How Fruit Fly Brains Are Improving Smart Phone Apps

This research is helping scientists overcome a fundamental machine learning problem.

What do a fruit fly and a search engine have in common? This isn’t some weird joke, but a serious line of inquiry by scientists at the Salk Institute and UC San Diego. Search engine algorithms go through great pains to match items you’ve clicked on or purchased, songs you’ve listened to, or things searched for, to similar ones. As a result, we constantly need ever faster and more efficient search engines, and so computer scientists must work tirelessly to keep up. They have to constantly tackle what they call “a fundamental machine learning problem: approximate similarity (or nearest-neighbors) search.” 


Turns out, fruit fly brains go through a similar matching process, and the way they do it is fast, efficient, and dare I say, elegant. It occurs in the fly’s olfactory circuit and is what could be called a neural algorithm. It operates as a variation of what is known as locality-sensitive hashing (LSH). Hashes are a kind of shorthand used to quicken searches by limiting the amount of information known about each item.

Instead of having a number of different kinds of cats let’s say, bunched together, where it’s hard to pick out a specific breed, you put them all in the cat hash or container. Now you’ve got one bin essentially that holds all the cats. So when the algorithm is asked to search for a Siamese, instead of searching through all information available, which would be timely and cumbersome, it goes directly to the cat hash and pulls out the fussy fur ball.

Nature performs a search differently. The fruit fly’s olfactory circuit works by ascribing neural operating patterns to items which have a similar smell. Though we’ve known how these circuits work for some time, this is among one of the first studies to show a direct correlation between neural circuits and how algorithms process information. It’s also the very first to outline how such a process could be used to speed up and innovate search engines for future computers.

When a fly identifies a new smell, it can quickly tailor its behavior, depending on experiences with a similar odor in the past. The innovation here is that a fruit fly’s brain uses a non-traditional approach, a three computational process, which is more efficient than that used by computers today.

Search engine databank. Modeling a search engine’s algorithm after a fruit fly’s olfactory neural circuit may someday help make a search faster and more efficient. Credit: Getty Images.

In their paper in the journal Science, researchers wrote, “This perception helps illuminate the logic supporting an important sensory function and provides a conceptually new algorithm for solving a fundamental computational problem.” Saket Navlakha was the lead author of the study. He’s an assistant professor in Salk's Integrative Biology Laboratory. His work has mainly focused on algorithms present in nature. These in turn illustrate how organisms process information.

Navlakha told Science Daily, "In the natural world, you're not going to encounter exactly the same odor every time; there's going to be some noise and fluctuation. But if you smell something that you've previously associated with a behavior, you need to be able to identify that similarity and recall that behavior."

Each item a fruit fly encounters creates a “tag” somewhere in its olfactory circuit. This is a group of specific neurons assigned to recognize that particular smell. When the odor is present, the neurons in the tag fire. This tag allows the fly to learn how to respond properly when it encounters a certain odor.

Researchers perused the literature concerning these odor tags. 50 neurons are responsible for the olfactory circuit, and they fire in different combinations, each pattern unique to a particular smell. Rather than taking that information (or odor) and reducing it into a number of different categories, as a computer would, flies actually expand out.

From odor, a fruit fly can tell very quickly whether it should approach something or fly away. Credit: Pixababy.

The fly’s brain takes the 50 neurons in the olfactory circuit and use their connections to include another 2,000. By spreading the data more widely, each smell becomes as distinct as a fingerprint. The fruit fly’s brain from those 2,000 neurons, stores only about 5% of the top activity as a hash or tag. By reducing the dimension, the fly’s brain is better able to notice the subtleties between items.

Navlakha explained it like this,

Say you have a bunch of people clustered by their relationships, and they're bunched into a crowded room. Then take the same people and relationships, but have them spread out on a football field. It will be much easier to see the structure of relationships and draw boundaries between groups in the expanded space relative to the crowded space.

When Navlakha and colleagues took the process a fruit fly’s brain uses and applied it to three standard datasets, which are used to test algorithms for search engines, it boosted speed and efficiency significantly. "Pieces of this approach had been used in the past by computer scientists, but evolution put it together in a very unique way," Navlakha said.

Biomimicry is a new field which notices mechanisms in nature and tries to use them to create better computers and machines. One of its goals is to better understand the human brain and in doing so, improve A.I., allowing it to operate in a more natural and effective manner. This study gets us one step closer to that goal. So when you use a search engine in the future, it may be modeled after a fruit fly’s brain and someday even your own.

