Different Models of Attention

The topic of discussion continues to be attention in this paper,

Single-Mindedness:      

- We have the capacity to perform only one demanding task at a time.

It is believed that attention starts immediately after icon and ego

No higher level processing is performed at this time.

Some models suggest that attention must be a low level process

Early Selection Model

Blocks the information coming from the left ear as attention is paid to the right ear.

According to these models, attention happens early and it is a low level process.

Attention and Meaning

It can be inferred that if attention is a low level process than meaning should not have any relation with attention.

To see this, an experiment was designed by undergraduates at Oxford University.

- Shadow Meaningful Messages

The subjects were given the following messages in left and right ear respectively.

-          Left Ear: John Eleven books

-          Right Ear: Eight writes twenty

In this experiment, the subjects reported:

John writes books

This experiment illustrated how subjects switched between ears to get meaningful messages.

So, the findings of the experiment were as follows:

-          Attention can use meaning, a higher level process

-          Attention is probably not an early selector but a late selector

Triesman's Experiment

Triesman(1960) conducted the following experiment:

-          Asked the subjects to shadow a message in the left ear

The message shadowed in the left ear was:

Left Ear: I was going there when/China smoke lovely chirping

Right Ear: books, chairs, tables, elephant/ I saw a bright flash

The experiment revealed that many subjects switched between ears to follow the meaningful message.

That means that something is given meaning even before the attention is totally focused on that content.

This created a very important paradox in cognitive psychology.

It may be possible that attention is an early selector. Triesman did not said that attention is a high level process. He said that higher level processes in the brain may be playing a role on early on from the point of view of attention.

One experiment is telling that physical features like pitch, loudness ad which ear it is presented to are more important than meaning. Other experiments tell you that the meaning plays a central role in terms of how attention is focused. This created a very important paradox in cognitive psychology.

Suppose you go on a wedding dinner, and people are chatting in groups and you are paying attention in the group in which you are chatting. All of a sudden someone in the other part of the group said your name; all of a sudden your attention will shift from the group you were in to the group where your name was spoken.

This is an example of what Triesman was saying, that is an example of what Gray and Wiederberg was saying.

How is it that if we are using attention for selection

Information is coming from the left. The arrow represents different visual or auditory information.

The information falls on our senses. Senses take that information in their own limitation, majority of the information that goes to the short term storage.

We are not getting all the information that is falling on the senses.

There are many things which our eyes cannot possibly see.

e.g. ultraviolet or infrared

Our sensory memory has some limitations. Short term store seems to be almost limitless.

This short term store is known as sensory store. We will talk about short term memory ahead. It is not good to get confused with that.

Don not confuse short term store and sensory register with short term memory.

Short term store is where all the information acquired by the senses is retained but fir a very short time.

Selective filter is followed by Limited Capacity Channel.

It is because of the limited capacity channel that the filter is previous to it. If you put load on the filter, it will be worthless.

Limited capacity channel is sending 3 channels:

1.       Some information goes back to short term store. While you are listening to this lecture, somebody else is talking and somebody else is talking to somebody else.

With this feedback loop, attention is paid to the thing which we are already attending.

2.       Store of conditional probabilities of past events

Information is send to the store of conditional possibilities of past events to see what kind of conditional probability does it has.

If something is important to us, the attention automatically goes to t hat.

Cocktail party phenomena

Your name is said somewhere and your attention goes there.

Whenever your name was taken in the past, you were attending to that event. Because the sound came even though you were paying attention to something else. Because it was something you have heard in the past over and over again, it was automatic.

Your attention automatically shifts to the group where your name is taken.

Based in your past experience you switch your attention and there is a feedback loop to the selective filter.

One arrow from the Limited Capacity Channel goes to:

3.       System for varying output until some input is secured

It changes our behavior in the direction of attention.

If I am doing something very important and all my attention is to that task and something else happens in the environment to which to pay attention, I will orient my body to it. I will probably move closer  to that situation and I will make sure that I direct all my physical orientation to that situation.

Effectors on the top of the slide refers to the mascular response or the motor response that may be given

So, Broadbent model of attention is an early selection model in which there is a short-term storage and from that short term storage immediately attention selects some information for further processing. It is a filter model or it is also called a bottleneck model.

When you hear your name for that your response is varied.

From this phenomena it is decided what your effectors will do,

Selective filter is immediately after short term store.

Attenuator Image

Shadowed message has same pitch, loudness, etc.

In between that there is no filter but an attenuator.

Attenuator is one which weakens a signal and lets one remain strong.

Attention weakens information coming from one ear and the information coming from another ear goes without problem.

After Attenuator, there are thresholds of high and low.

Words like table, green are ordinary in your mental dictionary.

Words like your name or some subject you are interested in have a very high importance in your mental dictionary.

The subjective loudness like that of your brain escapes the weakening of your attenuator.

Attenuation means the weakening of something(signal), weakening a signal

The attenuator in the system tells us.

Norman Model

Norman's model is not very popular anymore.

He tried to say that attention is very later.

It is reverted because it is starting from above.

If you see it from up, you will see that sensory input is coming from up and It is processed without any filter of attenuator. Everything is processed.

To conclude, we have two competing models:

1. Early selection model

2. Late selection model

Early selection model has two types:

-          Filter model by Broadbent

-          Attenuator Model

Filter means it lets something go and makes something stay.

Attenuator is one that lets everything go but weakens some signals.