Cognitive Neuroscience Final

Speech Production

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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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)

• 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

• 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

• (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)

• 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

• 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

• 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

• 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

• 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

• 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

• Regulates autonomic nervous system (fight/flight or rest/relax)

• Output connections with amygdala

  • How amygdala is controlling the bodily state

Limbic System: Problems

• No systematic definition of what the limbic system is

• Hippocampus is NOT an emotion-mediating structure

  • Studies prove this

• Does not control all kinds of emotions (no complex emotions)

Kluver-Bucy Syndrome: Symptoms

• 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

• 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

• Emotion recognition task

• Amygdala activates for all 6 basic emotions (not just fear!)

Insula and Disgust

• 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

• 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