How Stress Affects Your Memory

Ever had a hard time remembering people’s names when you run into them somewhere? What you remember is often determined by your mental, physical, and/or emotional state when you require the recall: it could be your gut reaction, your anxiety state, pressure you may feel, what drugs are in your system, how tired you are, or other similar factors. It can be far harder to remember or to recite anything that’s boring to you. Stress is an emotional response and as such, stress can stimulate and sharpen your memory.

Distress, on the other hand, can cause you to forget a name, the answer to an easy question, your keys, etc. Reportedly, even Albert Einstein had difficulty finding his way home after a hard day at work! Once stress becomes chronic or severe, the normal setback of a momentary memory lapse could yield to a greater problem of memory loss.

Memory Basics

That all memory is locked away in a specific place in the brain is a common misconception. Memory comes in many different types:

• Short-term memory involves remembering what groceries to buy or what a new phone number is before writing it down.
• Long-term memory involves remembering what you did yesterday, the date of your birth, or a line from a poem or a movie.
• Remote memory involves remembering what happened in kindergarten or the games you played. Studies of patients with dementia show that in comparison to other long-term memories, childhood memories are not easily forgotten. Childhood memories thus seem to be stored separately from those that are recently long-term.
• Explicit memory involves the self-awareness of knowing certain facts such as your name and what day it is.
• Implicit memory involves knowing how to do things unconsciously such as tying your shoelaces, roller-skating, or swimming.

Memory is also located in more than one part of the brain. Areas prominently associated with memory function are:

The cortex or surface area of the brain that is involved in memory storage.

The hippocampus or region beneath the cortex that provides the means by which memories are sent to and retrieved from the cortex. This region makes it possible for short-term memories to turn into long-term ones and is largely responsible for explicit memory.

The cerebellum or region situated at the back of the brain behind the brain stem that controls muscle coordination. This region is crucial to implicit memory.

A microscopic view of the brain will reveal neurons: specialized cells that are the building blocks of nervous tissue. Rather than being stored in single neurons, memories are stored in the pattern of excitation among neurons. Different neurons basically contribute different pieces of information to a single memory. When something is on the tip of your tongue and you try to make connections in order to remember, you take advantage of this networking system.

Networking occurs at the synapse or gap between neurons via the release of neurotransmitters. Especially vital to memory making is one such chemical messenger known as glutamate. When a neuron releases glutamate, it does so again and again, gradually increasing in amount, until it breaks a certain threshold before passing glutamate on to the next neuron. Once this happens the synapse becomes more sensitive and next time it won’t need as much glutamate to break the threshold.

Remarkably, this strengthening of synapses is not a one-time deal. In fact, this long-term potentiation or long-lasting reinforcement of neuronal connections is the reason why memories—and learning—can last a lifetime.

Memory Under Pressure

It’s getting late. The streets are deserted. Imagine that you hear footsteps following behind you. Your heart is racing, bringing more oxygen and glucose into your bloodstream and into your brain. Steroid hormones called glucocorticoids are also released along with other stress hormones. Luckily, remembering exactly where you parked your car isn’t a problem and you escape quickly. With more energy delivered to your brain, an acute stress response can make the task of remembering something a whole lot easier.

When the stress response lasts beyond thirty minutes or so, this initial boost of glucose and hormones builds up and will begin to interfere with your memory. Although your brain takes up about 3 percent of your total body weight, it consumes around 20 percent of your total energy! Prolonged stress will deprive your neurons of the energy needed to strengthen the connections between them. That’s why stressing out five minutes before a test does less harm than stressing out days or weeks before: The more time you spend being anxious, the more memory loss you will suffer!

Forgetfulness follows when neurons disconnect as a result of weakened connections. Fortunately, this sequence can be reversed. As the stressful moment passes, poor connections can actually regrow. Unfortunately, regrowth seems to become very difficult, if not near impossible, when stress fails to ease up. Distress sustained at chronic high-levels can make neurons more vulnerable to damage caused by heart attacks, strokes and other diseases. At the very worst, such distress may be capable of destroying neurons completely. Any memory loss at this point may be irreversible.