roachhd/roachhd.github.io

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layout: post
title: Your Memory
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######How It Works and How to Improve It

The book, Your Memory by Kenneth L Higbee, has a balance between layman techniques and scientific research.
Higbee himself is fascinated with the area of memory and follows many of the newly developed
techniques to improve it. He's also a psychologist whose area of study is in memory.

# Ten Myths

```
* Memory is a thing
* There's a secret to good memory
* There's an easy way to memorize
* Some people are stuck with bad memories
* Some people are blessed with photographic memories
* Some people are too old/young to improve it
* Memory benefits from exercise
* A trained memory never forgets
* Remembering too much can clutter your mind
* People only use 10% of their mental potential
```

# What is memory?

Memory isn't a physical structure, most scientists can't even define where we store our memory.
Memory can actually be thought of in stages and processes.

The 3 stages are:

1. Acquisition or encoding, when you first learn the material
2. Storage is keeping the material as needed
3. Retrieval is getting the material when needed

The 2 processes are:

1. Short-term memory (aka primary or working memory)
2. Long-term memory (aka secondary memory)

Information stored in short-term is often forgotten within 30 seconds, less if there are any sort of
distractions.

There are tricks to improve your short-term memory. For example, numbers are easy to forget when
presented in one chunk (4501235678). But when presented in multiple chunks like a phone number, it
becomes easier.

Short-term memory is desirable because:

1. Imagine how cluttered our minds would be if we remembered everything.
2. It helps us maintain the current state of the world around us.
3. It keeps our intentions in active memory, guiding our behavior.
4. Keeps track of recent topics in conversation or reading. So if you read a passage that mentions a
   "John", your mind can infer any usages of "he" as meaning "John".

Higbee compares short-term memory to the registers in a CPU.

Long-term memory is composed of 3 types:

1. Procedural - how to do something (ie Math)
2. Semantic - remembering factual information (ie word meanings)
3. Episodic - personal events

Long-term memory is not as easily interrupted as the ongoing, active short-term memory. Its storage
is virtually unlimited (short-term has a limited capacity). Retrieval from short-term is automatic,
retrieval from long-term is often more problematic.

Information goes through short-term and gets stored permanently in your long-term memory. That makes
short-term the bottleneck. Information must be coded before they're stored and that coding takes
time. A systematic approach is needed to improve your long-term memory.

Higbee compares it to a filing cabinet. We all have the same size filing cabinet. Remembering new
things won't push old ones out. But some of us place files in an organized fashion (like
alphabetical) whereas others just toss files in. If the filing cabinet is organized, it's much
easier to retrieve it. If it's a mess, retrieval becomes hard or even impossible.

Measuring memory can be done via:

```
1. Recall
2. Recognition
3. Relearning
```

# How does it work?

The most common explanations for forgetting are:

1. Decay, like a physical trace of your memory in your brain is slowly decaying over time
2. Repression was suggested by Sigmund Freud that we don't want to remember and push it down into
   our unconscious mind
3. Distortion, memory can be affected by our mind and we remember what we want to believe
4. Interference occurs when you learn new facts that might interfere with the ones you already
   remember (such as trying to remember multiple names and getting them mixed up)
5. Cue dependency happens when a memory doesn't fade away, but it depends on the correct cue to set
   it off

Information can be recorded in either visual form or verbal form. Concrete words are stored
differently than abstract words. Many studies have shown that using pictures is a better way to
memorize than just words. Many people are able to recall/recognize pictures better than words as
time passes.

Eidetic memory is what most people call "photographic memory". It has a few misconceptions:

1. The "photo" fades soon after viewing the scene, it's not kept forever
2. The "photo" is heavily influenced by the subjective view or the viewer
3. The person requires more than a split-second, studying is required
4. Images cannot be brought back after they are forgotten

There are some people with exceptional eidetic memory that do not have those limitations. A woman
could remember a poem in a foreign language and repeat it forwards/backwards one year later.

Higbee touches a little bit about sleep-learning. Some conditions of it are:

1. You cannot learn anything during deep sleep, the subject must be at the correct stage of
   drowsiness or light sleep
2. No complex materials that require reasoning may be learned
3. It's usually not sufficient in itself, but can work as an aide to daytime learning

Some research shows that people remember better when they go to sleep right after they acquire
knowledge. They remember worse in the reverse order, if they wake up and then acquire knowledge.

# Remember anything, basic principles

The basic principles for better memory are:

```
* Meaningfulness
* Organization
* Association
* Visualization
* Attention
```

It's much easier to remember something simple/meaningful than something that is complex/meaningless.
Remembering meaningless things is called rote memory, and techniques such as repetition is used for
it (remembering many digits like Pi, or remembering random strings of characters). For example, it's
much easier to remember words with meaning than random syllables.

