Cognitive Neuroscience Final

Speech Production

* Begins with air being expelled by the **lungs**


* Produces air stream that passes through **vocal folds** of the **larynx**
* Gives rise to a **vibration** of a certain frequency that is determined by the **muscles of the larynx** (they control tension of the vocal cords)
* High voice and low voice
* Vibrations then go into the **vocal tract**
* Vocal tract adjusts muscles of all involved structures, including the **tongue**, to make different sounds

Phone

Production of sound

Phones

Speech sounds

Phonemes 

Perception of speech sounds

Making a sentence

Phonemes → Syllables → Words → Sentences

How many phonemes are in the English language?

44

Interpreting Sounds

* Physical properties of sound are not nearly as discrete: no one to one mapping of how we perceive sounds
* If we focus on the physical breakups of sounds, they do NOT match our perception
* Speech is as much PSYCHOLOGICAL as it is PHYSICAL

Sentences

Express complete and meaningful thoughts

* Have rules and expectations about sentences: cannot be random words

Grammar

Rules by which words are properly formed and combined

* Varies between languages
* Absolutely critical to our understanding of spoken and written language

Syntax

Governs all of the grammatical rules, the correct way to use words and phrases, what sentences follow certain sentences

* Visual information is also used to understand language

McGurk Effect

*“Ba” vs “Fa” -* same sound, but changes for what you see

* **Visual information** is also important
* Works even if you know about the effect!

Brain Anatomy of Language

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* Broca’s Area
* Inferior frontal cortex
* Sylvian fissure


* Superior temporal gyrus (holds Heschl's Gyrus/A1)
* Supramarginal Gyrus
* Inferior parietal lobule
* Angular Gyrus
* Wernicke’s Area
* Also occipital lobe (reading) and somatosensory (braille)

Language Deficits in Neurological Disorders: Aphasia

Speech comprehension or production deficit. 

Language Deficits in Neurological Disorders: Anomia

Naming deficit. 

Language Deficits in Neurological Disorders: Dysarthria

Slurring of speech. 

Language Deficits in Neurological Disorders: Paraphasia

Unintended near sound substitute. 

Language Deficits in Neurological Disorders: Logorrhea

Incomprehensible speech. 

Language Deficits in Neurological Disorders: Alexia

Reading deficit. 

Language Deficits in Neurological Disorders: Agraphia

Writing deficit. 

Language Deficits in Neurological Disorders: Neologism

 A new, generally nonsensical word.

* Psychosis patients

Broca’s Aphasia

***Expressive*** **deficit**

* Speech production and articulation difficulty
* Speech comprehension (understanding) is *completely normal*
* Effortful, slow, and telegraphic speech (characteristic of young children)
* Varies in intensity

Broca’s Aphasia - Patient Tan

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* French hat maker who had severe epilepsy
* Age of 30, lost ability to speak
* Hospitalized in a psychiatric wards
* *Could only say “tan” – how he communicated with the staff*
* Normal intellect
* Muscle weakness on the right side of his body
* Could suggest left hemisphere damage
* Towards the end of his life, met Broca

Wernicke’s Aphasia

**Receptive - trouble comprehending both written and spoken language**

* Some problems with speech production, but in a different way
* No trouble producing words: fluent
* Syntax, amount of words, all is *normal*
* *The* *contents, however, is nonsensical*
* Damage to both *gray and white matter*

Broca’s Area & Wernicke’s Area

* Wernicke's area connects to Broca’s area through the arcuate fascicules 
* Loops to Wernicke's area through the angular gyrus

Broca’s Aphasia Mnemonic

*Broca is broke.* \n *Speaks broken words.* \n *He is also frustrated because he is broke.*

Wernicke’s Aphasia Mnemonic

*Wernicke's like What?* \n *Wernicke's is all confused.* \n *Makes Word salads for a living.*

