Cockroach’s brain fires out walking commands

Washington, May 7 (ANI): Researchers have, for the first time, found that cockroach’s brain fires out commands to walk and run—a feat that has paved way for better rescue robots.

A team led by Roy Ritzmann, Case Western Reserve University biology professor, has shown a direct link between neurons at the center of an insect brain and changes in behaviour.

They recorded neural activity in the central complex of walking cockroaches and found that in the same area of the brain where visual, chemical and tactile information from the world outside is processed, the firing of neurons is correlated to the insect”s stepping rate.

This means that cockroaches walk or run when their brains decide to do so.

“Robots were sent into the World Trade Center after 911. By the time the driver would see an obstacle, they were stuck,” said Ritzmann.

“We see in these animals an ability to adapt to difficult and changing terrain and conditions. What we”d like to see is a robotic brain that can make these kinds of decisions,” he continued.

He believes that the research could help lead to better robots to search collapsed mines and buildings, to pilot drones, and for space exploration, where signals from Earth to a far off planet takes minutes, hours or longer.

Thus, to make a robot that can turn, back up, climb over or burrow under and obstacle without the guidance of a far off rescue worker using computer controls, the best thing would be to mimic an insect”s comparatively simple brain.

However, to get these first recordings of neural activity, Research Assistant Allan Pollack spent more than a year perfecting techniques to perform brain surgery in an area the size of the head of a pin.

After delicately cutting through the brain sheath and exposing the central complex, he inserted a hair-thin braid of four wires that can monitor activity of groups of neurons or stimulate the groups with electricity.

With the braid implanted, cockroaches were tethered over the simplest version of a treadmill—a greased glass plate.

The researchers waited, sometimes for three hours or more, for a cockroach to begin walking, and to change speeds, all without prodding.

“We wanted to study the cockroach when it wants to move,” said Ritzmann.

He found that when he graphed the sums of the insects” step rates and sums of the neural firing, they produce a similar pattern.

The steps come about 450 milliseconds after the neural firing.

“This is a breakthrough on a number of different levels. It was a real accomplishment to record the neural activity of walking. The interesting finding is the cockroach can control speed with the brain,” said Dr. Sasha Zill, a professor of anatomy and pathology at the Joan C. Edwards School of Medicine at Marshal University.

Zill explained research shows animals from humans to – now, cockroaches – walk by sending a signal from the brain down to a part of the spinal cord or the equivalent, which generates a pattern of signals that direct the orderly contraction of muscles needed for each step.

The findings are published online in Current Biology. (ANI)

Brain scans can tell ‘honest’ person from ‘dishonest’ one even when both tell the truth

Washington, July 14 (ANI): Researching into the cognitive process involved with honesty, Harvard University psychologists have come to the conclusion that truthfulness depends more on absence of temptation than active resistance to temptation.

Assistant Professor Joshua Greene and graduate student Joe Paxton, the duo that led the study, have revealed that they used neuroimaging to look at the brain activity of people given the chance to gain money dishonestly by lying, and found that honest people showed no additional neural activity when telling the truth.

The researchers say that that observation implied that extra cognitive processes were not necessary to choose honesty.

However, the researchers also found that individuals who behaved dishonestly, even when telling the truth, showed additional activity in brain regions that involve control and attention.

“Being honest is not so much a matter of exercising willpower as it is being disposed to behave honestly in a more effortless kind of way. This may not be true for all situations, but it seems to be true for at least this situation,” says Greene.

The researchers say that they carried out the study to test two theories about the nature of honesty – the “Will” theory, in which honesty results from the active resistance of temptation, and the “Grace” theory in which honesty is a product of lack of temptation.

Writing about their findings in the journal Proceedings of the National Academy of Sciences, they have suggested that the “Grace” theory is true, because the honest participants did not show any additional neural activity when telling the truth.

To prompt participants to lie, the researchers created a cover story about the focus of their study. The research was presented as a study of paranormal ability to predict the future.

The researchers asked those participating in the study to predict the outcomes of a series of coin tosses.

The subjects were told that the research team believed predicting the future was more likely when given a monetary incentive, and when the prediction was not shared in advance of the outcome. That gave the participants the opportunity to lie and say that they had correctly predicted the coin toss to win the money.

The subjects’ honesty was assessed based on whether their number of correct responses was statistically feasible.

According to the researchers, the participants who reported improbably high levels of accuracy were classified as dishonest, and those reporting statistically feasible levels of accuracy were classified as honest.

With the aid of fMRI technique, Greene found that the honest individuals displayed little to no additional brain activity when reporting their prediction of the coin toss. However, the dishonest participants’ brains were most active in control-related brain regions when they chose not to lie.

Greene notes that there was an important distinction between the brain activity when the honest participants told the truth, and when the dishonest participants told the truth.