Organization plays an important role. A dictionary provides alphabetical organization so it's easy
to look up the definition of a word. When you're recalling the states, it's usually easier to do it
in order of geography or alphabet. When you remember new facts, you usually organize it so you can
recall it later on. Higbee notes that not all data structures provide equal look-up time, for
instance an alphabetically organized dictionary is not optimized to find all words that rhyme with
"stealthy".

Association is a technique used when you encode a memory. For example, a golfer always remembers his
wife's birthday because it is exactly one week after his first hole-in-one.

"Think around it" is similar to association, where you think around what you want to remember to
trigger a memory. For example, in police investigations it's useful to ask any witnesses to recall
everything about a crime-scene to trigger the memory of a once forgotten license-plate. Whereas
association occurs during the encoding step, "think around it" occurs during retrieval.

Visual memory is often better than semantic memory. It's much easier to visualize your house to
remember how many windows there are instead of just remembering the fact.

Attention is required to actually record the memory in the first place. Higbee asks us if we
remember if Lincoln had a tie on the penny. Not many people can recall it because it's unimportant -
we never pay attention.

# Remember almost anything, more principles

More principles that can be applied towards a better memory are:

```
* Repetition
* Relaxation
* Context
* Interest
* Feedback
```

Repetition alone may not be enough to remember everything, but it's a great technique to use.
Studies show that people who relearn will remember better than others who do 0% overlearning. For
instance, after a subject repeats a series of words until he memorizes it - overlearning occurs when
he repeats it again 100% of the time.

Relaxation helps while you're trying to retrieve information. Anxiety will usually cause
difficulties during recall.

Context has been shown to help or hinder retrieval. Research has shown that if a subject is in the
same physical location as where the material is learned, there is a higher rate of recall. Higbee
suggests that you study where you'll take your exam. If that's not possible, then study in a similar
environment. During recall, you can imagine and place yourself into the environment where you first
encoded a memory to help recall it ("think around it").

Just like how attention is required to learn something, interest in a subject will usually help
memorization.

Feedback is very helpful for the learning process. It's much easier to learn something when you can
measure your progress towards a goal. It helps sustain your interest in the subject and will help
you make adjustments to improve your techniques.

# Effective learning

Higbee gives readers tips to improve their learning abilities. This chapter was written specifically
for students but is general enough to apply to most learning situations.

To learn more effectively, you should:

```
* reduce interference
* space out learning sessions
* decide to either break up the learning material or learn it as a whole
* recite it
* use a study system (SQ3R is recommended)
```

Reducing interference means eliminating distractions while you're encoding new memories. You can
also minimize the harmful effects of interference by making sure any activities between
encoding/recall is as dis-similar to the learning material as possible.

Studies have shown that multiple short study sessions split over a period of time is much better for
memorization than one single massive study session. Higbee goes on to give reasons why this might
occur, such as letting your memories settle during sleep or having breaks causes better attention.

The 2 approaches to learning is either break down the materials into sections and learn one at time,
moving on when a section is mastered, or learning it as a whole and repeating until the material is
mastered. Each has their pros and cons, for smaller/simpler subjects it's usually easier to break it
down (as this provides feedback). Some material needs to be understood as a whole.

Reciting is repeating out-loud what you've learned from memorization as opposed to repeating it
directly by reading. It helps via repetition but is also practice for the recall/retrieval process,
which is its major benefit.

Higbee recommends the SQ3R study system: survey, question, read, recite, review.
* survey - do a quick glance over your material/section, noting the outline and any other
  headings/subheadings
* question - create questions as you glance over the material that will be important for you to
  answer as you read
* read - this is where most students do their "studying", by reading the material. Higbee suggests
  that this part of the system is only a small portion of what's required to really memorize for
  exams.
* recite - repeat your learning material while also practicing retrieval
* review - after you've answered your questions and recited, be sure to go over the outline again
  and re-answer your questions. This conclusion helps reinforce what you just learned for
  remembering later on.

# Intro to Mnemonics

Mnemonics refer to general techniques that improve memory, but most people only consider
narrow/unusual methods that aid memory as mnemonics.

Common mnemonic techniques use acronyms and acrostics (first letter of every word in a sentence
represents something). Rhymes and other sentences with rhythms may also be used (when did Columbus
sail the ocean blue?)

