Historical Context of Neuroscience PDF

## **What is the purpose of the brain? What does it do?** ### The true job of the brain is behavior - The A, B, C's of Psychology: - Affect (Emotion, feeling, value, arousal, motivational intensity) - Behavior (Movement, in all its forms) - Cognition (Memory, reasoning, thinking, perception...

## **What is the purpose of the brain? What does it do?** ### The true job of the brain is behavior - The A, B, C's of Psychology: - Affect (Emotion, feeling, value, arousal, motivational intensity) - Behavior (Movement, in all its forms) - Cognition (Memory, reasoning, thinking, perception) - Affect and cognition exist to guide behaviors that allow us to survive. Emotional responses and cognitive responses are critical to obtaining food and water, maintaining safety, and reproducing. ### **The brain as a "system"** - The goal of behavioral neuroscience is to explain behavior by determining what physiological processes control it. - In the modern era, this involves understanding the connections between the body and brain and between different parts of the brain and then determining the functions of these connections. We call these functional connections "systems”. ### Thinking about the function of a system * INPUT --> PROCESSING --> OUTPUT ### How did we get here? ### Humans want to explain behavior - Theories of the mind, body and soul: - Dualism - Belief that body is physical but mind (or soul) is not - Monism - Belief that world consists only of matter and energy and that mind is phenomenon produced by workings of nervous system ### Timeline of Discoveries in Neuroscience | Date | Description | |---|---| | 1700 BC | Egyptians describe the brain; Heart is considered the seat of the soul | | 460 BC | Hippocrates concludes that the brain is the seat of thought and emotion. | | 1645 | Descartes suggests that the brain is the sense organ for the 'soul', providing information so the soul can decide on action | | 1780 | Galvani determines that electrical stimulation can move the legs of dead frogs. | | ~1840 | Johannes Müller shows that the messages carried by nerves depends on the sense organ. | | 1815 | Pierre Flourens begins studies using experimental ablation to show that specific parts of the brain perform specific functions. | | 1861 | Broca studies lesions in patients and discovers that lesions of a specific part of frontal lobe cause speech aphasia. | | 1870 | Helmholtz discovers that nerves conduct signals more slowly that predicted, unknowingly revealing that neurons use chemical messaging. | | 1849 | Gustav Fritsch and Eduard Hitzig show that stimulating parts of the cortex can cause movement, thereby discovering motor cortex. | | ~1890 | Santiago Ramón y Cajal begins using Golgi staining to see neurons, eventually winning the Nobel prize for his work demonstrating that the brain is composed of billions of individual cells. | | 1935 | Eccles, Dale, Katz, Loewi, and Axelrod begin a long debate that eventually leads to the discovery of chemical messengers and the synapse. | | 1938 | Hodgkin and Huxley discover that nerves conduct messages using a rapid electrical spike called an 'action potential.' | | 1920's - 1950's | B.F. Skinner publishes The Behavior of Organisms. This is a founding moment for behavioral psychology, which is now merged with behavioral neuroscience. | | 1950's - 1970's | David Rioch (and others) begin emphasizing that basic anatomical and physiological methods can inform human behavior and psychopathology. | | 2019 | We can now sequence individual cells, cause action potentials to fire with a flash of light, record from single neurons, image thousands of neurons at a time, and much more. |