Aphasia Tree: Global Aphasia

1. Is speech fluent?
* NO
2. Can you comprehend spoken messages?
* NO
3. Can you repeat words or phrases?
* NO

Aphasia Tree: Mixed Transcortical Aphasia

1. Is speech fluent?
* NO
2. Can you comprehend spoken messages?
* NO
3. Can you repeat words or phrases?
* YES

Aphasia Tree: Broca’s Aphasia

1. Is speech fluent?
* NO
2. Can you comprehend spoken messages?
* YES
3. Can you repeat words or phrases?
* NO

Aphasia Tree: Transcortical Motor Aphasia

1. Is speech fluent?
* NO
2. Can you comprehend spoken messages?
* YES
3. Can you repeat words or phrases?
* YES

Aphasia Tree: Wernicke’s Aphasia

1. Is speech fluent?
* YES
2. Can you comprehend spoken messages?
* NO
3. Can you repeat words or phrases?
* NO

Aphasia Tree: Transcortical Sensory Aphasia

1. Is speech fluent?
* YES
2. Can you comprehend spoken messages?
* NO
3. Can you repeat words or phrases?
* YES

Aphasia Tree: Conduction Aphasia

1. Is speech fluent?
* YES
2. Can you comprehend spoken messages?
* YES
3. Can you repeat words or phrases?
* NO

Aphasia Tree: Anomic Aphasia

1. Is speech fluent?
* YES
2. Can you comprehend spoken messages?
* YES
3. Can you repeat words or phrases?
* YES

Broca’s vs. Wernicke’s Aphasia

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* __**Broca’s Aphasia**__
* *Halting speech*
* Repetitive (perseveration)
* Disordered syntax
* Disordered grammar
* Disordered structure of individual words
* __**Wernicke’s Aphasia**__
* *Fluent speech*
* Little repetition
* Syntax adequate
* Grammar adequate
* Contrived or inappropriate words

Wernicke-Geschwind Model

* What the Aphasia Tree is based on (clinical training)!
* Assumes that auditory and visual information through primary cortical areas


* Works its way to *Wernicke's area*
* Where *meaning* is extracted 
* To produce speech, words are sent from *Wernicke’s Area via the arcuate fasciculus to Broca’s Area*
* Send *motor programming* to *primary motor cortex*

Wernicke-Geschwind Model: Problems

* Associations between the areas of the brain that are damage are not always consistent
* Aphasia tree and lesion location doesn’t often hold up


* Some symptoms of aphasias can occur *without* damage to the language areas
* Damage usually has to be deep to produce the clear deficits we are talking about
* Deep white matter damage, usually
* Comprehension vs. production doesn’t adequately capture all of the key differences in the clinical cases
* Some can discriminate between speech sounds, but can’t discriminate between words

Dual-Stream Model of Language

* Has dorsal and ventral branches 
* Heshel’s Gyrus (green box)
* Spectro-temporal analysis (frequency and sound processing)
* Yellow box = Process phonemes 
* Dyslexia

Dual-Stream Model of Language: Dorsal

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* Purpose: maps acoustic signals to frontal articulatory networks (**sound/language for action network**)
* “*How*” rather than “*where*”
* Left lateralized
* More vulnerable to damage 
* Corresponds roughly to the Wernicke-Geschwind Model

Dual-Stream Model of Language: Ventral

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* Processes speech for comprehension/meaning
* “*What*”
* **Processes sound for meaning**
* Mostly bilateral (still a little bit left lateralized)

Dual-Stream Model of Language: Arcuate Fasciculus

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* Connects **Dorsal stream**
* Connects regions in the same hemisphere
* Part of the superior longitudinal fasciculus
* Conduction aphasia = damage to Arcuate Fasciculus

Dual-Stream Model of Language: Uncinate Fasciculus

* Connects **Ventral stream**


* Connects anterior portions of temporal lobe to Broca’s area
* Understood more poorly than the dorsal network 

Executive functioning is also known as …

Cognitive control

* achieving your behavioral goal, whatever that may be

3 primary executive functions

1\. The ability to *establish and modify* *rules*

2\. The ability to engage in *contextual control* 

3\. The ability to *actively process information*

3 primary executive functions: 1. Rules

* Our rules are particularly *complex*


* Rules are *abstract* and *vague*
* Rules are *flexible*: lots of exceptions
* The actual engagement of these rules are difficult, more difficult that creating these rules

