The biological GPS

Feb 1, 2008

We use basic stra­te­gies to guide us in space… and we do the same when navigating websites.

When it comes to navi­ga­tion per­for­mance, there are many the­o­ries sta­ting what is right and what is wrong. But before we make any deci­si­ons regar­ding navi­ga­tion per­for­mance in digi­tal inter­fa­ces, it is impor­tant to unders­tand how our brain works when the issue at hand is spa­tial localization.

We have a com­plex cog­ni­tive sys­tem which employs 3 basic stra­te­gies to guide us in space

Human beings pos­sess the abi­lity to situ­ate them­sel­ves in space. It works like a bio­lo­gi­cal posi­ti­o­ning device – a GPS (Glo­bal Posi­ti­o­ning System) – except it fea­tu­res a capi­tal advan­tage: our abi­lity does not stop wor­king in case part of the direc­tion sys­tem fails because of the seve­ral tasks it performs.

We pos­sess a com­plex cog­ni­tive sys­tem which employs three basic stra­te­gies to guide us in space: ori­en­ta­tion, tra­jec­tory inte­gra­tion and course follow-up. They may be used at the same time or not.

Ori­en­ta­tion

“Look over there. Do you see that gray buil­ding with blue win­dows? Go that way; the Post Office is on the ground floor”. Accor­ding to neu­ro­lo­gists, “ori­en­ta­tion” is the stra­tegy peo­ple use to guide them­sel­ves via an easily noti­ce­a­ble point of reference.

Tra­jec­tory Integration

“Do you remem­ber how you got here? Then go back to the bakery and turn right. Walk two blocks to the Post Office”. In the stra­tegy cal­led “tra­jec­tory inte­gra­tion”, the brain recre­a­tes indi­vi­dual stret­ches of the way in a cumu­la­tive pro­gress report which takes into con­si­de­ra­tion the recol­lec­tion of our own movements.

In tra­jec­tory inte­gra­tion, the cog­ni­tive memory is the one uti­li­zed the least. It deals only with some gene­ral ins­truc­ti­ons and with the so-called direc­tion vec­tor. Tra­jec­tory inte­gra­tion works because it is based pri­ma­rily on the kno­wledge of the movement’s gene­ral direction.

Course Follow-up

“Go ahead on Bour­bon Street; turn left on Tou­louse, then right on Char­tres and walk up to the mid­dle of the block”. This stra­tegy, cal­led “course follow-up”, employs refe­ren­ces such as names of stre­ets and buil­dings, besi­des ins­truc­ti­ons on how to get to in-between points.

It is much more accu­rate than ori­en­ta­tion or tra­jec­tory inte­gra­tion, but in course follow-up, any detail you for­get might give you pro­blems in get­ting to your des­ti­na­tion. All the points of refe­rence and midway direc­ti­ons must be remem­be­red. It is the most tho­rough sys­tem and, the­re­fore, the most reli­a­ble, but it may fail due to ordi­nary memory lap­ses. Course follow-up is usu­ally a chal­lenge to the brain.

As you move along a graphic inter­face, your the brain gathers infor­ma­tion in order to deter­mine the route taken.

Our cog­ni­tive system’s three basic stra­te­gies above are also put to use in vir­tual envi­ron­ments. As you move along (navi­gate) a web­site or graphic inter­face, the brain gathers infor­ma­tion on such envi­ron­ment – colors, sha­pes, sounds, ligh­ting, move­ments, sen­sa­ti­ons of time going by, etc. – in order to deter­mine the route taken.

The part of our brain con­trol­ling direc­tion is cal­led by neu­ro­bi­o­lo­gists “cog­ni­tive map”. That map is essen­ti­ally metapho­ri­cal, and looks more like a hie­rar­chi­cal frame of con­nec­ti­ons, in which posi­ti­ons and dis­tan­ces are rela­tive, than like an actual map. That is so because we tend to memo­rize only what is necessary.

The cog­ni­tive maps we use are simi­lar to a graph, a set of dots and con­nec­ti­ons – much like a subway map. The dots repre­sent the seve­ral refe­ren­ces, and the con­nec­ti­ons between them cor­res­pond to the acti­ons that take us from one point to the next. Like a subway map, accu­rate dis­tan­ces and pre­cise angles are unne­ces­sary. Our men­tal map pro­vi­des only the appro­xi­mate pro­por­ti­ons between indi­vi­dual stret­ches and direc­ti­ons, and dis­plays the dots accor­ding to the con­nec­tion between them.

For a website’s good navi­ga­tion per­for­mance, it is essen­tial to pro­vide seve­ral forms of loca­li­za­tion – navi­ga­tion bars, menus, bre­ad­crumbs, site maps, des­crip­tive links, and so on – and let the users them­sel­ves cho­ose which stra­tegy to use when cre­a­ting their men­tal maps.