Curation Tutorial

After spike sorting and computing quality metrics, you can automatically curate the spike sorting output using the quality metrics that you have calculated.

Import the modules and/or functions necessary from spikeinterface

import spikeinterface.core as si

Let’s generate a simulated dataset, and imagine that the ground-truth sorting is in fact the output of a sorter.

recording, sorting = si.generate_ground_truth_recording()
print(recording)
print(sorting)
GroundTruthRecording (InjectTemplatesRecording): 4 channels - 25.0kHz - 1 segments
                      250,000 samples - 10.00s - float32 dtype - 3.81 MiB
GroundTruthSorting (NumpySorting): 10 units - 1 segments - 25.0kHz

Create SortingAnalyzer

For this example, we will need a SortingAnalyzer and some extensions to be computed first

analyzer = si.create_sorting_analyzer(sorting=sorting, recording=recording, format="memory")
analyzer.compute(["random_spikes", "waveforms", "templates", "noise_levels"])

analyzer.compute("principal_components", n_components=3, mode="by_channel_local")
print(analyzer)
estimate_sparsity (no parallelization):   0%|          | 0/10 [00:00<?, ?it/s]
estimate_sparsity (no parallelization): 100%|██████████| 10/10 [00:00<00:00, 487.88it/s]

compute_waveforms (no parallelization):   0%|          | 0/10 [00:00<?, ?it/s]
compute_waveforms (no parallelization): 100%|██████████| 10/10 [00:00<00:00, 348.71it/s]

noise_level (no parallelization):   0%|          | 0/20 [00:00<?, ?it/s]
noise_level (no parallelization): 100%|██████████| 20/20 [00:00<00:00, 281.94it/s]

Fitting PCA:   0%|          | 0/10 [00:00<?, ?it/s]
Fitting PCA: 100%|██████████| 10/10 [00:00<00:00, 180.54it/s]

Projecting waveforms:   0%|          | 0/10 [00:00<?, ?it/s]
Projecting waveforms: 100%|██████████| 10/10 [00:00<00:00, 2623.74it/s]
SortingAnalyzer: 4 channels - 10 units - 1 segments - memory - sparse - has recording
Loaded 5 extensions: random_spikes, waveforms, templates, noise_levels, principal_components

Then we compute some quality metrics:

metrics_ext = analyzer.compute("quality_metrics", metric_names=["snr", "isi_violation", "nearest_neighbor"])
metrics = metrics_ext.get_data()
print(metrics)
         snr  isi_violations_ratio  ...  nn_hit_rate  nn_miss_rate
0   9.550875                   0.0  ...     0.802581      0.024819
1   6.559130                   0.0  ...     0.811765      0.026853
2  16.254619                   0.0  ...     0.863804      0.019124
3  38.071867                   0.0  ...     0.929936      0.003779
4  27.614734                   0.0  ...     0.896732      0.006087
5   5.504213                   0.0  ...     0.785034      0.022367
6   6.504990                   0.0  ...     0.786765      0.017752
7   0.973576                   0.0  ...     0.750649      0.024801
8  10.940392                   0.0  ...     0.812766      0.024282
9  12.656074                   0.0  ...     0.829299      0.021076

[10 rows x 5 columns]

We can now threshold each quality metric and select units based on some rules.

The easiest and most intuitive way is to use boolean masking with a dataframe.

Then create a list of unit ids that we want to keep

keep_mask = (metrics["snr"] > 7.5) & (metrics["isi_violations_ratio"] < 0.2) & (metrics["nn_hit_rate"] > 0.80)
print(keep_mask)

keep_unit_ids = keep_mask[keep_mask].index.values
keep_unit_ids = [unit_id for unit_id in keep_unit_ids]
print(keep_unit_ids)
0     True
1    False
2     True
3     True
4     True
5    False
6    False
7    False
8     True
9     True
dtype: bool
['0', '2', '3', '4', '8', '9']

And now let’s create a sorting that contains only curated units and save it.

curated_sorting = sorting.select_units(keep_unit_ids)
print(curated_sorting)


curated_sorting.save(folder="curated_sorting", overwrite=True)
GroundTruthSorting (UnitsSelectionSorting): 6 units - 1 segments - 25.0kHz
NumpyFolder (NumpyFolderSorting): 6 units - 1 segments - 25.0kHz
Unit IDs
    ['0' '2' '3' '4' '8' '9']
Annotations
  • name : GroundTruthSorting
Properties
    gt_unit_locations[[26.456076 22.340033 44.60738 ] [-1.7142388 -8.898202 49.796104 ] [25.857384 26.384842 10.055858 ] [ 0.42740878 8.674909 8.462751 ] [-4.4521766 10.816391 38.197483 ] [13.575532 8.800223 25.278723 ]]


We can also save the analyzer with only theses units

clean_analyzer = analyzer.select_units(unit_ids=keep_unit_ids, format="zarr", folder="clean_analyzer")

print(clean_analyzer)
SortingAnalyzer: 4 channels - 6 units - 1 segments - zarr - sparse - has recording
Loaded 6 extensions: random_spikes, waveforms, templates, noise_levels, principal_components, quality_metrics

Total running time of the script: (0 minutes 0.543 seconds)

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