The Brain The Developing Brain Parts of the Brain & their Function Lobes of the Brain Split Brain Studies Environment’s affect on Brain Brain Plasticity

Early Brain Mapping: Phrenology By studying the lumps on a person’s skull, early scientists thought that they could map out the brain. Not accurate But did lead to the idea of localization of brain functions.

The Brainstem

Hindbrain Structures Cerebellum Brainstem medulla reticular formation pons Discovering psy p 63 fig 2.14

Medulla Breathing Heart rate Digestion Other vital reflexes swallowing coughing vomiting sneezing

Cerebellum Word actually means “little brain” Coordinated, rapid voluntary movements e.g., playing the piano, kicking, throwing, etc. Place where procedural memories are kept. e.g. how to ride a bike, swim Lesions to cerebellum jerky, exaggerated movements difficulty walking loss of balance shaking hands Hockenbury slides

Middle Region involved in visual & auditory processing. Midbrain Structures Middle Region involved in visual & auditory processing.

Forebrain Structures Thalamus Limbic System Cortex Bloom, Nelson, and Lazerson, Brain, Mind, and Behavior Introduction to the Nervous System Figure 1.07r

The Limbic System Hypothalamus Amygdala Hippocampus Discovering Psy p. 67 Fig 2.18

Parts of the Limbic System Amygdala Emotional Center of the Brain. Deals primarily with fear & aggression. Gray, 3e fig 5.6

Amygdala and Emotion Identify emotion from facial expressions Plays a role in fear & aggression Amygdala damage makes this task difficult From Hockenbury slides (click on picture to advance photos)

Parts Of The Limbic System Hippocampus Helps us form new memories. What happens when this is damaged? View the video of Clive Wearing. Gray, 3e fig 5.6

Parts of the Limbic System Hypothalamus Provides us with pleasurable feelings for doing the things that keep our species alive. Gray, 3e fig 5.6

Hypothalamus Involved in the 4 F’s (1. Food, 2. Flight, 3. Fight, 4. Fornication) sexual behavior hunger, thirst sleep water and salt balance body temperature regulation circadian rhythms role in hormone secretion The hypothalamus is made up different subregions or nuclei. These nuclei generally differ in terms of gross anatomy and function. Sexual behavior: The medial preoptic and medial anterior hypothalamic nuclei of the hypothalamus are heavily involved in mating behaviors of animals. Damage to these areas results in a loss of mating behaviors. Electrical stimulation of these areas (or insertion of sex hormones in these areas) can elicit sexual behaviors. Hunger: Lesions to the hypothalamus can lead to severe obesity or extreme weight loss, depending upon the region damaged. Thirst: Electrical stimulation of the hypothalamus can cause an animal to start drinking even in animals that have plenty of water in their systems. Neurons in the supraoptic nucleus of the hypothalamus are sensitive to changes in the osmolarity of blood. These neurons control the secretion of vasopression, which is more commonly known as "anti-diuretic hormone" or ADH. ADH acts in the kidney to increase fluid retention. Sleep: Temperature regulation: Your body tries to keep the same body temperature regardless of how hot or cold it is outside. The hypothalamus helps maintain a constant body temperature. Hypothalamus contains temperature-sensitive neurons. Neurons in the posterior hypothalamus become active when you are cold; whereas, heat activates the anterior hypothalamus. Changes in body temperature can cause the hypothalamus to initiate such behaviors as shivering, hunger, adrenaline secretion and fever to help you get back to the proper body temperature. Circadian rhythms: the suprachiasmatic nucleus (or SCN) of the hypothalamus is thought to be involved in regulating the body's natural 24 hour rhythms.

Hypothalamus – Pleasure Center of the Brain Rat with an electrode implanted in a reward center of its hypothalamus, Rat readily crosses an electrified grid, accepting the painful shocks, to press a lever that sends electrical impulses to its "pleasure centers." How often did the rat press the lever in an hour? 7,000 times!!! It finally collapsed from exhaustion (Olds 1958)

Thalamus Sensory Relay station in brain Processes most information to and from higher brain centers Like the Post Office taking incoming messages and delivering them Gray, 3e fig 5.6