Olfactory Memory Slides Scent and Soul
The Olfactory System & The Limbic Connection
Psychology: Sensory Processes
The Nose Knows
"Smell is a potent wizard that transports you across thousands of miles and all the years you have lived."
— Helen Keller
Quick Discussion:
What scent immediately takes you back to 3rd grade?
Why does smell feel more "emotional" than sight or sound?
Olfactory Anatomy
1
Chemical Catchers
Molecules in the air dissolve in the mucous membrane of the nasal cavity.
2
Olfactory Cilia
Hair-like receptors transmit signals to the Olfactory Bulb .
3
Neural Highway
Signals bypass the Thalamus (the only sense to do so!) and head straight to the brain.
The Limbic Shortcut
Most sensory info stops at the Thalamus (the sensory switchboard) before being routed to the cortex.
Why Olfaction is Unique:
Direct connection to the Amygdala (Emotion).
Direct connection to the Hippocampus (Memory).
Olfaction's direct neural pathway creates "Flashbulb Memories" of scents.
The Evolutionary Edge
Detection of Danger
Smoke, gas, rotting food, or predators. Olfaction is our primitive early warning system.
Social Connection
Pheromones and individual scents play roles in mate selection and kin recognition.
Check for Understanding
If a person has a stroke that damages their thalamus but leaves the olfactory bulb intact, would they still be able to smell a fresh-baked cookie?
Yes—olfaction is the "thalamus rebel"!
Scent Association Activity Scent Association Activity
Olfaction & The Limbic Connection
Psychology
Unit: Minor Senses
Student Name
Date
The Goal: To observe the immediate emotional and mnemonic (memory) triggers associated with various chemical stimuli. As you smell each sample, record your instinctive reaction before analyzing the scent.
Sample Immediate Emotional Response Autobiographical Memory / Association A B C D
Analysis & Reflection
1. Which scent produced the strongest "visceral" or emotional reaction? Why do you think that specific smell is so evocative for you?
2. Using your knowledge of neural pathways, explain why these scents were able to trigger memories faster than if you had simply seen a picture of the object.
3. Define Anosmia . How would a sudden loss of smell impact a person's quality of life beyond just flavor perception?
Neural Mapping: The Olfactory Pathway
Cilia Receptors
Olfactory Bulb
Amygdala Emotion Processing
Hippocampus Memory Encoding
Note: Observe that there is NO stop at the Thalamus. This direct route is unique to olfaction.
Self-Correction Task
Review your scent memories from Page 1. Below, categorize each memory as either "Affective" (based on emotion/feeling) or "Declarative" (fact-based/situational).
Affective Memories
Declarative Memories
Taste Buds Slides The Taste Test
Gustation & The Supertaster Phenotype
Lesson 2: Psychology of Sensation
The Five Basic Tastes
Sweet
Energy source / Carbohydrates
Salty
Sodium for physiological process
Sour
Potential toxic acid / spoilage
Bitter
Potential poisons / alkaloids
Umami
Protein to grow and repair tissue
Evolutionary Psychology Note: We like sweet/salty/umami because they signal survival resources. We are wary of sour/bitter because they signal danger.
The "Tongue Map" Myth
You've likely seen diagrams showing "Sweet" at the tip and "Bitter" at the back.
The Reality:
All parts of the tongue with taste buds can detect all five basic tastes. Sensitivity levels vary only slightly across different regions.
DEBUNKED
Anatomy of the Tongue
Papillae
The visible "bumps" on your tongue. Most contain taste buds, some provide texture (friction).
Taste Buds
Microscopic structures inside papillae. Each bud contains 50–100 receptor cells that refresh every 10–14 days.
The Supertaster Phenotype
What is it?
A person with an unusually high density of fungiform papillae and a genetic predisposition to taste bitterness (PTC/PROP).
25% Non-Tasters
50% Tasters
25% Supertasters
Why it matters:
Supertasters often dislike strong flavors (coffee, kale, dark chocolate).
They may have better health outcomes due to lower preference for fatty/sugary foods...
...or worse outcomes if they avoid healthy bitter vegetables!
Supertaster Lab Guide Supertaster Bio-Assay
Investigation: Genetics & Gustation
Psychology Lab
Lesson 2
Investigator Name
___________________________________
Date
___________________________________
Materials
Blue food coloring
Cotton swabs
Mirror
Hole reinforcer (sticker)
Flashlight
PTC Test Strips
Procedure
Dab the front of your tongue with a cotton swab dipped in blue food dye. Swallow once to clear excess.
Place a paper hole reinforcer on the tip of your tongue. The blue dye will stain the tongue, but NOT the fungiform papillae (which will appear as pink circles).
