BESA Research ERP Processing - Revision history

Abinash at 13:29, 5 May 2021

2021-05-05T13:29:59Z

Harald at 09:15, 4 May 2021

2021-05-04T09:15:41Z

Harald at 08:52, 4 May 2021

2021-05-04T08:52:21Z

Jaehyun: /* Grand Averaging and Combining Conditions */

2019-07-01T13:08:23Z

‎Grand Averaging and Combining Conditions

Jamie: /* Tutorial 1: Using a P300 Paradigm for Averaging */

2019-03-26T13:46:08Z

‎Tutorial 1: Using a P300 Paradigm for Averaging

Jaehyun: /* Paradigms for Averaging */

2018-11-12T14:36:24Z

‎Paradigms for Averaging

Show changes

Jaehyun: /* Introduction */

2017-06-06T12:33:18Z

‎Introduction

Show changes

Jaehyun: /* Top View of Data Segments */

2017-06-01T14:14:54Z

‎Top View of Data Segments

Show changes

Jaehyun: /* Creating Triggers from EMG/EEG Channels */

2017-06-01T14:08:42Z

‎Creating Triggers from EMG/EEG Channels

Jaehyun: /* Creating Triggers from EMG/EEG Channels */

2017-05-31T13:06:05Z

‎Creating Triggers from EMG/EEG Channels

@@ Line 2: / Line 2: @@
 |title = Module information
 |module = BESA Research Basic or higher
-|version = 6.1 or higher
+|version = BESA Research 6.1 or higher
 }}
 ==  <span style="color:#3366ff;"><span style="color:#00000a;">ERP Processing and Averaging</span></span> ==
@@ Line 29: / Line 29: @@
 Paradigms allow to use scripting techniques for averaging of multiple recordings.
-They keep track of all relevant settings for averaging and make it easy to perform all necessary steps for optimal averaging of the data with a few mouse clicks. Each experimental task is described by a condition, in which trigger events are selected for averaging on the basis of user-defined boolean statements. Conditions can later be combined, e.g. to create grand averages or to form difference conditions.
+They keep track of all relevant settings for averaging and make it easy to perform all necessary steps for optimal averaging of the data with a few mouse clicks. Each experimental task is described by a condition, in which trigger events are selected for averaging on the basis of user-defined boolean statements. Conditions can later be combined, e.g. to create grand averages or to form different conditions.
 The process of editing paradigm definitions is started using the menu entries <span style="color:#3366ff;">'''ERP / Open Paradigm'''</span> or <span style="color:#3366ff;">'''ERP / Edit Paradigm'''</span>, or the<span style="color:#3366ff;">''' ERP'''</span> push button in the main window, as shown in the figure below.
@@ Line 45: / Line 45: @@
 * Trigger: define trigger codes by assigning names and other attributes. Attributes (e.g. "intensity") help to group triggers.
-* Condition: define a condition which selects trigger events from the experiment. Logical expressions can be combined to filter, for example, only the correct responses to a given task.
+* Condition: define a condition that selects trigger events from the experiment. Logical expressions can be combined to filter, for example, only the correct responses to a given task.
 * Epoch: define epochs for averaging, baseline, artifact rejection, stimulus artifacts, and possibly a delay in trigger administration
 * Filter: edit filter settings for averaging
@@ Line 82: / Line 82: @@
 A condition holds all information connected with a task or a specific event type.
-In the ERP module, averaging is performed on the basis of conditions. A condition is given by a logic expression that defines which trigger events are accepted for averaging. The "condition" tab makes it possible to define complex logic expressions and to see immediately how many matching trigger events result.
+In the ERP module, averaging is performed on the basis of conditions. A condition is given by a logical expression that defines which trigger events are accepted for averaging. The "condition" tab makes it possible to define complex logic expressions and to see immediately how many matching trigger events result.
 The example conditions shown in the figure below are defined in Tutorial 1: ''‘Using a P300 Paradigm for'' ''Averaging ''' in help chapter ''“ERP / Functions… / Paradigms for Averaging”,'' which gives a comprehensive overview of the features of the averaging module.
@@ Line 118: / Line 118: @@
 The ''Artifact'' dialog tab provides an easy way to define artifact rejection thresholds and to exclude bad channels and bad sweeps from the analysis. This is achieved by scanning the data file and then using the graphics display presented in the center of the dialog tab, which shows channels and sweeps sorted according to user-defined criteria.
-If the user does not check any of the options ''Fixed Thresholds'' and ''Artifact Scan Tool'', only regions which were explicitly marked as artifacts by the user will be excluded from the averages. If the option ''Fixed Thresholds'' is checked, the thresholds given in the edit boxes for amplitude and gradient are used to reject sweeps contaminated by artifacts.
+If the user does not check any of the options ''Fixed Thresholds'' and ''Artifact Scan Tool'', only regions that were explicitly marked as artifacts by the user will be excluded from the averages. If the option ''Fixed Thresholds'' is checked, the thresholds given in the edit boxes for amplitude and gradient are used to reject sweeps contaminated by artifacts.
