This episode I explain how we sense chemicals by way of smell, taste and pheromones. How things smell and taste and chemicals in the tears, breath, and on the skin of others have a profound effect on how we feel, what we do and our hormones. I explain the 3 types of responses to smell, the 5 types of tastes, the possible existence of sixth taste sense and how the act of sniffing can make us learn and focus better. I explain how smell and taste reflect brain health and can be used to assess and even promote brain regeneration. I discuss how eating specific categories of foods makes us crave more of those foods. Both basic science and protocols are described including how to make sour things taste sweet and how to develop a heightened sense of smell and taste.   Thank you to our sponsors: ROKA - https://www.roka.com - code: huberman InsideTracker - https://www.insidetracker.com/huberman Athletic Greens - https://www.athleticgreens.com/huberman   Our Patreon page: https://www.patreon.com/andrewhuberman   Supplements from Thorne: http://www.thorne.com/u/huberman   Social: Instagram - https://www.instagram.com/hubermanlab Twitter - https://twitter.com/hubermanlab Facebook - https://www.facebook.com/hubermanlab Website: https://hubermanlab.com   Links: What Is Color? By Arielle & Joann Eckstut https://www.amazon.com/What-Color-Questions-Answers-Science/dp/1419734512 The smell of tears lowers testosterone DOI: 10.1126/science.1198331 Inhaling (sniffing) improves non olfactory attention & cognition: https://pubmed.ncbi.nlm.nih.gov/31089297/ Smelling Salts & Improved Athletic Performance https://pubmed.ncbi.nlm.nih.gov/28922211/ Taste Receptors Are Expressed By Ovaries & Testes doi:10.1093/molehr/gat009   Timestamps: 00:00:00 Introduction  00:06:02 Sensing Chemicals: Smell, Taste & Chemicals That People Make To Control Each Other  00:09:10 Vision Protocols Recap (Brief): Near-Far Viewing & 2 hours/day outside, & Correction  00:12:20 Color Vision: Excellent Resource: What is Color? (The Book)  00:13:54 How We Sense Chemicals: Enter Our Nose, Mouth, Eyes, Skin  00:17:28 The Chemicals From Other People’s Tears Lower Testosterone & Libido  00:21:16 SMELL: Sniffing, A Piece of Your Brain In Your Nose, 3 Responses To Smells  00:24:40 Smells and Memory: Why They Are So Powerfully Associated  00:26:40 Pheromone Effects: Spontaneous Miscarriage, Males & Timing Female Puberty  00:28:56 Sniffing Creates Alertness & If Done Properly Can Help You Focus & Learn Better  00:34:00 Protocol 1: Sniffing (Nothing) 10-15X Enhances Your Ability to Smell & Taste  00:35:50 Smelling Salts, Ammonia & Adrenaline   00:38:25 How You Can Become A Human Scent Hound, Detecting Cancer, & Tasting Better  00:43:45 Smell As A Readout Of Brain Health & Longevity; Regaining Lost Sense Of Smell  00:48:30 Dopamine, Sense Of Smell, New Neurons & New Relationships  00:50:20 Why Brain Injury Causes Loss Of Smell; Using Smell To Gauge & Speed Recovery   00:53:33 Using Smell To Immediately Becoming Physically Stronger  00:54:40 Smelling In Our Dreams, Active Sniffing In Sleep, Sniffing As a Sign Of Consciousness  00:57:35 Mint Scents Create Alertness By Activating Broad Wake-Up Pathways Of Your Nervous  00:59:48 Protocol 2 Pleasant Or Putrid: The Microwave Popcorn Test, Cilantro, Asparagus, Musk  01:03:00 Skunks, Costello, All Quiet On The Western Front    01:04:32 TASTE: Sweet, Salty, Bitter, Umami, Sour; Your Tongue, Gustatory Nerve, NST, Cortex  01:08:45 Energy, Electrolytes, Poisons, Gagging, Amino Acid & Fatty Acid Sensing, Fermentation  01:13:48 Our 6th Sense of Taste: FAT Sensing  01:15:05 Gut-Brain: Your Mouth As An Extension Of Your Gut; Burned Mouth & Regeneration  01:19:30 Protocol 3: Learn To Be A Super-Taster By Top-Down Behavioral Plasticity  01:22:20 The Umami-Sweet Distinction: Tigers Versus Pandas. Aggression Versus Passivity  01:25:05 Eating More Plants Versus Eating More Meat, Cravings and Desire  01:27:15 Food That Makes You Feel Good Or Bad: Taste