Chapter 8-Early Developments In Physiology And The Rise Of Experimental Psychology Flashcards
Mathematical formulae used to correct for differences in reaction time among observers
Personal equations
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-Magendie law
Radically changed the view of neural transmission. Bell operated on rabbits and demonstrated that sensory nerves enter the posterior roots of the spinal cord and the motor nerves emerge from the anterior roots. His discovery separated nerve physiology into the study of sensory and motor functions-that is, into a study of sensation and movement
**Significant because it demonstrated that specific mental functions are mediated by different anatomical structures. That is, separate nerves control sensory mechanisms and responses
A monumental figure in the history of science who did pioneer work in the areas of nerve conduction, sensation, perception, color vision, and audition
Hermann von Hemholtz
Each sensory nerve, no matter how it is stimulated, releases an energy specific to that nerve
Doctrine of specific nerve energies
Stimulation to which a sense modality is maximally sensitive
Adequate stimulation
Describe Hemholtz’s position with respect to vitalism
He did not stand for vitalism, he sided with the materialists, who believed that the same laws apply to living and nonliving things, as well as to mental and non-mental events
He and several of his fellow students believed immaterialism so strongly that they signed an oath rejecting vitalism and excepted the belief that living organisms, including humans, we’re complex machines and that these machines consist of nothing but material substances
The energy within a system is constant; therefore, it cannot be added to or subtracted from but only transformed from one form to another
Principle of conservation of energy
Hemholtz Applied this principle to living organisms after his experimentation concerning the metabolic processes in the frog
Describe Hemholtz’s position with respect to The rate of neural transmission
Whereas Mueller had maintained that nerve conduction was almost instantaneous, making it too fast to measure, Helmholtz disagreed, excluding nothing from the realm of science, not even the rate of nerve conduction
To measure the rate of nerve conduction, he isolated the nerve fiber leading to a frogs leg muscle. He then stimulated the nerve fiber at various distances from the muscle and noted how long it took the muscle to respond. He found that the muscular response follow more quickly when the motor nerve was stimulated closer to the muscle than farther away. By subtracting one reaction time from the other, he concluded that the nerve impulse travels at a rate of about 90 ft./s. He then turned to humans, asking his subjects to respond by pushing a button when they felt their leg being stimulated. He found that reaction time was slower when the tow was stimulated than one if I was and he concluded that the rate of nerve conduction in humans was between 165 and 330 ft./s
He was able to show that nerve impulses are measurable and that they are fairly slow but because the measure of reaction time very considerably among subjects and for the same subject at different times, he concluded that reaction time was too unreliable to be used as a valid measure and abandoned it
The rudimentary mental experience caused when sense receptors are stimulated by an environmental stimulus
Sensation
According to Helmholtz, the mental experience arising when sensations are embellished by the recollection of past experiences
Perception
According to Helmholtz, the process by which the remnants of past experience are added to sensations, thereby converting them into perceptions
Unconscious inference
Describe Hemholtz’s position with respect to sensation versus perception
Thought that the past experience of the observer is what converts a sensation into perception. Sensations are the raw elements of conscious experience, and perceptions are sensations after they are given meaning by one’s past experiences. In explaining the transformation of sensations into perceptions, he relied heavily on the notion of unconscious inference
Decided that the perception of depth arises because the retinal image an object causes is slightly different on the two redness. Previous experience with such retinal disparity causes the unconscious inference of depth.
