Early Developments in Physiology and the Rise of Experimental Psychology

1. Early Developments in Physiology and the Rise of Experimental Psychology Chapter 8

2. -Leonardo Da Vinci - made many anatomical sketches despite papal ban. -Michelangelo�s appreciation for the impact of physiology on behavior -�A third image was clearly revealed when centuries of soot, dirt and grime were removed from the fresco in a recent cleaning. Surrounding God is the unmistakable shape and detail of a human brain. Michelangelo�s image is strikingly similar to depictions of the medial aspects of the brain shown in contemporary anatomy texts. Meshberger concludes that Michelangelo�s intent in painting this enveloping brain was to show God giving to Adam not life, but intellect. -Robert Whytt (1714-1766) Experimented with Frogs: -When the hinder toes of a frog are wounded, immediately after cutting off its head, there is either no motion at all excited in the muscles of the legs or a very inconsiderable one. But if the toes of this animal be pinched, or wounded with a pen-knife, ten or fifteen minutes after decapitation, the muscles, not only of the legs and thighs, but also of the trunk of the body, are, for the most part, strongly convulsed, & the frog sometimes moves from one place to another. -Definitely makes us question the mind-body interaction.-Leonardo Da Vinci - made many anatomical sketches despite papal ban. -Michelangelo�s appreciation for the impact of physiology on behavior -�A third image was clearly revealed when centuries of soot, dirt and grime were removed from the fresco in a recent cleaning. Surrounding God is the unmistakable shape and detail of a human brain. Michelangelo�s image is strikingly similar to depictions of the medial aspects of the brain shown in contemporary anatomy texts. Meshberger concludes that Michelangelo�s intent in painting this enveloping brain was to show God giving to Adam not life, but intellect. -Robert Whytt (1714-1766) Experimented with Frogs: -When the hinder toes of a frog are wounded, immediately after cutting off its head, there is either no motion at all excited in the muscles of the legs or a very inconsiderable one. But if the toes of this animal be pinched, or wounded with a pen-knife, ten or fifteen minutes after decapitation, the muscles, not only of the legs and thighs, but also of the trunk of the body, are, for the most part, strongly convulsed, & the frog sometimes moves from one place to another. -Definitely makes us question the mind-body interaction.

3. Individual Differences 1795 David Kinnebrook, a research assistant of Nevil Maskelyne, was to assess the precise time that a star crossed the crosshairs of a telescope. He was consistently � s different from his advisor. He was fired. Reaction Time: The period of time between presentation of and response to a stimulus. Personal Equations: Mathematical formulae used to correct for differences in reaction time among observers. -Friedrich Bessel speculated that Kinnebrook�s error was not really error, but due to individual differences. -Bessel showed that the observer influenced observations. -Because all science is based on observations, we must study the process that converted physical stimulation into conscious experience.-Friedrich Bessel speculated that Kinnebrook�s error was not really error, but due to individual differences. -Bessel showed that the observer influenced observations. -Because all science is based on observations, we must study the process that converted physical stimulation into conscious experience.

4. Discrepancy Between Objective and Subjective Reality Discrepancies between a physical event and a person�s perception of it was of great concern to natural scientists who viewed their jobs as accurately describing and explaining the physical world. The question of interest to the early scientists was �How do empirical sense impressions come to be represented in consciousness?� Physiology provided the link between mental philosophy and the science of psychology. The discrepancy made a science of psychology almost inevitable. -Though we perceive white light, Newton showed us the sensations were actually ROYGBIV. -Van Musschenbroek discovered that if yellow and blue are presented on a rotating disc, the perception is of gray. -Because all science is based on observations, we must study the process that converted physical stimulation into conscious experience. -Though we perceive white light, Newton showed us the sensations were actually ROYGBIV. -Van Musschenbroek discovered that if yellow and blue are presented on a rotating disc, the perception is of gray. -Because all science is based on observations, we must study the process that converted physical stimulation into conscious experience.

5. Bell-Magendie Law Bell-Magendie Law: There are two types of nerves: sensory nerves carrying impulses from the sense receptors to the brain and motor nerves carrying impulses from the brain to the muscles and glands of the body. -Bell, Charles (1774-1842) Discovered, in modern times, the distinction between sensory and motor nerves. -Magendie, Fran�ois (1783-1855) Discovered, in modern times, the distinction between sensory and motor nerves. -Before 1800 two views of nerves prevailed, Descartes� notion of hollow tubes, and Hartley�s view of nerves as the source of vibrations. -Bell published a paper in 1811 and printed 100 copies. -Magendie published similar results 11 years later. -The Bell-Magendie law not only demonstrates separate sensory and motor neurons, but also suggests that different regions of the brain are responsible for sensory and motor functions. -Bell, Charles (1774-1842) Discovered, in modern times, the distinction between sensory and motor nerves. -Magendie, Fran�ois (1783-1855) Discovered, in modern times, the distinction between sensory and motor nerves. -Before 1800 two views of nerves prevailed, Descartes� notion of hollow tubes, and Hartley�s view of nerves as the source of vibrations. -Bell published a paper in 1811 and printed 100 copies. -Magendie published similar results 11 years later. -The Bell-Magendie law not only demonstrates separate sensory and motor neurons, but also suggests that different regions of the brain are responsible for sensory and motor functions.

6. Doctrine of Specific Nerve EnergiesJohannes M�ller -M�ller, Johannes (1801-1858) Expanded the Bell-Magendie law by demonstrating that each sense receptor, when stimulated, releases an energy specific to that particular receptor. This finding is called the doctrine of specific nerve energies.-M�ller, Johannes (1801-1858) Expanded the Bell-Magendie law by demonstrating that each sense receptor, when stimulated, releases an energy specific to that particular receptor. This finding is called the doctrine of specific nerve energies.

