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.

Older/Lower Level Brain Structures

Primitive Parts of Brain Like the oldest part of a tree is in the center that is then surrounded by newer growth, the older parts of the brain that we share with other animals, are found at the central lower region of the brain.

The Brainstem

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

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

Pons Helps coordinate movements on left and right sides of the body Sends motor info to Cerebellum e.g., postural reflexes which help you maintain balance while standing or moving Gray, 3e fig 5.6

Thalamus Sensory control center in brain Sends sensory info to parts of the brain that can understand it Receives replies back from higher brain areas and sends them to lower level structures Like the Post Office taking incoming messages and delivering them _______ Gray, 3e fig 5.6

Reticular Formation/Activating System Network of neurons in the brainstem (and thalamus) Sleep and arousal Attention – filters incoming sensory info Myers, Exploring psy 4e Figure 2.10

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

Midbrain Structures Middle Region involved in visual & auditory processing. Early warning system gets you ready for flight or fight

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 Emotional Center: Hypothalamus Amygdala Hippocampus Discovering Psy p. 67 Fig 2.18

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

Parts of the Limbic System Amygdala Fear: Aggression: Gray, 3e fig 5.6

Amygdala damage makes this task difficult Amygdala and Emotion Helps us identify emotion from facial expressions From Hockenbury slides (click on picture to advance photos) Amygdala damage makes this task difficult

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

Hypothalamus Involved in the 5 F’s sexual behavior hunger, thirst 1. Food/Thirst, 2. Flight, 3. Fight, 4. Furnace (Temperature) 5. 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, See some actual footage of this. 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)

Hypothalamus and Hormones The Feedback Loop Feedback Loop lets brain know when to start & stop secreting hormones Hypothalamus tells pituitary gland to send messages to other glands to release their hormones. Once hormones are released, hypothalamus registers this and sends message to pituitary gland to send continue or stop message out to glands. Gray, psychology 3e fig 5.27

DAILY DOUBLE

What are the 5 F’s that the Hypothalamus influences? Food/Thirst Flight Fight Furnace – Body temperature Fornication