Time representing cortical activities: two models inspired by prefrontal persistent activity

Area of Science:

• Neuroscience
• Computational Neuroscience
• Cognitive Science

Background:

• Behavior is closely linked to timing perception, comparison, and generation, particularly in the second range.
• Understanding the neural underpinnings of these timing-dependent cognitive behaviors is crucial but remains limited.
• The prefrontal cortex is implicated in various timing-related tasks.

Purpose of the Study:

• To model two distinct neural mechanisms for representing timing information in the seconds range.
• To explore how these mechanisms relate to observed prefrontal cortex activities during timing tasks.

Main Methods:

• Developed a recurrent network model of bistable spiking neurons to represent internal time durations.
• Utilized synfire chains and spike-timing-dependent plasticity to model the prediction of event timing.
• Inspired model parameters by analyzing prefrontal cortex activity in monkeys performing timing tasks.

Main Results:

• The bistable neuron network model demonstrated a quasistable state lasting seconds, potentially representing internal time.
• The synfire chain model showed how neural populations can be conditioned to predict event timing.
• Both models offer plausible neural substrates for timing-related behaviors observed in the prefrontal cortex.

Conclusions:

• Two distinct neural mechanisms can account for the representation of timing information in the seconds range.
• The prefrontal cortex likely plays a key role in providing the necessary timing information for organizing complex behaviors.