User`s guide

E-Prime User’s Guide
Chapter 2: Using E-Studio
Page 14
For example, in the lexical decision experiment, the core experimental procedure was described
in the abstract: The subject will be presented with a fixation (+) displayed in the center of the
screen for one second. Then a probe display will present a letter string stimulus in the center of
the screen for up to 2 seconds. The lexical decision procedure can be specified in a list of events
as follows:
- Select the stimulus from the DesignList
- Present the Trial Procedure which contains: Fixation, then Probe, and collect the response
In E-Prime, the core structure of the experiment is specified through the combination of a List
object (e.g., DesignList) to select the conditions, a Procedure object (e.g., TrialProc) to specify
the sequence of events in a trial, and events specific to that procedure (e.g., Fixation and Probe
display). The E-Prime Structure view below shows the outline of the experimental procedure.
The structure shows the outline of the experiment with the core being the DesignList and the
TrialProc, including the Fixation and Probe events.
2.2.5 Step 1.5: Set the non-default and varying
properties of the trial events
The specific nature of each stimulus can be specialized by setting critical properties of the stimuli.
E-Prime provides defaults for dozens of properties for each stimulus (e.g., font style, forecolor,
background color, location, duration, etc.). The properties that do not have a default value must
be set (e.g., text in the fixation display to be a “+”), as must any properties that differ from the
default. Also the properties that vary in the experiment (e.g., based on the condition) must be set.
The abstract specified a series of properties that must be set:
The stimuli will be words and non-words, presented in random order in black text on
a white background. The subject will be presented with a fixation (+) displayed in
the center of the screen for one second. Then a probe display will present a letter
string stimulus in the center of the screen for up to 2 seconds. The stimulus
display will terminate when the subject responds. Subjects are to respond as
quickly as possible as to whether the stimulus was a word or a non-word by pressing
the “1” or “2” key respectively.
Select
Stimulus
Fixation
Probe Display/
Collect Response