304: Wechsler Intelligence Scale Pt2

WAIS-IV SUBTEST STRUCTURE

Vocabulary Subtest
This is simply the ability to define words.  This is the most stable measure of intelligence.  This means that injury does not affect it as much so it is a good estimate of pre-morbid intelligence.  Because of this ability to measure pre-morbid intelligence through vocabulary it is often referred to as a "hold" subtest.

Similarities Subtest
Consists of paired items of increasing difficulty.  You would basically get to words such as rhinoceros and elephant, and then you would be asked how they are alike.  This is a "non-hold" subtest.

Information Subtest
Still on the WAIS but it is now an optional subtest on the WISC.  This probably indicates that it is not going to be a part of the test much longer.  The information subtest includes the ability to comprehend, follow directions, and respond.  It seems that college students do really well on this and it is VERY culturally specific.

Block Design
This uses 9 colored blocks and you will get a picture shown to you in a booklet that you will have to make with the blocks.  This is also a non-hold subtest.  It is not the most stable subtest but it is a really good predictor of g.

Matrix Reasoning Subtest
This is where you get a number of pictures that form a sort of pattern and you have to identify the missing picture that would fit into the pattern.  This is non-verbal, not very biased, and a very nice measure of fluid intelligence.

Digit Span Subtest
You simply repeat a list of digits that the tester gives to you back to him.  Sometimes you need to repeat them as he said them and sometimes you need to repeat them backwards.  The tester has to read them at a smooth and easy pace because if he is too fast it is much easier to remember the digits.  You should practice reading them at about 1/second.  Non-intellectual factors easily influence performance on this subtest such as anxiety, distractions, inattention.

Digit Symbol-Coding Subtest
Requires the subject to copy symbols.

CALCULATING INDEX SCORES

Say Ronald, a 10 year old,  got a raw score in vocabulary of 37.  So you just add up all his points and you get 37.  Remember that you are normed to the age for each subtest.  So you would look up vocabulary and his raw score to find his scaled score which in this case is 12.  This scaled score is where he gets compared to other people of his age.  So with a score of 12, what does this mean in comparison to other students of his age? If he were 12 years old instead of 10 and still got a vocabulary score of 37 his raw score at age 12 would instead be 9.  What does a raw score of 9 mean in comparison to other students?  Make sure that you know the mean, SD, and range of both scaled score and index score.  There is a slide on this with a nice little table.

PATTERN ANALYSIS

If the IQ is not interpretable due to variability then you want to ask yourself, "where does that variability come from?"

370: Sound 2 - The Ear

SOUND QUALITY

Timbre
All qualities of sound except loudness and pitch are what constitute timbre.

Complex Sounds
Higher frequency elements of a sound are called overtones or partials.  Partials whose frequency is a whole integer multiple of the fundamental frequency are called harmonics.  Together, the partials that make up a sound are referred to as its frequency spectrum, which is in part responsible for a sound's timbre.  Good musical instruments produce sounds which have mostly harmonics and not many non-harmonic partials.  He played 3 piano example and some of them have extra harmonics and frequencies that are non-harmonic partials and the last one was a Stienway which has very few of these non-harmonic partials and it sounded much better.  Class members described the sound of the non-harmonic partials as making the piano sound tinny.

HOW DO WE GO FROM A PHYSIOLOGICAL EXPERIENCE TO A PHENOMENOLOGICAL EXPERIENCE?



Here is a video clip that was shown in class.

Outer Ear
Pinna helps with sound location.  Auditory Canal is 3 cm long tube-like structure.

Middle Ear
Separates the inner from the outer ear.  Contains the malleus, incus, and stapes.

Inner Ear
The main structure is the cochlea which is a fluid filled snail-like structure that is set into vibrations by the stapes.  The organ of corti is where transduction is actually happening.

Outer and middle ear are filled with air where the inner ear is filled with a more dense fluid.  This increase in density makes it so pressure changes in the air transmit more poorly; this is why it is harder to hear underwater.  Ossicles act to amplify the vibration for better transmission to the fluid.

The Organ of Corti
Some of the key structures included the basilar membrane, the inner and outer hair cells, and the tectorial membrane.  The basilar membrane moves up and down and the tectorial membrane moves side to side in response to the basilar membrane.