Using a mirror and flashlight, count the number of pink papillae visible inside the circle of the reinforcer. Have a partner double-check your count.
Observation Data
Part A: Papillae Count
Total papillae inside 6mm circle
Part B: PTC Sensitivity
No Taste (Non-taster)
Mild Bitterness (Taster)
Intense/Unbearable (Supertaster)
Classification Count Range Predicted Phenotype Non-Taster < 15 papillae Requires higher concentrations of spice/sweet to detect. Medium Taster 15 - 30 papillae Average sensitivity to flavors and chemicals. Supertaster > 30 papillae High sensitivity; often avoids bitter greens and strong coffee.
1. Classification: Based on your count and PTC test, which category do you fall into? Does this match your personal food preferences (e.g., likes/dislikes for bitter foods)?
2. Genetic Connection: Gustation is heavily tied to genetics (the TAS2R38 gene). Why might "Supertasting" have been an evolutionary advantage for our ancestors?
3. Debunking: Why is the "Tongue Map" considered a myth in modern neuroscience, and how did this lab help disprove it (consider where you placed the reinforcer)?
Touch and Pain Slides Touch and Tension
Somatosensation & Pain Modulation
Lesson 3: The Somatosensory Cortex
The 4 Primary Skin Senses
Pressure
The only skin sense with identifiable receptors.
Warmth
Signals increasing temperature to the brain.
Cold
Signals decreasing temperature to the brain.
Pain
Critical survival signal for potential damage.
Combination Note: Hot = Warmth receptors + Cold receptors activated simultaneously!
The Somatosensory Cortex
The Parietal Lobe contains the somatosensory cortex—a map of your body.
Sensory Homunculus
"The Little Man inside the brain." Areas of the body that are more sensitive (lips, hands) have more cortical space dedicated to them.
CORTICAL MAPPING
Sensitivity ≠ Physical Size
Gate Control Theory
Proposed by Melzack & Wall , this theory suggests the spinal cord contains a neurological "gate."
Why do you rub a bumped elbow?
Rubbing activates large fibers , sending competing signals to the brain that "jam" the gate and block the pain signals from small fibers.
Psychology also plays a role: distraction, endorphins, and expectations can also close the gate.
Pain is a Construction
Biological
• Activity in spinal cord
• Genetic differences in endorphin production
• Brain's interpretation of CNS activity
Psychological
• Attention to pain
• Learning based on experience
• Expectations of relief
Social-Cultural
• Presence of others
• Empathy for others' pain
• Cultural expectations
Pain is NOT just what happens in the body; it's what the brain perceives.
Gate Control Worksheet Gate Control & Body Mapping
Psychology: Somatosensory Systems
Lesson 3
Unit 4: Minor Senses
Student Name
Date
1 Sensation Vocabulary
1. Nociceptors
2. Endorphins
3. Phantom Limb
A. Sensation of pain in an amputated part of the body.
B. Natural opiate-like neurotransmitters linked to pain control.
C. Sensory receptors that enable the perception of pain in response to potentially harmful stimuli.
2 The Spinal Gate
Spinal Cord "Gate"
SMALL FIBERS (Pain Signals)
LARGE FIBERS (Touch/Rubbing)
TO BRAIN
Task: Draw symbols inside the gate box showing how Large Fibers "jam" the transmission of Small Fiber signals.
3 Clinical Applications
Scenario A: The TENS Unit
Transcutaneous Electrical Nerve Stimulation (TENS) is a therapy that uses low-voltage electrical current to provide pain relief. It works by stimulating the skin near the site of pain. Using Gate Control Theory, explain why electrical stimulation of the skin can reduce the sensation of a deeper muscle ache.
Scenario B: The Athlete's High
During a high-stakes championship game, a soccer player sprains their ankle but continues to play for 20 minutes without noticeable pain. Only after the whistle blows and the adrenaline subsides does the intense pain set in. Identify the biological and psychological factors that likely "closed the gate" during the game.
4 Cortical Mapping
Below are four body parts. Rank them (1-4) from most to least amount of space they occupy in the somatosensory cortex.
Lips
Back
Finger Tip
Elbow
Critical Thinking Question:
Why would it be an evolutionary disadvantage to have the same amount of cortical space dedicated to your back as you have for your fingertips?
Balance and Motion Slides Balance and Body
Vestibular vs. Kinesthetic Processing
Lesson 4: Systems of Motion
Kinesthesia
"The Sense of Self-Movement"
Kinesthesia (or Proprioception) is your system for sensing the position and movement of individual body parts.
The Mechanism:
Receptors in your joints, tendons, and muscles send constant feedback to the brain about where your limbs are.
