Lecture 9 Flashcards
How is information exhanched between hemispheres ?
- The corpus callosum
- The anterior commisure
- The hippocampal commissure
- A few other small commissures
What does the corpus callosum allow ?
Allows each hemisphere of the brain access information from both sides
How do the hemispheres communicate with the body ?
The hemispheres communicates with the rest of the bosy controlaterally
* left - right
* right - left
What does the left hemisphere connect ?
Left hemisphere connect to skin receptors and muscles on the right side of the body and vice versa
What is the left side specialized for ?
In most humans, the left side is specialized for language
What section in the temporal cortex is larger for some people ?
The planum temporale (Wernicke’s Area) is larger in the left side for 65% of people
Who activates the right hemisphere more ?
Young children activate the right hemisphere during speech more than adults do
* As they grow older, most of them gradually surpress the right hemisphere during speeach and emphasize the left hemisphere
What are the visual connections to the hemispheres
- Each hemisphere of the brain gets input from the opposite half of the visual field
- The left half of each retina connect to the left hemisphere ( sees the right visual field)
- The right half of each retina connects to the right hemisphere (sees the left visual field)
What are the auditory connections to the hemispheres ?
- Each ear sends the information to both sides of the brain
- Brain areas must compare input from both ears for localization
- Each hemisphere does pay more attention to the ear on the opposite side
What does damaage to the courpus callosum cause ?
Damage tothe corpus callosum prevents the hemispheres from exchanging information
What is epilepsy ?
Condition characterized by repeated episodes of excessive synchronized neural activity
What is the focus ?
The point in the brain where the seizures begin
What does cutting the corpus callsoum cause ?
- Restircts the seizure to one hemisphere
- A surprising bonus was that the seizures became less frequent
What are the outcomes of a split brain operation ?
- Maintain normal intellect and motivation
- Still able to walk and talk
- But they tend to use hands independently
What occurs in most split brain people ?
Have difficulty naming objects briefly viewed in the left visual field since the left side of the brain is dominant for language
How can a small amount of information be transferred ?
A small amount of information can still be transferred via smaller comissures
What are these two commissures ?
- The Anterior commissure
- The Hippocampal commissures
Who proposed the left brain as a interpreter ?
Gazzaniga
What did Gazzaniga mean by interpreter ?
Tendency to invent and depend explanations for actions, even when true causes are unconscious
What is the right hemisphere more adept to ?
Right hemisphere is more adept at comprehending spatial relationships
* Helps see the “big picture”
* Helps relate what one hears to the overall context
What is the left hemisphere important for ?
Left hemisphere is important for understaning speech
* rules based, details
What can damage to the right hemisphere cause ?
Damage to the right hemisphere casues difficulty perceiving other’s emotions, failure to understand humour and sarcasm, and a monotone voice
What occurs when both hemispheres are inactive ?
- Left hemisphere: cannot speak
- Right hemisphere: can describe traumatic or emotional expereinces but don’t remember feeling the emotion
How did language evolve ?
- Language may have evolved from communication by gestures
- Brain-based language development theories
- Not really known
What does research suggest in regards to learning a language ?
Research suggests a sensitive period exists for the learning of language
* Lac of early language exposure can lead to permanent impairment
How does learning a second language differ ?
Ease of learning a second language differes with age
* Adults are better at memorizing vocabulary
* Children excel at learning pronunciation and unfamiliar aspects of grammar
What occurs during the sensitive period and bilingualism ?
- No sharp cutoff exists for second language learning
- Those who begin after age 12 rearely gain fleuncy equal to a native speaker
- Most people who are bilingual from a young age show bilateral activity during speech for both lanugages
- Second language learners after age 6 tend to show only left hemisphere activity
- Hemispheric control of second language comprehension is variable
What are the two important areas for Language ?
- Broca’s area
- Wernicke’s area
What occurs in Wernicke’s aphasia?
