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, 401.87it/s]

compute_waveforms (no parallelization):   0%|          | 0/10 [00:00<?, ?it/s]
compute_waveforms (no parallelization): 100%|██████████| 10/10 [00:00<00:00, 334.97it/s]

noise_level (no parallelization):   0%|          | 0/20 [00:00<?, ?it/s]
noise_level (no parallelization): 100%|██████████| 20/20 [00:00<00:00, 274.29it/s]

Fitting PCA:   0%|          | 0/10 [00:00<?, ?it/s]
Fitting PCA: 100%|██████████| 10/10 [00:00<00:00, 138.77it/s]

Projecting waveforms:   0%|          | 0/10 [00:00<?, ?it/s]
Projecting waveforms: 100%|██████████| 10/10 [00:00<00:00, 1373.34it/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   1.067009                   0.0  ...     0.821477      0.021916
1   3.774984                   0.0  ...     0.787970      0.023316
2  28.125997                   0.0  ...     0.910000      0.006545
3  17.369948                   0.0  ...     0.874026      0.015538
4  26.680813                   0.0  ...     0.957500      0.004482
5   9.096503                   0.0  ...     0.843478      0.018097
6   8.593956                   0.0  ...     0.779310      0.022613
7  12.506880                   0.0  ...     0.825564      0.019379
8   9.561181                   0.0  ...     0.839726      0.021713
9  23.902758                   0.0  ...     0.918797      0.005450

[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    False
1    False
2     True
3     True
4     True
5     True
6    False
7     True
8     True
9     True
dtype: bool
['2', '3', '4', '5', '7', '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): 7 units - 1 segments - 25.0kHz
NumpyFolder (NumpyFolderSorting): 7 units - 1 segments - 25.0kHz
Unit IDs
    ['2' '3' '4' '5' '7' '8' '9']
Annotations
  • name : GroundTruthSorting
Properties
    gt_unit_locations[[27.058624 29.117393 20.088305 ] [-8.512754 12.31634 27.978498 ] [29.29864 8.7452545 7.502887 ] [ 3.3559396 21.63203 11.517672 ] [-0.39902905 29.59485 36.942146 ] [29.9122 8.652286 38.899067 ] [17.706957 -6.4207563 30.860006 ]]


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 - 7 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 0.594 seconds)

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