Prefrontal Cortex “Executive functions”: planning, behavioral inhibition, emotional regulation, forward thinking, achieving goals, personality expression, guilt, reality check… The Phineas Gage case: Late-maturing (early 20’s!) “Teen-age brain” Emergence of cognitive disorders in early 20’s Fred Gage, PhD

Areas involved in language – Broca’s Area Initially described in 1861 by French neurosurgeon Paul Broca in a patient (“Mr. Tan”) who lost the ability to speak. Has been confirmed many, many times in patients with similar language difficulties Typically, people with damage to this area can understand spoken speech fairly well, but speak in short, “telegraph” sentences (“Walk dog.”, “Book book two table.”) Example: https://www.youtube.com/watch?v=f2IiMEbMnPM Corresponds to Brodman Area 44 & 45 in Left Hemisphere of 90% of Right-handers, 70% of Left-handers

Wenicke’s Area  First described by German neurologist Carl Wernicke in 1874 People with Wernicke's aphasia speak with natural-sounding rhythm and a relatively normal syntax but add unnecessary words, and even create made-up words. As a result, it is often difficult to follow what the person is trying to say. People with Wernicke's aphasia usually have difficulty understanding speech, and they are often unaware of their mistakes. major impairment of language comprehension, Wernicke’s aphasia caused by damage in “dominant hemisphere”; studies suggest that non-dominant hemisphere BA 22 appears to be involved in interpreting speech, https://www.youtube.com/watch?v=B-LD5jzXpLE Includes Brodman Area 22, maybe more.

The “Language Loop” Broca's area and Wernicke's area are connected by a large bundle of nerve fibers called the arcuate fasciculus. Wernicke proposed that language involves separate motor and sensory programs located in different cortical regions. The motor program, located in Broca’s area was suitably situated in front of the motor area that controls the mouth, tongue, and vocal cords. The sensory program, located in Wernicke’s area, was suitably surrounded by the posterior association cortex that integrates auditory, visual, and somatic sensations Modern techniques for studying the arcuate fasciculus in detail reveal that it does more than just connect those two areas . Deaf people who sign with American Sign Language (ASL) use these same areas of the brain in the same way as those who speak language. Lesions in Wernicke area of deaf people loose ability to comprehend sign (ASL). Those with lesions in Broca’s area lose the ability to make signs. One last comment: Language is not something our brains are “designed” for, language is something designed for our brains

“Split Brain Experiments” – Roger Sperry 90-95% of right-handers have language in left, 70~ of left handers have in right.

Monozygotic (“Identical”) Twins Brains are not Identical

But there is a lot going on “below” cortex

And even consciousness it not everything Blindsight: The ability of people say that they cannot see, but still respond to visual input Riddoch’s Syndrome – ability to perceive only moving stimulit, but still not identify them http://thebraingeek.blogspot.com/2012/08/blindsight.html

Our brains do things we don’t even realize Posopagnosia – inability to recognize faces (Oliver Sacks) Capgras Syndrome (“Impostors around me”) Damage to Fusiform face area? Auditory (voice) input still interpreted appropriately Patient not aware that has lost this function, it becomes apparent only in behavior

Facial Recognition Area Fusiform Facial Area Blue= identification Green = salience Red = expression

The brain is part of your body, an organ like your heart or lungs. Week 1- Under the hood: Basic anatomy and function of selected brain structures – Final Comments The brain is part of your body, an organ like your heart or lungs. With rare exceptions, all human brains have the same overall features, but each brain is unique due to genetics, environment, experience. Different brain areas serve different functions, but there is a lot of “cross-talk” and “hierarchical processing”; functions are “distributed”. Much of what goes on in our brains is “subconscious”. Much is known about what’s where in the brain, but there is little detailed understanding of how it does what it does. Our brains are constantly learning, and adapting to their use.