7. Doctrine of Specific Nerve EnergiesJohannes M�ller -�. . . The same cause, such as electricity, can simultaneously affect all sensory organs, since they are all sensitive to it; and yet, every sensory nerve reacts to it differently; one nerve perceives it as light, another hears its sound, another one smells it; another tastes the electricity, and another one feels it as pain and shock. One nerve perceives a luminous picture through mechanical irritation, another one hears it as buzzing, another one senses it as pain. . . He who feels compelled to consider the consequences of these facts cannot but realize that the specific sensibility of nerves for certain impressions is not enough, since all nerves are sensitive to the same cause but react to the same cause in different ways. . . Sensation is not the conduction of a quality or state of external bodies to consciousness, but the conduction of a quality or state of our nerves to consciousness, excited by an external cause.� -Press your eyeball and you�ll see spots. Physical energy, striking the eye nerves, is translated as vision. -However, each nerve is optimally sensitive to a specific type of energy. -Emil Du Bois, one of Muller�s students went so far as to say that if you cut the nerves to the eyes and ears, then reattached them to the wrong sense organ, we would be able to see sounds and hear colors.-�. . . The same cause, such as electricity, can simultaneously affect all sensory organs, since they are all sensitive to it; and yet, every sensory nerve reacts to it differently; one nerve perceives it as light, another hears its sound, another one smells it; another tastes the electricity, and another one feels it as pain and shock. One nerve perceives a luminous picture through mechanical irritation, another one hears it as buzzing, another one senses it as pain. . . He who feels compelled to consider the consequences of these facts cannot but realize that the specific sensibility of nerves for certain impressions is not enough, since all nerves are sensitive to the same cause but react to the same cause in different ways. . . Sensation is not the conduction of a quality or state of external bodies to consciousness, but the conduction of a quality or state of our nerves to consciousness, excited by an external cause.� -Press your eyeball and you�ll see spots. Physical energy, striking the eye nerves, is translated as vision. -However, each nerve is optimally sensitive to a specific type of energy. -Emil Du Bois, one of Muller�s students went so far as to say that if you cut the nerves to the eyes and ears, then reattached them to the wrong sense organ, we would be able to see sounds and hear colors.

8. Doctrine of Specific Nerve EnergiesJohannes M�llerAdequate Stimulation All the sense organs are not equally receptive to all types of stimulation. Each of the sense organs is maximally sensitive to a certain type of stimulation (specific irritability). Adequate Stimulation: Stimulation to which a sense modality is maximally sensitive. -As we experience the world, this differential sensitivity provides a picture of the physical environment, but this picture is influenced by the nature of the sense organs. -If a blind and a deaf person both �witnessed� a crime and were asked to testify, they would provide radically different testimony.-As we experience the world, this differential sensitivity provides a picture of the physical environment, but this picture is influenced by the nature of the sense organs. -If a blind and a deaf person both �witnessed� a crime and were asked to testify, they would provide radically different testimony.

9. Doctrine of Specific Nerve EnergiesJohannes M�llerWe are Conscious of Sensations, not Physical Reality Accepted idea of Kant�s categories of thought. Instead though, the sensory systems always modify the sensations before we perceive them. -It is the nature of our sense organs, not the nature of physical reality, that determines our sensations. -We are not aware of the physical objects, but rather the sensory impulses. -Our knowledge of the physical world is limited by the sense receptors we possess. -We �see� energy waves that are only in a very narrow range. Other energies are not detected.-It is the nature of our sense organs, not the nature of physical reality, that determines our sensations. -We are not aware of the physical objects, but rather the sensory impulses. -Our knowledge of the physical world is limited by the sense receptors we possess. -We �see� energy waves that are only in a very narrow range. Other energies are not detected.

10. Hermann von Helmholtz -Helmholtz, Hermann von (1821-1894) A monumental figure in the history of science who did pioneer work in the areas of nerve conduction, sensation, perception, color vision, and audition. -Eventually he realized his lifelong dream and became a professor of physics at the University of Berlin. -In 1882 the German emperor elevated him to nobility and he added the von to his name. -In 1893 he came to the U.S. for the Chicago World�s Fair and to visit with William James. -While traveling back to Germany he slipped and fell aboard ship. -Following the accident, which didn�t seem like a big deal, he never felt right and died of a cerebral hemorrhage a year later. -Many consider him the greatest scientist of the nineteenth century.-Helmholtz, Hermann von (1821-1894) A monumental figure in the history of science who did pioneer work in the areas of nerve conduction, sensation, perception, color vision, and audition. -Eventually he realized his lifelong dream and became a professor of physics at the University of Berlin. -In 1882 the German emperor elevated him to nobility and he added the von to his name. -In 1893 he came to the U.S. for the Chicago World�s Fair and to visit with William James. -While traveling back to Germany he slipped and fell aboard ship. -Following the accident, which didn�t seem like a big deal, he never felt right and died of a cerebral hemorrhage a year later. -Many consider him the greatest scientist of the nineteenth century.

11. Hermann von HelmholtzHelmholtz�s Stand Against Vitalism Vitalism: The belief that life cannot be explained solely as the interaction of physical and chemical forces. Johannes M�ller was a vitalist Materialism: The belief that there is nothing mysterious about life and assumed that it could be explained in terms of physical and chemical processes. No reason to exclude the study of life from the realm of science. -Helmholtz so strongly believed in materialism that he and several of his students signed the following oath: -�No other forces than the common physical-chemical ones are active within the organism. In those cases which cannot at the time be explained by these forces one has either to find the specific way or form of their action by means of the physical mathematical method, or to assume new forces equal in dignity to the physical-chemical forces inherent in matter, reducible to the force of attraction and repulsion.� -The vitalism/materialism debate in physiology is similar to the empiricism/nativism debate in psychology.-Helmholtz so strongly believed in materialism that he and several of his students signed the following oath: -�No other forces than the common physical-chemical ones are active within the organism. In those cases which cannot at the time be explained by these forces one has either to find the specific way or form of their action by means of the physical mathematical method, or to assume new forces equal in dignity to the physical-chemical forces inherent in matter, reducible to the force of attraction and repulsion.� -The vitalism/materialism debate in physiology is similar to the empiricism/nativism debate in psychology.

12. Hermann von HelmholtzPrinciple of Conservation of Energy Principle of Conservation of Energy: The energy within a system is constant; therefore, it cannot be added to or subtracted from but only transformed from one form to another. Applies to living organisms as well. The energy from food and oxygen will equal the energy expended by muscles and organs. Clearly a materialistic statement! -Helmholtz obtained his medical degree at 21 and was inducted into the army. -While in the army, he built a small laboratory to study the metabolic processes in the frog. -Food and oxygen consumption account for all of the energy an organism expended. -Helmholtz published a paper called �The Conservation of Force� which was so influential that he was released from his obligation to the army.-Helmholtz obtained his medical degree at 21 and was inducted into the army. -While in the army, he built a small laboratory to study the metabolic processes in the frog. -Food and oxygen consumption account for all of the energy an organism expended. -Helmholtz published a paper called �The Conservation of Force� which was so influential that he was released from his obligation to the army.

