Unit 3 - Chapter 8 - Physiology & Psychophysics Flashcards
Describe the Bell-Magendie law of neural transmission and explain its significance.
States there are two types of nerves:
1) sensory nerves carrying impulses from sense receptors to the brain
2) motor nerves carrying impulses from the brain to muscles and glands.
Significance → specific mental functions are mediated by different structures.
Describe the Doctrine of Specific Nerve Energies and its significance.
Each sensory nerve releases an energy specific to that nerve.
significance –> central nervous systems determines our sensations.
- Muller
Briefly describe the work of Johannes Muller (1801–1858) with respect to adequate stimulation (or specific irritability)
each type of sense organ is sensitive to a certain type of stimulation.
ex: eye stimulated by light waves
Briefly describe the work of Johannes Muller (1801–1858) with respect to the relationship between consciousness and sensations and reality.
physical objects –> nervous system & sensory impulses –> consciousness.
Describe Hermann von Helmholtz’s positions and theories with respect to vitalism
rejected vitalism
accepted mechanistic-materiliast viewpoint
Describe Hermann von Helmholtz’s positions and theories with respect to the principle of conservation of energy
energy is never created or lost, just transfered
Describe Hermann von Helmholtz’s positions and theories with respect to the rate of neural conduction
research showed that nerve impulses are measurable and relatively slow.
Describe Hermann von Helmholtz’s positions and theories with respect to the theory of perception (including his notion of unconscious inference)
memories of previous learning experiences must interact with current sensations
unconscious inference –> remnants of past experience + sensations = perceptions.
Sensations
sense receptors are stimulated by an environmental stimulus.
What did Helmholtz and Kant agree on?
the perceiver transforms what the senses provide.
Describe Hermann von Helmholtz’s positions and theories with respect to the theory of colour vision
young-helmholtz theory of color vision: there are three different cone systems in the eye that perceive blue, green and red
- non primary colours stimulate various subjective combinations
- helpful in explaining forms of color blindness
- address lack of correspondence between the physical stimuli and sensations.
Describe Hermann von Helmholtz’s positions and theories with respect to the theory of auditory perception.
tiny fibers on the basilar membrane of the inner ear are stimulated by different frequencies of sound.
shorter the fiber = the higher the frequency
Describe Ewald Hering’s views concerning spatial perception
- is a priori
- each point on the retina automatically provides height, left-right position, and depth of the stimulus.
Describe Ewald Hering’s views concerning his theory of colour vision.
There are 3 types of receptors on the retina;
- red-green, yellow-blue, black-white.
Catabolic process
tearing down
-red, yellow and white
Anabolic process
building up
- green, blue, and black
What did Hering say could not be explained by Young-Helmholtz theory?
1) the sensation of gray.
2) afterimages
3) people who cant tell difference between red and green can still see yellow.
Gray occurs when …
catabolic and anabolic processes are canceled out.
Describe Christine Ladd-Franklin’s theory of colour vision.
assumed that color vision evolved in 3 stages;
1) achromatic vision → most difficult to disrupt.
2) blue-yellow sensitivity → less frequent, less likely to be defective.
3) red-green sensitivity
According to Ladd-Franklin, the most highly evolved part of the eye is the
fovea (provided by cones)
Night vision and movement perception are better in the
periphery of the retina (provided by rods) because it is primitive & crucial for survival
Physiognomy
belief that a persons character could be determined by analyzing their facial features, body structure, etc.
- ex: phrenology
Franz Joesph Gall
made three claims that changed the history of faculty psychology;
1) mental faculties are unique in all humans.
2) faculties are in specific areas of the brain.
3) developed faculty = bump, undevelopped faculty = a hollow.
Phrenology
belief that the magnitude of ones faculties could be determined by examining the bumps and depressions on ones skull.
- Gall
First to distinguish the functions of gray matter and white matter in the brain.
Franz Gall
Found that larger cortices were associated with more intelligent behavior.
Franz Gall
First to suggest a relationship between cortical development and mental functioning.
Franz Gall
Influence of phrenology on education
formal discipline –> mental muscle approach to education
Briefly describe the life and work of Pierre Flourens in relation to the phrenologists.
Used method of ablation in brain research.
Found that the cortical hemispheres function as a unit.
Paul Broca
- said brain is larger in eminent men, supposed superior races, men & mature adults
- brocas area: left cortical hemisphere, speech articulation or production.
Wernicke’s area
left temporal lobe of the cortex
responsible for speech comprehension.
Briefly describe the work of Gustav Fritsch & Eduard Hitzig and their work with electrophysiology.
found that when a certain area of the cortex is stimulated, there are muscular movements on opposite side of the body.
Briefly describe David Ferrier’s work with electrophysiology.
mapped cortical regions corresponding to senses
Briefly describe the work of Ernst Heinrich Weber especially with respect to touch and kinesthesis
first to demonstrate that the sense of touch is several senses (2 point threshold, involves JND)
- kinesthesis: sensations caused by muscular activity.
Briefly describe the work of Ernst Heinrich Weber with respect to the relative versus absolute nature of psychophysical judgments (including Weber’s law).
weber’s law states that JND corresponds to a constant proportion/ratio of a standard stimulus.
considered first quantitative law in psychology’s history.
believed that consciousness cannot be separated from physical things → reflects panpsychism
Fechner
Describe Gustav Fechner’s other half, Dr. Mises
- pseudonym used to talk about views incompatible to science
Describe Gustav Fechner’s work in psychophysics & use of the jnd as a unit of sensation
as a stimulus gets larger, the magnitude of the change must get greater = differential threshold.
- proposed absolute (lowest intensity) threshold
Describe Gustav Fechner’s three methods for determining thresholds.
1) method of limits = JND
2) method of a constant stimuli
3) method of adjustment = average error
Describe Fechner’s contributions to the development of psychology.
- creation of psychophysics
- book launched psychology as experimental science
