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What did Franz Gall aim to find out?
He sought to scientifically find modularity and localization of brain functions.
What did Gall develop?
The first cohesive ideas about phrenology.
However, he was focused on organology (Spurzheim would later develop it into phrenology).
What is phrenology?
A 19th century pseudoscience that attempted to determine a person's character and intellectual potential by feeling the bumps on their skull.
What was Gall the first person to do?
First person to study faculties of the mind empirically.
How did Gall study the brain?
He dissected animals and humans.
He used a bottom-up approach and noticed there was no central processing unit for the brain, but rather it proliferated outwards to regions of the cortex, rather than cutting into the cortex directly.
What technique did Gall use for his research?
Cranioscopy.
What did Gall examine to decipher the magnitude of one’s faculties (in the mind)?
Bumps and depressions on one’s skull.
What did Gall believe about the shape of a person’s head?
It revealed intelligence and emotional character.
What did Gall believe about the faculties of the mind?
They act upon and transform sensory information, but these faculties don’t exist to the same extent in all people.
If a faculty is well developed, the brain region will grow, and a bump will be noticeable on the skull.
If the faculty is underdeveloped, it will cause an indent.
What does Gall’s atlas show?
The different plates, some overlapping, some far apart.
What did Gall sugget regarding the brain?
It was divided into 27 separate "organs,” with each organ corresponding to a discrete faculty.
Of these, 19 were shared with other animal species, and 8 were specific to humans.
Who was Johann Gaspar Spurzheim?
A young colleague of Gall’s. Whereas Gall was interested in the science behind organology, Spurzheim saw it as an opportunity to advance his own career.
They parted ways in 1813, when Spurzheim developed organology into a more elaborate and systematic practice called phrenology.
Why did Spurzheim become a popular lecturer and writer?
The public was very interested in phrenology, specifically because of the mental muscle approach suggesting that if you were lacking in one area, you could work towards improving it.
Why did phrenology move away from scientific evidence?
More and more research suggested that Gall and Spurzheim weren’t entirely correct.
What is the psychograph?
A novelty device featured in department stores and theatre lobbies during the Great Depression.
In only 5 minutes, the operator was able to describe a patient’s personality by printout in 32 different categories.
These categories included: perceptiveness, constructiveness, alimentiveness (love of food + drink), conjugal love (sexual enthusiasm), and suavity.
When did Phrenology come to the US and why?
In 1820, with a lecture to the Massachusetts Medical Society by John Collins Warren.
As the US is a pragmatic society, Americans were interested in what works, what helps, and what is practical.
What did Pierre Flourens try to do?
He attempted to scientifically disprove phrenology in 1815.
He used the method of ablation or extirpation (destroying part of the brain and noting behavioural consequences).
He also investigated localization of brain functions.
His finding were contrary to the phrenologists.
What did Flourens experiments result in?
In his experiments with pigeons and rabbits, ablation resulted in behavioral disturbances.
What did Flourens discover about the vestibular system?
The pigeon, with its vestibular system removed, was left without a sense of proprioception (balance and spatial orientation).
What did Flourens discover about the cerebellum?
The pigeon, with its cerebellum removed, was left with no muscular coordination or sense of equilibrium.
What did Flourens discover about the medula oblongata?
Destroying the medulla oblongata resulted in the death of the animal.
What did Flourens discover about the mid brain?
That parts of it control visual and auditory reflexes.
Overall, what did Flourens discover about the brain?
Although there is some localization, much of the brain works as a single unit.
He also observed that, in some cases, the function that was lost to an ablation was regained later.
What other aspects did Flourens challenge about Gall’s views?
That personality could be attributed to the size or shape of the brain.
Behaviours such as balance could be tested but possibly not personality.
Moreover, Flourens never really saw different-sized brains.
The indents on the skull were hardly ever reflective of the state of the brain,
What was Flourens wrong about?
Although he proved the phrenologists wrong, he was wrong about the idea that we could ablate humans.
So the next best thing is to observe someone with a brain disorder in a clinical setting (the clinical method).