Prefrontal Cortex

* PFC
* Planning complex cognitive behavior, personality expression, decision making, and moderating social behavior

Subdivisions of the Prefrontal Cortex: Orbitofrontal Cortex

* OFC
* Hard to study due to nasal cavities blocking fMRI research 

Subdivisions of the Prefrontal Cortex: Anterior Cingulate Cortex

* ACC
* Broken into sub regions

Dorsal (d)

Towards the top

Ventral (v)

Towards the bottom

Posterior

Towards the back

Anterior

Towards the front

Planes of the Prefrontal Cortex - Gradients

* Gradient from lateral (side) to medial (midline)


* Gradient from anterior (front) to posterior (back)
* Gradient from dorsal (top) to ventral (bottom)

WHACH Model

* __**What-How**__
* *From dorsal (how) to ventral (what)*
* Bigger on “how” than “what”
* Similar to dorsal & ventral pathways discussed previously 


* __**Abstraction**__
* *From anterior (abstract) to posterior (concrete)*
* Front of brain deals with abstraction
* __**Cold-Hot**__
* *From lateral (cold) to medial (hot)*
* Emotional salience of information

WHACH Model: What-How Gradient

* Similar to dorsal & ventral pathways discussed previously 


* Bigger on “*how*” than “what”

Nagel et al. (2008) - What/How

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* Testing this dorsal/ventral route
* *Semantic task* (semantically-related verb generation based on a picture of a noun) or *response selection task* (noun was presented, but here it was a paired-associate word task)
* Easy, medium, and hard conditions for both
* Measured BOLD effect
* **DOUBLE DISSOCIATION!**

Nagel et al. (2008): Results for Dorsolateral Prefrontal Cortex

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* Responds more to the *response selection task*
* Semantic selection task is more muted

Nagel et al. (2008): Results for Ventrolateral Prefrontal Cortex

* Responds more to *semantic meaning (what information)*


* Not responding the response selection task

WHACH Model: Abstraction Gradient

* Anterior- Posterior gradient
* Anterior (Rostral) PFC = *abstract*
* Posterior (Caudal) PFC = *concrete*
* Front of the brain deals w/ abstraction

Badre & D’Esposito (2007): Abstract-Concrete Gradient

* fMRI task
* __Condition A: Response__
* Press a colored key to indicate a certain color was present 
* Make it more complicated… 
* __Condition  B: Feature to Response__
* Multiple rules considered
* More fingers mapped, based on texture and color
* __Condition C: Dimensions__
* Multiple stimuli, stimuli can match on different properties
* Comparing multiple objects for features, maps onto keys
* __Condition D: Context__
* VERY complex!

**Mapped out the Anterior to Posterior gradient** ***almost perfectly***

WHACH Model: Hot-Cold Gradient

* Lateral to Medial gradient (in PFC)
* *Cold* *(Lateral)*= non emotional cognitive processing
* *Hot* *(Medial)*= emotional cognitive processing

Goel & Dolan (2003): Hot-Cold Gradient Findings

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* Neutral condition activated more lateral parts of the PFC
* Medial parts of PFC activated for emotional problems

Libet Study

***Do we have free will?***

* Before you're aware that you're making the decision, your brain is already ramping up activity (full 2.5 seconds before)
* 150-250 milliseconds for human response time
* 200 milliseconds *before* they press the button, feels the urge

Fried et al. (2011)

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* Used single unit recordings (brain surgery subjects)
* __Targeted areas__: Supplementary Motor Area, pre-SMA, ACCd, ACCr
* *ACC = monitoring* (particularly errors)
* Motivation, goal-setting
* *SMA = internally generated motor action*
* W = the urge (not the actual button press)

Fried et al. (2011): Findings

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* Activity begins *up to 2 seconds before* *you are even aware* that you want to press the button
* Accuracy of prediction is about 80%!
* Evidence that even before the urge, brain gets ready to have a motor response
* Proof that your brain makes decisions w/out you

Intuition: Iowa Gambling Task

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* (Vegas Deck) One deck: *high risk, high reward*
* Other deck: *lower risk, lower reward*
* Repeat over multiple trials. Measured:
* SCR = skin conductance response (measures if you are uncomfortable)
* Behavioral response = # of cards selecting from each deck
* ***Healthy participants*****: show a physiological response to the disadvantaged deck even before consciously aware of why.**
* ***Damage to Ventromedial area patients:*** **continued to select bad deck - do not show learning (unlike controls)**
* Phineas Gage’s problem!

