8. Short-Term Memory Is Limited

Before you read any further in this chapter, read over the following list of terms for about 30 seconds, and then keep reading the chapter:

• Meeting

• Work

• Presentation

• Office

• Deadline

• Computer

• Papers

• Pen

• Staff

• Whiteboard

• Phone

• Chair

• Shelf

• Table

• Secretary

We’ll come back to this list later in the chapter. First, let’s learn about the frailties and complexities of human memory.

Everyone has experienced a moment like this: You’re on the phone, and the person you’re talking to gives you the name and number of someone you need to call right away. You don’t have a pen or paper to write down the information, so you repeat the name and number over and over to help yourself remember them. You try to get off the phone quickly so you can make the call while the number is still running through your head. You may find that your memory isn’t very reliable in this situation.

Psychologists have many theories about how this type of memory works—some refer to it as short-term memory, others as working memory. In this chapter, we’ll call this type of quick memory—the memory you need for less than a minute—working memory.

Working Memory and Focused Attention

There’s only so much people can hold in working memory before they forget it. Information in working memory is easily interfered with. For example, if you’re trying to remember a name and phone number and someone starts talking to you at the same time, you’re probably going to get very annoyed. You’re also going to forget the name and number. If you don’t concentrate, you’ll lose it from working memory. This is because working memory is tied to your ability to focus attention. To maintain information in working memory, you must keep your attention focused on it.

Working Memory vs. Sensory Input

Interestingly, there is an inverse relationship between working memory and the amount of sensory input you are processing at any given time. People with high-functioning working memories are better able to screen out what’s going on around them. Your prefrontal cortex determines what you should pay attention to. If you can tune out all the sensory stimuli around you and instead focus your attention on the one thing in your working memory, you’ll be able to remember it.

Presentations Can Easily Overload Working Memory

Typically, presentations are in given in a short amount of time. Most presentations aren’t a semester-long college course. They are a short burst—for example, 2 hours, 1 hour, or even 20 minutes. Presenters often feel compelled to pack as much information as possible into that time period. It’s easy therefore to overload working memory by giving people more information than they can possibly process or store in long-term memory.