What does the clinical method involve?
It involves a posthumous examination of brain structures to detect damaged areas assumed to be responsible for behavioural conditions that existed before the person died.
What did Paul Broca do?
He treated a man called Louis Victor Leborgne who was only capable of saying the word “Tan,” even though he could comprehend speech.
When Mr. Leborgne died, Broca dissected his brain and found a lesion in the left hemisphere’s frontal lobe (broca’s area) caused by neurosyphilis, which, he concluded, had been responsible for Leborgne’s loss of speech.
What is Broca’s Area?
The left, lateral portion of the frontal lobe.
The disorder associated with Broca’s Area called?
Broca’s aphasia (impairment in langauge).
What else did Broca use to study the brain?
Craniometry.
He used it to determine the relationship between brain size and intelligence.
He concluded that a larger brain meant the person was more intelligent (basically using this to suggest men are smarter than women).
What did Carl Wernicke do?
He identified a similar type of problem as Broca, however, these patients were able to speak but not able to actually comprehend language.
What was the cause for the problem Wernicke discovered in language comprehension?
After examining the brain of patients, lesions were found at a junction of the parietal, temporal, and occipital loves.
This region of the brain is now known as Wernicke’s area and is associated with the understanding of spoken and written language.
The disorder associated with Wernicke’s Area is called?
Wernicke’s Aphasia (ability to produce speech but not understand language).
What did Broca and Wernicke prove?
That although there is localization of function in certain regions, there is also some distribution.
What happened to the patient Phineas Gage?
He was working on a railroud when a tamping iron flew through Gage’s left cheek, into his brain, and exited through his skull.
What happened to Gage?
He survived the accident, but started acting very differently.
He became irritable, used profanity, had difficulties making and following through with plans, unable to maintain a job or relationship.
What did Gage become?
The exemplar of what the frontal lobe is responsible for, specifically executive functioning (planning, emotional regulation, delaying gratification).
What did Eduard Hitzig do?
He worked with soldier wounded in battle. Many soldiers had parts of their skull removed (exposed brain visible).
He then applied wires from a battery to the cortex and then observed what happened. Often the soldiers had involuntary rections, twitching and/or screaming.
What did Hitzig and Fritsch do in 1870?
Hitzig joined another physicist, Gustav Theodor Fritsch, to test the hypothesis that the motor area is in the cortex.
They restrained live dogs and removed parts of their skulls to expose the cortex.
With a current from a battery, they stimulated different regions.
What did Hitzig and Frisch discover?
They noticed that the cortex is not insensitive.
Furthermore, if a region on the right hemisphere was stimulated, the left leg moved, and vice versa, thus discovering both the motor cortex and contralaterality.
The sensory cortex was also discovered.
What did David Ferrier do in 1876?
He used similar methodology as Fritsch and Hitzig, but on non-human primates to produce a more articulate map of the cortex.
He was able to fine tune regions that would provoke the movement of one finger or even the twitch of an eyelid.
Who was David Hartley?
A physician and became known as the father of associationism (due to his physiological perspective of this process).
He was influenced by Newton and Locke.
What did Hartley believe regarding the mind-body connection?
He contended that a physiological response was required to engage the physical mind.
What was Hartley’s goal?
To synthesize Newton’s conception of nerve transmission (one involving vibrations in the nerves) with empiricism (requiring sensory experience).
Newton had contended that nerves were solid, unlike Descartes’ hollow tube theory. Also, Newton believed that when a vibration in the nerves had started, the law of inertia maintained it.
What did Hartley suggest based off of Newton’s theories?
That whenever there is an interaction with the world, there begins a vibration in our nerves. The nerves carry this vibration (or impression) to the brain.
What did Hartley believe the vibrations in the brain caused?
Sensations.
The vibrations in the brain are sustained via inertia, even after the impression is gone. It was this lingering vibration that formed an idea.
What did Hartley believe ideas were?
Ideas are less intense vibrations (or vibratiuncles) formed from sensations. Ideas may become associated through contiguity.
Similar to Locke, Hartley postulated simple and complex ideas.
