Neuronal Signal Dynamics during Preparation and Execution for Behavioral Shifting in Macaque Posterior Parietal Cortex

Abstract

Cognitive flexibility arises from our ability to shift behaviors depending on demand changes. Behavioral shifting recruits both a preparatory process for an upcoming behavior and an execution process for the actual behavior. Although neuroimaging studies have shown that several brain regions, including posterior parietal cortex (PPC) participated in each component process, it remains unresolved how such processes are implemented at the single-cell level or even whether these processes are distinctively carried out across microstructures in such regions. By recording single-unit activity from PPC of two monkeys performing an analog of the Wisconsin Card Sorting Test, we found that, in the execution process, two types of neurons exhibited activity modulation depending on whether shift was (shift trial) or was not required (nonshift trial): one type showing larger activity and the other showing smaller activity in the shift trial than in the nonshift trial. In the preparatory process, in contrast, the population activity of both types became larger in the shift trial than in the nonshift trial. The majority of both types exhibited shift-related activity modulation in both processes, whereas the remaining was specialized in the execution process. The former and the latter neurons were spatially intermingled within PPC. Significantly, when the animals performed set shifting spontaneously in prospect of a demand change, the shift-related activity modulation still emerged in both processes. We suggest that both execution and preparation signals are represented within PPC, and that these signals reflect behavioral shifting mechanisms that can be driven by either internal or external triggers.

Dimensions of Attention Associated With the Microstructure of Corona Radiata White Matter

“…Our findings also add to the neurobiological basis of the shift dimension by showing significant relationships bilaterally between the shift dimension and the superior and posterior corona radiate diffusion tensor imaging measures. This finding corroborates data where authors found activation of the posterior parietal cortex of primates during set-shifting 35 .…”

Executive Control Over Cognition: Stronger and Earlier Rule-Based Modulation of Spatial Category Signals in Prefrontal Cortex Relative to Parietal Cortex

“…Other work on the neural mechanisms of executive control has shown that neurons participating in rule-dependent computations are found both within posterior parietal cortex (Stoet and Snyder, 2004; Asari et al, 2005; Kamigaki et al, 2009, 2011) and prefrontal cortex (Wallis et al, 2001; Nakahara et al, 2002; Mansouri et al, 2006; Muhammad et al, 2006). A recent study of particular relevance characterized the neural mechanisms of executive control in prefrontal cortex specifically as it applied to object categorization (Roy et al, 2010).…”

Neurodynamics of Cognitive Set Shifting in Monkey Frontal Cortex and Its Causal Impact on Behavioral Flexibility

“…The activity of single neurons was recorded extracellularly from the posterior bank of the inferior arcuate region (Petrides, Cadoret, & Mackey, 2005;Romo, Hernández, & Zainos, 2004;Kurata & Hoffman, 1994;Kurata & Tanji, 1986;Figure 2;ipsilateral [left] hemispheres in Monkeys I and Y and both contralateral and ipsilateral hemispheres [left and right] in Monkey M) using a glass-coated tungsten or elgiloy microelectrode (Kamigaki et al, 2009(Kamigaki et al, , 2011; ∼1 MΩ at 1 kHz). The microelectrode was advanced through the intact dura mater into the cortex along a stainless steel guide tube using a hydraulic micromanipulator (MO-95C, Narishige, Tokyo).…”