How Memory Functions: Learn It 1—Encoding

  • Explain how sensory information is encoded into memory
  • Describe the three stages of memory storage
  • Understand the difference between implicit and explicit memory and semantic and episodic memory
  • Explain retrieval cues and the three types of retrieval

Memory is an information processing system; therefore, we often compare it to a computer.

Memory and encoding

Memory is the set of processes used to encode, store, and retrieve information over different periods of time.

A diagram shows three boxes, placed in a row from left to right, respectively titled “Encoding,” “Storage,” and “Retrieval.” One right-facing arrow connects “Encoding” to “Storage” and another connects “Storage” to “Retrieval.”
Figure 1. Encoding involves the input of information into the memory system. Storage is the retention of the encoded information. Retrieval, or getting the information out of memory and back into awareness, is the third function.

We get information into our brains through a process called encoding, which is the input of information into the memory system. Once we receive sensory information from the environment, our brains label or code it. We organize the information with other similar information and connect new concepts to existing concepts.

Encoding information occurs through automatic processing and effortful processing.

automatic and effortful processing

If someone asks you what you ate for lunch today, more than likely you could recall this information quite easily. This is known as automatic processing, or the encoding of details like time, space, frequency, and the meaning of words. Automatic processing is usually done without any conscious awareness. Recalling the last time you studied for a test is another example of automatic processing.

But what about the actual test material you studied? It probably required a lot of work and attention on your part in order to encode that information. This is known as effortful processing (Figure 2).

A photograph shows a person driving a car.
Figure 2. Recalling the route to your home demonstrates automatic processing. As you drive or walk home regularly, your brain automatically encodes the familiar landmarks, turns, and street names without conscious effort. You effortlessly navigate the route, relying on previously stored information, and arrive at your destination without actively thinking about each step of the way.(credit: Robert Couse-Baker)
What are the most effective ways to ensure that important memories are well encoded? Even a simple sentence is easier to recall when it is meaningful (Anderson, 1984).

Read the following sentences (Bransford & McCarrell, 1974), then look away and count backward from 30 by threes to zero, and then try to write down the sentences (no peeking back at this page!).

  1. The notes were sour because the seams split.
  2. The voyage wasn’t delayed because the bottle shattered.
  3. The haystack was important because the cloth ripped.

How well did you do? By themselves, the statements that you wrote down were most likely confusing and difficult for you to recall. Now, try writing them again, using the “answers” shown below:

Next count backwards from 40 by fours, then check yourself to see how well you recalled the sentences this time. You can see that the sentences are now much more memorable because each of the sentences was placed in context. Material is far better encoded when you make it meaningful.

There are three types of encoding.

semantic encoding

The encoding of words and their meaning is known as semantic encoding. Semantic means “meaning,” so semantic encoding refers to mentally processing the meaning of information.

Semantic coding was first demonstrated by William Bousfield (1935) in an experiment in which he asked people to memorize words. The 60 words were actually divided into 4 categories of meaning, although the participants did not know this because the words were randomly presented. When they were asked to remember the words, they tended to recall them in categories, showing that they paid attention to the meanings of the words as they learned them.

visual encoding

Visual encoding is the encoding of images. It involves encoding information based on its visual characteristics and appearance. It emphasizes the visual details of an item or concept. For instance, if you are trying to remember a picture of a beautiful sunset, visual encoding involves mentally capturing and storing the colors, shapes, and scenery of the sunset.

To see how visual encoding works, read over this list of words: car, level, dog, truth, book, value. If you were asked later to recall the words from this list, which ones do you think you’d most likely remember? You would probably have an easier time recalling the words car, dog, and book, and a more difficult time recalling the words level, truth, and value. Why is this? Because you can recall images (mental pictures) more easily than words alone. When you read the words car, dog, and book you created images of these things in your mind. These are concrete, high-imagery words. On the other hand, abstract words like level, truth, and value are low-imagery words. High-imagery words are encoded both visually and semantically (Paivio, 1986), thus building a stronger memory.

acoustic encoding

Acoustic encoding is the encoding of sounds.

Here’s an example of acoustic encoding. You are driving in your car and a song comes on the radio that you haven’t heard in at least 10 years, but you sing along, recalling every word. In the United States, children often learn the alphabet through song, and they learn the number of days in each month through rhyme: “Thirty days hath September, / April, June, and November; / All the rest have thirty-one, / Save February, with twenty-eight days clear, / And twenty-nine each leap year.” These lessons are easy to remember because of acoustic encoding. We encode the sounds the words make. This is one of the reasons why much of what we teach young children is done through song, rhyme, and rhythm.

The Best Way to Encode

Which of the three types of encoding do you think would give you the best memory of verbal information? Some years ago, psychologists Fergus Craik and Endel Tulving (1975) conducted a series of experiments to find out. Participants were given words along with questions about them. The questions required the participants to process the words at one of the three levels. The visual processing questions included such things as asking the participants about the font of the letters. The acoustic processing questions asked the participants about the sound or rhyming of the words, and the semantic processing questions asked the participants about the meaning of the words. After participants were presented with the words and questions, they were given an unexpected recall or recognition task.

Words that had been encoded semantically were better remembered than those encoded visually or acoustically. Semantic encoding involves a deeper level of processing than the shallower visual or acoustic encoding. Craik and Tulving concluded that we process verbal information best through semantic encoding, especially if we apply what is called the self-reference effect. The self-reference effect is the tendency for an individual to have better memory for information that relates to oneself in comparison to material that has less personal relevance (Rogers, Kuiper, & Kirker, 1977). You can easily apply the self-reference effect when learning for your classes by relating the things you learn to your own life. For example, can you think of things you’ve learned through semantic, visual, or acoustic encoding? What are examples of things today where you’ve used automatic processing or effortful processing?