13. Hermann von HelmholtzRate of Nerve Conduction Johannes M�ller had maintained that nerve conduction was instant. Helmholtz felt nothing was outside the realm of science. He isolated a nerve leading to a frog�s leg muscle. He stimulated the nerve at various points and measured how long for the muscle to respond. Concluded nerve conduction occurs at 27.4 meters per second. -He measured humans and found that different parts of the body had different rates, slower at the toes, faster at the thighs. -Rate is between 50 and 100 meters per second in humans. -Unfortunately, there was also variability in speed in the same person at different times. -Though Helmholtz gave up on this work, it showed that NOTHING was beyond scientific scrutiny. -Physical-chemical processes are involved in our interactions with the environment.-He measured humans and found that different parts of the body had different rates, slower at the toes, faster at the thighs. -Rate is between 50 and 100 meters per second in humans. -Unfortunately, there was also variability in speed in the same person at different times. -Though Helmholtz gave up on this work, it showed that NOTHING was beyond scientific scrutiny. -Physical-chemical processes are involved in our interactions with the environment.

14. Hermann von HelmholtzTheory of Perception Sensation: The rudimentary mental experience caused when sense receptors are stimulated by an environmental stimulus. Perception: According to Helmholtz, the mental experience arising when sensations are embellished by the recollection of past experiences. Unconscious Inference: According to Helmholtz, the process by which the remnants of past experience are added to sensations, thereby converting them into perceptions. -Helmholtz had a problem with the word �unconscious inference� because it sounded too much like �magic�, but he could not come up with a more materialistic word.-Helmholtz had a problem with the word �unconscious inference� because it sounded too much like �magic�, but he could not come up with a more materialistic word.

15. Hermann von HelmholtzTheory of Perception Previous experience intervenes and makes a sensation into a perception. An empirical theory of perception. The innate categories of thought proposed by Kant were actually derived from experience. The axioms of geometry are not innate, they are a product of the sensations we�ve had. If the world were different, and we therefore had different sensations, the axioms would be different. Individuals who had been blind since birth who acquired sight needed to learn to perceive.

16. Hermann von HelmholtzTheory of Color Vision Newton had discovered that pure orange wavelengths were indistinguishable from orange created by mixing red and yellow. The property of color cannot be in the wavelengths themselves. Young-Helmholtz Theory of Color Vision: Separate receptor systems on the retina are responsive to each of the three primary colors: red, green, and blue-violet. Also called the trichromatic theory. An extension of the doctrine of specific nerve energies. Not just a single nerve energy for vision, but three types of receptors on the retina. -Given RGB sense receptors, all other colors can be explained as the firing of various amounts of them. -Computers use the RGB system to describe all colors in the world. -�The deficiencies and imperfections of the eye as an optical instrument, and the deficiencies of the image on the retina, now appear insignificant in comparison with the incongruities we have met with in the field of sensation. One might almost believe that Nature had here contradicted herself on purpose in order to destroy any dream of a preexisting harmony between the outer and the inner world.�-Given RGB sense receptors, all other colors can be explained as the firing of various amounts of them. -Computers use the RGB system to describe all colors in the world. -�The deficiencies and imperfections of the eye as an optical instrument, and the deficiencies of the image on the retina, now appear insignificant in comparison with the incongruities we have met with in the field of sensation. One might almost believe that Nature had here contradicted herself on purpose in order to destroy any dream of a preexisting harmony between the outer and the inner world.�

17. Hermann von HelmholtzTheory of Color Vision

18. Hermann von HelmholtzTheory of Auditory Perception The ear also has multiple receptors, literally thousands. Resonance Place Theory of Auditory Perception: The tiny fibers on the basilar membrane of the inner ear are stimulated by different frequencies of sound. The shorter the fiber, the higher the frequency to which it responds. -In modern times this is called the place theory of pitch perception. -Proposes we hear different pitches because different sound waves trigger activity at different places along the cochlea's basilar membrane. -Place theory only explains how we hear high pitch sounds. -High pitches close to oval window -Low pitches at far end of cochlea -In modern times this is called the place theory of pitch perception. -Proposes we hear different pitches because different sound waves trigger activity at different places along the cochlea's basilar membrane. -Place theory only explains how we hear high pitch sounds. -High pitches close to oval window -Low pitches at far end of cochlea

19. Hermann von HelmholtzHelmholtz�s Contributions

20. Ewald Hering Received medical degree from University of Leipzig. Worked with Joseph Breuer. Took Jan Purkinje�s job at the University of Prague. Purkinje Shift: As twilight approaches, hues that correspond to short wavelengths such as violet and blue appear brighter than hues corresponding to longer wavelengths such as yellow or red. Hints at the phenomenon of negative after images. -Hering, Ewald (1834-1918) Offered a nativistic explanation of space perception and a theory of color vision based on the existence of three color receptors, each capable of a catabolic process and an anabolic process. Hering's theory of color vision could explain a number of color experiences that Helmholtz's theory could not. -Purkinje worked on vision and felt that any theory of vision needed to explain not only normal phenomena, but also weird stuff.-Hering, Ewald (1834-1918) Offered a nativistic explanation of space perception and a theory of color vision based on the existence of three color receptors, each capable of a catabolic process and an anabolic process. Hering's theory of color vision could explain a number of color experiences that Helmholtz's theory could not. -Purkinje worked on vision and felt that any theory of vision needed to explain not only normal phenomena, but also weird stuff.

21. Ewald HeringSpace Perception When stimulated, each point on the retina provides three types of information about the stimulus: height, left-right position, and depth. Similar to Kant�s categories of thought, but an innate characteristic of the eye. -Hering was a nativist. -Modern researchers put these bits of understanding in the brain, at the point of perception.-Hering was a nativist. -Modern researchers put these bits of understanding in the brain, at the point of perception.

22. Ewald HeringTheory of Color Vision Unexplained by the Young-Helmholtz theory of color vision, mixing red/green or blue/yellow or black/white makes gray. Similarly, if you stare at red, then look away, you see a green afterimage (ditto for BY). If a color blind person is unable to see red, then they cannot see green either (same with BY). -A color blindness detection apparatus -A color blindness detection apparatus

23. Ewald HeringTheory of Color Vision Opponent Process Theory: Three receptors in eye, but each responds in two ways. One type responds to RG, one to BY, one the BW R, Y, and W cause a tearing down (catabolic process) and G, B, and B cause a building up (anabolic process). If the opponent colors are seen simultaneously, then gray results. -Opponent-process theory of color vision -Modern thinking holds that both Young-Helmholtz and Opponent-process are true. However, RGB is at the level of the eyes whereas RG, BY, and BW are at the level of the neurons. -Opponent-process theory of color vision -Modern thinking holds that both Young-Helmholtz and Opponent-process are true. However, RGB is at the level of the eyes whereas RG, BY, and BW are at the level of the neurons.

