Reading spike timing without a clock: intrinsic decoding of spike trains.
The precise timing of action potentials of sensory neurons relative to the time of stimulus presentation carries substantial sensory information that is lost or degraded when these responses are summed over longer time windows. However, it is unclear whether and how downstream networks can access information in precise time-varying neural responses. Here, we review approaches to test the hypothesis that the activity of neural populations provides the temporal reference frames needed to decode temporal spike patterns. These approaches are based on comparing the single-trial stimulus discriminability obtained from neural codes defined with respect to network-intrinsic reference frames to the discriminability obtained from codes defined relative to the experimenter's computer clock. Application of this formalism to auditory, visual and somatosensory data shows that information carried by millisecond-scale spike times can be decoded robustly even with little or no independent external knowledge of stimulus time. In cortex, key components of such intrinsic temporal reference frames include dedicated neural populations that signal stimulus onset with reliable and precise latencies, and low-frequency oscillations that can serve as reference for partitioning extended neuronal responses into informative spike patterns.
Institute of Neuroscience and Psychology, University of Glasgow, , Glasgow G12 8QB, UK.
Stefano
S
Panzeri
Robin A A
RA
Ince
Mathew E
ME
Diamond
Christoph
C
Kayser
D000200:Action Potentials / Q000502:physiology*; D006801:Humans; D007257:Information Theory; D008959:Models, Neurological; D011984:Sensory Receptor Cells / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*; D013997:Time Factors; D013998:Time Perception / Q000502:physiology*
decoding; information theory; neural code; oscillations; sensation; spike patterns