According to [[Pragmatic Thinking and Learning]], stress kills cognition because it triggers the brain's primitive "fight or flight" mechanism, causing it to shut down advanced thinking resources to focus on immediate survival. The sources highlight several specific ways this happens: **1. R-mode Shutdown** The most critical cognitive failure under stress is the loss of the **R-mode** (the intuitive, creative engine of the brain). - **Time and L-mode:** The brain's linear processing mode (L-mode) handles the concept of time. When you feel time pressure, the L-mode dominates completely. - **The Result:** Because the R-mode cannot function under these conditions, you lose your "search engine," creativity, and ingenuity precisely when you need them most. **2. Physical and Mental Tunnel Vision** Under pressure, the brain enters a state often referred to as **"lizard logic"**. - **Narrowing:** Your vision literally and figuratively narrows. You stop considering options and focus strictly on the immediate threat. - **Resource Conservation:** The brain actively shuts down "extra" resources to prepare for a physical fight or flight response. - **Bad Decisions:** This state leads to disastrous decision-making. The text describes a simulation where managers under pressure began making decisions so bad it appeared they had "had lobotomies",. **3. The "Pressure Hangover"** The damage to cognition lasts longer than the stressful event itself. The text cites a study by Dr. Teresa Amabile showing that creativity suffers on the day of the pressure and remains depressed for **two days** afterward. **4. Ethical Blindness** Stress can even override deep-seated values. The book cites a study where seminary students, normally driven to help others, stepped over a person in distress (an actor) simply because they were told they were late for a meeting. The pressure of the deadline panicked their minds, preventing them from noticing or acting on their values,,. In short, "trying too hard" or working under the gun is a guarantee of failure because the brain interprets that pressure as a crisis, effectively switching off its higher-level problem-solving capabilities.