24. Christine Ladd-Franklin Graduated from Vassar. Completed requirements for doctorate in mathematics from Johns Hopkins University, but denied the doctorate due to her gender. Given honorary doctorate by Vassar Eventually given doctorate from Johns Hopkins. Studied in Germany under Helmholtz and Georg Muller (where Hering�s theory was supported). -Ladd-Franklin, Christine (1847-1930) Proposed a theory of color vision based on evolutionary principles. -Ladd-Franklin, Christine (1847-1930) Proposed a theory of color vision based on evolutionary principles.

25. Christine Ladd-Franklin Proposed color vision theory based on evolution. Motion detection is most primitive form of vision. Color detection is more modern. Within color vision, BW vision most primitive. Then comes BY, since it evolved earlier, it is less likely to be faulty. Then comes RG, the newest form is the one most likely to be problematic. -Her theory did not oppose either Young-Helmholtz or Opponent-process theory. -Dogs are not color blind, they lack RG color vision.-Her theory did not oppose either Young-Helmholtz or Opponent-process theory. -Dogs are not color blind, they lack RG color vision.

26. Early Research on Brain Functioning Physiognomy: The attempt to determine a person's character by analyzing his or her facial features, bodily structure, and habitual patterns of posture and movement. -Caricatures were a way for physiognomy's pseudo-learning to base itself by illustrative means. -One popular type of physiognomy was body typing as described by William Sheldon, Endomorphs, Ectomorphs, Mesomorphs. -The popularity of physiognomy grew throughout the eighteenth century and into the nineteenth century. It influenced the descriptive abilities of many European novelists, notably Balzac; and a host of other nineteenth century English authors, notably the highly descriptive passages of characters and their physiognomical appearance in the novels of Charles Dickens, Thomas Hardy, and Charlotte Bront�. -Caricatures were a way for physiognomy's pseudo-learning to base itself by illustrative means. -One popular type of physiognomy was body typing as described by William Sheldon, Endomorphs, Ectomorphs, Mesomorphs. -The popularity of physiognomy grew throughout the eighteenth century and into the nineteenth century. It influenced the descriptive abilities of many European novelists, notably Balzac; and a host of other nineteenth century English authors, notably the highly descriptive passages of characters and their physiognomical appearance in the novels of Charles Dickens, Thomas Hardy, and Charlotte Bront�.

27. Early Research on Brain FunctioningCesare Lombroso Criminality is inherited and the born criminal can be identified by physical defects which confirm the criminal is a savage. Large jaws, forward projection of jaw, Low sloping forehead High cheekbones, flattened or upturned nose Handle-shaped ears Hawk-like noses or fleshy lips. Hard Shifty eyes, scanty beard or baldness Insensitivity to pain, long arms

28. Early Research on Brain FunctioningCesare Lombroso -Lombroso claimed that the modern criminal was the savage throwback of degeneration. -Lombroso concluded that skull and facial features were clues to genetic criminality, these features could be measured with craniometers and calipers with the results developed into quantitative research. -Lombroso claimed that the modern criminal was the savage throwback of degeneration. -Lombroso concluded that skull and facial features were clues to genetic criminality, these features could be measured with craniometers and calipers with the results developed into quantitative research.

29. Early Research on Brain FunctioningPhrenologyFranz Joseph Gall Faculties of the mind act on and transform sensory information. The faculties do not exist to the same extent in all people. The faculties are located in specific areas. If a faculty is well developed, the brain will push the skull. -Gall, Franz Joseph (1758-1828) Believed that the strengths of mental faculties varied from person to person and that they could be determined by examining the bumps and depressions on a person's skull. Such an examination came to be called phrenology. -The magnitude of one�s faculties could be determined by examining the bumps and depressions on the skull. -Gall's cerebral organs carried the names of their supposed functions or faculties and were numbered: -1. impulse to propagation 15. faculty of language 2. Tenderness for the offspring, or parental love 16. disposition for colouring, and the delighting in colours 3. friendly attachment or fidelity 17. sense for sounds, musical talent 4. valour, self-defense 18. arithmetic, counting, time 5. murder, carnivorousness 19. mechanical skill 6. sense of cunning 20. comparative perspicuity, sagacity 7. larceny, sense of property 21. metaphysical perspicuity 8. pride, arrogance, love of authority 22. wit, causality, sense of inference 9. ambition and vanity 23. poetic talent 10. circumspection 24. Good-nature, compassion, moral sense 11. aptness to receive an education, or the memoria realis 25. Mimic 12. sense of locality 26. Theosophy, sense of God and religion 13. recollection of persons 27. Perseverance, firmness 14. faculty for words, verbal memory -Gall, Franz Joseph (1758-1828) Believed that the strengths of mental faculties varied from person to person and that they could be determined by examining the bumps and depressions on a person's skull. Such an examination came to be called phrenology. -The magnitude of one�s faculties could be determined by examining the bumps and depressions on the skull. -Gall's cerebral organs carried the names of their supposed functions or faculties and were numbered: -1. impulse to propagation 15. faculty of language 2. Tenderness for the offspring, or parental love 16. disposition for colouring, and the delighting in colours 3. friendly attachment or fidelity 17. sense for sounds, musical talent 4. valour, self-defense 18. arithmetic, counting, time 5. murder, carnivorousness 19. mechanical skill 6. sense of cunning 20. comparative perspicuity, sagacity 7. larceny, sense of property 21. metaphysical perspicuity 8. pride, arrogance, love of authority 22. wit, causality, sense of inference 9. ambition and vanity 23. poetic talent 10. circumspection 24. Good-nature, compassion, moral sense 11. aptness to receive an education, or the memoria realis 25. Mimic 12. sense of locality 26. Theosophy, sense of God and religion 13. recollection of persons 27. Perseverance, firmness 14. faculty for words, verbal memory

30. Early Research on Brain FunctioningPhrenologyFranz Joseph Gall Phrenology: The examination of the bumps and depressions on the skull in order to determine the strengths and weaknesses of various mental faculties. Developed out of the notion of faculty psychology. -Gall would find someone with a pronounced brain structure and a well developed skill and attribute one to the other with no actual evidence. -After observing the relationship in one individual, he would generalize to others. -However, exceptions can always be made. -When a cast of Descartes skull revealed deficiencies in the areas of reasoning, phrenologist�s said, Descartes rationality had always been overrated. -His work sparked research into the relationship between cortical development and mental functioning. -He was the first to identify the functions of gray and white matter in the brain.-Gall would find someone with a pronounced brain structure and a well developed skill and attribute one to the other with no actual evidence. -After observing the relationship in one individual, he would generalize to others. -However, exceptions can always be made. -When a cast of Descartes skull revealed deficiencies in the areas of reasoning, phrenologist�s said, Descartes rationality had always been overrated. -His work sparked research into the relationship between cortical development and mental functioning. -He was the first to identify the functions of gray and white matter in the brain.

