Quadrant time and quadrant entries

In probe trials, a significant preference for the target quadrant, with the platform in the centre of the quadrant, shows spatial memory regardless of start point. It is useful only when platforms sit at quadrant centres; otherwise use close encounters and Gallagher proximity.

Subjects with strong spatial memory may quickly realise the platform is not there and search elsewhere, so a time slice can reveal an early preference hidden in whole-trial values (Blokland et al., 2004, found quadrant measures may overestimate spatial ability). Maei et al. (2009) found mean proximity outperformed quadrant occupancy in detecting group differences.

Entry counts show how broadly the subject explored, which time in quadrant cannot: a single long visit and many short ones look the same in cumulative time. Sequential visits suggest chaining, repetitive switches suggest perseveration, and an early direct entry suggests initial spatial memory.

Ordered entries (including doubling back) can be saved as .qad text files for sequence analysis, useful in models of rigidity, perseveration or procedural strategy use.

Set a slice start and duration in ‘Advanced’ to re-run plots and measures on that window, including in batch. The first 10–20 seconds after release are the best indicator of where the animal expects the platform to be.

Blokland et al. (2004) analysed a 2 min probe in four 30-s intervals: target quadrant preference was present in each, but annulus time changed across intervals, and they concluded that 60-s probes may underestimate spatial ability. Slices do not give heading angle or close-encounter measures, and Direct Path classifications are not produced for slices.

Quadrants start at NE and go clockwise (on screen the layout is 4 1 / 3 2), and results include the platform number used. Whole-trial quadrant time can mislead, so use average speed as a control and time slices.

Quadrant time is also useful during learning to see strategy develop, and in reversal to detect perseveration in the old quadrant. The software's quadrants are fixed, so N/S/E/W-centred quadrants need a custom module or a change of set-up.

Sequential visits round the quadrants suggest chaining; repeated switching suggests perseveration; an early direct entry suggests initial memory; a random order suggests no strategy.

With the quads-list box checked, ordered entries (including doubling back) are saved as .qad text files. Quadrants are NE, SE, SW, NW with North at the top of the image.

Slice latency is the time to reach the platform within that slice, or the slice duration if the platform is not reached in it. Name each results file after its slice. Probe analyses often use the first 10–20 s.

Slices do not give heading angle or close encounter measures; latency and path are shorter and target quadrant % may be larger. Slice plots omit start, heading and end markers.