Frontotemporal Dementia (FTD) 

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* Can attack younger people
* Fairly rare
* Highly variable course (T.O.D. could be 2 to 20 years post diagnosis)
* Behaviors become abnormal (childlike, aggressive with others, things out of character)

Duffy et al.: Schizophrenia Patients

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* Trouble deactivating the daydreaming default 
* Also characteristic of other MIs and dementia
* Processing external information *too much*
* Salience networks

Emotion

* Intersection/confluence of behavior, physiology, and feeling!
* More scientific approach then just feeling

Six Basic Facial Expressions of Emotion

* Anger
* Happiness
* Disgust
* Surprise
* Sadness
* Fear

Basic Emotions

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* *Innate*
* *Pan-cultural*
* Evolutionarily old
* Conserved across species
* Conveyed with specific facial features

Complex Emotions

* *Learned*


* *Culturally specific*
* Evolutionary new
* Not conserved
* No obvious

Common-Sense Emotion Theory

***Stimulus → Perception → Emotion → Bodily Arousal*** 

* Ex: Shark → “Shark!” → Fear → Increased HR, Increased BP, sweating
* In reality… *this is not quick enough to be accurate!*

James-Lange Theory

__“Do we run from a bear because we are afraid, or are we afraid because we are running from a bear?”__

* James says you're **afraid** *because* you're **running**
* Bodily arousal and the resulting flight or flight response happens *first* - emotions come last as a result of what is happening
* Lange assumed that brain stem nuclei that control cardiac function are critical to informing the higher level cortices about what is actually happening

James-Lange Theory: Problems

* This theory ultimately *fails*, but it does explain why we can react so quickly to threats!
* This theory suggests that you ***don’t feel afraid unless you first feel the physiological effects***
* Has been experimentally studied using deafferentation experiments (alter the brain so that the animal is unaware of physiological changes)
* The animals *show the same emotional response*… so the J.L. theory is wrong about this point

Cannon-Bard Theory

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* Argues that the autonomic nervous system response is too undifferentiated to yield a variety of emotional states
* Not enough specificity in our A.N.S. to link to a direct feeling
* **Propose instead that bodily arousal and feelings are experiences** ***simultaneously*** **through** ***different pathways***
* Still not the right model, but getting there…

Papez Circuit

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* More complicated…
* Informed by clinical data
* Other structures getting involved
* ***Direct predecessor of the limbic system!!***

Limbic System

***Structures that mediate emotion***

* Not a simple direct pathway
* Not 100% agreement on what structures are included in the limbic system, except for:
* **Hypothalamus**
* **Amygdala**
* **Thalamus (kind of…)**
* **Hippocampus**
* **Mamillary Body**

Limbic System: Amygdala

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* Strongly associated with feelings/emotions
* __Stimulation of amygdala__= anger, violence, fear, anxiety
* __Destruction of amygdala__ = calmness, mellowness, and loss of fear
* Connected to *hippocampus* via fornix
* Explains why our memories are tinged w/ emotions
* And why we remember emotionally charged memories better
* *Olfactory tract* linked w/ limbic system - smells can bring up memories

Limbic System: Hypothalamus

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* **Regulates autonomic nervous system (fight/flight or rest/relax)**
* Output connections with *amygdala*
* How amygdala is controlling the bodily state

Limbic System: Problems

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* *No systematic definition* of what the limbic system is
* **Hippocampus is NOT an emotion-mediating structur**e
* Studies prove this
* Does not control *all kinds of emotions* (no complex emotions)

Kluver-Bucy Syndrome: Symptoms

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* Docility 
* Hyperorality (explores object w/ mouth)
* Visual agnosia (inability to recognize familiar objects)
* Hypersexuality 
* Loss of fear