How did Hartley describe simple ideas?
Simple ideas become associated to form complex ideas when vibratiuncles come together, either through the law of contiguity or simultaneous association.
How did Hartley describe complex ideas?
Complex ideas are formed from simple ideas and can become associated with other complex ideas to form “decomplex” ideas.
What else is nerve vibration responsible for, according to Hartley?
For the experience of pleasure and pain, suggesting a hedonist perspective of motivation, such that excessive nerve vibration produced pain and mild to moderate vibration produced pleasure.
eg. If you accidentally bang your hand on the desk really hard, you will feel pain (you might even feel a vibration pulsing through your hand and arm).
How do vibrations lead to associations?
Through experience, we come to associate certain behaviours with pleasure or pain and will either continue this behaviour or not (eg if hand slammed on table hurts, won’t do it again).
This suggests that the laws of association can be applied to behaviour to describe how involuntary behaviour can lead to voluntary behaviour.
Who is Luigi Galvani and what did he study?
Galvani was an Italian physician and physicist who studied the electrical nature of nerve impulses.
His research became a book, which was fundamental in terms of the scientific community either seeking to support or refute his findings.
What was Galvani’s discovery?
That electricity could generate a muscular contraction. This happened serendipitously when his assistant was using a scalpel on a nerve in a frog’s leg, when a spark from a nearby generator caused the leg to twitch.
What did Galvani believe this twitch was caused by?
After mutliple experiments, he concluded that animal tissue contained within it an “animal electricity”.
Who was Alessandro Volta and what did he do?
Volta proved that Galvani’s idea of “animal electricity” was wrong, electricity did not emerge from the animal tissue itself, but rather from the effect produced by the contact of two different metals.
What did Giovanni Aldini do?
Galvani’s nephew travelled around Europe to show crowds how he could make dead animals move using electrical stimulation.
What did Aldini do in 1803 to reanimate a corpse?
Aldini really pushed the envelope in 1803 when he “Galvanized” the corpse of George Forster, a man who had just been executed for murdering his wife and child.
Not only did Aldini electroshock the face resulting in the twitches of the eyes and mouth, he inserted an electrified rod into the corpse’s rectum causing the body to spring up and animate, terrifying the onlookers.
Fun fact: Mary Shelley was so taken in by Galvani and Aldini’s work that she was inspired to write Frankenstein.
What did Charles Bell and Francois Magendie disprove about Descarte’s theory of hollow tubes having no directionality?
They demonstrated that sensory nerves enter the dorsal roots of the spinal cord and motor nerves emerge from the ventral roots.
What did Bell and Magendie prove?
Although Bell and Magendie never worked together, they shared the acclaim for nerve specificity and proved that nerve physiology could be divided into sensory and motor function.
What did Bell specifically find?
In 1811, Bell suggested that there were two different types of nerve fibers: motor and sensory.
He stimulated both nerves on a dead animal and realized that only the stimulation of motor nerves resulted in movement of muscle tissue.
However, the fact that he was experimenting on dead animals could not actually prove the existence of sensory nerves.
What did Magendie specifically find?
In 1822, Magendie used live animals to fill in the gap that Bell had left.
Magendie used live puppies and severed either the anterior or posterior nerve.
He noted that stimulation of the anterior portion of the spinal cord resulted in movement (motor neurons) with no sign of pain.
On the other hand, stimulation of the posterior resulted in pain sensory neurons) without the ability to pull away.
How was Descarte’s theory altered?
There was a progression from hollow tubes to the specificity and directionality of nerves.
Sensory nerves carried impulses from sensory receptors to the brain, whereas motor nerves varied impulses from the brain to muscles and glands. This suggested separate sensory and motor regions, making it no longer possible to think of nerves as general conveyers of vibrations or spirits.
Who was Johannes Müller?
A physiologist who researched and wrote extensively about the human and animal visual sytem.
What did Johannes Müller do?
He demonstrated that each sensory nerve contains a specific energy that, when stimulated, will create the sensation.
How did Müller expand on Bell & Magendie’s findings?
