Memory Encoding and Rajan Mahadevan's Pi Record

• Dilara Varan is a Ph.D. candidate studying Memory.

Incredible Memory of Rajan Mahadevan

• Rajan Mahadevan memorized the first 31,811 digits of Pi.
• Typically, Pi is rounded to 3.14.
• Rajan made no mistakes until the 31,812th digit.
• The feat took 3 hours and 44 minutes, and Rajan Mahadevan cried when his name was entered into the Guinness World Records.
• Rajan can repeat a sequence of 60 digits after hearing them once.
• Usually people can only remember 7-10 random digits.
• Despite Rajan's ability to memorize numbers, his face recognition is below average.
• Rajan often forgets where he puts his keys.

Memory Processes

• Memory enables one to retrieve information after a time lapse.
• This happens in three processes: Encoding, storage, and retrieval.
• Memories are representations of the world, but not exact.
• Memories can be distorted and inaccurate.

Encoding

• Rajan used a code to help him remember numbers, this is called encoding.
• Encoding makes mental representation of information so it can be stored in memory.
• As an example, Rajan associates the number 111 with Admiral Nelson, who had one eye, one arm, and one leg.

Storage

• Rajan used associations to encode information
• These associations help with information storage.
• Storage is placing encoded information into permanent mental repositories for future use.
• New information is stored by associating it with known information, which is easier to recall later.

Retrieval

• Retrieval retrieves or recalls information that moved into short or long-term memory.
• Rajan recalled/retrieved 31,811 digits.
• There are approximately only a half dozen people who can approach Rajan's skill to retrieve thousands of digits from encode and storage.
• Recall varies between people.

Topic Preview

• The presentation covers the three types of memory.
• It will also review how memories are encoded.
• Also covered is why emotional memories last longer.
• Repressed memory and extraordinary memory abilities will also be discussed.

Three Types of Memory

• Memory is typically referred to as a single process.
• One model states recall divides memory into three processes: Sensory, Short-term, and Long-term.

Sensory Memory

• Sensory memory initially holds raw information from the environment for a short duration, from a fraction of a second to a few seconds.
• Without focus, sensory memory will leave without much trace.
• The sound of a guitar will remain in sensory memory for a second or two after reaching the ears.
• With focus, information in sensory memory will transfer to short-term memory.
• What you do will determine what happens to the sound of the guitar in sensory memory.

Short Term Memory

• Short-Term Memory (Working Memory) holds limited information, about seven items on average.
• This memory lasts a brief period of time, approximately 2 - 30 seconds.
• A small amount of information goes to short-term (working) memory, where it remains for up to 30 seconds.
• Actively engaging wih information will keep it in short-term memory longer, such as humming a melody.
• Information will leave after a short time without transferring to long-term memory(permanent storage) .

Long Term Memory

• Mentally repeating a melody increases transfer from short to long-term memory.
• Long-term memory stores infinite data for long periods.
• Hundreds of songs and conversations remain potentially retrievable in long-term memory.
• Not everything learned or known can always be recalled.

Moving Memories

• Information in sensory memory will be forgotten without attention.
• With attention, short-term memory gets the information.
• Without attentention in short-term, data will not be encoded and will disappear.
• Attention through repeating or taking notes will encode and move the information to long-term memory.
• Taking notes in class is helpful.

Encoding for Storage

• Data remains in long-term memory in a permanent manner.
• Insufficient notes leads to inadequate encoding for retrieval during exams.
• The secret for encoding/retrieval relies on associating new information with old.

Types of Memory Transmission

• Information turns into sensory memory.
• Selective attention improves information.
• Short-term memory strengthens information again.
• Then the memory encodes for stroage as long-term memory.
• Memories can be lost/forgotten because of a lack of attention or by failing to encode.

Types of Sensory Memory

• Visual sensory memory is known as visual memory.
• Auditory sensory memory is known as auditory memory.
• Visual memory automatically holds visual data for one quarter of a second.
• The image leaves as soon as attention goes elsehwere.
• Eyes blink around 14,000 times a date, which blinds a person temporarily.
• Visual memory helps make the world seem unbroken during blinks.

Auditory Memory

• Auditory memory holds auditory information for 1-2 seconds.
• When absorbed by a book and a friend asks a question, one might ask 'What did you say?'
• The words said will be available as soon as they leave the friends mouth.
• The words stay in auditory memory for around 1-2 seconds and are replayed.
• Auditory memory helps hold enough speech sounds to understand what is said.