31. Early Research on Brain FunctioningPhrenologyFranz Joseph Gall In the introduction to his main work The Anatomy and Physiology of the Nervous System in General, and of the Brain in Particular, Gall makes the following statement in regard to the principles on which he based his doctrine: That moral and intellectual faculties are innate That their exercise or manifestation depends on organization That the brain is the organ of all the propensities, sentiments and faculties That the brain is composed of many particular organs as there are propensities, sentiments and faculties which differ essentially from each other. That the form of the head or cranium represents the form of the brain, and thus reflects the relative development of the brain organs.

32. Early Research on Brain FunctioningPhrenologyThe Popularity of Phrenology The Physiognomical System of Drs. Gall and Spurzheim (1815) Phrenology provided a possible objective science of the mind. Phrenology produced useful predictive information about people (Formal Discipline). -Spurzheim, Johann Kasper (1776-1832) A student and colleague of Gall, who did much to expand and promote phrenology. -Formal discipline-The belief that the faculties of the mind can be strengthened by practicing the functions associated with them. Thus, one supposedly can become better at reasoning by studying mathematics or logic.-Spurzheim, Johann Kasper (1776-1832) A student and colleague of Gall, who did much to expand and promote phrenology. -Formal discipline-The belief that the faculties of the mind can be strengthened by practicing the functions associated with them. Thus, one supposedly can become better at reasoning by studying mathematics or logic.

33. Early Research on Brain FunctioningPhrenologyThe Popularity of Phrenology The Lavery electric phrenometer was invented to increase precision in measuring bumps on the head. Phrenology used the phrase �Know thyself� to promote. -Phrenology parlors arose across the USA -Advertisements such as this one were popular: -Apprentice wanted�a stout boy not over 15 years of age of German or Scotch parents, to learn a good but difficult trade. It will be necessary to bring a recommendation to his abilities from Messrs. Fowler and Wells Phrenologists, Nassau Street. -Other areas in which phrenology emerged? -Marriage counseling -During a presidential campaign, candidates assessments were published in the Journal of Man -Walt Whitman liked his reading so much that he published it five times! -Phrenology parlors arose across the USA -Advertisements such as this one were popular: -Apprentice wanted�a stout boy not over 15 years of age of German or Scotch parents, to learn a good but difficult trade. It will be necessary to bring a recommendation to his abilities from Messrs. Fowler and Wells Phrenologists, Nassau Street. -Other areas in which phrenology emerged? -Marriage counseling -During a presidential campaign, candidates assessments were published in the Journal of Man -Walt Whitman liked his reading so much that he published it five times!

34. Was Phrenology that far off? Modern studies using MRI imaging have shown that brain size correlates with IQ (r = 0.35) among adults. A study on twins showed that frontal gray matter volume was correlated with g and highly heritable. A related study has reported that the correlation between brain size (reported to have a heritability of 0.85) and g is 0.4, and that correlation is mediated entirely by genetic factors. A study involving 307 children (age between six to nineteen) measuring the size of brain structures using magnetic resonance imaging (MRI) and measuring verbal and non-verbal abilities has been conducted (Shaw et al, 2006). The study has indicated that there is a relationship between IQ and the structure of the cortex - the characteristic change being the group with the superior IQ scores starts with thinner cortex in the early age then becomes thicker than average by the late teens.

35. Early Research on Brain FunctioningJean Pierre Flourens -Flourens, Pierre (1794-1867) Concluded that the cortical region of the brain acts as a whole and is not divided into a number of faculties, as the phrenologists had maintained. -Using dogs and pigeons -Removing the cerebellum disturbed coordination and equilibrium. -Removing the cerebrum resulted in passivity. -Removing the semi-circular canals resulted in loss of balance.-Flourens, Pierre (1794-1867) Concluded that the cortical region of the brain acts as a whole and is not divided into a number of faculties, as the phrenologists had maintained. -Using dogs and pigeons -Removing the cerebellum disturbed coordination and equilibrium. -Removing the cerebrum resulted in passivity. -Removing the semi-circular canals resulted in loss of balance.

36. Early Research on Brain FunctioningJean Pierre Flourens -�The nervous system is not a homogeneous system; the cerebral lobes do not act in the same way as the cerebellum, nor the cerebellum like the spinal cord, nor the cord absolutely like the nerves. But it is a single system, all of its parts concur, consent, and are in accord; what distinguishes them is the appropriate and determined manner of action; what unites them is a reciprocal action through their common energy.� (Flourens, 1824 ) -�The nervous system is not a homogeneous system; the cerebral lobes do not act in the same way as the cerebellum, nor the cerebellum like the spinal cord, nor the cord absolutely like the nerves. But it is a single system, all of its parts concur, consent, and are in accord; what distinguishes them is the appropriate and determined manner of action; what unites them is a reciprocal action through their common energy.� (Flourens, 1824 )

37. Early Research on Brain FunctioningPaul Broca -Broca, Paul (1824-1880) Found evidence that part of the left frontal lobe of the cortex is specialized for speech production or articulation. -The clinical method was first applied by Jean-Baptiste Bouillaud in 1825, but unfortunately for Bouillaud, he was strongly associated with the phrenologists and good scientists wanted to distance themselves as much as possible. -He arrived at the discovery of Broca�s area by studying the brains of aphasic patients (persons unable to talk), particularly the brain of his first patient in the Bic�tre Hospital, named "Tan,� who Broca discovered in 1861 to have a neurosyphilitic lesion in one side of the brain, precisely in the area which controlled speech.-Broca, Paul (1824-1880) Found evidence that part of the left frontal lobe of the cortex is specialized for speech production or articulation. -The clinical method was first applied by Jean-Baptiste Bouillaud in 1825, but unfortunately for Bouillaud, he was strongly associated with the phrenologists and good scientists wanted to distance themselves as much as possible. -He arrived at the discovery of Broca�s area by studying the brains of aphasic patients (persons unable to talk), particularly the brain of his first patient in the Bic�tre Hospital, named "Tan,� who Broca discovered in 1861 to have a neurosyphilitic lesion in one side of the brain, precisely in the area which controlled speech.

