lecture 11 - Cognitive Neuroscience: the biology of the mind Flashcards
aphantasia
A term coined by a researcher here at Exeter – Prof. Adam Zeman
Disconnect between frontal attention networks and posterior areas on the brain involved in imagery (both real and imagined)
Points to the different inner experiences our minds and brains create
Studying the mind – Philosophy
People have long been fascinated by this question and the study of the mind-body problem:
The hard problem of consciousness
Why and how do humans have subjective conscious experiences?
The subjective POV: the inner movie of the mind composed of vision, sound, touch, taste, emotions, thoughts, memories, sense of body.
Think of looking at a red apple or tomato. What is the experience of ‘redness’?
Behaviouralism
First part of the 20th Century psychology was defined by behaviourism, founded by Watson.
Influenced by Pavlov’s work, in conditioning
They believed psychology can be objectively studied through observable action.
An attempt to understand cognition such as perception, imagery, problem solving or consciousness is speculative
Cognitive revolution
Chomsky rejected these views – not every behaviour is a result on a learnt conditioned response.
Cognitive revolution = the study of the mind and its processes
He was a linguist and believed behaviourism underplayed humans ability to manipulate language and be creative.
By 1970 cognitive science had surpassed behaviourism. By 1980 become the dominant
Cognitive neuroscience
What aspects of the mind might we study with cognitive neuroscience?
Language
Memory
Perception / sensory processing
Visual imagery
Decision-making
Problem-solving
Emotion regulation
Social cognition
Consciousness
Broca’s area
The first ability to relate cognition to brain function was the famous case study of Tan –
In April of 1861, a 51-year old man was transferred to Paul Broca’s surgical ward in a hospital in France. The man, whose name was Leborgne, had epilepsy but was near death due to an uncontrolled infection. There was something curious about Leborgne, however: he had extreme difficulty speaking voluntarily. In fact, one of the only sounds he was able to make–unless antagonized, which could prompt him to curse–was an utterance that resembled the word “tan.
Tan died six days after he came under Broca’s care. Broca performed an autopsy and found that, although Tan’s brain was in relatively bad shape overall, there was an especially distinct lesion in his left frontal lobe. This supported the hypothesis that language was localized to the frontal lobes, as it could be interpreted that Tan’s brain damage was the root cause of his speech deficit
Over the next several years, Broca discovered a number of other patients who had left frontal lobe damage along with a deficit in producing articulate speech. Over time, the area that Broca repeatedly observed to be lesioned in these cases came to be called Broca’s area.
This was the first example of relating brain structures and localisation to function.
Modern Neuroimaging Methods:
Other methods
Cognitive tasks
Used to isolate specific brain processes, often used alongside brain imaging.
Allows researchers to focus on one cognitive function and reduce interference
Provide building blocks to understand more complex cognition
But can be criticized for lacking ecological validity
Old myths debunked
Phrenology – measured bumps on the scalp to predict mental traits (18th and 19th centurary)
Modularity
Functional specialisation of brain regions e.g. broca’s area
Distributive processing
Processing in the brain is interconnected and more about networks and regions working together to produce complex behaviour
Functional and structural connectivity is more and more frequently studies in the brain
Modularity and distributive
The brain is modular to an extent (regions are still important for particular functions) the brain and nervous system connects different regions to form cognitive processes.
Neural activity
- locally and between brain areas - is changing every moment, giving rise to circuits that account for our perceptions, decisions, and actions
Does modularity increase with age?
Modern cognitive neuroscience approaches - Computational modelling
– build models and simulations that mimic the brain and perform cognitive tasks
It has helped to:
Understand hew networks process information, makes decisions and generate behaviour
Interpret data from fMRI and EEG about how brain regions interact
This method is used in an example shown on the next slide….
Limitations of cognitive neuroscience
- Reductive
- ## Correlation vs causation - Unless we use TMS…
Reductive
Reduces complex behaviour down to simple phenomena
Task-based imaging might lack ecological validity (may not reflect the true behaviour we’re interested in)
Often attempts to isolate brain regions or networks, but may not reflect how the brains is truly interacting in complex behaviour
Correlation vs causation
Unless we use TMS…