Observed that individuals who are blind at birth and then acquire site need to learn to perceive, even though all the sensations furnished by the visual apparatus are available. His classic experience with lenses that distorted vision provided further evidence. He had subjects wear lenses that displaced The visual field several inches to the right or left. At first, the subjects would make mistakes and reaching for objects; but after several minutes perceptual adaptation occurred, and even while wearing the glasses, the subjects could again interact accurately with the environment
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
Young-Helmholtz theory of color vision
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
Resonance place theory of auditory perception
Describe Hemholtz’s position with respect to auditory perception
Found that the ear is a highly complex system of many receptors, he removed the main membrane of the inner ear, the basilar membrane, and went on coil that was shaped much like a harp. He assumed that this membrane is to hearing what the retina is to seeing, and speculated that the different fibers along the basilar membrane are sensitive to differences in the frequency of sound waves
The short fibers respond to the higher frequencies, the longer fibers to the lower frequencies. A wave of a certain frequency causes the appropriate fiber of the basilar membrane to vibrate, thus causing the sensation of sound corresponding to that frequency. This process was called sympathetic vibration, and this theory is referred to as the resonance place theory of auditory perception
Describe Hemholtz’s position with respect to his theory of signs
Postulated an active mind where the minds task was to create a reasonably accurate conception of reality from the various signs that it receives from the body sensory systems. He assumed that a dynamic relationship exists among volition, sensation, and reflection as the mind attempts to create a functional view of external reality.
Summarize Helmholtz contributions to psychology
He showed that nerve transmission is not instantaneous, as had previously been believed, but that it is rather slow and reflects the operation of physical processes.
Showed with experimental rigor the mechanisms by which we do commerce with the physical world-mechanisms that could be explained in terms of objective, physical laws.
His work brought physics, chemistry, physiology, and psychology closer together which pave the way for the emergence of experimental psychology
The attempt to determine a person’s character by analyzing his or her facial features, bodily structure, and habitual patterns of posture and movement
Physiognomy
The examination of the bumps and depressions on the skull in order to determine the strengths and weaknesses of various mental faculties
Phrenology
Believed that the strengths of mental faculties varied from person to person and that they could be determined by examining the bombs and depressions on a person skull. Such an examination came to be called phrenology
Franz Joseph Gall
Describe the development of phrenology and the influence it had on education in the form of the notion of formal discipline
Toward the end of the 18th century, it was widely believed that a person’s character could be determined by analyzing his or her facial features, body structure, and habitual patterns of posture and movement and one version of this that became extremely popular was phrenology.
Gall was among the first to attempt to relate certain personality traits and overt behavior patterns to specific brain functions. He observed that someone had a pronounced personality characteristic and a well-developed brain structure and then attribute one to the other. After observing such a relationship in one individual, he would generalize it to all individuals
Formal discipline: became highly influential in the realm of education. Several people made the additional claim that the faculties become stronger with practice, just as muscles do. This belief influenced a number of educators to take a mental muscle approach to education through strengthening mental faculties by practicing the traits associated with them. For example, improving one’s reasoning ability by studying mathematics. The belief that educational experiences could be arranged so that they strengthen certain faculties was called 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
Formal discipline
The technique that Broca used. It involves first determining a behavior disorder in a living patient and then, after the patient had died, locating the part of the brain responsible for the behavior disorder
Clinical method
The speech area on the left frontal lobe side of the cortex which is involved in speech articulation or production
Broca’s area
What is Broca’s area significance in the history of psychology?
Broca’s localizing of a function on the cortex supported the phrenologists and damaged Flouren’s contention that the cortex acted as a unit. Unfortunately for the phrenologists, he did not find the speech area to be where they said it would be
Using the two-point threshold and the just noticeable difference, he was the first to demonstrate systematic relationships between stimulation and sensation
Heinrich Ernst Weber
The sensations caused by muscular activity
Kinesthesis
The smallest distance between two points of stimulation at which the two points are experienced as two points rather than one
Two-point threshold
Weber used a Compass like device consisting of two points and simultaneously applying the two points of pressure to a subject skin. The smallest distance between two points at which the subject reporting sensing two points instead of one was called the two-point threshold. Found the smallest one to be on the tongue and the largest in the middle of the back
The sensation that results if a change in stimulus intensity intensity exceeds the differential threshold
The just noticeable difference JND
Weber found that when the variable weights were only slightly different from the standard, they were judged to be the same as a standard.
