Protocol (Continuous Mode)

While this tab page has a similar layout to the same-named tab in Trial mode, there are substantial differences. In Continous mode, the investigator can separately and independently turn on data recording, enable fixation checking, and start or stop a stimulus protocol. The fundamental stimulus protocol in this mode is a stimulus run. Like trials, stimulus runs are organized into run sets, and this tab provides controls for selecting both the run set and a particular stimulus run from that set. However, Continuous mode lacks a means of sequencing the different stimulus runs in a set; the user must manually select each run to be presented.

Presenting stimuli

Run Set -- This combo box displays the name of the set from which a stimulus run is selected. The dropdown list includes an entry for each stimulus run set currently defined under the Stimulus Runs node in the document object tree. Obviously, a stimulus run cannot be selected and presented until a parent run set is chosen.

Current Run -- This combo box displays the name of a stimulus run in the currently selected run set. The dropdown list will include the entry NONE, plus the names of all the runs in the selected set. Use it to select the stimulus run you wish to present.

Exec Mode -- Use this combo box to select the stimulus run execution mode. Maestro currently offers three different ways to present a stimulus run. Note that all of the execution modes involve presentation of the Current Run only. Continuous mode does not offer run set sequencing schemes analogous to those available in Trial mode, although such sequencing methods may be introduced in a future version.

- Manual. In this mode, starting a stimulus run is completely independent from starting to record a data file. These actions are coordinated in the other execution modes.
- Auto Record. In this mode, when the Start button is pressed, data recording is initiated just prior to starting the selected stimulus run. Conversely, data recording is halted just after the stimulus run comes to a stop (unless the run is aborted).
- Single-run Repeat. This mode lets the user automatically record behavioral and neuronal response data during repeated presentations of the selected stimulus run. The data collected during each presentation is stored in a separate data file. Data recording begins approximately 500 milliseconds prior to the stimulus run, but stops immediately after the run auto-stops. Maestro saves the data file, increments the file extension to generate a new, nonexistent file, then repeats whole process over and over until the user presses the Stop or Abort button. Note that stimulus runs executed in this mode must auto-stop after one or more duty cycles have elapsed.

Start/Stop -- When the Start button is pressed, the stimulus run begins in accordance with the Exec Mode, as described above. The button's label then changes to Stop, and pressing the button again tells Maestro to stop the run at the end of the current duty cycle -- a "soft stop". The button's label reads !!!WAIT!!! and the button itself is disabled until the run reaches the end of the duty cycle, at which point the label reverts to Start. If the Exec Mode is not Manual, the recorded data file is saved immediately after the run stops, and the file extension is incremented to create a new filename for the next file to be saved. If a stimulus run auto-stops after a set number of duty cycles, the Stop button will automatically revert to Start when the run has finished.

Abort! -- This button is enabled only while a stimulus run is in progress. Pressing the button immediately aborts the run; in the Auto Record and Single-run Repeat modes, any data collected is discarded.

Restart -- This button is also enabled only during a stimulus run. It is merely a convenient short-cut for pressing the Abort! and Start buttons in rapid succession. [Note: Do not use this feature when the stimulus run drives the animal Chair. Maestro always assumes that the Chair starts at the face-forward position (0 deg) at the beginning of a stimulus run. In fact, Maestro continually compensates the turntable's velocity command to keep it at this resting position when it is not being driven. If a stimulus run is aborted and immediately restarted when the Chair is not at rest, this assumption is violated and the Chair will not move as expected.]

Fixation and reward delivery

Toggle the Fixation ON/OFF button (or use the keyboard shortcut Ctrl-spacebar) to enable or disable fixation checking in Continuous mode. The button's label will read Fixation ON while fixation checking is enabled. The size of the fixation window, the length of time fixation must be maintained to earn a reward, and the reward pulse length are all specified on the separate Fix/Reward tab. The fixation target is identified on the Active Targets tab.

Recording data

In Trial mode, the trial definition itself includes the channel configuration, which determines what data channels are recorded and displayed during that trial. A Continuous-mode stimulus run lacks a similar construct. Instead, use the combo box labelled Channel Cfg on the Protocol tab to select the desired channel configuration. The combo box's dropdown list will include the names of all channel configurations listed under the Channels node in the experiment document tree. You can select a new channel configuration at any time in Continuous mode unless a stimulus run or data recording is in progress (in which case the combo box will be disabled). Whenever a new selection is made, the Data Traces panel is cleared and reconfigured in accordance with the selected channel configuration object, and the displayed data traces immediately begin scrolling across the panel.

In the Manual execution mode, the data recording function is independent of stimulus control. In this case, the Record ON/OFF pushbutton is visible near the bottom of the tab page. The button's label reflects the current state: Press Record OFF to initiate recording, and the button's label changes to Record ON. Press the button again to turn off recording and close the data file. The button is hidden in the other two execution modes, since data recording is synchronized with stimulus run presentations in those modes.

The nearby file path control works in the same manner as the file path control on the Trial-mode Protocol tab. It displays the full pathname of the Maestro data file to which data will be streamed the next time recording starts. You can change the path by clicking on the embedded browse button or typing directly into the edit window. The file specified should not yet exist and must end in a 4-digit numeric extension. While a recording is in progress, the file path control is disabled. If a recording is successfully completed, the numeric extension of the file is automatically incremented, creating a new filename for the next chunk of data.

Finally, to include the 25KHz-sampled version of analog input channel 15 (dedicated to monitoring the extracellular electrode signal, i.e., the "spike waveform") in the recorded data file, be sure to check the box labelled Save high-resolution spike trace?. Bear in mind that this will substantially increase the size of the data file; one minute's worth of the high-resolution data stream will typically add 0.75-1MB to the file size.