Chapter 1-7: Introduction to Behavioral Neuroscience (Vocabulary Flashcards)
What is Behavioral Neuroscience?
Definition: Behavioral neuroscience is the neural and biological underpinnings of behavior; it focuses on how brain mechanisms support behaviors we perform on a moment-to-moment basis as well as over longer timescales.
Examples of behavior: walking, eating, listening, learning, deciding.
In this course, these behaviors will be linked to brain mechanisms to understand what brain processes enable them.
What is neuroscience?
A broad, multidisciplinary field that studies many aspects of the nervous system.
Key areas include:
Brain organization and structure in three dimensions (anatomy).
Neural development across the lifetime.
Neural activity: electrical signaling that supports sensation, memory, decision making, etc.
Neuropathology: how lesions, diseases, or disorders affect brain and behavior.
Computational neuroscience: modeling how the brain computes information.
The core question of behavioral neuroscience:
What is the link between brain activity and behavior? How do brain events on short and long timescales drive and constrain behavior and cognition?
Course trajectory:
Start with neural communication between neurons to build fundamentals, then connect these processes to behavior, sensation, memory, and higher cognitive functions.
Topics include how neurons talk to each other, spinal reflexes (e.g., knee-jerk), spatial hearing, memory formation, and irrational decisions, among others.
The circle from brain to behavior and back to brain is closed over the semester as mechanisms of behavior are linked to brain circuits.
Historical Foundations and Mind–Body Relationships
The historical impulse: before formal “behavioral neuroscience,” thinkers explored mind–body relationships and the brain's role in behavior.
Edwin Smith Papyrus (c.1600 ext{ BC}): earliest written document touching nervous system function; descriptions of head trauma, shuddering, paralysis; observations that brain/spinal injury affects behavior.
Hippocrates (5^{ ext{th}} century BC): quote linking emotions and mental states to the brain—"Pleasure, joy, and laughter, but also sorrow, pain, grief, and tears rise from the brain and the brain alone." (brain as the source of affect and action)
Aristotle (4^{ ext{th}} century BC): cardiocentric view—mind or soul residing in the heart; brain proposed as a radiator for cooling the blood due to many surface blood vessels.
Galen (2^{ ext{nd}} century AD): physician with gladiator observations; argued about the brain’s role via pneuma (air/gas) and CSF; observed that loss of pneuma from brain during injury correlates with loss of movement and sensation; foreshadowed importance of cerebrospinal fluid (CSF) and brain function.
Renaissance: Leonardo da Vinci (late 15^{ ext{th}}–16^{ ext{th}} centuries AD)
Interest in brain ventricles (ventricles filled with CSF) and how they look inside the brain.
Challenge: hard to reconstruct 3D ventricles from dissected brains after death.
Innovative approach: molten wax in the ventricles of ox brain to create a tangible, 3D model of ventricles; his drawings anchored to direct observation and experimentation rather than purely philosophical reasoning.
This marks a shift toward experimental anchoring of anatomical ideas in data.
Rene Descartes (16^{ ext{th}}$-$17^{ ext{th}} centuries): mind–body relation and dualism
Dualism: mind (spiritual/mental) and body (physical) are separate but interact.
Interaction proposed at the pineal gland, a small brain structure; Descartes suggested a mechanism for mind–body interaction, despite the mind being nonphysical.
The dualism debate raised challenges: how can a physical brain influence a nonphysical mind and vice versa?
He acknowledged that mind and body interact (e.g., foot in fire changes mental calculation) and proposed a specific interaction site (pineal gland).
Schools of thought about mind–body relation:
Dualism: mind and body are separate but interact; potential for mind to survive body after death; interaction via a specific brain structure (historically the pineal).
Reductionism/Monism: the mind is fully derived from brain; there is nothing nonphysical; in principle, a complete brain model could replicate all mental phenomena.
Emergentism: the mind emerges from brain activity as a higher-order property that may not be reducible to simple component-level explanations; connections can be highly complex (analogy: ocean waves arise from water molecules, but predicting every wave from molecules alone is impractical).