38. Early Research on Brain FunctioningCarl Wernicke -Wernicke, Carl (1848-1905) Discovered an area on the left temporal lobe of the cortex associated with speech comprehension. -Wernicke, Carl (1848-1905) Discovered an area on the left temporal lobe of the cortex associated with speech comprehension.

39. -Some months after the accident, probably in about the middle of 1849, Phineas felt strong enough to resume work.� But because his personality had changed so much, the contractors who had employed him would not give him his place again.� Before the accident he had been their most capable and efficient foreman, one with a well-balanced mind, and who was looked on as a shrewd smart business man.� He was now fitful, irreverent, and grossly profane, showing little deference for his fellows.� He was also impatient and obstinate, yet capricious and vacillating, unable to settle on any of the plans he devised for future action.� His friends said he was �No longer Gage.� -As far as we know Phineas never worked at the level of a foreman again.� According to Dr. Harlow, Phineas appeared at Barnum�s Museum in New York, worked in the livery stable of the Dartmouth Inn (Hanover, NH), and drove coaches and cared for horses in Chile.� In about 1859, after his health began to fail he went to San Francisco to live with his mother.� After he regained his health he worked on a farm south of San Francisco. In February 1860, he began to have epileptic seizures and, as we know from the Funeral Director�s and cemetery interment records, he died on 21st. May 1860. -Further evidence of localization of personality.-Some months after the accident, probably in about the middle of 1849, Phineas felt strong enough to resume work.� But because his personality had changed so much, the contractors who had employed him would not give him his place again.� Before the accident he had been their most capable and efficient foreman, one with a well-balanced mind, and who was looked on as a shrewd smart business man.� He was now fitful, irreverent, and grossly profane, showing little deference for his fellows.� He was also impatient and obstinate, yet capricious and vacillating, unable to settle on any of the plans he devised for future action.� His friends said he was �No longer Gage.� -As far as we know Phineas never worked at the level of a foreman again.� According to Dr. Harlow, Phineas appeared at Barnum�s Museum in New York, worked in the livery stable of the Dartmouth Inn (Hanover, NH), and drove coaches and cared for horses in Chile.� In about 1859, after his health began to fail he went to San Francisco to live with his mother.� After he regained his health he worked on a farm south of San Francisco. In February 1860, he began to have epileptic seizures and, as we know from the Funeral Director�s and cemetery interment records, he died on 21st. May 1860. -Further evidence of localization of personality.

40. Early Research on Brain FunctioningGustav Fritsch and Eduard Hitzig Discovered localization of motor areas in the cortex Stimulate an area electrically and parts of the body reliably moved The parts that moved were the opposite to the side stimulated. -Fritsch, Gustav (1838-1927) Along with Hitzig, discovered motor areas on the cortex by directly stimulating the exposed cortex of a dog. -Hitzig, Eduard (1838-1907) Along with Fritsch, discovered motor areas on the cortex by directly stimulating the exposed cortex of a dog. -Hitzig was a surgeon who applied mechanical stimuli to the exposed brain of a wounded soldier and witnessed different physical actions resulting from stimulating different areas. -Hitzig collaborated with Fritsch after the war. -Together they studied, systematically, electrical stimulation of the brains of dogs & rabbits. -A part of the convexity of the hemisphere of the brain of the dog is motor...another part is not motor. The motor part, in general, is more in front, the non-motor part more behind. By electrical stimulations of the motor part, one obtains combined muscular contractions of the opposite side of the body. -Fritsch, Gustav (1838-1927) Along with Hitzig, discovered motor areas on the cortex by directly stimulating the exposed cortex of a dog. -Hitzig, Eduard (1838-1907) Along with Fritsch, discovered motor areas on the cortex by directly stimulating the exposed cortex of a dog. -Hitzig was a surgeon who applied mechanical stimuli to the exposed brain of a wounded soldier and witnessed different physical actions resulting from stimulating different areas. -Hitzig collaborated with Fritsch after the war. -Together they studied, systematically, electrical stimulation of the brains of dogs & rabbits. -A part of the convexity of the hemisphere of the brain of the dog is motor...another part is not motor. The motor part, in general, is more in front, the non-motor part more behind. By electrical stimulations of the motor part, one obtains combined muscular contractions of the opposite side of the body.

41. Early Research on Brain FunctioningDavid Ferrier Created a �map� of the motor cortex using monkeys. Proposed the monkey map = human map Discovered the sensory areas of the cortex. Researchers after him discovered visual and auditory areas. -Ferrier, David (1843-1928) Discovered the sensory area of the cortex. -Low intensity faradic stimulation of the cortex in both animal species indicated a rather precise and specific map for motor functions. The same areas, upon being lesioned, caused the loss of the functions which were elicited by stimulation. Ferrier was also able to demonstrate that the high-intensity stimulation of motor cortical areas caused repetitive movements in the neck, face and members which were highly evocative of epileptic fits seen by neurologists in human beings and animals, which probably were due to a spread of the focus of stimulation. -He was also the first physiologist to make an audacious (if scientifically incorrect) of transposing cortical maps obtained in monkeys to its analogous in the human brain. -Ferrier, David (1843-1928) Discovered the sensory area of the cortex. -Low intensity faradic stimulation of the cortex in both animal species indicated a rather precise and specific map for motor functions. The same areas, upon being lesioned, caused the loss of the functions which were elicited by stimulation. Ferrier was also able to demonstrate that the high-intensity stimulation of motor cortical areas caused repetitive movements in the neck, face and members which were highly evocative of epileptic fits seen by neurologists in human beings and animals, which probably were due to a spread of the focus of stimulation. -He was also the first physiologist to make an audacious (if scientifically incorrect) of transposing cortical maps obtained in monkeys to its analogous in the human brain.

