Prueba de hipótesis específicas

Introduction.

If the information in the short-term memory is rehearsed, it will then be transferred into the long-term memory. It is believed that information is stored in the long- term memory for an unlimited time period, although frequently there can be retrieval problems. One major disadvantage of long-term memory is the time that it takes to access information from it.

The long-term memory can be divided into three types:

• Semantic memory.

• Episodic memory.

• Procedural memory (Motor Programmes).

Semantic Memory.

Semantic memory stores general knowledge of the world, storing answers to such questions as: Are fish animals? Do birds fly? Do cars have wheels? It is believed that semantic memory holds concepts that are represented in a dense network of associations. Language is also held in semantic memory. It is generally thought that once information has entered semantic memory it is never lost. It is certainly more accurate than episodic memory. When we are unable to remember a word, it is often because we are unable to find where the item is stored, not because it has been lost from the store.

Episodic Memory.

Episodic Memory is a memory of events or episodes in our life: a particular flight, meeting, or incident. However, episodic memory is prone to change along the lines of how we would have liked an event to have occurred, rather than how it really occurred.

Procedural Memory (Motor Programmes).

Although some experts in the field of Information Processing agree that long-term memory consists of only episodic and semantic memories, there are those who include motor programmes or skills as a third constituent of long-term memory.

Figure 8.7 Episodic Memory.

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Perception involves the converting of sensory information into a meaningful structure.

For example, a pattern of vibrations in the air becomes recognised as sound carrying a particular message.

The percept (what we perceive) is not a complete representation of the information in the sensory store, but an immediate interpretation of it. For example, read the words in the yellow triangle (Figure 8.8) out loud:

The words actually read: “a bird in the the hand”. Most people will read the sign incorrectly the first time, missing out the second “the”. The reason for this, in this case, is simple. The words form the beginning of a well known phrase and, having read the first three lines of the triangle, the reader believes he knows what is coming next and may automatically pass on to the last word to confirm his belief, missing out the extra “the”.

It follows that the sensory information that we expect to receive is more easily perceived and integrated than totally unexpected information. This should serve as a warning to pilots. Anticipating information, for instance in a particular standard radio message, that sounds like a message a pilot has heard many times before, may cause him to miss a small but important piece of information or instruction.

It is true that we can perceive only something that we can conceive. It is also true that we perceive only a fraction of the information reaching our senses at any moment.

Therein lies the importance of the attention mechanism in our model in Figure 8.1.

The process of perception is greatly assisted by our ability to form mental and three-dimensional visual models of what we are perceiving.

Consider the following text.

Aoccdrnig to a rscheearch at an Elingsh uinervtisy, it deosn’t mttaer in what oredr the ltteers in a word are, the olny iprmoetnt tihng is that frist and lsat ltteer is at the rghit pclae. The rset can be a toatl mses and you can still raed it wouthit porbelms. This is bcuseae we do not raed ervey lteter by itslef but the word as a wlohe.

We perceive the meaning of all the words in the text because we have already formed models - which are stored in our long term memory - of the individual words. So, even though the letters are jumbled, all except the first and the last letters of the word, that is, we recognise the words instantly.

Funnelled Perception.

Perception of a situation can differ depending upon the point of view from which the process of perception begins. Consider two men walking through some woods when they come across a family group having a picnic (See Figure 8.9). The first man may perceive the overall picture of a family enjoying themselves together in the open air, whereas his companion may, first of all, perceive details of the scene, rather than the whole picture. The second man may perceive the contrast between the red

Figure 8.8.

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CHAPTER 8: THE INFORMATION PROCESS

of one woman’s top and the white and blue clothing of the baby she is holding, or, perhaps, the picnic basket that the family is using.

It is possible, of course, that after a few seconds both observers will perceive the same picture. The first man may narrow his overall perception to include the detail of the scene, and the second may expand his perception to include the generalities. So, the initial perception that the two men had of the same scene

was entirely different, but each man eventually perceived all the available information.

This process is called funnelled perception.

ATTENTION.

Introduction.

Attention is the deliberate devotion of the cognitive resources to a specific item. A person must be alert to be attentive. But being alert is not sufficient guarantee that attention will be paid to the right item at the right time.

Choice of Item.