 The option ''Artifact Scan Tool'' provides an interactive tool for the comprehensive detection and rejection of both artifact-loaded channels and sweeps.
@@ Line 157: / Line 157: @@
 The tutorial in help chapter ''"ERP / Functions... / Paradigms... / Tutorial 1: Using a P300 Paradigm for'' ''Averaging"'' gives an introduction to the available features. Different conditions can be combined to analyze experimental paradigms of high complexity.
-A detailed description of the features can be found in electronic help chapter ''"ERP / Reference / Using Paradigms to Average".''
+A detailed description of the features can be found in the electronic help chapter ''"ERP / Reference / Using Paradigms to Average".''
@@ Line 239: / Line 239: @@
-All three lines are highlighted, since they all hold the same epoch settings which were entered into the edit boxes in the top half of the tab.
+All three lines are highlighted since they all hold the same epoch settings which were entered into the edit boxes in the top half of the tab.
 The epoch which is used for calculating the baseline is set to -100 ms (start position) and 0 ms (end position) by default.
@@ Line 249: / Line 249: @@
 '''2. Filter Settings'''
-In the "Filter" tab, the low frequency cutoff filter and the high frequency cutoff filter can be edited.
+In the "Filter" tab, the low-frequency cutoff filter and the high-frequency cutoff filter can be edited.
-* If the high cutoff filter is enabled for either artifact scan or averaging, disable it by clicking off the check boxes. Switch to the "Artifact" tab.
+* If the high cutoff filter is enabled for either artifact scan or averaging, disable it by clicking off the checkboxes. Switch to the "Artifact" tab.
 '''3. Artifact Rejection'''
-The artifact rejection tool offers two methods of artifact rejection. If the check box "''Fixed Thresholds''" is checked, the thresholds given at the right of the tab are used as limits which must not be exceeded in a trial. If the check box "''Artifact Scan Tool''" is checked, a scan of the data set is used to find artifacts.
+The artifact rejection tool offers two methods of artifact rejection. If the check box "''Fixed Thresholds''" is checked, the thresholds given at the right of the tab are used as limits that must not be exceeded in a trial. If the check box "''Artifact Scan Tool''" is checked, a scan of the data set is used to find artifacts.
 * Press the green "<span style="color:#3366ff;">'''Start Scan'''</span>" button. The data file is scanned for artifacts. After the scan is completed, a color-coded representation of maximum signal in channels and trials appears. This scan only has to be performed once for a data file, unless conditions are changed. The next time the paradigm is opened with the "<span style="color:#3366ff;"><span style="color:#00000a;">''Edit Paradigm"''</span> command (cf. part C of this tutorial), the scan result will be available.
@@ Line 374: / Line 374: @@
 [[Image:ERP Processing (10).png]]
-''Topographic view of averaged data in a 32-channel auditory auditory evoked ERP experiment. Two conditions are overplotted. A map of the N100 in one condition is shown. Channel amplitudes at the N100 latency are displayed''
+''Topographic view of averaged data in a 32-channel auditory evoked ERP experiment. Two conditions are overplotted. A map of the N100 in one condition is shown. Channel amplitudes at the N100 latency are displayed''
@@ Line 422: / Line 422: @@
 * 3D whole head mapping of voltage or current source density.
 * Changing display options such as tick marks, channel labels, baseline information, font sizes, colors, and more.
-* Display of standard deviations, and event-related (de-)synchronization (this requires band pass filtering of the data during averaging, see the corresponding help chapter).
+* Display of standard deviations, and event-related (de-)synchronization (this requires bandpass filtering of the data during averaging, see the corresponding help chapter).
@@ Line 433: / Line 433: @@
-The ERP Module allows for quick combination of averaged segments, e.g. to create Grand Averages over subjects or to compute weighted sums and differences of conditions.
+The ERP Module allows for a quick combination of averaged segments, e.g. to create Grand Averages over subjects or to compute weighted sums and differences of conditions.
 Conditions from different recordings/subjects can be combined in a convenient way using scripts. The menu entry "<span style="color:#3366ff;">'''ERP/Combine Conditions, Channels, Find Peaks'''</span>" allows for grand averaging and creating sums and differences between conditions. It also provides a tool for spatial and temporal resampling, and allows to perform an automatic peak analysis of multiple averaged files. For a detailed description of the 'Combine Conditions, Channels, Find Peaks' functions, please refer to the help chapter "'''[[BESA_Research_Batch_Processing#Combine_Conditions.2C_Channels|Batch Processing and Combining Conditions / Combine Conditions]]'''".
@@ Line 448: / Line 448: @@
 Briefly, the procedure to create triggers for a recurring pattern is as follows:
-. Mark a typical occurrence of the pattern by a left mouse drag.
+. Mark a typical occurrence of the pattern by left mouse drag.
 . Use menu item <span style="color:#3366ff;">'''ERP / Create Triggers from EMG/EEG'''</span> to open the ''Schmitt Trigger'' dialog box.