John Locke (17^{ ext{th}}–18^{ ext{th}} centuries): tabula rasa
Mind at birth is a blank slate; experience writes knowledge and behavior into the mind; emphasizes nurture.
Empiricism: knowledge should be grounded in experience and observation.
Thought experiment on testing blank slate idea: how to distinguish innate instincts or morality from experience; suggested using unique cases and controls (e.g., twins, adoption) to disentangle genes and environment.
Twins raised apart provide a key empirical strategy to separate nature vs nurture.
Baby lab and infant morality evidence (modern empirical test of Locke’s nurture concept):
Babies as young as 3 ext{ months} show preferences for prosocial (helpful) figures over antisocial (mean) figures in puppet-show experiments; longer looking times at the helpful puppet imply preference.
Result supports that infants are not blank slates; some social evaluation emerges early, indicating innate or early-developing social cognition.
The show underscores a developmental view that both nature and nurture shape behavior; infants exhibit moral-like preferences before extensive experience.
From Neurons to Networks: Neuron Anatomy and Early Theoretical Advances
Ramon y Cajal (late 19^{ ext{th}} to early 20^{ ext{th}} centuries): neuronal anatomy and the neuron doctrine
Used Golgi staining to visualize individual neurons after tissue preparation.
Produced careful drawings of well-known brain cells and regions: hippocampus, Purkinje cells in the cerebellum, cortical neurons.
Although he couldn’t record activity in living animals, his anatomical drawings allowed him to speculate about connectivity and communication between neurons (e.g., close appositions suggesting synaptic contact).
His ideas were later confirmed when functional recordings and circuit understanding advanced.
Golgi staining (Camillo Golgi): a revolutionary histological method enabling visualization of entire neurons in a tissue section.
The shift to function: anatomical illustrations provided a basis for hypotheses about how neural circuits could support memory, movement, perception, and other functions, later verified by physiological experiments.
Modern Trajectory: Linking Brain and Behavior in Real Time
The historical arc moves from descriptive anatomy to functional hypotheses and, finally, to experimental manipulation of the brain during behavior.
A landmark development: combinatorial experiments that record both behavior and brain activity, sometimes with causal manipulation
Example: optogenetics in a behaving mouse
An experimental setup where a mouse runs in a maze while light is delivered through an optic cannula to specific neurons.
Light activation of targeted neurons can drive or influence behavior in real time, allowing causal inferences about the role of those neurons in the observed behavior (e.g., aggression, hunger, social behavior, auditory/visual processing).
This integrated approach is relatively recent (roughly the last ~50 ext{ years}) and is a cornerstone of modern systems neuroscience.
Translational relevance:
Development of clinical technologies informed by brain–behavior links, such as:
Bionic retinas and robotic prosthetics controlled by brain signals.
Cochlear implants.
Deep brain stimulation for various disorders.
The course emphasizes moving from broad, historical understanding to mechanistic, circuit-level explanations that connect neural activity to behavior.
Clinical Case Studies: Brain–Behavior Links in Humans
Why clinical case studies?
Humans cannot be ethically subjected to deliberate brain lesions; case studies provide natural experiments to infer brain–behavior relationships.
Phineas Gage (circa 1840): frontal lobe injury from a tamping iron during railroad work
Injury through the frontal cortex altered personality and behavior: memory for events remained intact, but he became fitful, irreverent, unreliable, and disinhibited.
The case provided early evidence for a critical role of the frontal lobe in impulse control, judgment, and social behavior.
It spurred decades of investigation into frontal lobe functions such as inhibition, decision-making, and risk assessment.
Dr. P (The Man Who Mistook His Wife for a Hat) – case from Oliver Sacks
Neurological condition: agnosia (inability to interpret or assign meaning to visual information), despite intact basic vision and intelligence.
Example: he attempted to wear his wife as a hat; he could see objects but could not correctly link visual input to their meaning.
Illustrates the separation between perception (sensory input) and higher-level recognition/meaning; emphasizes the importance of brain pathways linking perception to semantic knowledge.
