age, the long-term effects on cognitive
function are often minimal, due to the
amazing neuroplasticity of the brain. On
the other hand, if a computer is physically damaged, it cannot repair itself.
Since there would not have been any
half-brained ‘hominids’ (ape-men), how
could ‘evolution’ create the ability of
the brain to reconfigure itself when half
The consciousness conundrum
No satisfactory explanation exists for
consciousness. In fact, there is not even
a satisfactory definition of it. However,
it certainly involves the quality of awareness. When talking about consciousness, issues such as the mind–body
problem often come up, concerning the
connection between mental processes
involving the mind (e.g., consciousness) and physical processes involving
the brain. The mind can be thought of
Fig 2. Exposure to bright light in the evening has been shown to suppress melatonin
production in preschool-age children, whose circadian system seems very sensitive
to light, suggesting that evening light exposure in early childhood could increase
the risk of developing evening sleep disturbances.1
1. Akacem, L. D., et al., Physiol Rep, 6( 5), 2018, e13617 | 10.14814/phy2.13617.
seizure rather than experiencing special
mental powers. The brain uses about
20% of the body’s energy, most of it by
nerve cells generating action potentials
to communicate with other cells. Hence,
using only the resources required to do a
task is an energy-efficient design feature.
Different regions of the brain
perform different tasks. For example,
if you are having problems with your
Internet connection, you call your
Internet service provider, not the post
office. Similarly, if the motor areas of
your cortex are planning a movement
of your foot, the command to move is
sent to the muscles via motor neurons
located in the spinal cord, not to a sound
processing area in the temporal lobe.
Brain activation is very dynamic; the
areas processing information changing
constantly, as the situation dictates.
Often the brain is compared to a
computer, and while they both contain
complex circuits that carry current, the
analogy only goes so far. Consider long-
term memory. Computer memory uses
transistors to store information, with
each transistor capable of two states (on
or off, equivalent to one or zero respec-
tively), and so with billions of these tiny
electronic devices you can store a lot of
information. But in the brain, it does
not appear to be in any specific region,
but is rather spread across the brain.
The hippocampus appears critical
for the consolidation of long-term
memories, with the strengthening of
synaptic connections between nerve
cells thought to be how long-term
memory is stored.
However, how exactly this allows
information to be stored or encoded,
and later retrieved, is a mystery.
A biological ‘computer’?
Both computers and brains will
malfunction if physically damaged.
However, the brain, depending on
the nature of the damage, often has
enough built-in redundancy and
neuroplasticity (the ability to reorganize its connections) that other parts
of the brain can take over the role of
the damaged regions. As an extreme
example, consider the removal of a
cerebral hemisphere (essentially half
the brain) as happens in the treatment
of some extreme seizure disorders (an
operation pioneered by the creationist
neurosurgeon Dr Ben Carson1). Where
this happens at a relatively young
Fig 3. The central and peripheral