Midterm 3 Flashcards
(112 cards)
Describe the Mental Lexicon
The mental lexicon is a mental store of information that includes semantic (word meaning) information, syntactic (how we combine words) information, and word form (sound patterns and spelling) information.
What is the Neighborhood effect?
We are slower to identify words with a large auditory neighborhood (more that differ on only a single phoneme)
What is auditory neighborhood?
The number of similar sounding words (differ from target by a single phoneme; late/rate/hate)
What is phoneme:
Smallest unit of sound that makes difference in meaning (L and R late vs. rate)
Describe Semantic Networks of Knowledge/Words
Our knowledge of words is organized into a semantic network, where words that are more closely related are represented more closely together in this network
What is the evidence behind Semantic Networks of Knowledge/Words
Evidence from studies of semantic priming; if subjects have to make a decision about a list of words, they are faster at making a decision about a word if the previously presented word is semantically related (“car” primes “truck”, but not “cloud”)
How are Semantic Networks organized?
Semantic Networks are categorically organized; words can be categorized by certain semantic properties (living, non-living)
Can brain damage destroy a particular category of words within the mental lexicon?
Yes; evidence from Category-Cpecific Word Deficits
Describe the Category-Specific Deficits
Warrington studied patients who had Category-Specific deficits for conceptual/semantic knowledge about certain categories of words: patients were fine at pointing to/naming pictures of living things, but they had great difficulty in pointing to/naming non-living, man-made objects like tools, other patient showed the opposite pattern (double dissociation)
How is Category-Specific deficit different from Visual Agnosia?
Can tell you that 2 objects are the same (i.e., can match 2
pictures of telephones), but don’t have access to what that object is for (not a problem of object recognition – deficit is in conceptual knowledge)
Describe Damasio et al. findings about Category-Specific Deficits
Locations of brain lesions are correlated with selective deficits in naming people (mostly anterior temporal lobe), animals, or tools (mostly posterior temporal lobe) anterior to posterior gradient for living to non-living things
Describe the similar pattern to Damasio in PET study of healthy subjects
Naming people activated mostly temporal pole (anterior portion of temporal lobe), naming animals activated middle portion of inferior temporal gyri, and naming tools activated mostly posterior portions of the inferior temporal gyrus
Why do we see this differentiable gradient of brain damage leading to different category-specific deficits?
Sensory-functional explanation
Describe the Sensory-functional explanation
Category-specific deficits due to brain damage can be attributed to differences in the processing of sensory/perceptual information vs processing of functional information
What is the compromise of the Sensory-functional explanation?
Organization of information within semantic memory network is a distributed network of specialized clusters
What is sound?
Pressure waves caused by vibration that vary in frequency
How does our speech system solve problems of speech perceptions?
Our speech system can solve these problems of speech perception by relying on higher order cues; prosody (tone of voice), syllable stress, and formant frequencies (complex sound waveforms that carry the most critical information about speech)
Describe Eric Ramsey and the results of the study conducted on him?
Eric Ramsey was in a vegetable state; can think of/imagine speech sounds, but cannot produce them; Kennedy and Guenther implanted electrodes in left premotor cortex (speech planning area) and measured activity; then they built a decoder that translates neural activity into formant frequencies, and output can drive a speech synthesizer
What is the key idea behind Kennedy and Guenther’s study?
Speech output areas represent intended speech sounds in terms of formant frequencies
What is aphasia?
Deficits in language comprehension or production following brain damage or disease
What is primary aphasia?
Problems in language due to direct disruption of language processing system
What is secondary aphasia?
Problems in language due to memory problems
Describe Lichtheim’s Classical Model of Language Processing
There is an auditory area that stores information about words sounds that you hear (Wernicke’s area) and another area for speech programming (motor) area that involves the motor component of word output, necessary for speaking (Broca’s area); these two are connected by a fiber tract; damage to these 2 areas result in different aphasias
What is Broca’s Aphasia, and who is Patient Tan?
Broca aphasia is a non-fluent aphasia in which the output of spontaneous speech is markedly diminished and there is a loss of normal grammatical structure. Patient Tan had Broca’s Aphasia; labored speech, repetition of words, can’t produce a full, fluent sentence. TMS to Broca’s area can disrupt fluent speech