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The number of items that we can hold in our memory that is immediately avialable is quite limited in number. In this experiment you can explore this limit with a set of different types of items and see how this limit varies with the type of item you are trying to recall. While the limit is never long it does depend upon the item time which allows us to make several conclusions about the nature of this immediately available memory. You can make conclusions about how hold information in this memory, at least when it is semantic as opposed to spatial items, and how we can chunck this material.

In this experiment you will be asked to recall a short list of items in order. If you get it correct, the list gets longer and if you do not, the list will get shorter. This experment does what is called a staircase procedure, but simplified. If you get an length correct a certain number of times before any others, that is taken as your memory span.

Setup Instrutions

You can adjust several parameters to design your own version of the experments. The settings are discuss below.

Settings for the Stimuli

The stimulus settings include the following:

New Study: when the study has been finished, you can press this button to start a new experiment.
Reset Stimulus: press this button to reset to the default conditions.
Font Size: the size of the letters or numerals.
Background Gray Level: the brightness the background behind the word from back to white.
Word Position Horizontal (relative): The left/right position of the word relative to the screen width. The lower the value, the more towards the left.
Word Position Vertical (relative): The up/down position of the word relative to the screen height. The lower the value the more towards the top.
Word Position Random: The position of the word randomly varies from trial to trial. The extent of the variation is determined by the Word Position variables above.
Fixation Duration (ms): The duration of the fixation mark.
Trial Delay before Fixation (ms): The duration delay before the fixation mark and between the words.
Duration of Stimulus (ms): How long each item is shown, or of the items are shown all at once, the duration of the total item is this value times the number of items in the the list.

Experimental Method Settings

New Study: when the study has been finished, you can press this button to start a new experiment.
Reset Method: press this button to reset to the default conditions.
Type of Span to Text: Select those conditions you want to run. Numerals: a random list of digits; Letters: any letters, Letters-Rhyme: letters that all rhyme; Letters-Not Rhyme: letters, none of which rhyme; Short Words: 3 to 4 letter words; Long Words: Words that are 6 letters or more.
Start List Length: How long is the first list.
How present list: Should the list be presented one at a time or all at onece.
Number Repeats for List: How many times should you get a list length correct to be deteremined to be the memory span for that item.


Settings for the Stimuli

Change the settings below to alter the stimulus parameters in this experiment.

Experimental Method Settings

Change the settings below to alter the parameters of the experimental method.

Instructions for Experiment

Below, press the spacebar or the Open Experiment Window button on the screen to open the window where the experiment will run. When this screen opens, press the spacebar or click the "Start" button to begin the experiment. There are instructions above the "Start" button. Read them to know how to perform the experiment. Keep your eyes fixated on the red plus sign in the middle of the screen even after the plus sign is removed.

Results Tab

Your data will be presented on the results tab. The x-axis will have the type of item. The y axis is the measured memory span taken as the length of the list you recalled the set number of times and is also the last list run for that type of item. To download your trial-by-trial, press the Show Data link. To download the summary data press the Show Summary link. This data will be stored in a csv format readable by most spreadsheet and statistical programs.

Your Results