Other than replicating the experiments to find the same results, he expanded on their findings by demonstrating even more specificity to sensory nerves.
Müller demonstrated that each of the five types of sensory nerves has its own energy and results in a characteristic sensation.
Ie. each nerve responds in its own characteristic way, regardless of the stimulation that activated it.
Eg. if you rub your eye really hard, you will notice flashes of light, even though there is no light entering the eye.
What else did Müller expand on regarding these stimulations and sensations?
Although these organs can be stimulated in any way and will achieve the sensation associated with that sensory modality, each sensory system is maximally sensitive to a specific type of stimulation or specific irritability, as Müller described this.
What are the adequate stimulations for each sensory system?
Light waves - Visual system
Sound waves - Auditory system
Temperature/Texture - Touch
Chemicals - Taste & Smell
What does adequate stimulation mean for our interaction with the physical world?
Correspondence between the physical world and our experience of it was reliant on our senses being adequately stimulated and our ability to bring all these sensations together to form a picture of the world.
This allows for a full experience of the world in a moment.
What is it that creates this picture of the world?
It is our nervous system, with the information from the body’s sensory modalities, that creates it rather than the stimuli themselves.
What did Müller suggest regarding Kant’s categories of thought?
That perhaps what Kant defined as categories of thought might actually be the nervous system.
It is the nervous system that is the intermediary between sensation and perception. Our nervous system gives us the phenomenal experience.
What is Müller’s stance regarding the schools of thought?
Although many of his views were inherently Empiricist, he advocated for an active mind which processed sensory experiences and allowed us to experience our subjective world.
Who was Hermann von Helmholtz?
He can be considered one of the greatest scientists of the 19th century.
He was a prolific researcher in physics and physiology. He made an instrumental contribution to psychology, specifically in terms of the study of metabolism as well as sensation and perception, specifically vision.
What did von Helmholtz emphasise?
Mechanism and Determinism.
He fought against Vitalism.
He assumed that the human sense organs functioned like machines and there was no need to focus on soul or an immaterial mind.
What did von Helmholtz discover in 1847?
While in the army, he researched metabolic processes in frogs.
He discovered that the food and oxygen that the frog took in could account for energy expenditure. This allowed him to extend the principle of conservation of energy to all living things.
What does the principle of conservation of energy suggest?
That energy within a system is constant, it cannot be added or subtracted but can be transformed from one thing to another in terms of taking in food energy and expending it.
Extending Newton’s laws to living organisms further helped solidify the materialist perspective.
What did it mean that von Helmholtz assumed the materialist perspective?
That nothing was immeasurable.
Our perceptions, as well as our interactions with the environment, were physical rather than due to some mysterious process.
What did von Helmholtz seek to do?
To measure the rate of nerve conduction, which others, like Müller, believed to be impossible.
This is because Müller believed in vitalism or something special that made nerve conduction almost instantaneous.
How did von Helmholtz prove that the rate of nerve conduction was measurable?
He used frogs and isolated the nerve that travelled to the frog’s legs. He stimulated this at different places and measured the response time. He measured the response time when the stimulation was further away from the muscle, then compared it to the response time when it was closer to the muscle. The difference in response time allowed him to calculate the rate of nerve conduction, which was approximately 90 feet per second.
What other reaction time did von Helmholtz study?
Human reaction time (in order to estimate the nerve impulse).
What is reaction time?
The amount of time it takes to respond to a specific stimulus.
How did von Helmholtz measure reaction time in humans?
He asked participants to push a button when they felt their leg being stimulated. Again, he found that the location of the stimulation made a difference in response time.
Stimulating the leg closer to the toe resulted in a longer response time than when stimulating the thigh.
By calculating the difference, he noted that the rate of nerve conduction was between 165 to 196 feet per second.
How did von Helmholtz’s measured rate of nerve conduction compare to Müller’s theory?
In comparison to Müller’s instantaneous theory, it was quite slow.
The slowness was also due to the reliance on reaction times which tend to be different between people.
How did von Helmholtz contribute to Psychology in terms of perception?
