16 Şubat 2008 Cumartesi


Abstract: CHRISTOPHER D. WICKENS has written an article titled ‘Multiple resources and performance prediction’ at University of Illinois at Urbana-Champaign, Institute of Aviation Willard Airport, Aviation Human Factors Division, Aviation Research Laboratory. This article proposes a model to predict human performance under conditions that require multiple mental resources. I will make use of the information provided in Wickens’s article to point at the importance of trigging in human cognition.

To my fellow Turkish aviator Mr. Servet BAŞOL,

A trigger is a simple, high “affordance”, easy to use mechanism. You should not think elaborate things to make it work. Its implementation should be independent from the logic of the system it starts. Starting the system must be totally insulated from the decision making. It should work as simple as a Texas cowboy firing his gun.

Our brain does multiprocessing, multitasking and distributed processing. We can talk and walk at the same time. We can talk to two different persons on different subjects in the same time interval. MRI pictures show that different parts of our brains get activated for different types of tasks. We perform these tasks using various resources of our minds.

“The multiple resource model proposes that there are four important categorical and dichotomous dimensions that account for variance in time-sharing performance. That is, each dimension has two discrete 'levels'. All other things being equal (i.e. equal resource demand or single task difficulty), two tasks that both demand one level of a given dimension (e.g. two tasks demanding visual perception) will interfere with each other more than two tasks that demand separate levels on the dimension (e.g. one visual, one auditory task). The four dimensions, shown schematically in figure 1, and described in greater detail in the following pages, are processing stages, perceptual modalities, visual channels, and processing codes. Consistent with the theoretical context of multiple resources, all of these dichotomies can be associated with distinct physiological mechanisms.”

Wickens’s model has been supported by many MRI works that study the brain locations activated by specific tasks. Unfortunately many mental tasks are complex. For ex. speech activates many parts of the brain at the same time. This makes it extremely difficult to drive some generalizations in regards to the character of these activated brain locations. Simply it is difficult to claim that there are simple, straight forward, seperate, ‘processors’ or even ‘centers’. Wickens’s aproach and ‘resources’ model serves its purpose without making unproved generalisations.

But, Wickens also states: “In employing multiple resource theory to guide such dichotomous categorical design decisions, it is of course important to bear in mind the other consequences of switching from one resource category to another, such as, for example, the fact that a visual-spatial map may be a more compatible means of delivering geographical information than via words.” Wickens’s statement points at the overload that arises because of changing the modality during task performance, namely driving a car and navigating at the same time. Wickens clearly assumes the existence of some sort of a trigging mechanism, which triggers an other modality with some mental performance cost.

Today, we certainly know that there are many neural networks in our brains. There are also connections between dedicated neural networks. My point is: Wickens’s ‘resources’ are triggable with some sort of trigging mechanisms, possibly hard and/or soft. Moreover believes this humble dreamer, mental triggers are ubiquitous. We can observe them beginning from low level physiological structures going up to skills, hobbies, professions, habits.

Trigging mechanisms can be built in many different ways. Seeing objects, images trigger our brain’s visual resources, hearing sounds triggers hearing resources… Visual and acoustic signals are recieved by different organs and this provides a hardware connection and filtering mechanism.

But it is not that simple. The sound and visual signals also have different data characteristics. The frequency bands for sound and image are different. It is not only the organs and physical connections that triggers our brain’s visual and acoustic centers but also the character, the format of the sound and the image signals.

It is amazing, how brain transforms and processes signals of different modalities such as sound and image. The signals loss their perception formats when they are taken into the working memory as semantic chunks… How does the central processor decide which processor to trig for which signal then?

There must be some encoding algoritm, maybe only the amount of data or the SPEED. The way the data is provided and processed could trigger the related processor. A neural network could simply work as an RC filter circuit besides its logical function and filter acoustic or visual signals as high or low pass filters, maybe.
Within a certain modality, content adrressing triggers related items at different semantic levels. For ex., when you see me, it triggers your previous impressions about me.

Trigging does not function linearly either. Same events do not trigger same reactions in our brain under all conditions. Anticipation, priming, mood, motivation, context and memory usage affects trigging mechanisms of our brain.

My second point is: Trigging is a vital element of our mental life both socially and individually… Sadly trigging can be used by people with bad intentions such as the assassination in the beginning of the first WW. On the other hand it is a rich human resource that can not be overused. Emergency psychology, decision making under stress, large systems, aviation, air traffic control have many applications for it. Slow progressing processes such as education, politics etc. also…

A trigger mechanism reduces flexibility but increases automacity when designed correctly. It brings a level of abstraction. There are different types of mental triggers: For remembering things, you could say ‘I will remember this tonight’, or ‘I will wake up 6 O’Clock in the morning’, ‘I will stop thinking about my job when I come to the stairs of my house, till I begin to drink my coffee after my dinner, I may remember it if necessary’…
It looks like the religious commitments that one makes before fasting etc…

Reaction triggers could be ‘I will push the brake to the bottom when it is inevitable’, but this should rather be a warmth in your right leg muscle rather than words… Sports is all about doing the right triggering.

Finally, cognition, a healthy mental life requires the development and maintenance of personal triggering mechanisms. Emergency processing, analysis, smalltalk, imagination, design, planning, mindfullness, high concentration, high concentration long duration working, recovering emotions after heavy cognitive work… Staying healthy as a successful professional requires maintenance and enhancement of your mental triggering processes so that you sustain your well-being.