Chapter 1: Introduction to Neuropsychology
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What is Neuropsychology?
- neuropsychologists attempt to describe, explain, predict, and change behavior.
- Neuropsychology is the study of the relation between behavior and the activity of the
- 2 main types of neuropsychologists:
- 1. clinical neuropsychology: the branch of neuropsychology concerned with psychologi-
cal assessment, management and rehabilitation of neurological disease and injury.
- 2. Experimental neuropsychology: focuses on how human behavior arises from brain
activity which includes explaining how patterns of behavioral impairments.
Heart, Mind and Brain: The Early History of Neuropsychology
- Empedocles (495-435bC) was a philosopher (best known for position that all matter
was composed of 4 elements: fire, air, water, earth) who believed that the heart was the
source of human behavior-this position became known as the cardiac or cadiocentric
- Aristotle (384-322 bC) came to the same conclusion, although fro different reasons.-
heart warm-so thought that it was the source of thought and sensation- and that it was
like a radiator to cool blood
- Hippocrates (450-350bC) and Galen (AD 129-199)-argued that the brain was responsi-
ble for these actions. This view is called cephalocentric hypothesis or brain hypothesis.
- Trephination: process of sawing into the skull.
- Brain viewed as a passive interpreter of signals, and mind was viewed as separate en-
tity from the brain.
The Mind-Body Problem
- Rene Decartes (1596-1650): presented a “reflexive theory” of the control of behavior in
which he described the flow of “animal spirits” through “valvules” within nervous tissue
filaments. This theory accounted for reflexive behaviors by describing how external stim-
uli would move the skin, in turn moving the filaments, releasing the animal spirits and in-
nervating the muscles. (however this theory cannot account for voluntary behavior).
- Decartes believed that voluntary behaviors depended on the interface of the mecha-
nistic body with a rational, decision-making soul. The location that decartes identified for
this interaction was the pineal gland. (unitary nature-compared to rest of brain). - Pineal gland is composed of a single structure along the midline of the brain, surround-
ed by cerebrospinal fluid (a clear fluid that supports and cleanses the brain).
- Decartes believed that cavities of cerebrospinal fluid were reservoirs for the animal
spirits necessary for action.
- Decartes theory relied heavily go what was modern technology at the time: hydraulics.
- Decartes proposed that the mind and body are separate but interacting entities, a posi-
tion that is referred to as dualism.
- The opposing position, called monism, posits that the mind and body are unitary
PART II: The Recent History of Neuropsychology
Cataloging the Effects of Lesions.
- serious critiques of the passive role for the brain in the production of behavior pro-
posed by Decartes began with the observations of Jean-Cesar Legallois (1770-1840),
Charles Bell (1774-1842) and Francois Magendie (1783-1840).
- Legallois was a french physiologist who discovered that lesioning (destroyed tissue in)
the medulla resulted in the immediate cessation of breathing.
- The discovery of the respiratory centre within the medulla was the first widely accepted
function to be localized within the brain.
- Bell, a scottish physiologist and Magendie a french physiologist, studied the nerves
that exited the spinal cord.
- They observed that the dorsal roots (the nerves that leave the spinal cord on the back
of the spinal cord) had sensory functions whereas the ventral roots (the nerves that
leave the spinal cord at the front)
- In 1811, Bell suggested that the entire nervous system should be investigated for func-
tional and anatomical segregation.
- Franz Joseph Gall (1758-1858) and his collegue Johann Spurzheim (1774-1832) un-
dertook the challenge, suggesting that the cortex was functionally localized.
- Gall, stated that there were 27 distinct cognitive abilities (which he called faculties) that
could be localized on the cortex of the human brain (nonhuman animals had only 19 of
- Gall also believed that the cortex behaved like muscles, in that increased size of an
area was associated with increased function. The increase in size of the cortical area
would result in a deformation of the skull, or a bump, which then could be empirically
measured by using a technique called cranioscopy.
- Measurements of the skull and pronouncements on personality became known as
phrenology, - Many people against phrenology.
- One of the strongest critics was marie-jean-pierre flourens (1794-1867), a french
- Believed that phrenology was at best subjective and that all analyses were per-
formed post hoc.
- Pierre was a firm believer in the empirical method. And he performed numerous
studies with nonhuman animalss using lesioning techniques to study corre-
sponding effects on behavior.
- Some of his observations were that the cerebellum was responsible for coordi-
nated movement and that the medulla performed vital functions for the organ-
- Also observed that sometimes following lesion, function may be restored.- be-
lieved that once one function was restored all functions were restored (support-
ed his concept of cortical equipotentiality)
- Was firmly opposed to the localization of cognitive function, instead proposing
that the cortex functioned as a wholeand that there was no functional special-
ization within the cortex. (called equipotentiality) (goltz held viewpoint too)
- Friedrich Goltz (1834-1902)
- German physiologist
- Performed a number of experiments involving the removal of the cortex in dogs
and cats and observed that only the size of the lesion, not the location of the le-
sion, affected the behavior of the nonhuman animal.
- From these observations, he concluded that the cortex could not be specialized
for specific cognitive functions.
- David Ferrier (1843-1928)
- English physiologist
- Suggeste that the behavioral observations of decorticate dogs and monkeys
were inconsistent with the position of cortical equipotentiality
- Suggested that the results of the lesion experiments were consistent with the lo-
calization of sensory and motor functions within discrete portions of the cortex
- Gustav Frisch (1838-1927) and Eduard Hitzig (1838-1907)
- Demonstatred that the frontal cortex of the dog was essential for the production
of normal movement.
- Successfully demonstatred that careful use of the techniques of Goltz and oth-
ers resulted in abnormal motor movements and intact sensation.
- Successfully overturned the theory of cortical equipotentiality. -Paul Broca (1824-1880)
- French anthropologist
- the first to gain widespread acceptance for the role of the frontal cortex in the
production of speech.
- Based his conclusions on the observations of an individual with left frontal dam-
- In 1861, Broca presented a case study (of a man he referred to as Tan) in which
a circumscribed lesion of the left frontal lobe (now called brocas areas) resulted
in an individual who was capable of productive speech,
- Broca suggested that tan had lost the capacity for speech but retained the abili-
ty to understand language.
- Broca referred to this phenomenon as aphemia, which later became known as
aphasia or broca’s aphasia.
- Jean-Baptiste Bouillaud (1796-1881), Simon Aubertin (1825-1865), and Marc Dax
(1770- 1837) and Gustave Dax (1815-1893)
- Suggested that the left hemisphere was important for speech.
- two major components of speech that Broca did not study directly were the emotional
tine of speech (prosody) and the loss of comprehension of language associated with the
preservation of speech.
- John Hughlings-Jackson (1835-1911)
- British neurologist
- Firat articulated that the content and emotional tone of speech were separable.
- Found that speech is a complex process that involves linguistic ability as well as
complex motor skills.
- Suggested that there could be disassociations between the semantic content of
language (the meaning) and the emotional tone.
- Carl Wernike (1848-1904)
- German neurologist
- 1874- suggested that there was an auditory center (now known as Wer-
nickes area) in the temporal lobes that, when damaged, would result in
an individual who could still produce speech but would be incapable of
using words correctly and be unable to understand the speech of others.
Focus of the Neuron
Anatomical Studies - Cells in the body range from 0.01-0.05 mm in diameter, although most neurons are ap-
prox.. 0.02 mm in diameter.
- By 1839, Theodore Schwann (a german zoologist) proposed that all living tissue was
composed of microscopic units called cells (now referred to as the cell doctrine).
- The study of thinly sliced, fixed, and staine