Embryonic Learning


Embryonic learning can be important (apparently) for species that are on their own once they hatch from the egg. Hatchlings of many species get help with protection, feeding and other life lessons from one or both parents, but this is not always the case.

Newly hatched turtles have to make a dash for the sea and learn on the fly. Cuttlefish hatchlings are already in the sea, but they too are on their own. Romagny et al decided to document the perception and learning of cuttlefish embryos in the latter stages of development (1,2). They have lots of stages, but stages 23, 25 and 30 were chosen for them to sit their tests.

Once they get big enough to flex their mantles, they are showing their ability to respond. They had to be taken out of their protected egg cases for their test program. They were exposed to the fishy smell of sea bass. That startled them and they flexed in consternation as sea bass like to lunch on young, succulent cuttlefish. They also weren’t very keen on being poked and prodded with a needle, blunt, of course, but nevertheless they flexed away.

Later on, they were exposed to light when their visuals were operational, and that too startled them into flexing. At stage 30, light was becoming a little boring and they would only bother flexing for a short while before quitting.

The team wondered if they were just getting tired from overwork so they decided on the willing horse solution – they spurred them on with a prod from their needle. That got them working again. They weren’t tired. They had learned that they didn’t need to respond to the light as nothing else happened. The spur, though, reminded them that they were supposed to be performing for the team of researchers and they went back to work with a will.

So it seems that it never to early to learn which side of your bread is buttered and to mind your p’s and q’s.

  1. http://jeb.biologists.org/content/215/23/4125.abstract
  2. http://jeb.biologists.org/content/215/23/i.2.full

Post-Election Blues


Anti-Phase Game Strategy


An anti-phase game strategy is often required to win in two-person sports. When we first learn any two-person sport we are usually uncoordinated at first. In a ‘sport’ like ballroom dancing we very quickly learn to get our movements in anti-phase with the other person. It matters not which role who is playing predator (moving forward) or prey (moving backwards). Alternating that phase relationship may result in severe digital consequences.

Experts will intuitively move to be coordinate phase, not just in ballroom dancing, but also in games such as tennis when long rallies develop. Not counting shot misplacements, such rallies are usually won by the player who moves to change the phase condition by moving in a different direction to place the ball in a position unexpected by the opposing player.

Kijima et al set out to study the way the dynamics and phase relationships develop in a two-person game and they present their information in yesterday’s PLoS ONE (1). They chose their university soccer team to learn a new game. (The goalie was left behind to tend his net.)

The game they had to play was called Play-Tag. It is played in a 5m square ring. (Why a square is called a ring is a subject for another day.) Each player has a chunk of nylon fabric Velcroed to each hip. The players have to rip off one of the tags of their opponent to win.  The game can be played to exhaustion. The experimental program consisted of 10 trials for each pair.

At first the players were uncoordinated as they played predator and prey and tried to work out the best strategy – should they minimize the risk of losing a tag or maximize their chance of gaining a tag?

These were all smart, able sportsmen who are used to anticipating teammates and opponents movements, but it took most of the trials before a general strategy evolved. The movement of the pairs ended up in an anti-phase coordination as the strategy to minimize their risk of loss took precedence. The result was that the anti-phase game strategy moved towards deadlock and long games.

Predator-prey alternation occurred with the players choosing a strategy in with neither have anything to gain by only changing his own strategy ­ if he does the risk is too great, hence the deadlock until a mistake through something like fatigue occurs.

These sorts of insights into game theories have applications to all sorts of other activities such as business negotiations. Even election politics when deadlock comes to the surface.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0047911

Getting Older


Getting older is an experience which is mixed for most of us. Experience grows as faculties slip away. Of course, most of us will agree that things don’t taste like they used to. Vegetables and fruit from the supermarkets have been extensively bred and, in some cases, genetically modified to be better shelf products at the cost of flavor.

We can tell our grandchildren about how things tasted when we were their age and they listen politely, look at each other and roll their eyes. But Campa et al have been putting this to the test in that they have published their study of how our judgment of bitterness changes with age (1).

They started from the knowledge that 25% of the variation in human lifespan is at the mercy of our genetic make up. Taste sensations are favorite metrics among psychologists and ‘bitter’ is one of the five classifications used. Geneticists like to find alleles that correspond to almost anything that we do, suffer from or enjoy, and they have ‘bitterness’ nicely tagged.

Current wisdom is that taste and hence the genes sequences that play their part in taste functioning also play a part in things like appetite, but more importantly in our endocrine systems secretions so that the function of our livers, pancreases etc. are influenced by these sequences in our DNA.

As all of this goes together we see that changes in our tastes may parallel our body aging in a more important manner than just our complaints about flavors not being what they used to be. This is what the study of Campa et al went into (1). They chose a group of 941 individuals ranging from 20–106 years old and checked out their genetic make up. They showed that the frequency of part of the gene associated with bitter taste sensation increased with age from 35% to 55% as the age range went from middle age to centenarians.

So it seems that getting older is a bitter pill to take.
  1.  http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0045232