Behavioral Neuroscience: Biological Foundations

• Behavioral neuroscience, previously known as physiological psychology, examines the biological foundations of behavior.
• The field integrates experimental methods from psychology and physiology to study perceptual processes, movement control, sleep, reproductive, ingestive, emotional behaviors, learning, language, and neurological and mental disorders.

The Biological Roots of Behavioral Neuroscience

• Humans have historically sought to understand the intangible aspect of being, such as the mind/soul, in relation to the physical body and the nervous system's role.
• The mind-body question explores whether the mind controls the nervous system, is part of it, or exists separately as a tangible or spiritual entity.
• Dualism posits that the mind and body are separate, with the body made of matter and the mind being distinct, while monism suggests that everything is composed of matter and energy, with the mind arising from nervous system activity.

Ancient World

• Evidence of early understanding of behavioral physiology comes from a 1700 B.C.E. papyrus scroll, including surgical records of head injuries and descriptions of the brain.
• Ancient cultures, including Egyptian, Indian, and Chinese civilizations, regarded the heart as the seat of thought and emotions, but Hippocrates (460–370 B.C.E.) proposed that the brain performed this role.
• Galen (130–200 C.E.) agreed with Hippocrates after dissecting and studying animal brains.

Seventeenth Century

• René Descartes, a French philosopher, theorized about the brain’s role in behavior control.
• Descartes viewed animals and the human body as machines governed by stimuli, with some movements being automatic reflexes not requiring mental participation.
• Descartes, a dualist, proposed a mind-body link where the mind controls the body's movements, receiving sensory information in return, which he believed occurred in the pineal body.
• Luigi Galvani's experiments disproved Descartes' fluid theory, demonstrating that electrical stimulation of a frog's nerve caused muscle contraction, indicating that the nerve and muscle themselves possess the ability to respond.

Nineteenth Century

• Johannes Müller used experiments in physiology by isolating organs, testing their responses to chemicals, and altering the environment, which led to advancements in understanding the body's functions.
• Müller's doctrine of specific nerve energies stated that nerves carry the same electrical impulse, but are perceived differently because they occur in different channels.
• Pierre Flourens employed experimental ablation, removing brain parts of animals to observe behavioral changes, to map brain functions.
• Paul Broca studied humans with stroke-induced brain damage, concluding that a region in the left frontal cortex, now known as Broca's area, is essential for speech production.
• Gustav Fritsch and Eduard Hitzig used electrical stimulation on a dog's brain to identify the primary motor cortex, which directly controls muscle contractions.
• Hermann von Helmholtz measured the speed of neural conduction at 90 feet per second, proving it was not just a simple electrical message.
• Jan Purkinje discovered Purkinje fibers, which are neurons that control the contractions of the heart within the central and peripheral nervous systems.
• Ramon Santiago y Cajal used Golgi staining to detail individual neurons, and proposed that the nervous system consists of billions of individual neurons.

Comtemporary

• Twentieth-century included the invention of inventions, such as sensitive amplifiers, neurochemical techniques, and histological techniques.
• Key discoveries include the electrical and chemical communication of neurons, the circuits and brain structures involved in behaviors like the mirror neuron system, and brain-based treatments for conditions like depression and schizophrenia.
• The twenty-first century has given researchers a deeper level of understanding of the structures and circuits of the brain.
• John O’Keefe, May-Britt Moser, and Edvard Moser won the 2014 Nobel Prize for the brain's spatial positioning systems (GPS).
• Deep brain stimulation is now used to treat conditions like depression and Parkinson’s disease, while optogenetics allows selective activation of single neurons using light to observe behavioral changes.
• Collaborative endeavors such as the European Human Brain Project and the U.S. BRAIN initiative are driving advancements by uniting experts from diverse scientific fields.

Behavioral neuroscience explores the biological underpinnings of behavior. It integrates psychology and physiology to study perceptual processes, movement, sleep, emotions, learning, and neurological disorders. The mind-body problem explores the relationship between the mind and the physical body, with dualism suggesting they are separate and monism proposing the mind arises from nervous system activity.