This information explosion has got me thinking. When we want a particular piece of information, we have to search for hours. When we do not want something, we are flooded with millions of them. So I decided to show a link between the human brain and the current information explosion, that has led the information overload. This Sanjoy Sanyal, Professor and Course Director of Neuroscience in the Caribbean Part of this PPTX is based on the work of Professor Rudolph Hanka of University of Cambridge. Educational Value: Shows relation between human learning capacity and information load in today's digital era of information plethora Tags: digital storage, human brain, information explosion, information overload, neural connectivity, neurons, sanjoy sanyal, synapse

1. BRAIN EVOLUTION AND
INFORMATION EXPLOSION
Dr Sanjoy Sanyal MBBS, MS, MSc, ADPHA
Professor of Neuroscience

2. Evolution of Mankind and Their Skull
Hominid BCE ~ Skull
Species Capacity
Australo- 4 million 400 cc
pithecus years
africanus
Homo habilis 1.7 million 600 cc
years
Homo 0.7 million 900 cc
ergaster / years
erectus
Homo sapien 30,000 1450 cc
neander- years
thalensis
Homo sapien Present 1500 cc
sapiens

3. Neurons and Neural Connectivity
 Humans have 1011 Neurons in their
Brain (Rudolph Hanka, Cambridge)
 They have been doubling every 3
million years (Dotted graph line)
 Brain capacity is not determined by
number of Neurons alone; Number
of Synapses are more important
 If ALL Neurons were connected to
ALL Neurons, there would be 5 x
1021 Synapses (Given by the
Formula n (n-1) / 2 (where n is the
number of Neurons))  But that is not the case.
 Such rate of synaptic connectivity Humans have limited Neural
would have doubled every 1.5 connectivity, of only 1014
million years (Green graph line) Synapses (Red graph line)

4. STM vs. General Intelligence Factor
 Postulate: General Intelligence Factor (G) is limited
by channel capacity of Short Term Memory (STM)
 Mental Power / Capacity of Short Term Memory
(STM) = Mental speed of information processing X
Duration of information in STM (memory span)
 This is given by the Formula: C(bits) = Ck(bits/sec) ×
D(sec), Where;
 C = Mental power or capacity of STM (in bits)
 Ck = Mental speed of information processing (in
bits / second)
 D = Duration of information in STM (in seconds)

5. Information Explosion
 Since 1400, Information has been
doubling every 3 decades or so
(Proved by Rudolph Hanka of
University of Cambridge)
 By 1500 it had increased 8-fold (23)
 By 1600 it had increased 64-fold (26)
 By 1700 it had increased 512-fold (29)
 By 1800 it had increased 4,096-fold
(212)
 By 1900 it had increased 32,768-fold
(215)
 In this millenium it is expected to
register a 262,144-fold increase (218 )
over 1400

6. Information Overload
 There is no change in
actual skull (and brain)
capacity over last
several thousand years
 Human Brain has only
limited number of
Neurons and Synaptic  Humans are already well past
connections the stage when their Brains can
 Channel capacity of handle all the information
available today.
Human Memory is
 Automation, Digital Storage
limited
and Seamless Access are the
 Information is
only solutions to leverage the
increasing exponentially value of Information Explosion