Dept of Neurophysiology -- Electrical Stimulation Option Documentation

The Electrical Stimulation Option of the COM Program

The electrical stimulation option of the COM program is not one of the behavioral task types of the program. Unlike the 7 possible task types, the electrical stimulation option is performed only when the user types the command "SP", and so it is not included in the random order of behavioral tasks that is determined by the parameter files initially specified by the user. Also, the electrical stimulation routine differs from the behavioral tasks in that the animal is not required to perform any visual spotting, and a reward is given anyway, each time the option is done.

Note that task type 7, saccade with electrical stimulation, is a behavioral task type which itself includes an electrical stimulation of the animal. There, however, the stimulation pulse is incorporated into the trial itself, and the "SP" user command plays no part in it. If, in fact, the user types the "SP" command during a type 7 trial, the program simply completes the trial and goes on to perform the "SP" command option as described here.

The electrical stimulation option is used to observe the visual response of the animal to a direct electrical stimulation. It can be done at any time during a run of the COM program. In this option, the animal is presented with a visual stimulus of a specified duration. At some point either before this stimulus ends, or after it ends, an electronic stimulation, or pulse, will be delivered to the animal. An automatic reward will also be given to the animal. This process is illustrated in Figure 1. The time of delivery of the stimulation, the reward, and the visual stimulus are all specified by the user when the electrical stimulation option is selected. The user starts all of this by typing the command "SP".

Figure 1. -- Electrical Stimulation Option

Explanation of terms for electrical stimulation:

led1 The visual stimulus that is presented in conjunction with the electrical stimulation. Its duration is esled1dur.
elec stim Electrical stimuluation, or pulse, that is delivered to the animal.
SY Starting point of trial.
L1 Time that led1 turns on. It occurs at a time esled1strt after SY.
S1 Time that the electrical stimulation pulse is delivered. It occurs at a time estime, which is measured from the end of the led1 duration. If estime is positive, the stimulation occurs after esled1dur is over, and if it is negative, the stimulation occurs beforehand. In Figure 1, estime is negative, and the stimulation occurs while led1 is on.
R Time that animal receives reward. It occurs at a time esreward, which is measured from the end of the led1 duration. As above, the parameter esreward can be positive or negative. In Figure 1, esreward is positive.

After typing "SP" to start the stimulation option, the user is given the following menu:

	Select one of the following options:

	C	Change stimulus presentation parameters
	D	Describe details of electrical stimulus
	Q	Quit this menu and return to com trials
	n	Specify led position and start presentation
		(where n=1,2,3,4,5,6,7,8,9,0,P,O,I,U, or Y)

	Type a SINGLE KEY to Select an Option:  ");

At this point, the user must use the "C" and "D" options (at least once) to set up various parameters. Once this is done, the last option is selected in order to start the actual stimulation. Note that "n" is a single number or letter that specifies the visual (led1) stimulus position, which ranges from 1 to 15. Values 1 to 9 are simply the number in question, while values above 9 are as follows:

	(zero) 0 means 10
	       P   "   11
	       O   "   12
	       I   "   13
	       U   "   14
	       Y   "   15

After the "n" option is typed, the electrical stimulation is done, as illustrated in Figure 1. During this process, the program collects position data from the cat's eye (and, optionally, ear and head) as a function of time. Note that unlike the regular behavioral trials of the COM program, no neuronal spike data is collected.

After the stimulation process is finished, the program again displays the above menu, and the user has the option of repeating the stimulation, with the same or with different parameters, or of typing "Q" to return to the COM program. Once returned to the COM program, the behavioral tasks will continue to be performed where they left off when the "SP" command was first given.

Com Program Documentation -- General
Task Types
Commands
Glossary of Parameters -- definitions of all parameters used

If you have questions or comments about this documentation, please send email to jane@neurophys.wisc.edu

This page last modified on : July 26, 1996

led1	The visual stimulus that is presented in conjunction with the electrical stimulation. Its duration is esled1dur.
elec stim	Electrical stimuluation, or pulse, that is delivered to the animal.
SY	Starting point of trial.
L1	Time that led1 turns on. It occurs at a time esled1strt after SY.
S1	Time that the electrical stimulation pulse is delivered. It occurs at a time estime, which is measured from the end of the led1 duration. If estime is positive, the stimulation occurs after esled1dur is over, and if it is negative, the stimulation occurs beforehand. In Figure 1, estime is negative, and the stimulation occurs while led1 is on.
R	Time that animal receives reward. It occurs at a time esreward, which is measured from the end of the led1 duration. As above, the parameter esreward can be positive or negative. In Figure 1, esreward is positive.