Let's Explore our Memory: Implicit Memory

Up to now in our blog-isodes, we've considered only methods of retrieval that are "explicit", specifically recall and recognition .

In both situations, the person is asked about something they experienced before. They might be asked to remember(recall): "Can you say the name of one of your old high school teachers?" Or they might be asked if they recognize(recognition): "Do you remember Mr. Halberdam from your old high school?" Either way, the question talks directly about things the person remembers from the past(explicitly).

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But retrieval need not be explicit .

An example comes from the performance of well - practiced skills.

The pianist is not consciously aware of when and where he learned to finger the keys as he strikes a chord , nor does the golfer consciously remember where and how he perfected his golf swing while swinging the club .

We know of course that the achievements of these skilled performers are honed by constant practice and thus depend on memory . To play the chord or hit the ball , both pianist and golfer necessarily retrieve something from memory, but these retrievals are implicit rather than explicit , for there is typically no awareness of "remembering" at the time. In other words, retrieval is done unconsciously.

Therefore the memory that underlies such retrievals is what we sometimes call implicit memory.

Scientists have studied implicit memory a lot in labs. In one study, people were shown some words, and then they had to do two memory tests.

The first was a test of explicit memory, in which a standard recognition procedure was used. The second was a test of implicit memory, in which the subject's task was to identify words that were flashed on a screen for 35 milliseconds .

Some of the words shown were the same as the ones from before(the first test). The results of the second test showed something called "repetition priming": People could recognize words from the original list more easily than new ones.

The crucial finding was that this priming effect held even for words that the subjects failed to recognize on the previous test of explicit memory. This simply means, subjects may have implicit memory for items that they cannot consciously (explicitly) remember.

Other tests have also shown effects similar to implicit memory using different priming methods. For example, in word completion, people are given a word fragment (like C_O_O_I_E for CROCODILE) and have to fill in the missing letters with the first word they think of. Here, when people use words from a previous list more often, it shows priming.

You might think that remembering things without thinking about them(implicit) isn't really different from remembering things consciously(explicit), except for being more sensitive. But there are differences, because tasks that use implicit memory seem to make use of different parts of memory compared to normal memory tests where you have to recall or recognize things.

One example concerns the depth of processing, which affects explicit and implicit memory differently. We've previously seen in our blog-isodes, that subjects who encode words for meaning (deep processing) tend to remember these words better than subjects who encode them by sound or visual appearance (shallow processing), and that they also benefit more from elaborative rehearsal than from mere maintenance rehearsal.

But recall and recognition are tests of explicit memory.

When the test is for implicit memory, these effects do not hold. Thus repetition priming is unaffected by whether the items were encoded deeply or shallowly, or whether the subjects employed maintenance or elaborative rehearsal.

All that matters is that the items have previously been seen.

These findings suggest that remembering things consciously(explicit) and unconsciously(implicit) use different memory abilities or functions. Some scientists involved in this study do think these differences come from separate memory systems, maybe controlled by different parts of the brain.

Now, this idea is supported by the fact that people with amnesia due to brain lesions (damage) struggle more with remembering things consciously than unconsciously.

The Bus Stops Here for today:

We'll delve deeper into this in our upcoming Blog-isodes. Thank you for joining me in today's section. I hope you found it enjoyable. As always, I'm eager to hear your thoughts and opinions on this topic. I love writing about this and want to ensure my readers enjoy reading it too. Catch you in the next episode. Stay safe, friends.