presence_ratio.rst

Presence ratio (presence_ratio)

Calculation

Presence ratio is the proportion of discrete time bins in which at least one spike occurred.

$$\textrm{presence ratio} = \frac{B_s}{B_s + B_n}$$

• B_s : number of bins in which spikes occurred.
• B_n : number of bins in which no spikes occurred.

Expectation and use

Complete units are expected to have a presence ratio of 90% or more. Low presence ratio (close to 0) can indicate incompleteness (type II error) or highly selective firing pattern.

Example code

import spikeinterface.qualitymetrics as qm

# Make recording, sorting and wvf_extractor object for your data.

presence_ratio = qm.compute_presence_ratios(wvf_extractor)
# presence_ratio is a dict containing the units' ID as keys
# and their presence ratio (between 0 and 1) as values.

Links to original implementations

• From the AllenSDK

References

spikeinterface.qualitymetrics.misc_metrics.compute_presence_ratios

Literature

Unknown origin.