To learn more about this study, click here:

Trusting your instincts is lazy: Poker pro Liv Boeree on Big Think Edge

International poker champion Liv Boeree teaches decision-making for Big Think Edge.

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Are you an overbuyer or an underbuyer?

One way to limit clutter is by being mindful of your spending.

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  • Overbuyers are people who love to buy — they stockpile things as a result. These are individuals who are prone to run out of space in trying to store their stuff and they may even lose track of what — and how much of what — they have.
  • One way overbuyers can limit their waste, both money and space wise, is by storing items at the store, and then buy them when they really need them.
  • Underbuyers tend to go to extraordinary lengths to not buy things. They save money and do fewer errands, however, they often make do with shabby personal items. They may also, when they finally decide to go out to buy a product, go without entirely because the item may no longer be available.

Five Hawks Down: watch the tragic migration of six Californian raptors

Tracking project establishes northern Argentina is wintering ground of Swainson's hawks

Image: @TrackingTalons / Ruland Kolen
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  • Watch these six dots move across the map and be moved yourself: this is a story about coming of age, discovery, hardship, death and survival.
  • Each dot is a tag attached to the talon of a Swainson's Hawk. We follow them on their very first migration, from northern California all the way down to Argentina.
  • After one year, only one is still alive.

Discovered: destination Argentina

Image: @TrackingTalons

Young Swainson's hawks were found to migrate to northern Argentina

The Buteo swainsoni is a slim, graceful hawk that nests from the Great Plains all the way to northern California.

It feeds mainly on insects, but will also prey on rodents, snakes and birds when raising their young. These learn to fly about 45 days after hatching but may remain with their parents until fall migration, building up flying skills and fat reserves.

A common sight in summer over the Prairies and the West, Swainson's hawks disappear every autumn. While it was assumed they migrated south, it was long unclear precisely where they went.

A group of researchers that has been studying raptors in northern California for over 40 years has now established exactly where young Swainson's hawks go in winter. The story of their odyssey, summarised in a 30-second clip (scroll down), is both amazing and shocking.

Harnessing the hawks

Image: @TrackingTalons, found here on imgur.

A Swainson's hawk, with tracking device.

The team harnessed six Swainson's hawks in July, as they were six weeks old and just learning to fly. The clip covers 14 months, until next August – so basically, the first year of flight.

Each harness contains a solar-powered tracker and weighs 20 grams, which represents just 3% of the bird's body weight. To minimise the burden, only females were harnessed: as with most raptors, Swainson's hawk females generally are bigger than males.

The first shock occurs just one month (or about 2.4 seconds) from the start of the clip: the first dot disappears. The first casualty. A fledgling no more than two months old, who never made it further than 20 miles from its nest.

By that time, the remaining five are well on their way, clustering around the U.S.-Mexico border in Texas. Swainson's hawks usually travel at around 40 mph (65 km/h) but can almost double that speed when they're stooping (i.e. dive down, especially when attacking prey).

'Migration unrest'

There's a strong genetic component to migration. As usual, the Germans have nice single word to summarise this complex concept: Zugunruhe ('tsook-n-roowa'), literally: 'migration unrest' (1). It denotes the seasonal urge of migratory animals – especially birds – to get on their way. Zugunruhe exhibits especially as restless behaviour around nightfall. The number of nights on which it occurs is apparently higher if the distance to be travelled is longer.

The birds may have the urge to go south, but genetics doesn't tell them the exact route. They have to find that out by trial and error. Hence the circling about by the specimens in this clip: they're getting a sense of where to find food and which direction to go. Their migratory paths will be refined by experience – if they're lucky enough to survive that long.

Each bird flies solo: their paths often strongly diverge, and if they seem to meet up occasionally, that's just an illusion: even when the dots are close together, they can still be dozens if not hundreds of miles apart.

Panama snack stop

Image: @TrackingTalons

The Central American isthmus is a major bird migration corridor

They generally follow the same route as it is the path of least resistance: follow mountain ranges, stay over land. Like most raptors, Swainson's hawks migration paths are land-based: not just so they can roost at night, but mainly to benefit from the thermals and updrafts to keep them aloft. That reduces the need to flap wings, and thus their energy spend – even though the trip will take longer that way.

