Chapter 5: Empiricism, Sensationalism, and Positivism Flashcards
How did Bessel contribute to physiology and psychology with his reaction time study? How was is different form what Maskelynne and Kinnebrook’s conclusions?
Bessel (1784-1846), who speculated that the error had not been due to incompetence but to individual differences among observers. Bessel set out to compare his observations with those of his colleagues and indeed found systematic differences among them. This was the first reaction-time study, and it was used to correct differences among observers. This was done by calculating personal equations. For example, if 8/10ths of a second was added to Kinnebrook’s reaction time, his observations could reliably be equated with Maskelyne’s. Bessel found systematic differences among individuals and a way to compensate for those differences, but his findings did not have much impact on the early development of psychology.
Why did physiologists and scientists in the 17th and 18th century take to examining physical differences in lieu of Galileo’s primary and secondary qualities?
Because the most likely source of the discrepancy was the responding organism, physical scientists had reason to be interested in the biological processes by which organisms interact with the physical world. Physiologists studied the nature of nerves, neural conduction, reflexive behavior, sensory perception, brain functioning, and, eventually, the systematic relationship between sensory stimulation and sensation.
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.
Charles Bell, the famous British physiologist, discovered the difference between sensory and motor neurons eleven years before Madendie did.
This clarified that sensation and movement, two things thought to be controlled by animals spirits or outside forces prior to this discovery, were actually mediated by the brain.
What was the ultimate contribution of the Bell-Magendie Law?
After Bell and Magendie, it was no longer possible to think of nerves as general conveyers of vibrations or spirits. Now a “law of forward direction” governed the nervous system. Sensory nerves carried impulses forward from the sense receptors to the brain, and motor nerves carried impulses forward from the brain to the muscles and glands.
Johannes Muller (1801-2858)
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.
Sensory receptors in the eye have a distinct reaction to light, just like mechanoreceptors in the ear respond in their own special way.
The Doctrine of Specific Nerve Energies
Each sensory nerve, no matter how it is stimulated, releases an energy specific to that nerve.
Theory of Adequate Stimulation
Although Müller claimed that various nerves contain their own specific energy, he did not think that all the sense organs are equally sensitive to the same type of stimulation. Rather, each of the types of sense organs is maximally sensitive to a certain type of stimulation. Müller called this “specific irritability,” and it was later referred to as adequate stimulation.
what was the most significant implication of Muller’s research?
The most significant implication of Müller’s doctrine for psychology was that the nature of the central nervous system, not the nature of the physical stimulus, determines our sensations.
Kant vs. Muller - similarities and differences
An ardent Kantian, Müller believed that he had found the physiological equivalent of Kant’s categories of thought. According to Kant, sensory information is transformed by the innate categories of thought before it is experienced consciously. For Müller, the nervous system is the intermediary between physical objects and consciousness. Kant’s nativism stressed mental categories, whereas Müller’s stressed physiological mechanisms. In both cases, sensory information is modified, and therefore, what we experience consciously is different from what is physically present.
Legacy of Muller
Müller was one of the greatest experimental physiologists ever. His Handbuch summarized what was known about human physiology at the time. Müller also established the world’s first Institute for Experimental Physiology at the University of Berlin. In addition, Müller understood the close relationship between physiology and psychology. He said, “Nobody can be a psychologist, unless he first becomes a physiologist” (Fitzek, 1997, p. 46).
Hermann von Helmholtz (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.
He was a student of Muller’s, and was an ardent materialist (anti-vitalist).
Helmholtz and Muller
Although Helmholtz accepted many of Müller’s conclusions, the two men still had basic disagreements, one of them over Müller’s belief in vitalism. In biology and physiology, the vitalism-materialism problem was much like the mind–body problem in philosophy. The vitalists maintained that life could not be explained by the interactions of physical and chemical processes alone. For the vitalists, life was more than a physical process and could not be reduced to such a process. Furthermore, because it was not physical, the “life force” was forever beyond the scope of scientific analysis. Müller was a vitalist.
Conversely, the materialists saw nothing mysterious about life and assumed that it could be explained in terms of physical and chemical processes. Therefore, there was no reason to exclude the study of life or of anything else from the realm of science. Helmholtz sided with the materialists, who believed that the same laws apply to living and nonliving things, as well as to mental and nonmental events.
Helmholtz and nerve conduction
He measured the speed of nerve conduction in the legs of frogs in a lab set up while he was doing his time in the army medical program. he found out that when he stimulated a nerve fiber attached to a muscle from a short and far distance, it took longer for the muscle to react when he stimulated from further away. He measured the speed of nerve conduction in humans to be about 165-330 ft/sec.
unconscious inference
According to Helmholtz, the process by which the remnants of past experience are added to sensations, thereby converting them into perceptions.
sensations + elements of past experience = perception
Helmholtz: sensation vs. perception
Although he believed that the physiological apparatus of the body provides the mechanisms for sensation, Helmholtz thought that the past experience of the observer is what converts a sensation into a perception. Sensations, then, are the raw elements of conscious experience, and perceptions are sensations after they are given meaning by one’s past experiences.