An example mnemonic to remember the lakes in North-East US:

Hudson Ontario Michigan Eerie Superior

Mnemonics help with basic principles:

* Meaningfulness by adding meaning to your learning material, which may otherwise be dry or
  meaningless
* Organization by having a system to easily retrieve memories
* Association is usually the how mnemonics work, we associate previously learned memories with the
  new ones we're trying to save
* Visualization is not required but is often useful in mnemonics. For instance, to remember the
  phrase "dog broom" you can picture a dog sweeping the living room. The more vivid/lively/unusual
  the better.
* Attention is forced upon you when you concentrate to memorize using mnemonics

Research tells us that we should make our own mnemonic strategies. Names are easier to remember when
you've named something yourself, as is the case with memory strategies. This "generation effect" has
been found true for product names, computer commands, etc...

# Mnemonics limitations

Some of the limitations listed by Higbee are:

* Time: The encoding/retrieval processes usually take longer with mnemonics. Not only are you
  learning the material, you're organizing it for easy access later on. If you have a set limit on
  learning, you'll be unable to create a mnemonic association. Research has shown that subjects
  given ~2 seconds per item could not form an association. Higbee notes that with practice, this
  time goes down.
* Abstract Material: Visual mnemonics is difficult to do with abstract material. Whereas it's easy
  to picture a dog sweeping for "dog broom", it's difficult for abstract concepts like "theory" or
  "analyze".
* Learning vs Retention: Psychologists have argued whether mnemonics actually help retention rate or
  not. It's obvious that it helps learning (by making the learner pay closer attention and have an
  interest in the subject). It's not proven yet that it actually helps retention. It does help
  organizing the material, which will improve the retrieval rate.
* Imagery Ability: Adults may have trouble developing vivid images for their mnemonics. Higbee notes
  that with practice, people can overcome this limitation.
* Verbatim Memory: Sometimes verbatim memory is more appropriate, such as for abstract concepts. In
  those cases, Higbee suggests using the techniques mentioned in the previous chapter.
* Interference: Mnemonics adds a step of indirection which may hinder memory with interference. For
  example, imagery of a dog sweeping could be mistaken for the phrase "dog sweeping" instead of "dog
  broom". One image can represent multiple phrases.
* Maintenance and Transfer: All learning strategies suffer from this. Once you learn how to use
  mnemonics, will you use it? Psychologists have taught children to use it, but they found later on
  in their lives that children did not use it autonomously.

Pseudo-limitations are critiques that are not as valid/serious as the previously listed limitations.
Some of them aren't valid at all:

* Not practical: Mnemonics can be applied to everyday life like remembering errands, names, or
  learning foreign languages. They're not just for parlor tricks.
* Do not aid understanding: They weren't developed to aid understanding/reasoning. Instead, they're
  for memorization and learning.
* Give you more to remember: This is somewhat true, you have to remember the step of indirection and
  what it associates to. But it helps with organization which makes retrieval easier later on, so
  it's worth it.
* They're crutches: Critics say mnemonics are like crutches, you become dependent on them and you
  begin to require it for all memory tasks. Higbee says it's much better to use them than to forget
  what you've learned anyways. He compares it to a person staying blind without the use of
  eyeglasses.
* They're tricks: They aid in learning/memorization and should not be viewed as tricks. People are
  not born with "good or bad" memory, they can work at it and use these techniques to improve their
  learning/retrieval.

# Mental filing systems

Our filing system is disorganized as if our memories were written on 3x5 cards and thrown across the
floor.

Using mnemonic devices helps us organize and retrieve memories. Higbee describes two basic systems:
the Link and Story systems. These two work ideally for concrete word lists.

If you had to remember a list of words:

* paper
* tire
* doctor
* rose

The Link system works by linking two words at a time to form visual imagery. So in this case:

1. A car driving on paper tires
2. A tire running over a doctor
3. A doctor operating on a rose

The Story system works by integrating all the words sequentially in a single overarching story:

A paper tire ran over the doctor who happened to be operating on a rose.

Psychologists have done research on these systems by giving subjects lists of words to remember. The
retrieval rate is much higher after they're taught to use these two mnemonic systems.

Mark Twain used the link system to remember his speeches. Some other example usages include grocery
lists or todo lists. Long items and/or abstract words should be translated to a concrete word before
filing.

These systems rely heavily on memory cues to retrieve information. They're also weak in that if you
forget one item, you forget the rest of the list.

# Loci Mnemonic

The Loci system uses locations to form associative pairs.

It was originated sometime in 500BC, "Loci" is the plural of "Locus" which means place or location
in Greek. It's also sometimes known as the Topical system.