As this clip demonstrates, the land-migration imperative means the Central American isthmus is a hotspot for bird migration. Indeed, Panama and Costa Rica are favourite destinations for bird watchers, when the season's right. A bit to the north, Veracruz in Mexico is another bird migration hotspot.

It's thought most hawks don't eat at all on migration. This clip shows an exception to that rule: on the way back, one bird takes an extended stopover of a couple of weeks in Panama, probably spending its time there foraging for food.

So, when they finally arrive in northern Argentina, after 6 to 8 weeks' migration, the hawks are pretty famished. Until a few decades ago, they fed on locusts. For their own reasons, local farmers have been getting rid of those. The hawks now concentrate on grasshoppers, and basically anything else that's edible.

For first-time visitors, finding what they need is not easy. Three of the five dots go dark. These birds probably died from starvation. But two birds thrive: they roam the region until winter rears its head in South America, and it's time to head back north again, where summer is getting under way.

Both dots make it back across the border, but unfortunately, right at the end of the clip, one of the surviving two birds expires.

Harsh, but not unusual

Image: @TrackingTalons, found here on imgur.

This old lady is 27 years old, but still nesting.

While a one-in-six survival rate may seem alarmingly harsh, it's not that unusual. First-year mortality for Swainson's Hawks is between 50% and 80%. Disease, starvation, predators and power lines – to name just a few common causes of death - take out a big number.

Only 10% to 15% of the young 'uns make it past their third or fourth year into adulthood, but from then on, annual survival rates are much better: around 90%. Adult Swainson's Hawks can expect to live into their low teens. There's one documented example of a female Swainson's Hawk in the wild who was at least 27 years old (and still nesting!)

The Californian population of Swainson's Hawks plummeted by about 90% at the end of last century but is now again increasing well. The monitoring project that produced this clip has been going for about four decades but is seeing its funding dry up. Check them out and consider supporting them (see details below).

Image: Yale School of Forestry and Environmental Studies

Migration trajectory of B95, the 'Moonbird'.

Not all migrating birds shun the ocean. Here's an incredible map of an incredible migration path that's even longer than that of the Swainson's hawks.

In February 1995, a red knot (Calidris canutus rufa) in Tierra del Fuego (southern Argentina) was banded with the tag B95. That particular bird, likely born in 1993, was recaptured at least three times and resighted as recently as May 2014, in the Canadian Arctic.

B95 is more commonly known as 'Moonbird', because the length of its annual migration (app. 20,000 miles; 32,000 km) combined with its extreme longevity (if still alive, it's 25-26 years old now) means its total lifetime flight exceeds the distance from the Earth to the Moon.

As many other shorebirds do, the red knot takes the Atlantic Flyway hugging the coastline and crossing to South America via the ocean.

B95 has become the poster bird of conservationists in both North and South America. A book titled Moonbird: A Year on the Wind with the Great Survivor B95 (2012) received numerous awards, B95 has a statue in Mispillion Harbor on Delaware Bay and the City of Rio Grande on Tierra del Fuego has proclaimed B95 its natural ambassador.

Perhaps one day the nameless Swainson's Hawks in this clip, fallen in service of their ancestral instincts – against the odds of human increasing interference – will receive a similar honour.

Migration clip found here at the DataIsBeautiful subreddit. Read through the comments to learn a lot more about Swainson's Hawks, and raptors in general.

Check out the California raptor tracking programme 'Tracking Talons' on Twitter at @TrackingTalons, on their Facebook page, and on their website.

Strange Maps #965

Got a strange map? Let me know at strangemaps@gmail.com.

(1) 'Zug' is a wonderfully polyvalent German word. It can mean: a train, a chess move, a characteristic, a stroke, a draft (of a plan), a gulp (of air), a drag (from a cigarette), a swig (from a bottle), and more.

A new study has investigated who watched the ISIS beheading videos, why, and what effect it had on them

This is the first study to explore not only what percentage of people in the general population choose to watch videos of graphic real-life violence, but also why.

Mind & Brain

In the summer of 2014, two videos were released that shocked the world. They showed the beheadings, by ISIS, of two American journalists – first, James Foley and then Steven Sotloff. Though the videos were widely discussed on TV, print and online news, most outlets did not show the full footage. However, it was not difficult to find links to the videos online.

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