Helmholtz and Kant agreed on one important point: The perceiver transforms what the senses provide.
For Kant this transformation was accomplished when sensory information was structured by the innate faculties of the mind. For Helmholtz, the transformation occurred when sensory information was embellished by an individual’s past experience. With his notion of unconscious inference, Helmholtz came very close to what would later be considered part of psychology. That is, for unconscious inference to convert a sensation into a perception, memories of previous learning experiences must interact with current sensations.
Helmholtz: humans as energy systems
Applied law of conservation of energy to people by establishing the a human’s energy output was proportional to the amount of food and oxygen consumed but that person.
Helmholtzs’ legacy
Although Helmholtz was an empiricist in his explanations of sensation and perception, he did reflect the German Zeitgeist by postulating an active mind. According to Helmholtz, the mind’s task was to create a reasonably accurate conception of reality from the various “signs” that it receives from the body’s sensory systems. Helmholtz assumed that a dynamic relationship exists among volition, sensation, and reflection as the mind attempts to create a functional view of external reality. Helmholtz’s view of the mind differed from that of most of the British empiricists and French sensationalists because they saw the mind as largely passive. For Helmholtz the mind’s job was to construct a workable conception of reality given the incomplete and perhaps distorted information furnished by the senses (Turner, 1977).
Franz Joseph Gall (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. (See also Phrenology.)
Gall accepted the widely held belief that faculties of the mind acted on and transformed sensory information, but he made three additional claims that changed the history of faculty psychology:
The mental faculties do not exist to the same extent in all humans.
The faculties are housed in specific areas of the brain.
If a faculty is well developed, a person would have a bump or protrusion on the corresponding part of the skull. Similarly, if a faculty is underdeveloped, a hollow or depression would be on the corresponding part of the skull.
phrenology
The examination of the bumps and depressions on the skull in order to determine the strengths and weaknesses of various mental faculties.
Mental faculties are different in different people, and faculties are housed in different areas of the brain.
German tradition
Rationalist: Kant, Leibniz, and Spinoza
Physiologists: Muller and Helmholtz
Psychophysics: Psychological perceptions in response to physical attributes of a stimulus
what did phrenology spur in physiological science?
Initiated the search for localized functions
Stimulated interest in individual differences, mental testing
Weaknesses:
Skull shape reflects shape of brain underneath
Choice of specific psychological qualities
Explained away virtually every contradiction
One reason for the popularity of phrenology was Gall’s considerable reputation. Another was that phrenology provided hope for an objective, materialistic analysis of the mind: “The central theme that runs through all of the phrenological writings is that man himself could be studied scientifically, and in particular that the phenomena of mind could be studied objectively and explained in terms of natural causes”
legacy of phrenology
In time, the specific claims of the phrenologists were rejected, but phrenology did influence subsequent psychology in a number of important ways: It argued effectively that the mind and brain are closely related; it stimulated intense research on the localization of brain functions; and it showed the importance of furnishing practical information.
Pierre Flourens (1794-1867)
Tested phrenologists’ ideas by using ablation (destroying parts of the brain)
Often observed behavioral changes that didn’t correspond to phrenologists’ ideas
Showed some evidence of plasticity
Paul Broca (1824-1880)
Found evidence that part of the left frontal lobe of the cortex is specialized for speech production or articulation.
Discovered relation between left hemisphere injury and aphasia
First to link a disorderwith specific part of the brain
Ernst Webber (1795-1878)
Mapped two-point thresholds on entire body
Just Noticeable Difference (jnd): Smallest amount that must be added or subtracted to a stimulus before it is judged different
two-point threshold
The smallest distance between two points of stimulation at which the two points are experienced as two points rather than one.
Weber’s Law
Just noticeable differences correspond to a constant proportion of a standard stimulus.
During his research on kinesthesis, Weber made the startling observation that the jnd is a constant fraction of the standard weight. For lifted weights, that fraction is 1/40; for nonlifted weights, it is 1/30. Using lifted weights as an example, if the standard weight is 40 grams, the variable weight would have to be 41 grams to be judged heavier or 39 grams to be judged lighter than the standard. If the standard weight is 160 grams, the variable weight would have to be 164 grams or 156 grams to be judged heavier or lighter, respectively, than the standard.
Gustav Fechner (1801-1887)
Expanded Weber’s law by showing that, for just noticeable differences to vary arithmetically, the magnitude of a stimulus must vary geometrically.
He got a doctorate medical degree at 21 and then turned his attention to physics and mathematics. He then had a nervous breakdown and become depressed for several years, which turned his attention to philosophy. He accepted Spinoza’s view of double aspectism, and became disenchanted with materialism. He believed in panapsychism.
panapsychism
The belief that everything in the universe experiences consciousness.
psychophysics
The systematic study of the relationship between physical and psychological events.
absolute threshold
The smallest amount of stimulation that can be detected by an organism.