Short-Term Memory Explained

• Short-term memory (working memory) stores an average of seven chunks for a time of 2-30 seconds.
• Rehearsal can make the duration longer, if somewhat limited.
• Phone numbers are limited to seven digits due to the limited capabilities of the short-term memory.
• Limited duration and limited capacity are key aspects.

Short Term Memory Management

• Rehearsal repeats details to remember them for a longer time in short-term memory.
• Rehearsal extends time in short term memory.
• Interference happens when new information enters short-term memory and overwrites information.
• Interference happens if interrupted and can erase memories through questioning.
• Continuous rehearsal prevents interference.

Expanding Short Term Memory

• Short Term Memory has limits but these limits can be increased.
• Chunking will make increase short-term memory.
• Condensing separate items into bigger divisions lets one remember divisions instead of each piece.
• For example, Rajan memorized a sequence of 36 numbers on a 6x6 grid in 2 minutes.

Memorization Demonstration

• If using 14 numbers like 11131217351802, divide them into chunks
• 111 can be named "Nelson" due to Admiral Nelson having one of everything
• 312 named the Chicagos' area code
• 1735 can be labelled “29,” which was Benjamin Franklins age
• 1802 can labelled "plus 2", which is the year John Adams moved into the White House +2 years

Short-term memory functions

• Short-term memory is like a computer screen showing only a small amount of data that is erased after a small period and replaced.
• Short-term memory constantly repeats in short term.
• Working memory is another term.
• Attention, rehearsal, and storage are functions.

Long Term Memory Explained

• Retrieval moves data encoded into long-term memory back into short-term memory.
• Long-term memory has infinite storage ability.
• Without impact from disease, data lives there for a lifetime.
• Retrieval depends on information-encoded and the level of interference.

Separate Memory Systems

• If brain is damaged memory can be erased while short-term memory stays unaffected.
• Primacy is remembering data found at the start of a task because of rehearsal/ storage.
• The recent information will be recalled at a tasks end due to it being in short-term memory.

Distinct Memory Processing

• Rehearsal has a function which helps encode short-term data and send it to long-term storage.
• There are two categories of memory as a result of the primary-recency impact as short and long-term.

Declarative Processes

• Declarative memory has all memories connected with situations/events/conversations.
• Declarative memories are available for retrieval or recall.
• There are two types: Semantic (factual) and episodic (event-based) memories.

Declarative Memory

• Semantic is information related to facts/rules.
• Episodic memory is declarative that recalls habits,songs habits from events.

Memory Explained Through Actions

• Procedural/implicit memory includes learning how to read or any emotional reactions one learns.
• Procedural memories aren't available for recall.

Hormones Role

• Emotional times create memories according to Winningham
• These intense events make one have an urge that the memory is remembered fully.
• Hormones play an emotional role through adrenaline or cortisol.

Automatic vs Effortful Encoding

• Automatic encoding moves data from short to long without conscious thought.
• Most personal experiences we feel flow automatically into encoding for memory.
• Effortful encoding takes conscious effort and creation during transfer of data.

Transferring Memories

• Semantic data will likely need a lot of effort to encode due to need for many connections.
• This task will make many relationships which is hard.
• Repetition and connections are used.

Elaborative Rehearsal

• Elaborative rehearsal needs one to relate new data to old familiar data in long-term.
• One can recall by connecting a phone number to ages and ages.
• Using an instance to think will connect a dog biking and recall those three words.

Repressed Memory

• Repressed memory is built around Sigmund's idea of pushing psychoanalytic ideas.
• Repression will push experiences under surface .
• These types are hidden until triggered later .
• Many pediatric providers find those abused try to cope by hiding it.

False Memory

• Studies of false thoughts can turn into accurate personal recall in vivid detail shown by Ceci and loftus.
• Repeated suggestions are inaccurate due to those 'accurate" suggestions.
• Are suggestion effects real?

Cultural Memory

• Knowledge is expressed and taught in a specific way, which will influence memory on how that memory is encoded.
• Memory recall is based on encoding.

Photographic Memory

• Photographic memory makes one have clear recall to review images after a page exam.
• A very small number of children have it.

Flashbulb Memory

• Flashbulb memory saves details from life changing events.
• Details have unlimited time to encode.
• Flashbulb detail doesn't necessarily equal a complete or accurate memory.
• The content excites parts, giving one a vivid, long-term, memory in the brain, even with detail.

Remarks

• Everybody will have a wonderful system that handles unlimited periods, although recall can be off somehow.
• Objects or events are never actually there although impressions are real.
• It depends on experience, influence and emotional effect.