- Fluent aphasia: Characterized by impaired language comprehension and inability to remember object names
- Recognition of items is often not impaired, ability to find words is impaired
- Cognition is fully intact; just language is impaired
What are the typical characteristics of Wernicke’s aphasia ?
- Articulate/fluent speech - say words randomly
- Anomia: difficulty finding the right word
- Poor language comprehension - Difficulty understadning speech, writing, and sign language
What occurs in Broca’s aphasia?
- Serious impairment in laguage production
- Slow and awkward with all forms of language communication
- May omit grammatical words and endings because speech is a struggle
- Anomia: know what they want to say but struggle to get it out
- Trouble understadning the same kinds of words that they omit when speaking and misunderstand complex sentences
- Rely on logical guessing
Who was the person who’s brain was looked at having Broca’s aphasia ?
“Tan” (1861)
* Victor Leborngne
* Chronic language impairment; only able to say “tan”
* Damage to left, posterior frontal lobe
* Was able to sing popular French anthems and swear
Who looked at treatments for aphasia that included singing ?
Charles Karsnur Mills (1904)
What did Mills find ?
Unable to trasnfer the words in songs to proposotional speech
* Too strongly connected to the melody
Who came up with Musical Intonation Therapy ?
Robert Sparks, Nancy Helm & Martin Albert (1974)
What are the steps involved in MIT ?
- Humming while tapping hand
- Intoning sentence while tapping hand
- Unison intoning while tapping
- Unison intoning while fading
- Immediate repetition
- Time delay repetition (6 sec)
- Time delay probe questions
What are the critiques of MIT ?
- Unknown mechanisms of action
- Hemisphereic differentiation and melody ( pitch; right hemisphere and can help reactivate left hemisphere)
- Rhythm (but what about emtional speech, like sarcasm)
- Additional psychosocial impact of motivation, mood, and arousal
What are the benefits of group singing and wellbeing ?
- Expand social network
- Improve psychological well being through increased social connectivity
- Increase pain tolerance
- Reduce stress, seen through a reduction in coritsol
- Synchronization of Heart Rate Variability (amount of time between heart beat fluctuations)
What is the Neuronal Recycling Hypothesis ?
The brain repurposed brain systems that evolved to do other things and uses them to do reading and math
When was first form of reading created ?
~3500 BC (scrolls and pages by the Egyptians)
When was the first form of math created ?
~3000 BC (system of nephrology)
What occurs in the dorsal/decoding pathway ?
IFG - PrG - SMG-ANG-STG
* IFG- inferior frontal gyrus; stores and sequences speech
* PrG- Precentral gyrus; controls articulation
* SMG- Supramarginal gyrus; links letters and speech
* ANG- angular gyrus; processes meaning
* STG- superior temporal gyrus; processes speech
What occurs in the ventral/sight recognition pathway ?
IFG-OT-MTG
* OT- occipito-temporal region; letter & word recognition
* MTG- middle temporal gyrus; processes sight words and meaning
What is dyslexia ?
Specific reading impairment
* More common in boys
* High heritability though no common genetic variant has a large effect
* Occurs in all languages
* Diffculty converting words into sounds
What abnormalities occur with dyslexia ?
Abnoirmalities in the left hemisphere
* Visual word form area responds less strognly to words and more strongly to other objects
* Some have problems with poor auditory memory
* Some have impaired eye movements
Waht type of disorder is dyslexia ?
Heterogeneous Disorder
When did Hindu-Arabic numerals originate ?
origanted ~6th or ~7th century in India
* #’s aren’t rooted in a language systen
Where is the Verbal Word form located ?
Frontal lobe
* IFG
* SMG
* MTG
* STG
Where is the Visual number form area (VNFA) located?
Temporal lobe
* Ventral Visual Stream
Where is the Abstract magnitude located ?
Parietal Lobe
* process magnitude and quantities
* Intraparietal sulcus
* PS parietal lobule
* Angular gyrus
When does the angular gyrus appear ?
Comes up whenever youre dealing with numbers and it also combines different format labels for a abstract concept
What do non-numerical magnitude regions look at ?