NEURAL SIGNALS FOR FREQUENCY

The cochlea is sensitive to different frequencies.  There are two ways that nerve signal frequency; you want to know which are signally and how they are signaling.  Berkesy come up with a place theory of hearing.  He determined that frequency of sound is indicated by the place on the organ of corti that has the highest firing rate.  He determined this with direct observation of the basilar membrane and by building a model of it.  The base of the membrane is 3 to 4 times narrower than tat the apex and...

375: Language Pt2

WHY ARE WORDS HARD TO UNDERSTAND?

Initial research showed us that our brain had a hard time understanding words that were miss-said, like hack instead of hat.  But later, Gaskell et al found that people are actually faster for natural changes than they are for unnatural changes (e.g., pime bench would be interpreted as pine bench because the m in pime seems to be preparatory for the b in bench).

WHY ARE SENTENCES HARD?

He gave the example of the sentence "Time flies like an arrow" and how this particular sentence could have many different meanings.

Sentence Processing
To understand sentence processing we need to understand about syntax and grammar.  Grammar refers to a set of rules that describe the legal sentences that can be constructed in a language.  Proscriptive grammar is telling a person what to do and descriptive grammar is a description of what grammar is being used.

Syntax & Semantics
"The psychologist slept fitfully, dreaming new ideas." or "Fitfully the slept new, ideas dreaming psychologist" or The new ideas slept fitfully, dreaming a psychologist" show that sentences can have grammar, it can have semantic meaning, it can have both or it can have neither.

WORD CHAIN GRAMMARS

We have a tendency to select grammatical sentences word by word and we can fill in blanks because there are certain words we would expect to be next.  For example, "the boy hit the ____ with the bat" we would usually say "ball" but it could be any number of other things.  When we select a word to start a sentence we now have a specific path we have to follow because some words don't pair up such as "I" and "are."  We know that those two words don't go together but instead we would pair "I" with "am."

Dependencies
The basic idea behind word chain grammar and dependencies is that the verbs must agree; "either" implies "or," "at" implies a noun.  Dependencies like these can be embedded in each other.  When it comes down to it, word chain grammars don't work to explain sentence structure because they can be continually embedded in each other.

PHRASE STRUCTURE GRAMMAR

These use hierarchical organization and not linear organization.  They also specify a limited number of sentence parts and a limited number of ways the parts can be combined.  So how do we get embeddedness?  Basically the words themselves have meaning imbedded in them in this type of grammar.  What cues does the parser use to decide which phrase structures are which?

Cues
There are four specific cues that we use to decide phrase structures; key words, word order, context, and principle of minimal attachment.

Phrase Structure Ambiguities
Phrase structures can account for (some) ambiguities of language.  Ambiguity is basically the idea that interpretation of a phrase can be one way or another and it is not clear exactly which way is the "correct" way.  Our top-down expectations are what make us hear a sentence one way or another.

304: Wechsler Intelligence Scale

WAIS-IV

A good book about this is called "Essentials of WAIS - IV Assessment" that Dr. South has his graduate students read each year.

David Wechsler
Wechsler defined intelligence as "the aggregate or global capacity to act purposefully, to think rationally and to deal effectively with the environment."  He didn't like the idea of a single score representing someone's "intelligence" so he took into account the non-intellective factors in his theory.  He designed a test for adults.  He de-emphasized speeded, timed portions and considered that cognitive skills declined with age.  

370: Sound I - The Sound Stimulus

What are some of the functions of sound?  Well one important reason is that we can't see everything.  We need sound to alert us to certain stimuli.  What are two possible definitions of sound?  There is a physical definition and a perceptual definition.  The physical definition is pressure that changes in the air or another medium.  The perceptual definition is the experience we have when we hear.

SOUND WAVES

Objects make sound by moving back and forth rapidly through a medium.  There is a difference between water and air waves.  Water waves are transverse moving up and down, but sound waves move side to side.

Pure Tone
Pure tone is just a sine wave of a certain frequency.  It is the simples form of a sound wave and all other sound waves are composed of pure tones.

Natural Sounds
These are relatively simple sounds, such as those mad by musical instruments, and are made up of many pure tones.  Complex sounds have every at a broad range of frequencies and the relative energy at the different frequencies determine the pitch.

AMPLITUDE AND FREQUENCY

AMPLITUDE AND LOUDNESS: PHYSICAL VS PERCEPTUAL

The larger the amplitude is the larger our perception of that sound will be.  The amplitude of sound waves is the difference in the pressure between these things.  High pressure differences means that it has a high amplitude.  This pressure is typically measured in micropascals but perception is typically measured in Decibels (dB).

