Neural Variability in Premotor Cortex Is Modulated by Trial History and Predicts Behavioral Performance

Abstract

In the study of decision making, emphasis is placed on different forms of perceptual integration, while the influence of other factors, such as memory, is ignored. In addition, it is believed that the information underlying decision making is carried in the rate of the neuronal response, while its variability is considered unspecific. Here we studied the influence of recent experience on motor decision making by analyzing the activity of neurons in the dorsal premotor area of two monkeys performing a countermanding arm task. We observe that the across-trial variability of the neural response strongly correlates with trial history-dependent changes in reaction time. Using a theoretical model of decision making, we show that a trial history-monitoring signal can explain the observed behavioral and neural modulation. Our study reveals that, in the neural processes that culminate in motor plan maturation, the evidence provided by perception and memory is reflected in mean rate and variance respectively.

Distinct dynamics of ramping activity in the frontal cortex and caudate nucleus in monkeys

“…(Brostek et al 2013). It has been especially useful as a signature of neural computations related to temporal accumulation in the context of decision making (Churchland et al 2011;de Lafuente et al 2015;Marcos et al 2013). Specifically, a doubly stochastic Poisson process can generate different patterns of VarCE and temporal correlation, depending on whether or not the underlying rate parameter is a direct product of temporal accumulation (Churchland et al 2011): Accumulation results in upward-ramping mean spike count, VarCE, and correlation, whereas time-independent samples with the same upward-ramping mean spike count produce much dampened VarCE and flat correlation.…”

Correction and suppression of reaching movements in the cerebral cortex: Physiological and neuropsychological aspects

“…One possibility is that SMA activity determines the response threshold for initiating a movement (Chen et al, 2010). A second plausible recent proposal is that a contribution of the pre-SMA/SMA complex is in modulating the proactive control of movement inhibition and participating in performance monitoring (Marcos et al, 2013;Scangos et al, 2013;Stuphorn and Emeric, 2012).…”

The influence of recent decisions on future goal selection

“…These parameters yield a measure of the reactive response to stop signal presentation, which is also referred to as the stop signal reaction time (SSRT). A well-described effect of proactive control in this task is the elongation of the RT in go trials following trials with stop signal presentation [30], which corresponds to an increased probability of success in case of a further stop trial appearance [28,31]. The observation that a recent trial sequence can influence performance in the countermanding task suggests that factors other than the outcome of the two competitive processes in the race might play a role [27,29,30,[32][33][34][35][36].…”

“…In the PMd (right portion of the panel), the average neural activity is not modulated by changes in the trial history. Conversely, the neural variability (bottom right) increases in go trials following stop signal presentation, which predicts RT elongation (see also [28] Unfortunately, the role of the PM regions has not yet been fully explored in humans (but see [45]). …”