First, memorize a set of locations by over-learning it and keep these locations in a sequence. For
example:

1. Driveway: I pull into my driveway
2. Car door: I open the car door
3. Font door: I open my front door
4. Shoe area: I take off my shoes
5. Closet: I place my coat into the closet
6. Kitchen: I grab something to eat from the kitchen
7. Couch: I sit on the couch in the living room

Now for any list of items/words, picture each word at each location:

1. Driveway => large amounts of paper liter
2. Car door => swung open and hit a huge tire
3. Front door => doctor sitting and crying
4. Shoe area => covered with roses to cover up smell

Now to retrieve your list, just visualize yourself walking through your locis and retrieve each
associative pair.

Research has shown the loci system to be very effective. Subjects can learn multiple sets of locis
(at home, at school, at work, or even their body parts). The more distinct the locations, the
better. Higbee also mentions you can combine the Link system with the Loci system, just use linked
imagery at each loci.

The Loci system can be used to memorize the same types of lists as the Link and Story systems.

The Loci system is sequential just like link/story. Higbee suggests that we index our 5th multiple
and 10th multiple locations by associating them with a hand (with 5 fingers) and a 10 dollar bill.
So for example, my bed could have a 10 dollar bill on it and the 12th location is just 2 locis
after.

# Peg Mnemonic

The Peg system is similar to the Loci system, but instead of using locations as keys we use real
concrete words.

The words must represent numbers by looking like one, symbolic, or rhyme:

1. bun
2. shoe
3. tree
4. door
5. hive
6. sticks
7. heaven
8. gate
9. wine
10. hen

Then for any list, associate each pair of words with visual imagery. Whereas the loci system is
sequential, the peg system allows you to retrieve items out of order.

It's called the peg system because your concrete words act like pegs, on which you hang your items
to be memorized.

The Loci system is said to be much easier/more natural to learn. Another limitation is it's
difficult to come up with concrete words beyond the number ten. Interference may also be a problem
if you're trying to remember multiple lists and re-using the same pegs.

# Phonetic Mnemonic

The Phoentic system is the most complicated mnemonic system introduced in this book, but is very
powerful. It's similar to the peg system, you'll have words which act as your pegs. But it solves
the weakness of the peg system - you can easily create up over 1000+ pegs with a bit of practice.

Every number will have consonant sounds associated with it:
 
 | Number | Sound(s)             | Memory Aid                  |
 | --- | -------------------- | --------------------------- |
 | 1 | t, th, d             | "t" has one downstroke      |
 | 2 | n                    | two downstrokes             |
 | 3 | m                    | three downstrokes           |
 | 4 | r                    | last sound for "four"       |
 | 5 | l                    | roman numeral for 50 is "L" |
 | 6 | j, sh, ch, soft g    | reverse "j" looks like      |
 | 7 | k, q, hard c, hard g | "k" makes two 7s            |
 | 8 | f, v                 | script "f" resembles 8      |
 | 9 | p, b                 | p is mirror image of 9      |
 | 0 | z, s, soft c         | "z" for zero                |

The table above works well because all consonant sounds are used except for "w", "h", "y" (why) - so
most words can be used. The sounds are also mutually exclusive to prevent interference.

Higbee suggests using the consonant sounds as the first sound in your keywords. Sample keywords:

```
1. tie
2. Noah
3. ma
4. ray
5. law
6. jay
7. key
8. fee
9. pie
10. toes
11. tot
12. tin
13. tomb
14. tire
15. towel
```

The appendix has sample keywords for up to 100. Using adjectives, you can multiply your 100-word
list into a 1000 phrase list:

```
1. wet (wet tie = 0101 or 101)
2. new
3. my
4. hairy
5. oily
6. huge
7. weak
8. heavy
9. happy
10. dizzy
```

The phonetic system allows you to pick a word in your list without going in order. It has the added
benefit of encoding numbers in a more meaningful way with low interference. For example, you can use
it to remember PI where each digit is translated to your keyword. Chunking it provides a lower
amount of interference also.

# Absentmindedness and Education

The major problem with absentmindedness is with attention. We don't pay attention to what we're
doing either because it requires very little conciousness or we get distracted.

There are two types of absentmindedness, prospective and retrospective. Prospective concerns memory
for future events whereas retrospective concerns memory for past events.

For example, remembering a task for later on is prospective memory. Sometimes, we forget a chore
that we need to perform later. Higbee suggests using visual association to fix this. For example, if
you need to call the doctor when you get into the office - visualize a doctor in your office. When
you get in the morning, your office will trigger that memory.

An example of retrospective memory is forgetting where you last placed your keys. Higbee suggests
announcing actions you commonly forget as you do them. By hearing them out-loud, you're paying
attention and are more likely to remember later on.