<ep>¹ <cr>² <fd 1>³ <d 119>⁴ <t 1500>⁵ <id keyboard>⁶ <dbc 210210210>⁷

<dfs 36>⁸ <dwc 0 >⁹ <vm 1024,768,768,16,60>¹⁰ <nfb>¹¹ <rcot>¹² <eop>¹

!¹³ This is a very simple demo of a lexical decision task;¹⁴

! last edited on 10-25-05;

! Item number AB;

! A=condition (1=word, 2=non-word);

! B=Trial number;

0¹⁵ ”Press SPACEBAR to start”¹⁶;

+¹⁷11¹⁸ *¹⁹ “RABIES” <% 30>²⁰/²¹;

-22 * “BRANTLY” <% 30>/;

-23 * “SKELVE” <% 30>/;

+14 * “JUMP” <% 30>/;

0 ”The END! Thank you for your participation”;

Notes:

1: EP/Extended Parameters & EOP/End of Parameters should be used at the start and end of the header parameters if these parameters extend beyond one line.

2: CR/Continuous Run is used to override the DMDX’s default mode in which the user must press the space bar to request each item. If CR is set, the script will only pause on message items (items numbers of 0).

3: FD/Frame Duration is used to specify the default frame duration. However, this is rarely used b/c we tend to override this in all frames by specifying the frame duration in the item.

4: D/Delay is the default delay between items during which the subsequent item is assembled. If this value is too low for complex items (i.e., large bmp files are presented), you will see an error message in the output file indicating that a particular frame was delayed.

5: T/Time out is the total time that DMDX will wait for a subject’s response before proceeding to the next item. To avoid unexpected delay errors, the time out value must be shorter than the total elapsed time from the clockon(*) to the start of the next item (including the delay).

6: ID/Identify Device is used to indicate which devices DMDX should poll for input. At a minimum, you should always include the keyboard.

7: DBC/Default Background Color is the color of the background in RGB format. The first three digit number is the intensity of red (0-255), the next three is the intensity of green (0-255), the final three digits are the intensity of blue (0-255). 000 is black. 255255255 is white. 210210210 is a pleasing gray. Links to websites with RGB calculators are available on the utility page.

8: DFS/Default Font Size sets the default font size of displayed text.

9: DWC/Default Writing Color sets the text color in RGB format. 0 is equivalent to 000 or black. This will override the WYSIWIG features of DMDX.

10: VM/Video Mode sets basic parameters about the video mode. First value is the horizontal resolution. Second is vertical resolution. Third allows you to reduce the useable vertical resolution to decrease refresh interval if you will only use part of the screen (not typically used). Fourth value is color depth. Final value is refresh rate. If refresh rate is set to 0, DMDX will chose optimal refresh rate which tends to be 60Hz

11: NFB/No Feedback overrides DMDX default option to provide feedback after each trial. We almost always use this.

12: RCOT/Record Clockon Times. This will add a column to the output file that includes the time that each clockon was encountered. Very useful for verifying timing. We almost always use this for testing purposes.

13: ! is used to indicate a comment when used at the start of a line. The line must still be terminated with a ;

14: All items (including comments) should end with a ;

15: Each item will start with an item number. 0 is a special item number to indicate a message trial. Even in CR mode, the script will pause on 0 items and wait for the user to press the space bar to initiate the next item.

16: By default “Text” that appears between quotes will be displayed on the screen as text.

17: For items that will involve subject responding, you must include a CR (correct response) indicator. + stand for positive response, - stands for negative response, = for any response, ^ for no response. Any item that includes a clockon (*) must have a CR at the start of the item. By default the LEFT and RIGHT shift keys are mapped to the negative and positive responses.

18: This is a non-zero item number. If a response is collected, this item number will appear in the output file along with the RT

19: * stand for clockon and indicates that DMDX should start timing for a response.

20: <% N> sets the frame duration in ticks. This indicates the time that the next frame will begin and is essentially the same as the duration of the current frame (assuming there is a next frame). There can be no frame duration for the last frame of an item (as there is no next frame). The last frame will always take one tick to execute.

21: / is the frame delimiter. It separates frames. By default, when a new frame starts, the previous frame is erased. This default erasure can be overridden by placing a <ne> in the frame.