and Language the Brain
LING-001-601, Fall 2007 Instructor: Marjorie Pak December 6, 2007
These slides are adapted from David Embicks Fall 2004 LING-001 course at the University of Pennsylvania (http://www.ling.upenn.edu/courses/Fall_2004/ling001)
The human brain weighs about _________. The outer layer of the brain a gray wrinkled mass that sits like a cap on top of the rest of the brain is called the _______________. This part of the brain is responsible for most higher cognitive functions. This means that damage (even relatively shallow) to the brain can result in severe impairments in cognitive function
The cortex and subcortical structures
The brain is divided into two (roughly symmetrical) _______________, divided by a deep groove called the ____________________________.
The two hemispheres are connected by a band of nerve fibers known as the corpus callosum.
Some things that the brain does are l_______ized: performed primarily by one hemisphere as opposed to the other In the case of language, the dominant hemisphere is the ______ hemisphere for the great majority of right-handed people
hemisphere right 4% 15%
right-handed left-handed
left 96% 70%
both 0% 15%
The cortex is a kind of folded sheet; the folded configuration allows for more surface area inside the confines of the skull The folds of the cortex have two parts: _________: a groove or valley, where the cortex is folded in _________: a bump or convolution, where the cortex is folded out
Structures
The folds (gyri and sulci) in the brain can be used to identify common anatomical areas of the brain While some details of brain anatomy differ from individual to individual, the same common structures are found across individuals
Each hemisphere has four major lobes frontal, parietal, temporal, occipital. Label the lobes in the following picture.
central sulcus
Pink: Frontal Blue: Parietal Green: Temporal Yellow: Occipital
lateral fissure
front of head
Certain areas of the brain are known to be responsible for motor control and sensory processing These areas define a kind of map on the cortical surface, where different areas of the cortex correspond to different parts of the body
There are two primary language areas in the brain: _________s area, in the lower rear portion of the left frontal lobe, and __________s area, in the temporal lobe just below the back part of the lateral fissure.
Until recently, brain studies were restricted to cases in which patients showed language disorders after e.g. strokes. A language deficit caused by damage to the brain is called _______________. An area of severe damage to the brain is called a __________.
Brocas Aphasia
A type of nonfluent aphasia Agrammatism: halting speech, consisting typically of short utterances Absence of function words/morphemes (also called t___________ speech). At least at a first glance, relatively good comprehension of language
Wernickes aphasia
A type of fluent aphasia Easy production of connected speech, normal intonation, correct word order and use of function words/morphemes difficulty in recalling correct content words, especially nouns words may be meaningless neologisms Comprehension impaired
Which kind of aphasia? _______________ Ah ... Monday ... ah, Dad and Paul Haney name] [speakers and Dad ... hospital. Two ... ah, doctors ... and ah ... thirty minutes ... and yes ... ah ... hospital. And, er, Wednesday ... nine o'clock. And er Thursday, ten o'clock ... doctors. Two doctors ... and ah ... teeth. Yeah, ... fine.
Which kind of aphasia? _______________ Q: What kind of work have you done? -- We, the kids, all of us, and I, we were working for a long time in the... You know... it's the kind of space, I mean place rear to the spedawn... Q: Excuse me, but I wanted to know what kind of work you have been doing. -- If you had said that, we had said that, poomer, near the fortunate, porpunate, tamppoo, all around the fourth of martz. Oh, I get all confused.
For some time, it was thought that the basic difference between Brocas and Wernickes aphasia was a difference between production and comprehension disorders (or motor and sensory disorders).
But it turns out that Brocas patients have a hard time with comprehension as well notably when the syntax is complex:
Which of these sentences will probably be harder for a Brocas patient to understand? Why? The mouse was chased by the cat. The boy was chased by the girl.
Revised view: Wernickes area is crucial for lexical matters, and Brocas area for syntactic matters.
fMRI: another way to study the brain
Uses extremely strong magnetic field Measures changes in local blood flow Subjects lie within the bore of the magnet, with heads fixed Experimenters acquire structural images of the subjects brains Functional images, showing changes in blood flow/oxygenation, are acquired and registered with the structural images
Cortical activation results in a local increase in oxygenated blood, and blood flow, without an increase in oxygen consumption.
http://fmri.ucsd.edu/fmri/FMRI-TINS.html
Areas in which neuronal activity occurs show patterns of activation which the scanner detects.
The image is paired with a graph showing the blood flow in that region by exper...