsylvania, where he tried to combine psychology with physics. He emphasized, for example, that perceptual and physical force fields are the same because each tries to organize itself over time into simpler configurations. According to him, the brain was a physical system that divided electric charges and processed them. He proposed the hypothesis of psychophysical isomorphism, according to which psychological facts and the underlying events in the brain are similar to each other concerns their structural characteristics. This did not mean that perceptual and brain processes were the same in relation to each other, but that they shared the same structural and relational characteristics with which they both existed. The brain should therefore be studied as an organized system, not as a conglomeration of separate individual components. 

This idea was supported by Kurt Goldstein (1878- 1965). He was impressed by the Gestalt principles and was one of the publishers of Psychological Forschung, the original German-language magazine entirely devoted to Gestalt psychology. Kurt Lewin was a younger Gestalt psychologist, who came to America with his mentors. He claimed that every person stays in a unique psychological field, also called a person’s living space. This is the totality of his or her psychological situation at any arbitrary moment. It includes a person's physical and social environment as they are perceived, as well as someone's constantly changing motifs and actions, or locomotion, within this living space. This gets combined into forces or vectors within the field, which together determine a person’s behaviour. Lewin also studied the effects of democratic versus authoritarian leadership on group behaviour. This was one of the first experiments in social psychology.

ExamTips

• Kant was pretty wishy-washy, and he switched sides and theories a lot! Make sure you know who influenced him and in what was and be able to draw up his final schematics!
• This is the moment where things are starting to get confusing and overlapping. To make it clearer for yourself, maybe try to make a table, with the name of each pioneer and their believes, their view on empiricism/rationalism, their achievements and what change they brought to the modern psychology.
• Make a schematic drawing on the eye to understand the parts for instance Helmholz was working on.