“When the honest people leave money on the table, you don’t see anything special or extra going on in their brains at all. Whereas, when the dishonest people leave money on the table, that’s when you saw the most robust control network activation,” says the researcher.

The researchers hope that their findings may pave the way for a technique to detect lies by looking at someone’s brain activity, but they also concede that a lot more work must be done before this becomes possible. (ANI)

Scientists uncover origin of consciousness in the brain

Washington, Mar 17 (ANI): Scientists have uncovered where exactly lies the origin of consciousness in the brain.

While some neuroscientists have argued that consciousness may arise from a single “seat” in the brain, the new study has suggested that four specific, separate processes combine as a “signature” of conscious activity.

For the study, researchers analysed the neural activity of people who were presented with two different types of stimuli – one that could be perceived consciously, and the other that could not.

By using the above information, Dr. Gaillard of INSERM and colleagues showed that the four processes occurred only in the former, conscious perception task.

The new work addresses the neural correlates of consciousness at an unprecedented resolution, using intra-cerebral electrophysiological recordings of neural activity.

The researchers conducted all the challenging experiments on patients with epilepsy, who were already undergoing medical procedures requiring implantation of recording electrodes.

The authors presented them with visually masked and unmasked printed words, and then measured the changes in their brain activity and the level of awareness of seeing the words.

The method offers a unique opportunity to measure neural correlates of conscious access with optimal spatial and temporal resolutions.

When comparing neural activity elicited by masked and unmasked words, the researchers were able to isolate four converging and complementary electrophysiological markers characterizing conscious access 300 ms after word perception.

All the measures may provide distinct glimpses into the same distributed state of long-distance reverberation.

Thus, the researchers speculated that it is the convergence of these measures in a late time window (after 300 ms), rather than the mere presence of any single one of them, which best characterizes conscious trials.

“The present work suggests that, rather than hoping for a putative unique marker – the neural correlate of consciousness – a more mature view of conscious processing should consider that it relates to a brain-scale distributed pattern of coherent brain activation,” explained neuroscientist Lionel Naccache, one of the authors of the paper.

Te study has been published in the latest issue of PLoS Biology. (ANI)

Unexpected outcomes key to human learning

Washington, March 14 (ANI): Psychologists and neuroscientists at the University of Pennsylvania say that unexpected outcomes play a significant role in human learning.

Describing their study in the journal Science, the researchers revealed that they used a computer-based card game and microelectrodes to observe neuronal activity of the brain.

They said that their study suggested that neurons in the human substantia nigra (SN) play a central role in reward-based learning, modulating learning based on the discrepancy between the expected and the realized outcome.

“This is the first study to directly record neural activity underlying this learning process in humans, confirming the hypothesized role of the basal ganglia, which includes the SN, in models of reinforcement including learning, addiction and other disorders involving reward-seeking behavior,” said lead author Kareem Zaghloul, postdoctoral fellow in neurosurgery at Penn’s School off Medicine.

“By responding to unexpected financial rewards, these cells encode information that seems to help participants maximize reward in the probabilistic learning task,” the researcher added.

Previous studies on animal models suggested that learning occurs when dopaminergic neurons, which drive a larger basal ganglia circuit, are activated in response to unexpected rewards and depressed after the unexpected omission of reward.

The researchers explain this by giving the example that a lucky win is more likely to be retained than a probable loss.

“Similar to an economic theory, where efficient markets respond to unexpected events and expected events have no effect, we found that the dopaminergic system of the human brain seems to be wired in a similar rational manner — tuned to learn whenever anything unexpected happens but not when things are predictable,” said Michael J. Kahana, senior author and professor of psychology at Penn’s School of Arts and Sciences.

Working in collaboration with Associate Professor Gordon Baltuch, Zaghloul and Kahana used microelectrode recordings obtained during deep brain stimulation surgery of Parkinson’s patients to study neuronal activity in the SN, the midbrain structure that plays an important role in movement, as well as reward and addiction.

The researchers said that the patients showed impaired learning from both positive and negative feedback in cognitive tasks due to the degenerative nature of their disease, and the decreased number of dopaminergic neurons.

They analysed the recordings to determine whether responses were affected by reward expectation, and asked the participants to choose between red and blue decks of cards presented on a computer screen, one of which carried a higher probability of yielding a financial reward than the other.

If the draw of a card yielded a reward, a stack of gold coins was displayed along with an audible ring of a cash register and a counter showing accumulated virtual earnings. But where the draw did not yield a reward, or no choice was made, the screen turned blank and participants heard a buzz.

“This new way to measure dopaminergic neuron activity has helped us gain a greater understanding of fundamental cognitive activity,” said Baltuch, director of the Penn Medicine Center for Functional and Restorative Neurosurgery. (ANI)