- Size
- Duration
- Length
- Luminace
What do numerical magnitude regions look at ?
Symbolic (e.g., ‘3’ and ‘three’) and nonsymbolic (e.g., ‘ooo’) numbers
What is involved in the arithmetic brain ?
Fronto-parietal arithmetic network
* Frontal brain regions thought to be related to domain-general processes (cognitive control), working memory)
* Parietal brain regions thought to be more domain-specific (number processing)
What did Grabner et al look at ?
Verbal strategy reports to identify which trials were retrieved vs calcualted
* Compare brain activity for retreived trials vs calcualted trials
* Retrieval > calcualtion : Left angular gyrus
* Calculation > Retrieval: spread out
What is dyscalculia ?
Specific math impairment
What occurs in dyscalculia ?
Dysfuntion of parietal lobe
* Intraparietal sulcus
What is the root cause of dyscalculia ?
- Magnitude Representation
- Mapping Deficit
What is math anxiety ?
worry or fear about performing math calculations
What occurs within math anxiety and in who is it more common in ?
Overeaction of emotion regions
* Amygadala (fear)
* Insula (pain)
More common in females
What is the easy problem ?
What brain acitivty occurs during consciousness that does not occer during unconsciousness ?
What are the main two questions regarding consciousness ?
- What appens when an aler person becomes conscious of a particular stimulus ?
- What enables a person (or animal) to be aware of anything at all ?
What occurs during Flash Surpression ?
- White dots are flashing in different orientations
- One eye sees mulitple dots while another sees a singular dot
- Strong response to the flashing dots decrease awareness of the steady dot and the brains response to it
What occurs during Masking ?
- A brief visual stimulus is preceded, followed, or both by longer interfering stimuli
- Flash for 29 ms
What occurs during Binocular rivalry ?
- Slow and gradual shifts of the eye sweeping from one side to another
- Brain activity corresponds to reprts of which stimulus is salient
- Brain fuses together similar images
How is consciousness in the cerebral cortex ?
- Consciousness requires the integration of information
- Cerebral cortex has long-range reciprocal connections enabling each area to influence many others and receive feedback from the others
- The connections enable information to spread, compare and interact
What occurs during anesthesia ?
Loss of consciousness under anesthesia
* Marked by decreased overall brain activity
* Decreased overall activity - decreased dopamine levels connectivity b/w cerebral cortex and thalamus
* Inital recovery of scnsciousness involves reconnecting these areas
What are two examples of vegetative state?
Playing tennis and walking through the house
What is Top Down attention ?
- Intetional
- E.g., looking for someone you know in a group
- Prefrontal and Parietal cortex
What is Bottom up attention ?
- Reaction to a stimulus
- E.g., A deer run past you in the park, grabbing your attention
- Thalamus (?)
What is the stroop task ?
Look at congruent and incongruent list of colours and are asked to read it
* The anterior cingulate gyrus (ACG) is activated while doing this task
What is involved in lust ?
Testosterone and Estrogen
What is involved in attraction ?
- Dopamine
- Nonrepinephrine
- Serotonin
What is involved in attatchment ?
- Oxytocin
- Vasopressin
When is oxytocin released ?
Both men and women release it during sexual activity
What occurs when oxytocin is given as a nasal spray ?
- Rated their significant other much higer when given oxytocin
- Enhances fidelity - men stood further away from an attractive woman
What does oxytocin increase ?
- Comformity to the opinions of the ingroup but not the outgroup
- Trust between ingroups but not outgroups
- Attention to possible dangers - heightens reactions to threats especially from strangers
What is virtual social exclusion experiments ?
Studies that assess brain responses to peer rejection by making children think that they are being rejected or excluded by unknown children
What occurs in the “Cyberball” game ?
- Participants play “catch” with two other virtual players
- Child told two peers in another room controlled avatars
- Baseline: equal passing
- Experiment: virtual players only threw to eachother
What brain areas were activated in response to exclusion ?
Areas of the brain that respond to exlusion are those involved in feeling physical pain