42. Early Research on Brain FunctioningElectrical Stimulation of the Human Brain Roberts Bartholow Took advantage of a �clinical opportunity� Mary Rafferty, a 30 yr old domestic worker was admitted to the hospital for a small ulcer on her scalp. The skull had worn away exposing a 2 in. area. -Needles were inserted at various points into the dura mater and into the brain. When the irritable granulations of the surface of the ulcer were touched, pain was experienced, but when the needle points were engaged in the dura mater, Mary declared, in answer to repeated questions that she felt no pain. During the brain stimulation, Mary Rafferty complained of a very strong and unpleasant tingling in her arms and legs... Despite this Bartholow reported that she remained cheerful throughout. He decided to increase the strength of the electrical stimulation. He described the tragic effects: -�In order to develop more decided reactions, the strength of the current was increased....When communication was made with the needles, her countenance exhibited great distress, she began to cry. Very soon the left hand was extended as if in the act of taking hold of some object in front of her; the arm presently was agitated with clonic spasms; her eyes became fixed, with pupils stentorous; she lost consciousness and was violently convulsed on her left side. The convulsion lasted about five minutes and was succeeded by coma. She returned to consciousness and complained of some weakness and vertigo.� -3 days later Mary Rafferty was still pale and depressed, yet he still planned further sessions. Had difficulty walking, complained of numbness, tingling, and frequent dizzy spells. -4 days after, was incoherent, had seizure followed by paralysis of right side... fell into coma & died. -He performed an autopsy which revealed the multiple needle tracks deep into her brain. -He was cast from his position at the University and was run out of Cincinnati-Needles were inserted at various points into the dura mater and into the brain. When the irritable granulations of the surface of the ulcer were touched, pain was experienced, but when the needle points were engaged in the dura mater, Mary declared, in answer to repeated questions that she felt no pain. During the brain stimulation, Mary Rafferty complained of a very strong and unpleasant tingling in her arms and legs... Despite this Bartholow reported that she remained cheerful throughout. He decided to increase the strength of the electrical stimulation. He described the tragic effects: -�In order to develop more decided reactions, the strength of the current was increased....When communication was made with the needles, her countenance exhibited great distress, she began to cry. Very soon the left hand was extended as if in the act of taking hold of some object in front of her; the arm presently was agitated with clonic spasms; her eyes became fixed, with pupils stentorous; she lost consciousness and was violently convulsed on her left side. The convulsion lasted about five minutes and was succeeded by coma. She returned to consciousness and complained of some weakness and vertigo.� -3 days later Mary Rafferty was still pale and depressed, yet he still planned further sessions. Had difficulty walking, complained of numbness, tingling, and frequent dizzy spells. -4 days after, was incoherent, had seizure followed by paralysis of right side... fell into coma & died. -He performed an autopsy which revealed the multiple needle tracks deep into her brain. -He was cast from his position at the University and was run out of Cincinnati

43. The Rise of Experimental Psychology Perceptions were triggered by brain processes which were themselves triggered sensations. How are the domains of mental sensations and sensory processes related? A science of psychology was impossible unless consciousness could be measured as objectively as the physical world. -Not only does conscious experience need to be measurable, but there must be a systematic relationship between them and the physical stimulation. -Not only does conscious experience need to be measurable, but there must be a systematic relationship between them and the physical stimulation.

44. The Rise of Experimental PsychologyErnst Heinrich Weber Obtained doctorate from University of Leipzig and taught there until retirement. Interested in the senses of touch and kinesthesis (The sensations caused by muscular activity). With his brother Eduard Friedrich Weber he discovered inhibitory power of the vagus nerve. With another brother, W. E. Weber, he made studies of acoustics and wave motion. -Weber, Ernst Heinrich (1795-1878) Using the two-point threshold and the just noticeable difference, was the first to demonstrate systematic relationships between stimulation and sensation. -Weber was the first to conclude that the sense of touch is actually several senses. -Pressure, temperature, and pain all different. -Also proposed a muscle sense (later called kinesthesis) -Weber, Ernst Heinrich (1795-1878) Using the two-point threshold and the just noticeable difference, was the first to demonstrate systematic relationships between stimulation and sensation. -Weber was the first to conclude that the sense of touch is actually several senses. -Pressure, temperature, and pain all different. -Also proposed a muscle sense (later called kinesthesis)

45. The Rise of Experimental PsychologyErnst Heinrich WeberWeber�s Work on Touch Two-point Threshold: The smallest distance between two points of stimulation at which the two points are experienced as two points rather than one. He used a compass-like device to simultaneously apply pressure to two points on the skin. On Touch: Anatomical and Physiological Notes (1834) provided charts of the entire body in regards to the two-point threshold. -On the tongue, the two point threshold was 1 mm, on the back it was 60 mm. -Differences in threshold are due to differences in the anatomical arrangement of sense receptors for touch.-On the tongue, the two point threshold was 1 mm, on the back it was 60 mm. -Differences in threshold are due to differences in the anatomical arrangement of sense receptors for touch.

46. The Rise of Experimental PsychologyErnst Heinrich WeberWeber�s Work on Kinesthesis Just Noticeable Difference (jnd): The sensation that results if a change in stimulus intensity exceeds the differential threshold. -Weber did the weight experiments with people�s hands resting on the table and with the hands extended freely. -When resting on the table, presumably only the tactile sensations were used to make judgments. -When held freely, both tactile sensations and kinesthetic sensations provided information for judgments. -jnd�s much smaller when held freely.-Weber did the weight experiments with people�s hands resting on the table and with the hands extended freely. -When resting on the table, presumably only the tactile sensations were used to make judgments. -When held freely, both tactile sensations and kinesthetic sensations provided information for judgments. -jnd�s much smaller when held freely.

47. The Rise of Experimental PsychologyErnst Heinrich WeberJudgments are Relative The jnd is a constant fraction of the standard weight. For lifted weights it is about 1/40, for non-lifted weights it is about 1/30 Weber's Law: Just noticeable differences correspond to a constant proportion of a standard stimulus. -For lifted weights, if the standard was 40 g, then the variable weight would have to be 39 or 41 g in order to be noticed as different. -Came to the belief that there is not a one-to-one correspondence between what is physically present and what is experienced psychologically. -Discrimination does not depend on the absolute difference between two stimuli, but rather the relative difference between them, or the ratio of one to the other. -Weber extended the findings to other senses. -Weber�s law can be considered the first statement of a systematic relationship between the physical and psychological worlds. -Since Weber was a physiologist, he really didn�t care about psychology.-For lifted weights, if the standard was 40 g, then the variable weight would have to be 39 or 41 g in order to be noticed as different. -Came to the belief that there is not a one-to-one correspondence between what is physically present and what is experienced psychologically. -Discrimination does not depend on the absolute difference between two stimuli, but rather the relative difference between them, or the ratio of one to the other. -Weber extended the findings to other senses. -Weber�s law can be considered the first statement of a systematic relationship between the physical and psychological worlds. -Since Weber was a physiologist, he really didn�t care about psychology.

