A stimulus is an event that happens to the norn that it can react to in some manner. The stimulus gene allows the reaction to these stimuli to be defined. This can range from chemicals being injected to cell values in brain lobes being adjusted.
There are a number of stimulus responses that are hard coded within the Creatures program. The stimulus genes that are created override these hard coded responses giving a lot of flexibility in determining how the creature will react to the world.
The gene header is the same for all genes.
| Disappointment |
| Pointer pats me |
| Creature pats me |
| Pointer slaps me |
| Creature slaps me |
| It is approaching |
| It is retreating |
| I bump into wall |
| Object comes into view |
| Unrecognised word |
| Heard user speak |
| Heard creature speak |
| I am quiescent (periodic) |
|
I've activated1 |
| I've activated2 |
| I've deactivated |
| I am approaching (periodic) |
| I have retreated |
| I have got |
| I have dropped |
| I've stated need |
| I am resting (periodic) |
| I am sleeping (periodic) |
| I am traveling (periodic) |
| spare action 1-4 |
| Involuntary action 0-7 |
| <none> |
| I've been patted |
| I've been slapped |
| I've bumped a wall |
| I am near a wall |
| I am in a vehicle |
| User has spoken |
| Creature has spoken |
| Own kind has spoken |
| Audible event |
| Visible event |
| It is approaching |
| It is retreating |
| It is near to me |
| It is active |
| It is an object |
| It is a creature |
| It is my sibling |
| It is my parent |
| It is my child |
| It is opposite sex |
| spare 2-13 |
This turns out to be a gene that is quite difficult to track down what exactly each option does. This is mainly due to the fact that the effect of the options seems to change depending on what stimuli is selected.
The rest of this gene description is from a newsgroup message I posted on alt.games.creatures asking for information on this gene and it outlines some of the results of the experiments I tried. This may make some of the descriptions a little clearer.
I've found that if I have the stimulus set to 'Pointer Pats me' and significance set to some number (say 50), Sensory neurone set to 'I've been patted' and intensity set to 100 when I pat the norn cell number 1 in brain lobe 5 (general sense) increases by 100.
This is as I would expect as cell 1 relates to 'I've been patted'. Cell number 36 in brain lobe 2 (stimulus/source) increases by 50 (the amount of significance). Cell 36 is that relating to the object class of 'Norn'. This results in the Attention lobe being fired and usually the norn ends up looking at itself. From this I'm surmising that the 'Sensory Neuron' and 'Intensity' settings cause the given cell in brain lobe 5 to fire at the set intensity when the chosen stimulus is applied to the norn. This is pretty much obvious from the genetics kit dialog.
What is less obvious is what object class the significance amount is applied to in lobe 2. In the above example it was a norn. In a further test I set the stimulus to 'object comes into view', sensory neuron to none and intensity to zero. The significance was set to 200. Now whenever a new object appeared to the norn (like making the hand visible in the norns line of site) lobe 2 got activated for the class of object the norn is looking at by the value of 200.
I'm guessing that the result of all this means that a significance amount will cause a cell in lobe 2 to fire at the level of the given amount - the cell being fired will depend on the object causing the stimulus (although in the first example the norn didn't causes the stimulus - the hand did). This makes some sense as you can then set the stimulus genes to make an object more interesting to the norn (ie. more likely to capture/hold its attention) by increasing its stim/source value in lobe 2 via significance. I need to do some more research into this - does anyone have any knowledge of how this works?
If I leave 'object comes into view' selected and the other settings as above but this time check the 'modulate using sensory signal' box, now when a new object comes into view it doesn't fire the cell in lobe 2 by a value of 200 all the time. The cell does fire but by different amounts. I'd expect this from the name of the check box but I haven't yet worked out what it is being modulated by - the current value of the object causing the stimulus perhaps? Anyone got any ideas?
And finally (yes there is an end to this message!) I haven't been able to find any clues to what the 'add offset to neu' means. Still digging away at it but if anyone knows I'd love to hear from you :)
I did most of my testing with a norn with all stimulus genes deleted except for the ones I was testing. What I did notice was that even with no stimulus genes certain stimuli had an effect. Things like patting the norn caused the 'I was patted' cell in lobe 5 to be increased by 32. From this I'd guess that there are certain hard coded stimuli that can be overridden by genetic stimuli if desired - perhaps these relate to the STM# macro commands? I'd be interested to hear from anyone who has played around with this gene who may be able to shed some light on the grey areas. I hope some of the above was useful to those who are doing genetic engineering.