Due to the limitations of the Central Decision Maker (the brain), we are generally unable to pay attention to a number of different items at any one time. Although attention can move very quickly from item to item, it can only deal with one item at a time. Consequently, there is a need for the pilot, consciously, to prioritise between items of information; (See Figure 8.10).

Attention Mechanism.

The attention mechanism is required because of the following two potentially limiting stages in processing information:

• There is a limit to the number of items that can be held or maintained in the short-term memory.

• Our channel capacity is limited. We cannot devote conscious thought to, or Figure 8.9 Funnelled Perception.

Figure 8.10 The pilot constantly prioritises information.

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This limited channel capacity means that there must be a mechanism at an early stage of the perception process which allows us to select those stimuli which will be perceived consciously, and used as a basis for our consideration and our decisions, and to reject other stimuli. Some stimuli are extremely efficient for getting our attention. For example, the cocktail party effect, which relates to our hearing our own name mentioned in a background of many conversations.

For a pilot, flying his aircraft, an equivalent phenomenon may be hearing his RT call-sign among a lot of radio chatter, or detecting a smell of burning in the cockpit. Either of these two stimuli would focus a pilot’s attention on the need to obtain more information.

Types of Attention.

Attention is the process of directing and concentrating sensory resources to enhance perception, performance and mental experience. Attention has three basic characteristics:

• It improves mental processing.

• It requires effort.

• It is limited.

There are two types of attention:

• Selective Attention, when inputs are sampled continually to decide their relevance to the task at hand, a pilot’s call-sign being particularly attention-getting in the air.

• Divided Attention, when our central decision making channel can divide its resources between a number of tasks. A pilot flying a visual approach (Figure 8.12) will be dividing his attention between looking ahead to maintain his approach path, and checking his flight instruments for air speed, height, engine power etc.

Although we might think that the pilot is working on a number of tasks simultaneously, in reality the Central Decision Maker is spending a fraction of every second on a different, separate problem, in turn.

Lack of Attention.

It is important to remember that the mind is always paying attention to something - except during sleep.

Therefore, the major danger for pilots is the poor management of attention;

that is to say, paying attention to the

wrong item from a number of items of rival priority.

Figure 8.11 A pilot will hear his RT call-sign among the radio chatter.

Figure 8.12 Divided Attention.

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CHAPTER 8: THE INFORMATION PROCESS

Stress, Attention, and Performance.

This subject has been covered in a previous chapter. But, briefly, stress can have a significant effect on attention, especially during times of low and high arousal. Our limited ability to process information has implications for the level of performance we are able to achieve when subject to various levels of stress. The way in which performance is affected by arousal can be shown by the Performance/Arousal Curve.

See Figure 8.13.

Low Arousal.

At times, such as in the cruise, when a pilot is on track, sure of his position, on time, and on heading, a pilot may feel so satisfied with the progress of his flight that he enters into a state of low arousal. In this state, the pilot’s attention may wander with the result that important information that is presented to him, suddenly and unexpectedly, is either missed or misinterpreted. Continually monitoring airspeed, altitude, heading, location and timing in a systematic way is a method of addressing low arousal.

Optimum Arousal.

If a pilot is working normally, updating timings, checking speed, altitude, heading, location etc, he is optimally aroused and at his most efficient.

High Arousal Overload.

At times of high arousal, when the pilot is overloaded because of the limited channel capacity of the brain, there is a real danger of his attention becoming so narrowed that important information is disregarded. Indeed, if overloaded, the attention mechanism may even reject vital information.

Overload can be of two types:

• Qualitative Overload.

The information is perceived to be beyond the pilot’s attention capacity and the task too difficult.

• Quantitative Overload.

There are just too many responses to be made in the time available.

Figure 8.13 Performance/Arousal Curve.

In a state of low arousal, a pilot’s

attention may wander, and he may miss vital information.

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The symptoms of overload will vary from individual to individual. Among the most common are:

• A sharp degradation of performance.

• Funnelling of attention or focus.

• Regression, where the correct actions are forgotten and procedures learnt in the past are substituted.

• Mental blocking, where it becomes impossible to review or even to consider other solutions.

• Mood swings, some individuals becoming aggressive towards others.

• Restlessness.

• Panic.