← Older revision		Revision as of 09:15, 4 May 2021
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−	''The Edit Triggers dialog box is divided into different sections to convert tags to triggers, delete triggers, convert other event types like markers to triggers, and change trigger codes. Creating triggers for spectral processing using the artifact scan tool of the ERP paradigm is covered by a different dialog.''	+	''The'' Edit Triggers ''dialog box is divided into different sections to convert tags to triggers, delete triggers, convert other event types like markers to triggers, and change trigger codes.'' Creating triggers for spectral processing using the artifact scan tool of the ERP paradigm is covered by a different dialog.
		+
		+	''Converting other event types to triggers'': This feature requires BESA Research 7.1 or higher.

	==== Event Files ====		==== Event Files ====

@@ Line 484: / Line 484: @@
 ==== Editing Triggers ====
-Patterns and tags can be converted into trigger events using the <span style="color:#3366ff;"><span style="color:#00000a;">'''''Edit Triggers'''''</span></span><span style="color:#3366ff;"><span style="color:#00000a;"> tool. After conversion, tags found in a pattern search can be used in conditions: they can be analyzed by the paradigm tool which controls and stores the complete pre-averaging process. This facilitates for example the averaging of epileptic spikes which were hand-marked or found by a pattern search (cf. chapter </span></span><span style="color:#3366ff;"><span style="color:#00000a;">''"Review / Searching and Averaging"''</span></span><span style="color:#3366ff;"><span style="color:#00000a;">).</span></span>
+Patterns, tags, and markers can be converted into trigger events using the <span style="color:#3366ff;"><span style="color:#00000a;">'''''Edit Triggers'''''</span></span><span style="color:#3366ff;"><span style="color:#00000a;"> tool. After conversion, tags found in a pattern search can be used in conditions: they can be analyzed by the paradigm tool which controls and stores the complete pre-averaging process. This facilitates for example the averaging of epileptic spikes which were hand-marked or found by a pattern search (cf. chapter </span></span><span style="color:#3366ff;"><span style="color:#00000a;">''"Review / Searching and Averaging"''</span></span><span style="color:#3366ff;"><span style="color:#00000a;">).</span></span>
 The <span style="color:#3366ff;"><span style="color:#00000a;">'''''Edit Triggers'''''</span></span><span style="color:#3366ff;"><span style="color:#00000a;"> tool is also useful to delete triggers which were created earlier, to change trigger codes, or to create triggers for FFT averaging with graphical artifact rejection on the basis of the paradigm tool.</span></span>
@@ Line 494: / Line 494: @@
-''The Edit Triggers dialog box is divided into different sections to convert tags to triggers, delete triggers, change trigger codes, and to create triggers for FFT averaging using the artifact scan tool of the ERP paradigm.''
+''The Edit Triggers dialog box is divided into different sections to convert tags to triggers, delete triggers, convert other event types like markers to triggers, and change trigger codes. Creating triggers for spectral processing using the artifact scan tool of the ERP paradigm is covered by a different dialog.''
 ==== Event Files ====

