1 Neuroscience and Behavior Chapter 2 Neural Network Demo, Sections 6 and 7, Tools of Discovery

Neural Network - Demo Discussion Questions Did the network become more accurate at linking the input to the correct output? Is this increased accuracy learning? What role did reinforcement play in learning? What is Long-Term Potentiation (LTP)? How does LTP form the basis for memory? 2

3 Neural Network Demonstration The Brain and Neural Networks Interconnected neurons form networks in the brain. Theses networks are complex and modify with growth and experience.

Artificial Neural Networks Designed on computers to explore how natural neural networks can learn 4 Artificial Neural Network

Neural Network - Demo Set up a learning neural network where the students are the nodes Inputs: see the 6 basic emotions Outputs: when motivated to “fire”, they indicate their designated emotion Hidden layer: when excited by input neurons, they fire to some output neuron 5

Neural Network - Demo What should the threshold be for firing? What threshold will result in the fastest learning? Reinforcement of learning: when output is correct, that path is strengthened (LTP) Long-Term Potentiation: the post-synaptic neurons become more sensitive to those pre- synaptic neurons that are exciting it LTP becomes memory 6

Neural Network Demo Post your Notes from the lecture and discussion. Post a Reflective post: what do you think about this material? Go around and read your table group posts. Rate the Notes with a 6, and the Reflections with a 10. What questions do you have for them?

8 Discussion #6 How does the endocrine system – the body’s slower information system – transmit its messages? What do the different endocrine glands do? »hypothalamus »pituitary »thyroid »parathyroids »adrenal »pancreas »gonads

9 The Endocrine System The Endocrine System is the body’s “slow” chemical communication system. Communication is carried out by hormones synthesized by a set of glands.

10 Hormones Hormones are chemicals synthesized by the endocrine glands that are secreted in the bloodstream. Hormones affect the brain and many other tissues of the body. For example, epinephrine (adrenaline) increases heart rate, blood pressure, blood sugar and feelings of excitement during emergency situations.

11 Pituitary Gland Is called the “master gland.” The anterior pituitary lobe releases hormones that regulate other glands. The posterior lobe regulates water and salt balance.

12 Thyroid & Parathyroid Glands Regulate metabolic and calcium rate.

13 Adrenal Glands Adrenal glands consist of the adrenal medulla and the cortex. The medulla secretes hormones (epinephrine and norepinephrine) during stressful and emotional situations, while the adrenal cortex regulates salt and carbohydrate metabolism.

14 Gonads Sex glands are located in different places in men and women. They regulate bodily development and maintain reproductive organs in adults.

Discussion #6 Post your Notes from the lecture and discussion. Post a Reflective post: what do you think about this material? Go around and read your table group posts. Rate the Notes with a 6, and the Reflections with a 10. What questions do you have for them?

16 Discussion #7 What are the functions of the brainstem and its associated structures? What does each structure do? Medulla Thalamus Reticular formation Cerebellum

17 The Brain: Older Brain Structures The Brainstem is the oldest part of the brain, beginning where the spinal cord swells and enters the skull. It is responsible for automatic survival functions.

18 Brainstem The Medulla [muh- DUL-uh] is the base of the brainstem that controls heartbeat and breathing.

19 Brainstem The Thalamus [THAL- uh-muss] is the brain’s sensory switchboard, located on top of the brainstem. It directs messages to the sensory areas in the cortex and transmits replies to the cerebellum and medulla.

20 Brainstem Reticular Formation is a nerve network in the brainstem that plays an important role in controlling arousal.

21 The “little brain” attached to the rear of the brainstem. It helps coordinate voluntary movements and balance. Cerebellum

Discussion #7 Post your Notes from the lecture and discussion. Post a Reflective post: what do you think about this material? Go around and read your table group posts. Rate the Notes with a 6, and the Reflections with a 10. What questions do you have for them?

Close-up: The Tools of Discovery How do neurobiologists investigate the inner workings of the brain? - lesions - ElectroEncephaloGrams (EEG) - Positronic Emission Tomography (PET) - Magnetic Resonance Imaging (MRI) - functional MRI (fMRI) 23

24 The Brain Why do neuroscientists create brain lesions? A brain lesion experimentally destroys brain tissue to study animal behaviors after such destruction. Hubel (1990)

25 Clinical Observation Clinical observations have shed light on a number of brain disorders. How do the brain structures change when the brain has a physical or mental disease? Tom Landers/ Boston Globe

26 Electroencephalogram (EEG) An amplified recording of the electrical waves sweeping across the brain’s surface, measured by electrodes placed on the scalp. AJ Photo/ Photo Researchers, Inc.

27 PET Scan PET (Positron Emission Tomography) scan: a visual display of brain activity that detects a radioactive form of glucose while the brain performs a given task. Courtesy of National Brookhaven National Laboratories

PET Scan Here a PET scan compares the brain activity in a normal person to someone with Parkinson’s disease. (Pre-treatment and Post- treatment)

29 MRI Scan MRI (Magnetic Resonance Imaging) uses magnetic fields and radio waves to produce computer- generated images that distinguish among different types of brain tissue. Top images show ventricular enlargement in a schizophrenic patient. Bottom image taken using a functional MRI (fMRI) shows brain regions when a participant lies. Both photos from Daniel Weinberger, M.D., CBDB, NIMH James Salzano/ Salzano PhotoLucy Reading/ Lucy Illustrations

Discussion #8 Post your Notes from the lecture and discussion. Post a Reflective post: what do you think about this material? Go around and read your table group posts. Rate the Notes with a 6, and the Reflections with a 10. What questions do you have for them?