Although he believed sensations were raw elements of experience, he also believed perceptions were due to the assigned meaning of the sensation.
How did von Helmholtz explain the transformation from sensation to perception?
He relied on the ideas of unconscious inference from past experience. He even suggested that most of Kant’s categories of thought could be explained by experience.
Maybe we perceive space and time because we have experienced movement and the passage of time. He even suggested that if someone who has been blind all their lives suddenly were able to see, they would have to learn how to perceive.
What did von Helmholtz invent in 1851?
The Ophthalmoscope.
This machine allows doctors and researchers to look at the retina, ie it allows access to the posterior portion of the eye.
What was another one of Müller’s ideas von Helmholtz sought to challenge?
Müller’s idea that colour vision had one specific nerve energy.
Von Helmholtz suggests that there were, in fact, three types of color receptors corresponding to the three primary additive colours (red, green, blue).
What is von Helmholtz’s theory about color receptors called?
The Young-Helmholtz Theory of Color
or
The Trichromatic Theory of Color
How does the Trichromatic/Young-Helmholtz Theory of Colour work?
The firing of these 3 colour receptors in various combinations results in subjective colour experiences corresponding to various wavelengths of light.
How did von Helmholtz test his colour theory?
He used colour-matching experiments where participants would combine different wavelengths of light to match a test colour.
If the participants only had two wavelengths to play with, they could never match it, but if they had the three wavelengths, then they could match any colour.
How did von Helmholtz challenge Müller’s idea regarding hearing?
Instead of the idea that hearing just had one specific nerve energy, von Helmholtz thought it was a complex system.
He also proposed a resonance place theory of auditory perception in which pitches of sound we hear are determined to a great extent on where along the basilar membrane the most vibration is occurring in response to a sound vibration.
How did von Helmholtz prove his theory on hearing?
If you uncoil the basilar membrane, which is coiled in the cochlea (shaped like a snail shell), there are different-sized hair cells. He showed that these receptors are able to vibrate based on incoming sound. A certain frequency will cause the appropriate receptors to vibrate and, hence, we can experience the sound.
What did Ewald Hering do in 1892?
He proposed an alternative theory of colour vision to the tri-chromatic theory.
Hering noted that some colours do not blend (no reddish green colour), nor could the perception of yellow seem to be explained by the mixing of inputs from the three receptors discussed by von Helmholtz.
Therefore, Hering suggested that there are photoreceptors, which are linked together to respond in an opponent-process manner; red-green, blue-yellow, and black-white. Activation of one inhibits the other.
What is Hering’s colour theory called?
Opponent Process Theory
Who’s theory of colour was correct: von Helmholtz or Hering?
Both.
Von Helmholtz’s theory is correct at the retina level, but neural processes further up in the system work in Hering’s opponent process manner.
What did Christine Ladd-Franklin propose regarding theory of colour vision in 1892?
She proposed a theory based on evolutionary theory and evolution of the physiology of the system.
She believed that the ability to perceive colour combinations evolved over time.
What does Ladd-Franklin’s theory of colour propose?
She concluded that achromatic vision came first, then blue-yellow sensitivity, and finally red-green sensitivity.
Achromatic vision (black-white) was developed first throughout evolution since it occurs under the greatest variety of conditions and is the most adaptive.
Therefore, unlike red-green colour blindness, the majority of the population is unaffected by black-white colour blindness.
She further explained that the colour white later became differentiated into blue and yellow, and yellow differentiated into red-green vision.
Who was Johann Friedrich Herbart?
A German philosopher who took Kant’s contention that psychology needed to be mathematical for it to be a true science and set out to do just that.
What did Herbart propose?
That numbers could be assigned to psychological experiences of different intensities. It is in fact the study of these intensities and the resulting responses that will be further discussed in terms of psychophysics.
What are psychophysics?
A branch of study involving the physical measurement and qualification of psychological phenomena.
What did Herbart believe regarding ideas?
That ideas had a force or energy of their own, and the laws of association were not necessary to bind them.
He referred to this as psychic mechanics.
