Slashdot is powered by your submissions, so send in your scoop


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Neuroscientists Have Isolated The Part Of The Brain That Controls Free Will ( 285

An anonymous reader quotes a report from ExtremeTech: Free will might have been the province of philosophers until now, but we've cracked the problem with an fMRI. Neuroscientists from Johns Hopkins report in the journal Attention, Perception, & Psychophysics that they were able to see both what happens in a human brain the moment a free choice is made, and what happens during the lead-up to that decision -- how activity in the brain changes during the deliberation over whether to act. The team devised a novel way to track a participant's focus without using cues or commands, avoiding a Schrodinger's-like dilemma of altering the process of choice by calling attention to it. Participants took positions in MRI scanners, and then were left alone to watch a split screen as rapid streams of colorful numbers and letters scrolled past on both sides. They were asked just to pay attention to one side for a while, then to the other side. When to switch sides, and for how long to look, was entirely up to them. Over the duration of the experiment, the participants glanced back and forth, switching sides dozens of times. In terms of connectivity in the brain, the actual process of switching attention from one side to the other was tightly linked with activity in the parietal lobe, which is sort of the top back quadrant of the brain. Activity during the period of deliberation before a choice took place in the frontal cortex, which engages in reasoning and plans movement. Deliberation also lit up the basal ganglia, important parts of the deep brain that handle motor control, including the initiation of motion. Participants' frontal-lobe activity began earlier than it would have if participants had been cued to shift attention, which demonstrates that the brain was planning a voluntary action rather than merely following an order. A report from Fast Company details how technology is making doctors feel like glorified data-entry clerks.

Comment Prime (Score 1) 264

I remember K5 for being the original host of localroger and his "Metamorphosis of Prime Intellect", as well as a host of other original stories.

Tis a sad day indeed.

Comment Re:Does the User Control the Keys? (Score 4, Informative) 76

The user's device generates the private key, but only under the control of WhatsApp's closed-source app.

The key exchange is done through WhatsApp's server, much like message exchange. There is no revokation, though I imagine a user who loses his private key could generate and register a new one. There are no certificates except for the connection to the server.

An attacker would have to take control of WhatsApp's server, but once that is done, they could run classic MiTM attacks on all WhatsApp users.


Mathematicians Discover Prime Conspiracy ( 227

An anonymous reader writes with an intriguing story at Quanta Magazine, which begins: Two mathematicians have uncovered a simple, previously unnoticed property of prime numbers — those numbers that are divisible only by 1 and themselves. Prime numbers, it seems, have decided preferences about the final digits of the primes that immediately follow them. Among the first billion prime numbers, for instance, a prime ending in 9 is almost 65 percent more likely to be followed by a prime ending in 1 than another prime ending in 9. In a paper posted online today, Kannan Soundararajan and Robert Lemke Oliver of Stanford University present both numerical and theoretical evidence that prime numbers repel other would-be primes that end in the same digit, and have varied predilections for being followed by primes ending in the other possible final digits. "We've been studying primes for a long time, and no one spotted this before," said Andrew Granville, a number theorist at the University of Montreal and University College London. "It's crazy."

Slashdot Top Deals

According to all the latest reports, there was no truth in any of the earlier reports.