Midterm 2 Study Guide
1. What can we conclude about speech production by observing patterns of slips (speech errors)?
Slips of the tongue as clues to the process of speech production (psycholing) suggests that
speech planning is carried out a several different levels of analysis
• Phrases: I wouldn’t buy kids for the macadamia nuts. The Kids not The mac nut
• Words: I have to fill up the gas with car.
• Morphemes: Oh, that’s just a back trucking out. Morpheme is Back and ing
• Syllables: canpakes (pancakes), butterpiller and catterfly
• Phonemes: fost and lound (lost and found) the sound represented by f and l are different
phonemes; we’re going to have to fart very fide (fight very hard) the sound represented
by f and l are different phonemes
• Features: mity the due teacher (pity the new teacher; nasalstop exchange)
2. What is the lack of invariance problem in speech perception? There is not a distinct acoustic pattern
associated with each phoneme
• Different acoustic patterns can be heard as the same phoneme
• The same acoustic pattern can be heard as different phonemes depending on the
Actual physical acoustic signature of words varies widely from the context to context ex: say cat 100
times the measurement of the acoustic signals will be different, but we still recognize that the word is
No one to one correspondence with acoustic signal and how people perceive the word
Lack of invariance= two people from different parts of the world say one word, even though it sounds
different a person may be able to tell what the word is. Variance in production, but not in
3. Categorical perception is: tendency to have stable percepts of phonemes despite significant acoustic
variation. Categorical perception is unique to speech
taking synthesized speech sound and causing it to vary on a single dimension. Acoustically something
is varying continuously on this dimension and person will keep hearing it as da when you change the
onset the person will her ta.
4. Which of the following is a limitation of lesion studies? Lesion method typically involves stroke
patients. There’s almost always recovery after a stroke, but the person may have dysfunctions.
The wiring patterns of the brain can change after a stroke. You don’t know if the stroke effects
change in behavior, it’s at times ambiguous NOT generalizable because the lesion brain is now
organizing itself in ways normal brains won’t.
variations in the brain, unethical.
5. Match the following brain recording techniques with the signal that they are measuring. (You can use
an answer more than once.)
Singleunit recording: A microelectrode is inserted into brain tissue and recordings of action potentials
can be made from nearby neurons, ideally a single neuron. Extensively on animal studies. Spacial and
Lesion studies: Page 2
Transcranial magnetic stimulation (TMS): A method for producing temporary focal brain “lesion”
(disruption), via stimulation with a strong magnetic field. Directly stimulates cortex, not recording
Direct cortical stimulation: Delivery of a small electric current directly on the cortical surface
Causes temporary disruption or facilitation of function in cortex being stimulated. Also not
Splitbrain: Sectioning of corpus callosum as a treatment for medically intractable epilepsy
Can study the separate contributions of the left (language)and right hemispheres to various
WADA procedure: Injection of sodium amytal (a barbituate), into one and then the other carotid
artery temporarily (510min) puts half the brain to sleep allowing neurologists to assess
function in the awake hemisphere. Make sure they’re not taking away the better functioning hem.
Electromagnetic: (EEG, MEG) Scalp electrodes measure the summed electrical activity of large
populations of synchronously active neurons. Look for change in signals, or look at how signals
change when you assign a patient to a task. Good with temporal Magnetoencephalography
(MEG) Measures magnetic fields associated with large populations of synchronously active neurons. It
has advantages because the magnetic field is not effected by the tissue Expensive super cool device.
Measures electrical activity generated by neurons good with temporal moderate spatial resolution both
measure electrical activities of large population of neurons.
Hemodynamic: (PET, fMRI) Measures local changes in blood flow that are linked to neural
Neural activity => increased metabolic demand => local increase in blood flow the active
Involves injection of radiolabel oxygen or glucose into the blood stream, and measures
the location in the brain that this material accumulates
Functional magnetic resonance imaging (fMRI) Like PET, fMRI measures regional changes in
blood flow, but does it very differently As blood flow increases, so does the oxygen concentration in
the blood. MRI is sensitive to these O2 concentration changes good spacial resolution
Electric is with temporal, and blood is with spatial
6. A limitation of direct cortical stimulation mapping studies is that: The anatomy of the individuals
won’t line up perfectly. Also, the functional boundaries within the anatomical structures won’t line up
perfectly. Group averaging tends to lead to mislocalization.
issue of direct is that you’re doing it on people who have had strokes. Cost for subjects are high, and
the only people that need their skulls opened up already have problems. The only thing you learn is
based on population with unhealthy brains, not generalizable.
7. Which of the following constitute differences between EEG and single unit recording? Single unit is
primarily in animals and studies are only sampling a very small fraction of a functional neural system.
EEG Large portion of neurons.
Eeg has good temporal and poor spatial and large population of neurons are studied. Single recording
has both good spatial and good temporal but only from one neuron. Page 3
8. An advantage of using positron emission tomography (PET) and functional magnetic resonance