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