Fechner’s contributions
Each sense has an absolute threshold (limen) and difference threshold (jnd)
jnd is a psychological phenomenon that can be quantified
What we see does not only depend on whois looking but also what is really there
Fechner’s Law
S=k(log r)
Physical stimulus must change geometrically for us to notice an arithmetic change
It’s not a 1:1 correspondence!
Fechner’s legacy in psychology is:
- possible
- experimental
- quantitative
Wilhelm Wundt (1832-1920)
prolific scientist who published a total of 53,000 pages of research over his lifetime.
Muller was his professor and Helmholtz was impressed by him.
he disagreed with Galileo, Kant, and Comte who said that psychology could never be a science
his goal was to understand both the simple and complex conscious phenomena, the former using experimental research and the latter using naturalistic observation.
voluntarism
Wundt was the founder
The name given to Wundt’s school of psychology because of his belief that, through the process of apperception, individuals could direct their attention toward whatever they wished.
scientific study of human consciousness - sensation, perception, reaction time, attention, feeling, association
Anti-materialist and strong rationalist (leibniz)
what were Wundt’s two major goals of experimental psychology?
to discover the basic elements of though
to discover the laws by which mental elements combine into more complex mental experiences
elements of thought according to Wundt
sensation (A basic mental experience that is triggered by an environmental stimulus), and feelings (The basic elements of emotion that accompany each sensation. Wundt believed that emotions consist of various combinations of elemental feelings)
apperception
Attention and apperception go hand in hand; what is attended to is apperceived. Unlike perception, which is passive and automatic, apperception is active and voluntary. In other words, apperception is under the individual’s control. It was primarily because Wundt believed so strongly that individuals could direct their attention by exercising will that he referred to his approach to psychology as voluntarism.
active process directed by the will - engages in creative synthesis (complex thinking, arranging, and rearranging mental elements)
pure introspection
relatively unstructured slef-observation
experimental introspection
scientifically respectable, according to Wundt
physical vs psychological causation
Wundt believed that psychological and physical causality were “polar opposites,” because physical events could be predicted on the basis of antecedent conditions and psychological events could not. It is the will that makes psychological causation qualitatively different from physical causation. We have already seen that Wundt believed humans can willfully arrange the elements of thought into any number of configurations (creative synthesis). Wundt also believed that because intentions are willfully created, they cannot be predicted or understood in terms of physical causation
Edward Bradford Titchner (1867-1927)
For him, psychology was experimental psychology (as he defined it); and everything that preceded his version of psychology was not psychology at all: “To Titchener, the American psychologies prior to the 1880s—and much since then—were little more than watered-down Cartesianisms, codified phrenologies, or worst of all, thinly disguised theology” (Evans, 1984, p. 18). When the school of behaviorism was introduced by John B. Watson in the early 1900s (see Chapter 12), Titchener (1914) claimed that it was a fine technology of behavior but not psychology. Titchener was also opposed to pursuing psychological information for its applied value; science seeks pure knowledge, and psychology (his psychology) was a science: “Science deals, not with values, but with facts.
how did Titchner define consciousness?
as the sum total of mental experience at a given time. the mind was the accumulated experiences of a lifetime
structuralism
The school of psychology founded by Titchener, the goal of which was to describe the structure of the mind.
What Titchener sought was a type of periodic table for mental elements, what chemists had developed for the physical elements. Once the basic elements were isolated, the laws governing their combination into more complex experiences could be determined.
Titchner’s view of psychology
it must be scientific: use observation to study conscious experience
psychology involved finding the basic elements of experience
psychology involved finding how to combine those elements
he used highly trained introspectors that wouldn’t commit the stimulus error
stimulus error
Letting past experience influence an introspective report.
Titchener’s subjects, therefore, had to be carefully trained to avoid reporting the meaning of a stimulus. The worst thing introspectionists could do would be to name the object of their introspective analysis. If the subjects (more accurately, observers) were shown an apple, for example, the task would be to describe hues and spatial characteristics (red, round, smooth, etc)
what did titchner conclude that the elemental processes of consciousness consist of?
Titchener concluded that the elemental processes of consciousness consist of sensations (elements of perceptions), images (elements of ideas), and affections (elements of emotions).
According to Titchener, an element could be known only by listing its attributes. The attributes of sensations and images (remnants of sensations) are quality, intensity, duration, clearness, and extensity. Extensity is the impression that a sensation or image is more or less spread out in space. Affections could have the attributes of quality, intensity, and duration but neither clearness nor extensity.
laws that generate consciousness according to Wundt
perception - passive
apperception - active
perception
a passive process that depends on the nature of the stimulus and the perceiver (their anatomy and past experiences)
decline of structuralism
too narrow in its definition of psychology
it didn’t study the applied side of psychology, the unconscious, abnormal, children, animals, behavior, or unobservable events.
dismissed other schools that presented relevant and scientific information
introspection was the only method of study
significance of structuralism
it did establish psychology as an experimental science next to biology and physiology
it studied introspection very thoroughly
