Communication Process

Trading Symbols

This demonstration uses stream segregation to affect pattern recognition. A six-tone cycle is the test stimulus. We show that when it splits into two perceptual streams, it is very difficult to pay attention to members of the high and low streams at the same time.

It seems that the two- stream structure limits what attention can do. The difficulty of considering both high and low tones in the same act of attention is demonstrated by asking you to listen for a subset of three tones from among the six.

Detecting the subset within the full pattern can be done much more easily when the three tones are in the same stream than when they cross streams.

Pattern recognition, within and across perceptual streams

First you will hear a "standard" cycle containing three tones and three silences.

Then three additional notes replace the silences to form a 6-tone cycle in which three tones are high in frequency and three are low.

The three and 6-tone patterns are alternated twice.

Try to continue to hear the three-tone "standard" in the six-tone cycle.

In Part 1 the tones of the standard are all from the high range.

In Part 2, two tones of the standard are high and one low. Judge whether the standard can be heard more or less clearly than in Part 1.

You will hear a cycle of two high tones and one low tone, in a galloping pattern.

Listen to what happens to the experience of the gallop as we speed up the sequence by shortening the tones.

A Galloping Pattern first used by van Noorden.

First, the tones are far apart in frequency.

Next, the frequency separation is small.