Decibels
The log nature of the decibel scale compensates for the response compression of the auditory system.  So what is the response compression?  The idea is that you are more sensitive at the lower end but the louder the sound gets the harder it is to differentiate between differing sounds.  This is a non linear relationship.  So for example, if you increase the amplitude by 10 the perception in dB increases by 20, then amplitude going from 10 to 100 the dB goes only from 20 to 40, then the amplitude going from 100 to 1000 the dB only go from 40 to 60, and so on.  If I were to say that something is twice as loud usually this speak is referring to dB and not amplitude.

FRQUENCY

Frequency is the number of amplitude cycles per second and is measured in Hertz.  The higher we perceive frequency the higher the pitch.  Tone height is the increase in pitch that happens when frequency is changed.

Musical Scales and Frequency
The letters  in the musical scale repeats and notes with the same letter name have the same tone chroma, they sound similar.  So if you were to take a low A, 27.5 Hz, then each octave higher would be double of the A one octave lower.

THE AUDIBILITY CURVE

The idea is that the audibility curve tells us the relationship between frequency and your perceived loudness (dB).  Our hearing range is 20 to 20,000 Hz with greatest sensitivity to 2,000 to 4,000 Hz.  The audibility curve shows the threshold of hearing.  For really low turns it takes much more amplitude for us to be able to hear it.

EQUAL LOUDNESS CURVES

This is where you take 2 tones played at the same frequency but one with double the dB of the other.  then you change the frequency of one of these sound curves and ask how the dB changed compared to the unchanged frequency.  The basic idea of this curve is that low pitches have to be louder.

375: Language

LANGUAGE DIVERSITY

There are about 6-7000 different languages worldwide, however, more than half of those languages are spoken by fewer than 10,000 people.  Some people estimate that perhaps 90% of these languages will be gone within 100 years.

LANGUAGE CHARACTERISTICS

Communicative


Semanticity
Must stand for something other than itself.  A grunt has no semanticity for example.

Arbitrary
Relation between sound and reference is unimportant.  Different languages have different mappings.

Structured
Pattern of symbols is not arbitrary


Generative
The basic units can be used to build a limitless number of utterances.


Dynamic
Language is always evolving.

In general all languages share a few more characteristics; children can learn them, adults can speak and understand each other, they capture the ideas that people normally communicate, and they enable communication amongst groups.

So lets say that Dr. Kirwan is a super nerd and has learned to speak Na'vi.  He goes to a convention and speaks Na'vi with another nerd there.  Does this then qualify as a language under these conditions?  Maybe, it does allow communication between adults and groups but children probably don't learn this very often and it also lacks a certain amount of vocabulary.

SEMANTICS

Semantics is the study of meaning and, in this case, how people mentally represent the meaning of for words and sentences.  A related concept is a morpheme which is the smallest unit of speech used to code a specific meaning (e.g., s at the end of the word changes the meaning so s is a morpheme).  Phonemes build up to Morphemes which build up to Mental Lexicons.  Mental Lexicons is what assigns meaning to all your different utterances.  Syntax is the grammatical rules that specify how words and morphemes are arranged to yield acceptable sentences.

PHONEMES

Why is phonemes differentiation so hard?  Part of the reason is that we produce them so quickly.  We did a quick activity were he played different people with differing accents speaking the same paragraph then asked us to guess where they were from.  The dialect for each person was different but what made it possible for us to differentiate between a southerner, a northeaster, and a scottish speaker was the accent created by the different phonemes.

Coarticulation 
"Vowel" vs "Vole."  You start to form the vowel before you start the buzzing noise with your lips that produces the v sound.

Perception of Phonemes
They found that we automatically fill in some phonemes based on the context of the phoneme when part of the word is indistinguishable due to a cough.  People will not even notice when they are filling in for words that they didn't entirely hear.  For example, the *eel was on the axle and the *eel was on the shoe sound the exact same but when we hear them we know that the first one is wheel and the second is heel without even realizes we are hearing the same word in both situations.

The McGurk Effect
What you hear can be very influenced by what you are seeing.  Youtube the McGurk effect and you will find some pretty cool videos.  An interesting application of the McGurk effect is that when you speak to someone in person and then on the phone you will understand that person better than if you only spoke to them on the phone.

The Phonetic Boundary
From about 0-30 ms people reliably identified the sound as da then there is a dramatic decrease in response reliability (called the phonetic boundary) until around 50-80 ms people would reliably identify the sound as ta instead of da.