The Symmetry span task is a complex span partner to the matrix span task. The participant is shown a series of grid locations one-by-one form the 4x4 grid in the center of the screen. The participant must remember the grids and the order in which they appeared. Afer each grid is shown the participant is shown an 8x8 grid that has a number of grids filled black to form a pattern. The pattern will either be symmetrical along the vertical axis or it will not and the participant must make this judgement using the left/right arrow keys before the next grid will be shown.

# Task Details

## Screenshots

#### Presentation Phase

#### Recall Phase

# The XML

number of trials

randomised trials

matrix size

symmetry matrix dimensions/size

symmetry pattern fill range

You can download the default XML here. In this section I will point out the customisation options at your disposal by modifying values in the XML.

Under task settings there is a section of code where we tell the application where to find the executable that handles the digit span task. The property name/value keys here are where we can set task-specific properties.

### Storage Phase

This set of customisable properties relate to the storage component of the task, therefore they are the same as described for the simple span counterpart (matrix span. These properties are found in the bean with id "symm_span".

#### Number of trials

You can select how many trials of each span size you want. The properties to edit here are:

- 'spanTwoTrials'
- 'spanThreeTrials'
- 'spanFourTrials'
- 'spanFiveTrials'
- 'spanSixTrials'
- 'spanSevenTrials'
- 'spanEightTrials'
- 'spanNineTrials'

#### Sequential/Randomised trial order

This property decides if the trials are administered in sequential order or not with regards to the list lengths. If sequential then all list length 2 trials are given, followed by all list length 3 trials, and so forth. However, it is often the case that a researcher may wish to administer these trials in a random order so that the participant is not aware on any given trial how many digits they will have to store/recall. The property to edit is:

- 'randomisedTrials'

#### Matrix Size

It is possible to select how many grids you would like in the matrix. The property responsible is:

- gridDimension

In addition there is an option to control the actual size (on screen) of the matrix.

- ScalingFactor

### Processing Phase

This set of customisable properties relate to the processing component of the task where the participants are shown a grid with a pattern filled and must make a judgement on whether it is symmetrical. These properties are found in the bean with id "symm_processing".

#### Symmetry grid size

What do you want the dimensions of the matrix to be that delivers the pattern? The default value is "8" which produces an 8x8 grid with a pattern filled.

- GridDimension

- ScalingFactor

#### Pattern fill range

You can also control how many squares are used to make the patterns in the symmetry grid.

- MinSquares
- MaxSquares

# Data Analysis

After running the symmetry span processing script (download from here) you will get a data frame with the following variables. Information on running the script and obtaining the processed data is here

Variable Name | Description |
---|---|

fta.score | This is the score the participant achieved when the full-trial accuracy scoring method is used. |

prop.score | The score obtained by the participant when the proportion correct method of scoring is used. |

number.successes | The score obtained by the participant when the number of correctly recalled elements method of scoring is used. |

processing.accuracy | The proportion of the symmetry judgements that were successfully answered. |

processing.median.rt | The median response time for answering during the processing phase. |

max.span | Maximum list length at which the participant successfully recalled all the elements in the trial. |

span.2.corr | Number of trials successfully answered (all grids recalled) at list length 2 - "NA" value if there were no trials at this list length administered |

span.3.corr | Number of trials successfully answered (all grids recalled) at list length 3 - "NA" value if there were no trials at this list length administered |

span.4.corr | Number of trials successfully answered (all grids recalled) at list length 4 - "NA" value if there were no trials at this list length administered |

span.5.corr | Number of trials successfully answered (all grids recalled) at list length 5 - "NA" value if there were no trials at this list length administered |

span.6.corr | Number of trials successfully answered (all grids recalled) at list length 6 - "NA" value if there were no trials at this list length administered |

span.7.corr | Number of trials successfully answered (all grids recalled) at list length 7 - "NA" value if there were no trials at this list length administered |

span.8. corr | Number of trials successfully answered (all grids recalled) at list length 8 - "NA" value if there were no trials at this list length administered |

span.9.corr | Number of trials successfully answered (all grids recalled) at list length 9 - "NA" value if there were no trials at this list length administered |

user | The value of the username of the account which produced the data |