The sensory probe 2 task type is similar to the regular sensory probe task type (type 4), but with some additional features. As in the regular sensory probe tasks, there is a first stimulus, and a second stimulus which starts before the first stimulus ends. The second stimulus must end either before the first stimulus ends or at the same time. What makes task type 8 different from task type 4, is that the parameters defining the second stimulus can be set up differently for the visual and the auditory parts of the stimulus. In particular, one can specify different starting times for the led2 and speaker2 stimuli (led2strt and spk2strt, respectively). Also, different duration times can be specified (led2dur and spk2dur). One can also specify different locations (selections) for the visual and auditory stimuli (led2sel and (spk2sel).
As with the regular sensory probe task type, the animal is expected to spot or look in the direction of the first stimulus and continue to look there as long as it stays on (led1dur), even though there is a second stimulus going during this time period. If the animal first looks within the window of the first stimulus before the time period tspotl1 is over, and continues to looks there for the duration of the first stimulus, it will receive a reward. Otherwise, it fails the task. Unlike other tasks in which there is a second stimulus, this task trains the animal to not look at the the second stimulus at all.
All during this process, the COM program is collecting position data from the cat's eye (and, optionally, ear and head) and also neuronal spike data, as a function of time. After the animal either receives the reward or fails to spot a stimulus properly, the program will continue to collect data for the time period spontim (the spontaneous recording time). At the end of this time period, the trial, or task, is marked as finished, and the program then pauses for a prescribed duration known as the inter-sequence delay. (See the parameters isdrew and isdnorew.) After this, a new trial is begun. The trial process is illustrated in Figure 1.
Explanation of terms for sensory probe 2 tasks:
|first stimulus||Led1 or speaker1, or both. See spk1flg and led1sel parameters to disable one or both. In Figure 1, speaker1 is disabled.|
|second stimulus||Led2 or speaker2, or both. See spk2flg and led2sel parameters to disable one or both. In Figure 1, both led2 and speaker2 are used.|
|DSS dur||Duration of auditory stimulus (speaker2 above). It depends on the duration of the stimulus waveform, as stored in the DSS. It can be less than spk2dur, but not greater than it. See also stimtyp parameter.|
|SY||Starting point of trial.|
|L1||Time that led1 and/or speaker1 turns on. See led1strt parameter.|
|W1||Time that animal spots into window of first stimulus.|
|L2||Time that led2 turns on. See led2strt parameter, which must be negative for sensory probe trials. It is measured from the end of the first stimulus, so that L2 occurs before the first stimulus is over.|
|S2||Time that speaker2 turns on. See spk2strt parameter, which must be negative for sensory probe trials. It is measured from the end of the first stimulus, so that s2 occurs before the first stimulus is over.|
|R||Time that animal receives reward.|
|E||End of trial.|
In order to execute sensory probe trials in the COM program, the user must set up the following files:
Note that while a given trial is being executed, the user can type one of several available commands. The program will complete the current trial (so as not to disturb the timing of the trial), and will then process the command that has been typed.
Com Program Documentation -- General
Glossary of Parameters -- definitions of all parameters used