Specs for Navar1b

Basics.

This simple experiment will have 150 trials. On each trial, you present one of three stimuli (from the set {K, T, ?} in the center of the screen in large font) randomly chosen with the constraint that each of the 3 stimuli occurs equally often (i.e., 50 times). When the subject responds, you sometimes play a wavefile, and sometimes simply wait 3 seconds, before going on to next stimulus.

Instructions

This is an experiment examining your ability to ignore distraction. It will only take about 10 minutes. You will see a symbol in the center of the screen. If it is a K, you should press the left response key marked K. If it is a T, you should press the right response key marked T. Your responses to the letters should be as quick and accurate as possible. If the symbol is a ?, you can press either key -- it is up to you, and for this symbol, you do not need to respond quickly. Sometimes you will hear sounds playing. These may be distracting or even slightly annoying, but your task is just to ignore these sounds and respond as quickly and accurately to the letters when they appear. If you have any questions please ask the experimenter.

Specifics.

1. Please make 2 wavefiles. These will be called Early and Late. Both should be as close to 6 seconds as you can arrange it (it is important that they have the same duration). Start by finding a good wavefile with at least 3 seconds of the most annoying baby-cry you can find using http://www.findsounds.com/. Crop it down to 3 seconds using a sound editor (ask Noriko if you aren’t familiar with a sound editor, because we bought one). Then use the editor to create 2 files as follows:

Early: 3 seconds of baby-cry followed by 3 seconds of quiet.

Late: 3 seconds of quiet followed by 3 seconds of the same baby-cry.

So the only difference between Early and Late is whether the baby cry comes at the beginning of the 6 seconds, or at the end.

2. Procedure:

The 150 trials should consist of 50 with a K, 50 with a T, and 50 with a ?. The order of these should be randomized.

Mapping of Stimuli to Responses

K -> Z

T -> /

When the stimulus is K or T

As soon as the subject responds, whether the response is correct or incorrect, do the following:

Simply wait 3 seconds

When the stimulus is ?

As soon as the subject responds:

If they press the / key, play Early (with as little delay as possible)

If they press the Z key, play Late (with as little delay as possible)

Data Storage

Columns should be:

Subject number

Trial #

Stim presented

Subject’s Response

RT

Which sound was played after the trial? (Early, Late, None)