Kluver-Bucy Syndrome

* First, incorrectly attributed these symptoms with the *hippocampus*
* In reality, it was **the disconnection with the amygdala to the frontal cortex**
* Infection, poisoning, etc. for clinical cases
* *Most cases are experimental*

Charles Whitman

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* **UT Austin mass killer (1966)** 
* **Killed his wife, mother, and 14 other people (wounded 31)**
* Suicide note:
* “I do not really understand myself these days. I am supposed to be an average, reasonable and intelligent young man. However, lately (I cannot recall when it started) I have been a victim of many unusual and irrational thoughts”
* No clear reason why he was doing this - *seemed confused by his own actions*
* **Autopsy found a small tumor near his amygdala, exciting his amygdala** 
* Widely supported that this was the reason for his actions

Urbach-Wiethe Disease

Genetic mutation that results in the *calcification of the amygdala*

* VERY specific

Patient SM

* Diagnosed with Urbach-Wiethe Disease
* “The Fearless Woman”

Patient SM: Emotion

Struggles to identify basic emotions (*especially fear*)

Patient SM: Eye tracking

Spends a lot **less time looking at the eyes** than normal

* Emotions that are *not fear*: **pretty good**
* *Fear*: **not good**
* When she is told explicitly to focus on the eyes: she can do it!
* Very complicated…

Dual-Road Theory: Low Road

**Immediate input, threat, quick response**

* *Can be problematic*: responds to schemas, stereotypes, biases…

Dual-Road Theory: High Road

**Traditional processing stream**

* Moderates a more calm, rational response

Dual-Road Theory: Amygdala

* Amygdala *stores these threat memories*
* What is threatening?
* What is an emergency?


* Amygdala *recognizes threat* (**low road**), immediate *fight or flight response*

Amygdala and the Ventral Stream

* Can also affect your **perceptions** – *feedback loops to visual processing stream!*
* Majority of sensory resources focuses on that threat
* Good… but has the potential to be problematic
* Think about PTSD

Face Emotional Perception (fMRI): Amygdala Activation

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* Emotion recognition task
* Amygdala activates for **all 6 basic emotions** (*not just fear!*)

Insula and Disgust

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* __Anterior Insular cortex__
* Primary **taste** cortex
* __IAPS-Like Stimulus__
* *Cockroach Stimulus* - **physiological gag reflex ensues**
* Activates Anterior Insula

Ventral Medial PreFrontal Cortex (vmPFC)

Intuition, gut feelings, rewards, so many things!

Emotion Regulation and vmPFC

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* **4 patients w/** **vmPFC damage**
* Lots of overlapping damage
* Brain activity in the *right* and *left amygdala* 
* Aversive and Neutral stimulus 
* __Aversive Conditions__
* General pattern is the same, but *stronger activity with patients* (vs. controls)
* @@**Ventral PFC is regulating the emotional response of the amygdala (so when damaged, amygdala is unregulated)**@@
* These patients actually ***lose the ability to self-reflect*** and ***do not have a strong emotional response to the aversive stimuli*** (on the outside)
* *Pseudo-sociopathy symptom?*

Social Brain Hypothesis

Generally, the **bigger the brain**, the **more** **social cognition**

* Human’s brains are *particularly large* for our body size
* **Areas that are bigger** are related to **social behavior**

Bigger Areas of the Brain That are Related to Social Behavior

* __**Inferior Frontal Gyrus (IFG)**__
* *Executive functions*
* __**Super Temporal Sulcus (STS)**__
* *Language, speech, and memory*
* __**Temporal Parietal Junction (TPJ)**__

Theory of Mind (ToM)

__Chimp Study__

* ***Need Condition***: walk in with something in their hand, press button w/ foot
* ***Want Condition*****:** used their feet with nothing occupying their hands
* Given chimp opportunity to do the same thing
* ***Want condition*****: chimps are more likely to use their feet (imitate behavior… maybe b/c they find it fun!)** 
* *Need cognition*: equal use of hands and feet

Why is ToM Important?

**Predict/explain others behaviors and emotions (humans are good at this!)**

* Compassion/empathy for others 
* Understand sarcasm 
* Deception 
* *Key impairment in some disorders:* depression, autism, schizophrenia and some personality disorders