Lecture 7 Flashcards
What is cognitive neuroscience?
Exploration of the brain pathways that lead to cognition.
What does cognitive neuroscience include?
- Language
- Attention
- Decision making
- Learning/memory
- Consciousness
___________ techniques are a valuable tool in cognitive neuroscience…
Neuroimaging.
What is a fMRI?
- Functional Magnetic Resonance Imaging.
- It detects changes in blood flow in the brain.
- Using fMRI you’re able to detect changes in blood flow, which correlate with changes in activity of the brain.
- fMRI is good spatial resolution. (Spatial resolution means you’re able to resolve detail in very small areas of the brain).
What is a PET?
- Positron Emission Tomography.
- It detects positrons emitted by radioactive substance in brain.
-How PET works is you inject someone with glucose that is made to be radioactive, and as the neurons use the glucose and it’s broken down, it releases empty matter in the form of a positron.
(Positron: a positively charged electron).
-You would use PET when you need good temporal resolution.
(Temporal means time).
- It does not have good spatial resolution though.
- An example of this would be studying the motor system.
Babies and Sound.
- From birth, babies can discriminate between different sounds.
- Over time, the sounds used around the baby become associated with changes in the environment, giving sounds meaning.
Babies and Words.
- This process only occurs during a sensitive period.
- Long term isolation of a baby results in the lack of language development.
- New languages can be learned in adulthood, but only if language skills developed during the sensitive period.
- Language disorders resulting from brain injury have helped us to understand the brain regions associated with language.
Nonfluent/Agrammatic/ Expressive/Broca’s Aphasia
- Difficulty in producing, but not in understanding, speech.
- So, if someone talks to you, you can understand them, but when you try to communicate, you can’t quite get the words in the proper order, sometimes the words get jumbled and you can’t pattern the words properly.
- “Automatic speech,” such as “Hello,” is not a problem for these individuals to produce.
- Sentences are very difficult to fully form.
- There is a lack of connecting words.
- This issue results from the damage to the left inferior frontal lobe (Broca’s area).
- Damage in this area also affect people’s ability to write.
- So, it is not just about moving the mouth. It affects anything to do with generating motor plans for complex vocalizations.
Fluent/Receptive/Sensory/Wernicke’s Aphasia
- Speech is nonsensical but fluid, and comprehension of language is poor.
- Sometimes they will have sound substitutions. Instead of saying “girl,” they will say “curl.”
- Or sometimes there is complete word substitutions: “bread” becomes “cake.”
- This is a result of damage to the left superior temporal gyrus (Wernicke’s area).
- Thought to be a deficit in understanding the meaning of words.
Both aphasias also apply to…
- Any fluent early-learned language a person speaks.
- Written language.
- Sign-languages.
- In most people (90-95%) damage to left-hemisphere cortical structures results in language deficits, whereas damage to corresponding areas in the right hemisphere does not.
- Language is lateralized to the left hemisphere of the cerebrum in most people.
- In left-handed individuals, there is a high likelihood that this pattern is reversed.
Attention can be _________ or ________.
Endogenous or Exogenous.
Endogenous Attention
When we make a conscious effort to focus on something of interest to us, or some goal.
Overt Attention
Orient my senses towards what I am focused on.
Covert Attention
- When I am looking in one way, but paying attention to something else.
- It’s independent of sensory orientation. (A person can pay attention to other parts of the environment while looking or focusing on a very different part).
Exogenous Attention
Involuntary re-orientation of attention to an unexpected stimulus.
