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PSYB65: Human Brain and Behavior
Introduction to Neuropsychology
The 10% Myth: Claim that humans use only 10% of their brain, only a myth. The truth
being that the brain plays a major role in producing human behavior
Psychology: The study of behaviour and attempting to describe, explain, predict and
Neuropsychology: also the study of behaviour, including the relation between
behaviour and the activity of the brain, assuming that the brain is partially responsible for
one’s behaviour. There are 2 types of neuropsychology:
Clinical neuropsychology: the branch of neuropsychology dealing with
psychological assessment, management, and rehabilitation of neurological
disease and injury.
Experimental Neuropsychology: also known as cognitive neuroscience, the
branch of neuropsychology focusing on how human behaviour arises from brain
activity, including how behavioural changes can be explained in terms of neural
Heart, Mind and Brain: The Early History of Neuropsychology
Empedocles: A philosopher who proposed the idea of “the cardiac” or “cardiocentric
hypothesis”, where the heart was the source of behavior. This hypothesis still has an
effect on pop culture today, like how humans associate love with the heart and not the
Aristotle: also came to the conclusion that the heart was the centre involved with
thought and sensation because it is warm and active and that since heat rises, the brain
was the blood cooling centre. – He was incorrect !
Hippocrates and Galen: proposed the “brain hypothesis” or “cephalocentric hypothesis”
where the brain is responsible for thought and sensation. Also, that the brain’s ventricles
and cerebrospinal fluid (supports, nourishes, cleans brain) played a role in cognition,
which was later corrected by Magnus and Vesalius.
Finger (1994) – Suggests that there was recognition that damaging the brain would
result in the death or disabling of an individual
Trephination: producing a hole in the skull to produce therapeutic effects in ancient
times. It was thought that the brain interpreted signals and that the mind was a separate
--- Early theories of brain function was not recognized for higher cognitive function ; brain
was seen as a passive interpreter of signals MIND BRAIN
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PSYB65: Human Brain and Behavior
René Descartes proposed a “reflexive theory” of controlling behavior describes
as how an external stimuli would move the skin, in turn moving the filaments,
releasing animal spirits and innervating the muscles.
It could not account for voluntary behavior or the “variability in behavior”.
Descartes believed the voluntary behaviors depended on a mechanical body with
a decision-making soul, located in the pineal gland since it doesn’t have a left
and right component and was surrounded by cerebrospinal fluid (containing
animal spirits which produce movement during voluntary action).
Dualism: an idea proposed by Descartes that the mind and body are separate but
Monism: the idea that the mind and body are one.
The Recent History of Neuropsychology
Lesioning: destroying tissue in the medulla was discovered by Jean-Cesar Legallois to
Magendie and Bell: discovered that the dorsal roots has sensory functions and the
ventral roots had motor functions, which suggested that the brain could also be divided
for functional as well as anatomical reasons.
Franz Joseph Gall: states that the brain was divided into 27 different areas called
faculties, which could be found on the cortex of the brain. He also believed the cortex
acted as a muscle, where a larger area was associated with a larger function. This
increase in size(associated with increased function) would cause a bump, which could
be examined by cranioscopy. This measurement along with personality became known
Flourens: was a strong believer in phrenology and did experiments with it.
For example if one who was good at music had a bump in the music centre of the
head, and another good at music didn’t, it was assumed that the second person
was better at a different aspect of music and therefore had the bump elsewhere.
He concluded that the cerebellum was important to movement and the medulla
was important to vital processes.
Also, he found that regions with injury might restore function, not to the one area
but to all areas, as he believed the brain was equipotent and functioned as a
It was later determined by Goltz that the size of the lesion, not the location
Ferrier and Hitzig: found that lesioning was consisted with localizing sensory and motor
functions, for example that lesion to the frontal cortex caused abnormal motor behavior
and intact sensation.
Overall, Gall was right for the wrong reasons and Goltz and Flourens used the
right technique with wrong conclusions.
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PSYB65: Human Brain and Behavior
They also studied the relationship between the brain, movement and electricity
by observing electrical stimulations in a dog’s brain as a result of movement.
Although many basic functions had been successfully localized within the brain
(movement and respiration) the first cognitive function that was successfully
localized was language
Paul Broca: Anthropologist, was the first to gain widespread acceptance for the role of
the frontal cortex in the production of speech
Examined a patient named “TAN” with a problem in speech’s brain and
discovered a lesion or soft tissue on the anterior left hemisphere now known
as “BROCA’S AREA”
He discovered the deficit was in articulating speech and comprehension, and that
the left hemisphere in the frontal cortex of the brain was responsible for speech
in most people.
Aphemia (Broca’s Aphasia): Broca’s term for being unable to speak but able to
understand language. Some words are known, sentences are slow and spaced out but
prepositions, pronouns, conjunctions, if, and, or are left out similar to telegraphs called
agrammatism. They have trouble finding words (anomia), phenomic paraphasia, and
sense sentences with same words/diff order as equal in meaning.
Prosody: emotional tone of speech
Which Broca did not study directly, and the loss of comprehension of
- Jackson proposed that content and tone were separable
Jackson: content and tone in language were separable. He suggested there are
possible dissociations between the content of language (the meaning) and the emotional
Carl Wernike: suggested there was an auditory centre (WERNIKE’S area) in the
temporal lobes. When damaged, the individual could produce speech but not hear,
comprehend, or put meaning on words.
This is known as Wernike’s aphasia, involving non-random meaningless word
salad, neologisms (made up words), unawareness of condition, occurring without