Lecture 9: Cognitive Functions Flashcards
What is lateralization?
Division of labor between the two hemispheres
Information is exchanged between hemispheres through which areas?
– The corpus callosum
– The anterior commissure
– The hippocampal commissure
– A few other small commissures
What is the corpus callosum?
The corpus callosum allows each hemisphere of the brain access to information from both sides.
What is the left hemisphere?
The left hemisphere of the cerebral cortex connects to skin re- ceptors and muscles mainly on the right side of the body
What is the right hemisphere?
The right hemisphere connects to skin receptors and muscles mainly on the left side.
In most humans, the left side is specialized for what?
Language
What are the visual connections to the hemispheres?
■ Each hemisphere of the brain
gets input from the opposite half of the 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 pays more attention to the contralateral ear
What might happen if the corpus callum is damaged?
- If language centers are on the left side, the right side (which controls the left hand) may struggle to name objects seen only by the left eye
- Trouble integrating visual information from both fields of vision
What is the anterior commissure?
The anterior commissure is a small but important bundle of nerve fibers in the brain that also helps with communication between the left and right sides
What is the Hippocampal commissure?
This commissure allows for communication between the two hemispheres of the brain, specifically regarding the processing of memory-related information.
What is Broca’s Area?
A region in the frontal lobe of the brain that is primarily involved in speech production and language comprehension. It is typically located in the left hemisphere.
What is Wernicke’s Area?
This area plays a key role in understanding both spoken and written language.
What is the Planum Temporale?
The Planum temporale is thought to play a role in auditory perception, language comprehension, and semantic processing. It is connected to other areas involved in language, such as Wernicke’s area.
What is the Competition between the hemispheres?
There can be competition between them for control over certain cognitive tasks. This is most evident in split-brain patients, who have had the corpus callosum severed to treat severe epilepsy.
How did language evolve?
■ Language may have evolved from communication by gestures.
– A child’s ability to communicate by gestures predicts the onset of spoken
language.
■ Brain-based language development theories
– By-product of overall brain development (unlikely)
What are the Two Areas important for Language?
- Broca’s area
- Wernickes’s area
What is Broca’s Aphasia?
■ Serious impairment in language production
– Damage limited solely Broca’s area results in only minor or brief language impairment
■ Slow and awkward with all forms of language communication.
– Includes sign language of the deaf
■ English speakers seldom use pronouns, prepositions, helping verbs, similar words.
■ May omit grammatical words and endings because speech is a struggle
What is Wernicke’s Aphasia?
Characterized by impaired language comprehension and ability to remember object names.
– Recognition of items is often not impaired; ability to find words is impaired.
- Difficulty understanding speech, writing and sign language
What was The Brain of Broca’s First Patient?
(1861)
– Victor Leborngne
– Chronic language impairment; only able to say “tan”
– Damage to left, posterior frontal lobe
■ Despite being limited to saying “tan”, Leborgne was able to effortlessly sing popular French anthems..
Who is Charles Karsnur Mills (1904)?
Found early treatments for aphasia through singing. His work focused on the idea that music could serve as a bridge to help people with aphasia.
What is Melodic Intonation Therapy (MIT)?
The therapy uses singing and melody to help patients produce words and phrases when they have difficulty with normal speech.
–> Each target sentence is “composed” so that the
inflection pattern, rhythm, and stresses are similar to the speech prosody of that sentence
What is the Multistep Process of MIT?
- Humming while tapping hand
- Intoning sentence while tapping hand
- Unison intoning while tapping
- Unison intoning while fading
- Immediate repetition
- Time delay repetition (6 seconds)
- Time delay probe question
What is the recycling hypothesis?
It suggests that the brain repurposes or “recycles” pre-existing neural circuits that were initially evolved for one function and adapts them for a new, culturally specific task, such as reading or writing.
What are the 3 core areas in the reading brain?
- Phonological processor - processes sound
- Phonological assembly - connects letters to sounds
- Orthographic processor - automatic word recognition
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
– Difficulty converting words into sounds
What was Hoeo et al., findings?
For children with dyslexia: More activation during phonological awareness task predicted future reading gains.
What is The Math Brain?
Similar to reading, math is a relatively recent cultural invention, so the brain didn’t evolve specifically to do math.
What are the core regions in the math brain?
- The frontal cortex is involved in calculating
- The parietal cortex is involved in number processing
- The temporal cortex is involved in learning math facts
- The occipital and temporal cortex is involved in visual number forming
What is Dyscalculia?
Specific Math Impairment.. from the dysfunction of parietal lobe – Intraparietal sulcus
■ Root cause
– Magnitude Representation
– Mapping Deficit
What are the Overactivation of emotion
regions in math anxiety?
– Amygdala (fear)
– Insula (pain)
What brain activity occurs during consciousness that
does not occur during
unconsciousness?
In deep sleep or under anesthesia, the brain still shows some activity (e.g., sensory input might reach the cortex), but:
The information doesn’t get integrated or broadcast across the brain So, you’re not aware of it.
What is Flash Suppression?
A method in measuring consciousness..
White dots are flashing in
different orientations
■ Strong response to the flashing dots decreases awareness of the
steady dot and the brain’s response to it.
What is masking?
A brief visual stimulus is preceded, followed, or both by longer interfering stimuli.
What is Binocular Rivalry?
Slow and gradual shifts of the eye sweeping from one side to another..
In this case, Brain activity corresponds to reports of which stimulus is salient.
What is Consciousness in the Cerebral Cortex?