@@ Line 427: / Line 427: @@
 Please refer to the online help chapter “''ERP / Reference / Viewing and Analyzing Data in the Top View'' for more information.
-=== <span style="color:#3366ff;"><span style="color:#00000a;">Grand Averaging and Combining Conditions </span></span> ===
+=== Grand Averaging and Combining Conditions ===
@@ Line 435: / Line 435: @@
 The ERP Module allows for quick combination of averaged segments, e.g. to create Grand Averages over subjects or to compute weighted sums and differences of conditions.
-Conditions from different recordings/subjects can be combined in a convenient way using scripts. The menu entry "<span style="color:#3366ff;">'''ERP/Combine Conditions, Channels, Find Peaks'''</span>" allows for grand averaging and creating sums and differences between conditions. It also provides a tool for spatial and temporal resampling, and allows to perform an automatic peak analysis of multiple averaged files. For a detailed description of the 'Combine Conditions, Channels, Find Peaks' functions, please refer to the help chapter "''Batch Processing and Combining Conditions / Combine Conditions''".
+Conditions from different recordings/subjects can be combined in a convenient way using scripts. The menu entry "<span style="color:#3366ff;">'''ERP/Combine Conditions, Channels, Find Peaks'''</span>" allows for grand averaging and creating sums and differences between conditions. It also provides a tool for spatial and temporal resampling, and allows to perform an automatic peak analysis of multiple averaged files. For a detailed description of the 'Combine Conditions, Channels, Find Peaks' functions, please refer to the help chapter "'''[[BESA_Research_Batch_Processing#Combine_Conditions.2C_Channels|Batch Processing and Combining Conditions / Combine Conditions]]'''".
 [[Image:ERP Processing (17).gif ]]
 === Managing Triggers ===

← Older revision		Revision as of 13:46, 26 March 2019
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−	[[Image:~~ERP Processing (6)~~.~~gif~~ ]]	+	[[Image:ERP1.png]]

@@ Line 643: / Line 643: @@
 . Set the Schmitt Trigger parameters. The Schmitt Trigger is characterized by 4 parameters:
-* upper threshold: the threshold that the signal has to exceed
+* '''Threshold''' (upper threshold): the threshold that the signal has to exceed
-* lower threshold: the threshold that the signal must not exceed during the dead time before the trigger
+* '''Limit During Dead Time''' (lower threshold): the threshold that the signal must not exceed during the dead time before the trigger
-* dead time: the time interval before the trigger where the signal must be lower than the lower thresholds
+* '''Dead Time (Prior to Trig)''': the time interval before the trigger where the signal must be lower than the lower thresholds
-* return time: the time during which the signal has to return below the threshold
+* '''Return Time (Below Limit)''': the time during which the signal has to return below the threshold

@@ Line 631: / Line 631: @@
 ==== Creating Triggers from EMG/EEG Channels ====
-It is possible to create new trigger events from any of the recorded channels. This is achieved by defining parameters that characterize the features of the event. After the parameters are defined, the whole EEG /MEG is searched for events which match the parameters, and new trigger events are created. The steps to be taken are illustrated in the help tutorial chapter ''"ERP / Functions... / Managing Triggers / Tutorial 2'' ''Creating Triggers from EMG".''
+It is possible to create new trigger events from any of the recorded channels. This is achieved by defining parameters that characterize the features of the event. After the parameters are defined, the whole EEG /MEG is searched for events which match the parameters, and new trigger events are created. The steps to be taken are illustrated in the help tutorial chapter [[BESA_Research_ERP_Processing#Tutorial_2:_Creating_Triggers_from_EMG|"''ERP / Functions... / Managing Triggers / Tutorial 2: Creating Triggers from EMG''"]].
 Briefly, the procedure to create triggers for a recurring pattern is as follows:
@@ Line 646: / Line 646: @@
 * lower threshold: the threshold that the signal must not exceed during the dead time before the trigger
 * dead time: the time interval before the trigger where the signal must be lower than the lower thresholds
-* return time: the time during which the signal has to return below the threshold</div>
+* return time: the time during which the signal has to return below the threshold
@@ Line 668: / Line 668: @@
 ''The waveform of a trigger channel can be rectified and filtered to define trigger events. In the example above, the EMG channel FDIL is scanned for myoclonic discharges. The small window shows the waveform of the marked epoch after appropriate filtering.''
 ==== Editing Triggers ====