Neuro Anatomy Exam 1

• 1. The brain is the organ of the
• mind.
• 2. The mind is composed of multiple, distinct, innate faculties.
• 3. Each faculty must have a separate "organ" in the
• brain.
• 4. The size of an organ, other things being equal, is a measure of its
• power.
• 5. The shape of the brain is determined by the size of the various
• organs.
• 6. As the skull takes its shape from the brain, the surface of the skull
• can be read as an accurate index of psychological aptitudes and tendencies.

• •“Strict” localization
• of function in the brain.

• •Credited
• with the discovery (in 1861) of left frontal lobe lesions associated with
• inability to produce speech (motor aphasia) based on post-mortem dissection of
• the patient's brain

• •This
• provided strong evidence for localization of function within the brain

• •Broca also established the
• asymmetry of function between the two cerebral hemispheres (lateralization –
• language in left hemisphere, not in right).

-Broca’s area (BA 44 & 45)

In 1874, he described sensory aphasia emphasizing the impairment of auditory language comprehension (leading to erroneous speech output and patients’ unawareness of their errors!). This was associated with a lesion in the posterior portion of the 1st left temporal gyrus.

• Proposed that mental
• functions are NOT localized in the brain (all parts of the brain contribute)

Lashley studied memory function in animals and found that the amount, not the location, of brain matter removed was associated with impaired memory

• •Fell out of favor after the development of modern methods for studying the brain in living
• persons

Developed a new of theory of grammar

Argued that capacity for language learning and usage is innate rather than learned

• Theorized that grammar includes parallel neurologic
• language processes

Revitalized the study of language disorders and the localizationist-connectionist model

–Founded to field of Behavioral Neurology (which focuses on higher mental functions and the brain)

Helped to develope aphasia classifications

Part of the "Boston" classification system

Wilder Penfield conducted studies during brain surgery for intractable epileptic seizures through electro-stimulation or brain mapping (1st technique to map activity of living brain to specific behaviors)

Direct relationship between a specific area of the brain and a specific experience or behavior

Based on case studies (rather than experimentation)

• •Assumes that specific behavioral dysfunction are associated with lesion at specific
• locations in the brain

•One implication is that once such relationships are known, one can identify the location of a lesion by identifying the pattern of lost or disordered functions

• •Predominated over locationist-connectionist models
• during early 20th century.

• •Proposed that mental
• functions are NOT localized in the brain (all parts of the brain contribute)

• •Based on experimental work of Karl Lashley
• •Lashley studied memory
• function in animals and found the amount, not the location, of brain matter removed was
• associated with impaired memory

• •Fell out of favor
• after the development of modern methods for studying the brain in living
• persons

Towards the head

tt tail

tt back

tt stomach

tt outside

tt inside

on the back side

on the front (belly) side

on the top (skull) side

on the lower side

on the lowermost position

toward the outside?

toward the inside

• Spatial Resolution: The ability with which we can view details of
• the location of the activity in the brain. MRI
• has the best resolution.

• Temporal Resolution: How
• quickly we can get information about the course of the response from the time
• of stimulus presentation

cut having a left and a right

• cut having front and back
• 

cut having top and bottom

cut left to right

cut top and bottom

cut front and back

cut front and back

On the same side

on the opposite side

on both sides

• Electro-stimulation or brain mapping was the first
• technique that mapped the activity of the living brain to specific behaviors

• Wilder Penfield conducted studies during brain surgery
• for intractable epileptic seizures

• Direct relationship between a specific area of the brain
• and a specific experience or behavior

• Structural imaging: Imaging that
• can only show the static structure of the brain – what is there.
• Functional imaging: Imaging that
• shows the activity of the brain – what areas are active under certain
• circumstances

• Computerized (Axial) Tomography-Stuctural Imaging
• -1970
• -x-ray's pass through the body
• -show diff densities
• -Cross-sectional image produced in a single plane (like looking at a slice)
• -commonly used, inexpensive
• -head or brain, stoke, bleeding