Sana Inoue and Tetsuro Matsuzawa of Kyoto University showed a
computer screen grid of nine numbers to six chimpanzees. The chimps
were previously trained to recognize the ascending nature of the
numbers. They were also shown to nine college students. When
subjects touched one of the numbers, all of the others vanished.
They then had to touch the squares in the order of the numbers that
used to be there.
When the numbers flashed for just four-tenths of a second or less,
one of the chimps beat all of the college students.
Here's the press release from 'Current Biology', a publication
of Cell Press:
Young chimps top adult humans in numerical
memory
Young chimpanzees have an “extraordinary” ability to
remember numerals that is superior to that of human adults,
researchers report in the December 4th issue of Current Biology, a
publication of Cell Press.
“There are still many people,
including many biologists, who believe that humans are superior to
chimpanzees in all cognitive functions,” said Tetsuro
Matsuzawa of Kyoto University. “No one can imagine that
chimpanzees—young chimpanzees at the age of five—have a
better performance in a memory task than humans. Here we show for
the first time that young chimpanzees have an extraordinary working
memory capability for numerical recollection—better than that
of human adults tested in the same apparatus, following the same
procedure.”
Chimpanzee memory has been extensively
studied, the researchers said. The general assumption is that, as
with many other cognitive functions, it is inferior to that of
humans. However, some data have suggested that, in some
circumstances, chimpanzee memory may indeed be superior to human
memory.
In the current study, the researchers
tested three pairs of mother and infant chimpanzees (all of which
had already learned the ascending order of Arabic numerals from 1
to 9) against university students in a memory task of numerals. One
of the mothers, named Ai, was the first chimpanzee who learned to
use Arabic numerals to label sets of real-life objects with the
appropriate number.
In the new test, the chimps or humans were
briefly presented with various numerals from 1 to 9 on a
touch-screen monitor. Those numbers were then replaced with blank
squares, and the test subject had to remember which numeral
appeared in which location and touch the squares in the appropriate
order.
The young chimpanzees could grasp many
numerals at a glance, with no change in performance as the hold
duration—the amount of time that the numbers remained on the
screen—was varied, the researchers found. In general, the
performance of the three young chimpanzees was better than that of
their mothers. Likewise, adult humans were slower than all of the
three young chimpanzees in their response. For human subjects, they
showed that the percentage of correct trials also declined as a
function of the hold duration—the shorter the duration
became, the worse their accuracy was.
Matsuzawa said the chimps’ memory
ability is reminiscent of “eidetic imagery,” a special
ability to retain a detailed and accurate image of a complex scene
or pattern. Such a “photographic memory” is known to be
present in some normal human children, and then the ability
declines with the age, he added.
The researchers said they believe that the
young chimps’ newfound ability to top humans in the numerical
memory task is “just a part of the very flexible intelligence
of young chimpanzees.”
###
The researchers include Sana Inoue and
Tetsuro Matsuzawa, of Kyoto University, Japan.
The patient in the video had his corpus callosum removed in order to stop his seizures due to epilepsy. The procedure prevented the hemispheres from communicating with one another in any way and caused a sort of 'split consciousness'.
To reduce the severity of his seizures, Joe had the bridge between his left and right cerebral hemisphers (the corpus callosum) severed. As a result, his left and right brains no longer communicate through that pathway. Here's what happens as a result:
What are they and how do they work? Of
course everyone reading this already knows :) But it helps to have
a quick reminder to refresh our memory every once in a while.
Having a basic understanding about these special chemicals in our
brain and how they work helps us to understand memory, learning,
behavior, addiction, how drugs work, and emotions.
First we'll quickly go over some of the most important
neurotransmitters.
Acetylcholine: The first neurotransmitter to be
identified. It allows nerve cells to communicate with each other.
Noradrenalin (Norephinephrine): Acts as a stress hormone and
affects the parts of our brain where attention and responding
actions are controlled. It is what is behind the fight-or-flight
response.
Dopamine: Plays an important role in motivation and reward,
sleep, mood, attention, motor activity, cognition and learning.
Serotonin: Believed to help regulate anger, aggression,
mood, sleep, appetite, sexuality and body temperature.
GABA:
One of the most abundant neurotransmitters. It is an inhibitory
neurotransmitter - inhibiting all sorts of activating systems.
Glutamate: Heightens sensitivity to other neurotransmitters.
An excitatory neurotransmitter involved in cognitive functions like
learning and memory.
So... Neurons pass messages along themselves using electrical
impulses, but they use neurotransmitters to pass messages to other
neurons. Neurotransmitters are released from synaptic
vesicles, flow across gaps between neurons called
synapses and then bind with a receptor on the target
neuron.
