Decoding the Spike-Band Subthreshold Motor Cortical Activity

Okatan M., KOCATÜRK M.

Journal of Motor Behavior, vol.56, no.2, pp.161-183, 2024 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 56 Issue: 2
  • Publication Date: 2024
  • Doi Number: 10.1080/00222895.2023.2280263
  • Journal Name: Journal of Motor Behavior
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Social Sciences Citation Index (SSCI), Scopus, Academic Search Premier, IBZ Online, BIOSIS, CINAHL, Educational research abstracts (ERA), Psycinfo, SportDiscus
  • Page Numbers: pp.161-183
  • Keywords: amplitude thresholds, neural noise, population activity, primary motor cortex, spiking
  • Istanbul Medipol University Affiliated: Yes


Intracortical Brain-Computer Interfaces (iBCI) use single-unit activity (SUA), multiunit activity (MUA) and local field potentials (LFP) to control neuroprosthetic devices. SUA and MUA are usually extracted from the bandpassed recording through amplitude thresholding, while subthreshold data are ignored. Here, we show that subthreshold data can actually be decoded to determine behavioral variables with test set accuracy of up to 100%. Although the utility of SUA, MUA and LFP for decoding behavioral variables has been explored previously, this study investigates the utility of spike-band subthreshold activity exclusively. We provide evidence suggesting that this activity can be used to keep decoding performance at acceptable levels even when SUA quality is reduced over time. To the best of our knowledge, the signals that we derive from the subthreshold activity may be the weakest neural signals that have ever been extracted from extracellular neural recordings, while still being decodable with test set accuracy of up to 100%. These results are relevant for the development of fully data-driven and automated methods for amplitude thresholding spike-band extracellular neural recordings in iBCIs containing thousands of electrodes.