He found that subjects could detect much smaller wait differences when they lifted the weights then they could win the weights were simply placed on their hands. He believed it was the involvement of kinesthesis in the lifted-weight condition that provided the greater sensitivity to weight differences
Just noticeable differences correspond to a constant proportion of a standard stimulus
Weber’s law
He observed that discrimination does not depend on the absolute difference between two weights but on the relative difference between the two, or the ratio of one to the other
Expanded Webbers law by showing that, for just noticeable differences to vary arithmetically, the magnitude of a stimulus must vary geometrically
Gustav Theodor Fechner
Describe Fechner’s other half, Dr. Mises
In addition to Fechner the materialistic scientist, there was Fechner the satirist, so loss of her, and spiritualist and Fechner The mystic. For a young scientist to express so many viewpoints, especially because so many of them were incompatible with science, would have been professional suicide so he invented a person to speak for his other half and he called this person Dr. Mises.
He always used this doctor to express the Dayview, the view that the universe is alive and conscious
The belief that everything in the universe experiences consciousness
Panpsychism
The systematic study of the relationship between physical and psychological events
Psychophysics
Describe Fechner’s work in psychophysics
He wanted desperately to solve the mind-body problem in a way that would satisfy the materialistic scientists of his day. He accepted double aspect is him because he believed that the physical and mental or simply two aspects of the same fundamental reality. His insight was that a systematic relationship between Bartley and mental experience could be demonstrated if a person were asked to report changes in sensations as a physical stimulus was systematically varied. He speculated that for mental sensations to change arithmetically, The physical stimulus would have to change geometrically. He created the area of psychology that he called psychophysics in testing these ideas.
He stated mathematically Webbers law
The smallest amount of stimulation that can be detected by an organism
Absolute threshold
According to Fechner, sensations that occur below the absolute threshold and are therefore below the level of awareness
Negative sensations
The amount that stimulation needs to change before a difference in that stimulation can be detected
Differential threshold
Describe Fechner’s use of the JND as a unit of sensation
He assumed that as the magnitude of a stimulus increased from zero, a point would be reached where the stimulus could be consciously detected. The lowest intensity at which a stimulus can be detected is called the absolute threshold. Intensity levels below the absolute threshold do cause reactions, but those reactions are unconscious and are called negative sensations. He used a continue scale that showed how sensations above the absolute threshold varied as a function of level of stimulation by using the deferential threshold, which is defined by how much a stimulus magnitude needs to be increased or decreased before A person can detect a difference. He found that stimulus intensity’s must change geometrically in order for sensation to change arithmetically. Given a geometric increase in the intensity of a stimulus, he assumed that sensations increased in equal increments (jnds)
Fechner’s law assumed that sensations increased in equal units (jnds) as the stimulus intensity increased geometrically beyond the absolute threshold
Subsequent research demonstrated that the predictions generated by this equation were accurate primarily for the middle ranges of sensory intensities but less accurate for extremely high or low levels of physical intensity
What are Fechner’s three methods to further explore the mind-body relationship, his psychophysical methods?
Method of limits, method of constant stimuli, method of adjustment
A stimulus is presented at varying intensities along with a standard, constant, stimulus to determine the range of intensities judged to be the same as the standard
The method of limits. Also called the method of just noticeable differences
With this method, one stimulus is varied and is compared to a standard. To begin with, the variable stimulus can be equal to the standard and then varied, or it can be much stronger or weaker than the standard. The goal here is to determine the range of stimuli that the subject considers to be equal to the standard
A stimulus is presented at different intensities along with a standard stimulus, and the observer reports if it appears to be greater than, less then, or equal to the standard
Method of constant stimuli. Also called the method of right and wrong cases.
Here, pairs of stimuli are presented to the subject. One member of the pair is the standard and remains the same, and the other varies in magnitude from one presentation to another. The subject reports whether the variable stimulus appears greater than, less then, or equal to the standard
An observer adjusts a variable stimulus until it appears to be equal to a standard stimulus
Method of adjustment. Also called the method of average error
Here, the subject has control over the variable stimulus and is instructed to adjust its magnitude so that the stimulus appears equal to the standard stimulus. After the adjustment, the average difference between the variable stimulus and the standard stimulus is measured
Describe Fechner’s contributions to the development of psychology
Created psychophysics and created the field of experimental aesthetics. Wrote several articles attempting to quantify reactions to works of art
Showed that it was possible to measure mental events and relate them to physical ones
The period of time between presentation of and response to a stimulus
Reaction time