Discussion on brain plasticity, or
neuroplasticity, has increased during the past several years. What
is it and why should we be concerned about it? Our brains can
migrate activity associated with specific functions to a different
location as a result of neuroplasticity. This is an extremely
important ability to have after a brain injury or even after normal
experience (such as aging). Neuroplasticity allows the brain to
re-wire itself as a response to changes in the environment. It is
also what is behind the learning process and memory formation.
Plasticity consists of laying out preferred pathways within the
brain for circulating important information and is the brain's
ability to adapt.
Biofeedback/neurofeedback may play an important role in the future
if specific operant condition techniques can be designed to
increase voluntary control of neuron responses that will increase
neuroplasticity.
Here is a link to a great audio interview from CBC radio
with Dr. Norman Doidge. He is the author of "The Brain That Changes
Itself: Stories of Personal Triumph from the Frontiers of Brain
Science".
The DANA Foundation has decided to make
their book "The Dana Guide to Brain Health: A Practical Family
Reference from Medical Experts" section on brain disorders freely
available online.
With contributions from over one hundred of the most prominent
scientists and clinicians in the United States, The Dana Guide to
Brain Health is an extensive and wholly accessible manual on the
workings of the human brain. This richly illustrated volume
contains a wealth of facts and advice, on simple yet effective ways
to take care of our brains; the intimate connection between brain
health and body health; brain development from the prenatal period
through adulthood; and how we learn, remember, and imagine.
The brain is far too important to be
excluded any longer from our daily health concerns. The Dana Guide
to Brain Health remedies this oversight with a clearly written,
definitive map to our brains that reveals how we can take care of
them in order to sustain a long and rich life.
The browseable/searchable copy of the book can be found here.
Scientists from 'Wellcome Trust' claim
to have identified for the first time what happens in our brain in
the face of an approaching fear. They measured activity in the
brain using fMRI while a subject played a game similar to Pac-Man
and received an electric-shocks when they were caught by the video
game predator.
They found that activity in the ventromedial prefrontal cortex
(behind the eyebrows) increased when the enemy was in the distance
- this part of the brain is active when one is planning how to
respond to a threat. As the video game enemy approached,
predominant activity shifted to the periaqueductal grey - the part
of the brain responsible for flight or fight and preparing for
reaction to pain.
The title of their study is 'Free Will Takes Flight', as it shows
that we act more on impulse when a threat increases.
New experiments in light stimulation are
helping scientists learn more about neural systems. Optical
excitation using fiber optics can be used to stimulate specific
areas of the brain and is an alternative to electrode stimulation.
Electrode stimulation is unable to target single types of neurons
and instead activates the firing of all neurons in one neural area.
This new technology may allow us to uncover what roles specific
neurons play.
Light stimulation every 200 milliseconds generates electrical
activity in an area of the brain associated with depression.
Here is another article on using focused
beams of light to stimulate neurons from Howard Hughes Medical
Institute.
The illustration, which comes from a painting by
Duke University student Yifan Xu, conceptually illustrates a beam
of light shining into the olfactory bulb activating a mitral cell.
HHMI investigator Michael Ehlers and colleagues report they have
developed mice that express channelrhodopsin-2, a light-gated
cation channel from the green algae Chlamydomonas reinhardtii, in
neurons of the central nervous system. This enables researchers to
trigger neural activity with high spatial and temporal
precision—a powerful tool for those striving to map
functional circuits in the brain.
Researchers have devised a clever way to
activate neurons in a living mouse by shining light on the surface
of the animal's brain. The “light switch” that turns
neurons on is actually a light-sensitive protein that is produced
by algae. When this protein is genetically engineered into the
neurons of living mice, researchers can precisely trigger those
neurons with light, causing them to generate electrical impulses.
A new study (Aug 2007) published in the Archives of
General Psychiatry shows a direct correlation between ADHD and
low dopamine activity in the brain. This could shed light on what
seems to be large numbers of ADHD suffers among ex-methamphetamine
users. Article follows:
NEUROSCIENTISTS investigating a young woman with epilepsy believe
they have stumbled on an explanation why some people feel a ghostly
presence nearby or develop paranoia. The 22-year-old woman was
being assessed for brain surgery for epilepsy but was otherwise
psychologically healthy. Part of the evaluation pinpointed the area
for surgery, using thin electrodes implanted into a region of the
brain. Reporting the case in today's Nature, the weekly British
science journal, the doctors say that when they sent a small
current to the woman's left temporo-parietal junction, she said
she had the impression there was somebody behind her. The person
was a "shadow," young and of indeterminate sex and did not speak,
she said. The doctors slightly increased the current and changed
the woman's position from lying down to seated, and got her to hug
her knees. She then said she felt the creepy presence of man who
was also sitting and who was clasping her unpleasantly in his arms.
The temporo-parietal junction is used for social reasoning - to
assess oneself and distinguish oneself from others. - Sapa-AFP