Music, more than any art, is a beautiful mix of science and emotion: it follows a set of patterns almost mathematically to extract feelings from its audience.
Machines that make music focus on these patterns, yet give little consideration to the emotional response of their audience.
Now scientists have created a new machine-learning device that detects the emotional state of its listeners to produce new songs that elicit new feelings.
Professor Masayuki Numao of Japan's Osaka University and colleagues wanted to enhance the interactive experience by feeding to their machine the user's emotional state.
Users listened to music while wearing wireless headphones that contained brain wave sensors.
These sensors detected EEG readings, which the robot used to make music.
"We preprogrammed the robot with songs, but added the brain waves of the listener to make new music," Numao said.
The team found that users were more engaged with the music when the system could detect their brain patterns - a human-machine breakthrough that could lead to technology designed to motivate us, or simply cheer us up.
How smelly footprints lead bumblebees to food
Bumblebees have the ability to use "smelly footprints" to make the distinction between their own scent, the scent of a relative and the scent of a stranger.
And by using this ability, bees can improve their success at finding good sources of food and avoid flowers that have already been visited and mined of nutrients by recognising who has been there previously.
"Bumblebees secrete a substance whenever they touch their feet to a surface, much like us leaving fingerprints on whatever we touch," explained the University of Bristol's Richard Pearce, who made the discovery in a new study.
"Marks of this invisible substance can be detected by themselves and other bumblebees, and are referred to as scent-marks.
"We performed three separate experiments with bumblebees, where they were repeatedly exposed to rewarding and unrewarding flowers simultaneously that had footprints from different bees attached to them."
Each flower type either carried scent-marks from bumblebees of differing relatedness - either their own marks, sisters from their nest, or strangers from another nest - or were unmarked.
They discovered that bees were able to distinguish between these four different flower types, showing that not only can bees tell the marks of their own nest mates from strangers, but also that they can discriminate between the smell of their own footprints and those of their nest mate sisters.
Did eyes, not legs, point the way to our evolution?
A provocative new study suggests it was the power of the eyes and not the limbs that first led our ancient aquatic ancestors to make the momentous leap from water to land.
Crocodile-like animals first saw easy meals on land and then evolved limbs that enabled them to get there, a team of researchers have argued, in a paper that could re-write our earliest beginnings as a terrestrial species.
The scientists studied the fossil record and discovered that eyes nearly tripled in size before - not after - the water-to-land transition.
The tripling coincided with a shift in location of the eyes from the side of the head to the top.
The expanded visual range of seeing through air may have eventually led to larger brains in early terrestrial vertebrates and the ability to plan and not merely react, as fish do.
"Why did we come up onto land 385 million years ago? We are the first to think that vision might have something to do with it," said study co-author Professor Malcolm MacIver, a neuroscientist and engineer at Northwestern University in the United States.
The team found a huge increase in visual capability in vertebrates just before the transition from water to land.
"Our hypothesis is that maybe it was seeing an unexploited cornucopia of food on land - millipedes, centipedes, spiders and more - that drove evolution to come up with limbs from fins."
The enlargement of eyes is significant: by just popping those eyes above the water line, the fish could see 70 times farther in air than in water.
With the tripling of eye size, the animal's visually monitored space increased a millionfold.
This happened millions of years before fully terrestrial animals existed.
"Bigger eyes are almost worthless in water because vision is largely limited to what's directly in front of the animal," said co-author Lars Schmitz, an assistant professor of biology at US-based WM Keck Science Department.
"But larger eye size is very valuable when viewing through air. In evolution, it often comes down to a trade-off.
"Is it worth the metabolic toll to enlarge your eyes? What's the point? Here we think the point was to be able to search out prey on land."