Between Biological & Digital Memory

David WishartDepts. Biological Sciences & Computing Science

National Institute for NanotechnologyUniversity of Alberta

Outline

• Biological Memory & Biological Senses

• Biological Versus Digital

• How Digital Memory works

• Memory Capacity and Knowledge

• Integrating Biological with Digital

The Human Brain

The world’s fastest and most portable computer

The Human Brain• There are 1010 neurons in our brains

• There are roughly 1015 synapses operating at about 10 impulses/second (Biggest CPUs have 108 transistors)

• Approximately 1016 synapse operations per second (Fastest computer [Blue Gene] perform at 1014 FLOPS)

• Total energy consumption of the brain is about 25 watts (Blue Gene requires 1.5 Megawatts)

http://www.merkle.com/brainLimits.html

Human Memory• Declarative memory - the storage and recall of

information available to the conscious mind, which can therefore be expressed (declared) using language – There are 3 types:– Semantic memory (facts and knowledge)– Episodic memory (memory for specific events and

experiences)– Prospective memory (remembering to do

something in the future)

Persistence of Memory (Biological)

• Immediate memory 1-60 sec

• Short-term memory 10 min-2 weeks

• Long-term memory 2 weeks-20 yrs

• Max. memory (1 person) 100 yrs

• Max. memory (written) 5000 yrs

• Max. memory (humanity) 20,000 yrs

• Max. memory (biology) 1 billion yrs

How Memories Are Formed

Emotional Reinforcement

Mapping Sensory Memories

Decreasing Strength of the Memory

Evolution of Biological Sensors

2 billion 530 million 150 million

750 million 450 million

Mapping The Sensory Experience

Homunculus

Extending Our Senses

1 m 1 x 103 m 1x1018 m 1x1024 m

Free $500 $5000 $500,000,000

Extending Our Memory Capacity

20,000 BP 5000 BP 500 BP 100 BP Today

Powering Memory (Biological vs. Digital)

10 Watts for the Human Brain 12 Watts for a Laptop

Different Types of Biological Memory

Reflex Immunity Hippocampus Genetic

1 sec 10 years 100 years 1,000,000,000 years

Different Types of Digital Memory

RAM Floppy Disk CD/DVD Flash Memory

1 sec 3 years 10 years 100 years?

Digital vs. Biological

Terminator - Main Theme.mp3

How Digital Memory Works

Evolution of Digital Memory

Outline

• Biological Memory & Biological Senses

• Biological Versus Digital

• How Digital Memory works

• Memory Capacity and Knowledge

• Integrating Biological with Digital

Capacity of Human Memory?

• Von Neumann (1950) – 1020 bits or about 1 Exabyte (1 byte = 8 bits)

• Anatomists (1970’s) – 1013-1015 synapses allowing 1016 syn-ops/sec

• Landauer (1986*) – 100 Megabytes– Determined that we retain 2 bits/sec of

visual, verbal, tactile, musical memory– Human lifetime ~ 2.5 billion seconds

Thomas K. Landauer "How Much Do People Remember? Some Estimates of the Quantity of Learned Information in Long-term Memory" Cognitive Science 10, 477-493, 1986

Putting it into Perspective

• 1 Human = 100 Megabytes• Data on the Web = 1x1015 bytes• Library of Congress = 3x1015 bytes• # of Words ever written = 1015 (or about 1016

bytes)• # of Words ever spoken = 1018 (or about 1019

bytes)• Memory of all humans ever lived = 1x1019 bytes• Data on all Digital Media = 3x1019 bytes

http://www.lesk.com/mlesk/ksg97/ksg.html

The Data Explosion• 1 newspaper in 1605• 10,000 newspapers today• 3 scientific journals in 1750• 120,000 scientific journals today• 1 book title published in 1450• 900,000 book titles/year today• 1 page on the Web in 1990• 8,058,044,651 web pages on Google

Global Memory Capacity

• 30 billion CDs sold since 1990 (2x1018 bytes)

• 5 billion DVDs sold since 2000 (2x1019 bytes)

• 900 million computers ever sold (2x1018 bytes)

• 20 million MP3 players sold since 2002 (2x1017 bytes)

Can We Store All Personal (Text) Experience?

• The average person spends 1,578 hours watching TV, 12 hours a year at movies, at 120 words per minute that's 11 million words (~50 Mbytes)

• The average person spends 354 hours a year of reading periodicals and books at 300 words per minute reading speed would be another 32 Mbytes of text

• In seventy years of life you would be exposed to around 6 Gbytes of ASCII text

Can We Store All Personal (Visual) Experience?

• 1 hour of video on a DVD = 2.5 Gbytes

• Average # hours lived = 600,000 hours

• Total number of bytes is approximately 1500 Terabytes (~1.5 x 1015 bytes)

Can We Store All Human Experience & Knowledge?

• Global quantity of films (10,000+ titles/year) ~50 terabytes/year

• Global quantity of written words (900,000 book titles, 10,000 newspapers/year) ~160 terabytes/year

• Global quantity of photographs (~100 billion/year) ~1018 bytes/year

• 2 billion minutes/year of phone/voice transmission ~2 x 1019 bytes/year

http://www.lesk.com/mlesk/ksg97/ksg.html

IntegratingDigital with Biological

The CharmIT is a modular lightweight open-architecture wearable computer that's compact but fully featured, equipped with most everything you'd expect in a modern PC, from Charmed.com (SIGGRAF Fashion Show 2004)

Wearable Computing

Reaching Out

10m 100m 1000m 100km 10,000kmbluetooth

WiFi

WalkieTalkie

Cell phone

Satellite

Shrinking Down

Shrinking Way Down

Single Molecule Field Effect Transistor

Shrinking Way Down

Nanobot Challenge

• Build a bacterium that seeks a light source target, then touches the target and on touching sends out a flashing signal

Protein Memory Chips

h

Low Energy High Energy

N N

SS

Summary

• Biological Memory & Biological Senses

• Biological Versus Digital

• How Digital Memory works

• Memory Capacity and Knowledge

• Integrating Biological with Digital

Art Imitates Life

Engineers Imitate Life

Some Final Thoughts…

• "The best memory is that which forgets nothing, but injuries. Write kindness in marble and write injuries in the dust.“ – Persian Proverb

• "Everyone has a photographic memory. Some don't have film.“ – Anonymous

• "God gave us memory so that we might have roses in December.“ – James Matthew Barrie