The Brain Three pounds of tissue that makes all the difference Certain materials in this presentation are used under the Fair Use exemption of The US Copyright Law and should not be used without the permission of their owner.

Measuring brain activity Describing injured brains Lesions – purposeful destruction Scanning techniques PET scans – watching brain activity through glucose consumption PET scans – watching brain activity through glucose consumption MRI (functional) – highly detailed images as the brain works MRI (functional) – highly detailed images as the brain works Limitations – careful interpretation is key

Brain structures The Brain can be viewed as a collection of interacting neuronal circuits that have developed throughout our evolution Its basic layout is shared with all vertebrates, But some of its structures have developed unmatched intricacy and power to support our unique capacities for communication and thought But some of its structures have developed unmatched intricacy and power to support our unique capacities for communication and thought

Brain structures II The Brainstem – the bottom of the brain, responsible for our most basic survival skills Breathing, swallowing, vomiting, etc. Provides neural control of the muscles of the head, as well as the eyes and ears Includes the Midbrain, Pons, and Medulla The reticular activating system runs through

More structures The Cerebellum – the “little brain” Located at the back of the brainstem Indispensable for motor function Any damage will devastate coordinated movement in a body area Allows us to effortlessly perform intricate patterns of rhythmic actions Dribbling a basketball, typing, riding a bike

the hypothalamus the master regulatory structure Supervises our temperature, blood pressure, bodily rhythms, and glucose levels Controls the pituitary gland, the master gland of the endocrine system Governs sexual development and behavior

The Thalamus The brain’s switching center Differing neuronal messages go to differing processing areas But as for smell, odor perceptions go to the olfactory bulb Emotional implications

The hippocampus A subcortical structure essential for memory Allows us to store (and ultimately retrieve) new memories by creating new interconnections in our cerebral cortex Changes and grows with new experiences

The amygdala Plays a vital role in emotional processing and responsiveness Found right in front of the hippocampus Helps us associate things with emotional responses, especially fear Intensifies memory during times of emotional arousal Also processes aspects of sexual arousal

The cerebral cortex The outer layer of brain tissue, in humans the site of all thoughts, perceptions, and consciousness Wrinkled, “folded in” appearance For humans, relatively huge – as wide as a sheet of newspaper Two halves, called hemispheres control sensation and movement on the other side of the body

Significance of the cerebral cortex Much, much, more developed in humans Staggering complexity and versatility allows us to: 1) perform complex actions, 1) perform complex actions, 2) think before we act, 2) think before we act, 3) participate in our culture, and 3) participate in our culture, and 4) understand and communicate with others 4) understand and communicate with others

The four lobes Each hemisphere of the cerebral cortex is divided into four sections called the lobes They are known as the occipital, parietal, temporal and frontal The hemispheres, and their lobes, are connected by a massive bridge of millions of axons called the corpus callosum

The occipital lobe Almost exclusively devoted to the sense of vision Located in the lower back region of the head Contains many specialized areas relating to different aspects of vision, especially the primary visual center Many links to the temporal for visual tasks

The parietal lobe Primarily devoted to the sense of touch Contains the primary somatosensory cortex Area within it is taken up by the parts of the skin according to their sensitivity to touch, more to the finger tips than back Also tells us where we are in space relative to the objects around us

The temporal lobe Contains the primary auditory cortex Much of it is used for complex visual tasks in conjunction with the primary visual cortex These include recognizing faces and perceiving motion Also crucial to memory In the left hemisphere, aids language skills

The frontal lobes Its back region contains the primary motor cortex which takes information from the primary somatosensory cortex and then moves the body’s muscles Similarly, the parts of the body with more sophisticated muscle systems have more space in the primary motor cortex devoted to them

Prefrontal cortex Most of the frontal lobe is devoted to the ability to engage in directed behavior As it lets us understand what others think, behave according to society’s rules, and examine our existence, the prefrontal cortex makes us human and differentiates us from other mammals Site of judgment, strategy, planning and memory Left hemisphere is the seat of language