Close your eyes and touch your nose. You don't need a mirror to find it—that's Kinesthesia.
Vestibular Sense
"The Sense of Head Orientation"
The sense of body movement and position, including the sense of balance .
Location: Inner Ear
Specifically the Semicircular Canals and Vestibular Sacs .
SEMICIRCULAR CANALS
Fluid in these canals sloshes around, bending hair-like receptors that signal the brain about rotation and tilt.
When Fluid Won't Stop
Post-Rotatory Nystagmus
If you spin in a chair and stop suddenly, the fluid in your semicircular canals keeps moving due to inertia.
Result: Your brain thinks you are still spinning, but your eyes (and the rest of your body) know you aren't. Your eyes will "twitch" or jump as they try to compensate.
Sensory Conflict Theory
Motion sickness occurs when your Eyes and your Vestibular System disagree on what is happening.
Reading in a car? Your inner ear says "Moving!" but your eyes (on the book) say "Still!". Result = Nausea.
Summary: Body Senses
Kinesthetic
Position of specific body parts (Limbs/Muscles).
Receptors: Muscles, Tendons, Joints
Vestibular
Position of the whole head/body (Balance).
Receptors: Semicircular Canals, Inner Ear
"Vision usually serves as the tie-breaker when these two systems disagree."
Senses in Motion Lab Senses in Motion
Kinesthetic & Vestibular Field Lab
Lesson 4 Lab
ID: KIN-VEST-04
Subject Name
Observer Name
Trial 01: Proprioceptive Drills
These drills test the brain's ability to track body parts without visual feedback.
Drill A: Finger Localization
With eyes closed, try to touch your index fingers together in front of your chest starting from wide open arms. Perform 5 times.
#1
#2
#3
#4
#5
Drill B: Pose Mirroring
Subject closes eyes. Observer moves Subject's left arm into a specific pose. Subject must mirror that pose with their right arm exactly.
Accuracy: _________________
Trial 02: Vestibular Analysis
Experiment: The Visual-Balance Interaction
1. One-Leg Stand (Eyes Open)
__:__s
2. One-Leg Stand (Eyes Closed)
__:__s
Observation: What happened to your stability when visual input was removed? Why did your vestibular system "struggle" more without your eyes?
Trial 03: Fluid Inertia
The Spin Test
Observer: Watch the Subject's eyes immediately after they stop spinning in the chair.
Observer Report:
Describe the movement of the Subject's eyes (direction, speed, duration). Did they experience "Nystagmus"?
Lab Summary & Theory
1. Define the difference between Kinesthesia and Vestibular Sense based on your results today.
2. Sensory Conflict Theory Application: Virtual Reality
A user wearing a VR headset is "walking" through a digital forest, but their physical body is sitting perfectly still in a chair. Explain, using the concepts of visual and vestibular mismatch, why this user might experience nausea.
The Bottom Line
Your perception of "where you are" is a collaboration between your eyes , your inner ear fluid , and the stretch receptors in your muscles. When all three agree, you have perfect balance. When one lies, you have vertigo.
Flavor Fusion Project Guide Final Unit Project
Flavor Fusion
The Challenge: Multisensory Integration
We often talk about "taste" as if it happens only on the tongue. In reality, what we perceive as flavor is a complex construction of gustation (taste), olfaction (smell), and somatosensation (texture/mouthfeel).
"Your task is to design and execute an experiment that demonstrates how one sense influences the perception of another."
Essential Skills
Experimental Design
Data Analysis
Sensory Synthesis
Key Deadline
FRIDAY Presentations Begin
Student Investigator __________________________
Class Period __________
Phase 1: Experiment Selection
Choose one of the following sensory interactions to investigate:
Vision & Taste
Does the color of a drink (red vs. clear) change how "sweet" or "sour" people perceive it to be?
Smell & Flavor
Can people distinguish strawberry from grape jellybeans if their olfactory bulb is "offline" (nose pinched)?
Sound & Texture
Does a louder "crunch" in headphones make people perceive a potato chip as fresher?
Temp & Taste
Does chilling a solution make it taste less bitter than at room temperature?
Phase 2: Project Deliverables
1
The Lab Report
Document your Hypothesis (If...then...), Independent Variable (the sense manipulated), and Dependent Variable (the change in perception).
2
The Visual Data
At least 10 trials per condition. You must create a graph (bar chart or line graph) showing the statistical difference in perception.
3
Psychological Synthesis
Explain the results using neural concepts (e.g., Sensory Interaction, Olfactory Direct Pathway, or Threshold levels).
Grading Matrix
30% Scientific Rigor
40% Demo/Presentation
30% Concept Mastery