Note on the third case study (omitted here): mentioned as part of the broader set of clinical illustrations to show brain–behavior links.
Overall takeaway from clinical cases:
Brain injuries can cause selective deficits in behavior and cognition, revealing functionally specialized areas and networks.
These cases motivate more precise, mechanistic studies of how specific brain regions contribute to behavior.
Modern Experimental Approaches and the Brain–Behavior Trajectory
The goal is to connect brain activity to behavior at high resolution, from circuits to networks and beyond.
Today’s approach combines:
Behavioral measurements in controlled settings (e.g., mazes, sensory tasks).
Neural activity recording (electrophysiology, imaging).
Causal manipulation (optogenetics, pharmacology, stimulation, lesions).
This integrated strategy enables mechanistic explanations of how networks of neurons support specific behaviors, memories, and cognitive processes.
Course Logistics and Organization
Course materials and syllabus are online on Canvas.
Students are encouraged to access and read the syllabus, as it contains important information.
The lecture intends to blend historical context with modern neuroscience methods and clinical relevance, while focusing on how brain–behavior links are established through careful experiments and data.
Quick Reference of Key Terms and Concepts
Behavioral neuroscience: neural and biological underpinnings of behavior.
Neuroscience: broad study of the nervous system, including structure, development, activity, pathology, and computation.
CSF: cerebrospinal fluid; discussed in historical contexts and important for brain support (ventricles).
Brain ventricles: cavities within the brain that contain CSF; Leonardo attempted to model their shape using wax.
Pneuma: ancient concept of a circulating fluid or air thought to influence brain function; tied to early theories about consciousness.
Pineal gland: proposed by Descartes as the mind–body interaction site; now known as an endocrine structure regulating melatonin and circadian rhythms.
Dualism: mind and body as separate but interacting entities.
Monism/Reductionism: mind fully reducible to brain processes; no nonphysical substrate.
Emergentism: mind emerges from brain activity and may not be reducible to brain components alone.
Tabula rasa: John Locke’s idea that the mind is a blank slate at birth.
Empiricism: knowledge arises from experience and observation, not innate ideas.
Optogenetics: modern technique enabling precise control of specific neurons with light during behavior.
Memory-related structures: hippocampus (memory formation) and cerebellar Purkinje cells (cerebellar processing).
Important Dates and Quantities (formatted for reference)
1600 ext{ BC} — Edwin Smith Papyrus
5^{ ext{th}}- ext{century BC} — Hippocrates' brain-based view of emotion
4^{ ext{th}}- ext{century BC} — Aristotle (cardiocentric view)
2^{ ext{nd}} ext{ century AD} — Galen’s era
15^{ ext{th}}- ext{16}^{ ext{th}} ext{ centuries AD} — Leonardo da Vinci
16^{ ext{th}}- ext{17}^{ ext{th}} ext{ centuries} — Descartes and dualism
17^{ ext{th}}- ext{18}^{ ext{th}} ext{ centuries} — John Locke and tabula rasa
ext{about } 50 ext{ years} — time window for modern brain–behavior experiments (optogenetics era)
1840 — Phineas Gage incident
3 ext{ months} and 5 ext{ months} — infant puppet-task experiments demonstrating early social preferences
Connections to Foundational Principles
Mind–body problem has been approached from multiple angles across history, ultimately guiding modern experimental designs that test causality between brain activity and behavior.
The empiricist and nurture-focused view (Locke) coexists with early evidence of innate or early-developing social cognition (baby lab), highlighting the complexity of nature–nurture interactions.
The progression from philosophical speculation to experimental data underscores the scientific method's role in neuroscience.
Modern technologies (e.g., optogenetics) exemplify the ability to test causal roles of neural circuits in real-time behavior, moving beyond correlative observations.
Endnotes
The course emphasizes linking brain and behavior with mechanistic detail, from molecules and cells to circuits and networks, and finally to observable behavior and cognition.
The historical narrative provides context for how current concepts about mind, brain, and behavior have evolved and why certain questions remain central in neuroscience today.