48. The Rise of Experimental PsychologyGustav Theodor Fechner -Fechner, Gustav Theodor (1801-1887) Expanded Weber's law by showing that, for just noticeable differences to vary arithmetically, the magnitude of a stimulus must vary geometrically. -After physics, his interest shifted to sensation. -Published work on color vision and afterimages. -Was near blind due to looking through colored glasses at sun to study afterimages. -Fechner wrote at least 183 articles and 81 books.-Fechner, Gustav Theodor (1801-1887) Expanded Weber's law by showing that, for just noticeable differences to vary arithmetically, the magnitude of a stimulus must vary geometrically. -After physics, his interest shifted to sensation. -Published work on color vision and afterimages. -Was near blind due to looking through colored glasses at sun to study afterimages. -Fechner wrote at least 183 articles and 81 books.

49. The Rise of Experimental PsychologyGustav Theodor FechnerThe Adventures of Dr. Mises -Fechner�s panpsychic beliefs were definitely nonscientific and publication of these ideas under his own name would have been professional suicide. -Proof that the Moon is Made of Iodine was a satire against medicines use of iodine as a cure-all. -In The Comparative Anatomy of Angels he said: �Centipedes have God-knows-how-many legs; butterflies and beetles have six, mammals only four; birds, who of all earthly creatures rise closest to the angels, have just two. With each developmental step another pair of legs is lost, and �Since the final observable category of creatures possesses only two legs, it is impossible that angels should have any at all�� -In The Little Book of Life after Death he described human existence in three stages. -Stage one: before birth, spent alone in continuous sleep. -Stage two: life, spent alternating between sleeping and waking in the presence of others. -Stage three: One�s soul merges with other souls and becomes part of the Supreme Spirit and the ultimate nature of reality can be discerned. -Fechner�s panpsychic beliefs were definitely nonscientific and publication of these ideas under his own name would have been professional suicide. -Proof that the Moon is Made of Iodine was a satire against medicines use of iodine as a cure-all. -In The Comparative Anatomy of Angels he said: �Centipedes have God-knows-how-many legs; butterflies and beetles have six, mammals only four; birds, who of all earthly creatures rise closest to the angels, have just two. With each developmental step another pair of legs is lost, and �Since the final observable category of creatures possesses only two legs, it is impossible that angels should have any at all�� -In The Little Book of Life after Death he described human existence in three stages. -Stage one: before birth, spent alone in continuous sleep. -Stage two: life, spent alternating between sleeping and waking in the presence of others. -Stage three: One�s soul merges with other souls and becomes part of the Supreme Spirit and the ultimate nature of reality can be discerned.

50. The Rise of Experimental PsychologyGustav Theodor FechnerPsychophysics -Psychophysics came from Fechner�s interest in the relationship between mind and body. -Elements of Psychophysics (1860) -Psychophysics came from Fechner�s interest in the relationship between mind and body. -Elements of Psychophysics (1860)

51. The Rise of Experimental PsychologyGustav Theodor FechnerPsychophysicsWeber�s Law -Fechner formally stated Weber�s law mathematically. -�A dollar has much less value to a rich man than to a poor man. It can make a beggar happy for a whole day, but it is not even noticed when added to the fortune of a millionaire.�-Fechner formally stated Weber�s law mathematically. -�A dollar has much less value to a rich man than to a poor man. It can make a beggar happy for a whole day, but it is not even noticed when added to the fortune of a millionaire.�

52. The Rise of Experimental PsychologyGustav Theodor FechnerAbsolute Threshold -Negative sensations-According to Fechner, sensations that occur below the absolute threshold and are therefore below the level of awareness. -These negative sensations are also known as subliminal, (limen is the German word for threshold).-Negative sensations-According to Fechner, sensations that occur below the absolute threshold and are therefore below the level of awareness. -These negative sensations are also known as subliminal, (limen is the German word for threshold).

53. The Rise of Experimental PsychologyGustav Theodor FechnerAbsolute Threshold -Of course these are crude averages, they are different for everyone.-Of course these are crude averages, they are different for everyone.

54. The Rise of Experimental PsychologyGustav Theodor FechnerThe jnd as a Unit of Sensation S = sensation, k is the constant developed using Weber law, and R is the intensity of the stimulus. -The equation allowed for very accurate predictions of sensation at the middle ranges of sensory intensities. -Prediction falls off at the high or low extremes.S = sensation, k is the constant developed using Weber law, and R is the intensity of the stimulus. -The equation allowed for very accurate predictions of sensation at the middle ranges of sensory intensities. -Prediction falls off at the high or low extremes.

55. The Rise of Experimental PsychologyGustav Theodor FechnerEstimates of Weber Constants -Very large changes in saltiness are required to detect a difference. -Very, very small changes in Electric shock are needed to detect a difference. -Very large changes in saltiness are required to detect a difference. -Very, very small changes in Electric shock are needed to detect a difference.

56. The Rise of Experimental PsychologyGustav Theodor FechnerPsychophysical Methods -The subject sees a standard line and a comparison line.� They are asked to say if the comparison line is longer, shorter, or the same as the standard.� The comparison line adjusts accordingly.� If the comparison line is longer, it will shorten if the subject says it is longer.� It will continue to shorten if the subject again says it is either longer or equal to the standard stimulus.� If the subject says that it is shorter, the trial is over and the next trial begins. -The subject sees a standard line and a comparison line.� They are asked to say if the comparison line is longer, shorter, or the same as the standard.� The comparison line adjusts accordingly.� If the comparison line is longer, it will shorten if the subject says it is longer.� It will continue to shorten if the subject again says it is either longer or equal to the standard stimulus.� If the subject says that it is shorter, the trial is over and the next trial begins.

57. The Rise of Experimental PsychologyGustav Theodor FechnerPsychophysical Methods -The subject sees a comparison and a standard stimulus but cannot adjust them.� The subject simply indicates whether the comparison is longer or shorter. -The subject sees a comparison and a standard stimulus but cannot adjust them.� The subject simply indicates whether the comparison is longer or shorter.

58. The Rise of Experimental PsychologyGustav Theodor FechnerPsychophysical Methods -The subject sees a standard line and is asked to adjust another line to match it.� The subject can lengthen or shorten the line until they are satisfied. -The subject sees a standard line and is asked to adjust another line to match it.� The subject can lengthen or shorten the line until they are satisfied.

59. The Rise of Experimental PsychologyGustav Theodor FechnerFechner�s Contributions -The Elements of Psychophysics might be seen as the beginnings of experimental psychology. -However, psychology needed to be formally founded.-The Elements of Psychophysics might be seen as the beginnings of experimental psychology. -However, psychology needed to be formally founded.