The Miller Lab @ MIT

O’Neill and Schultz showed subjects visual stimuli that indicated different levels of risk. They found that orbitofrontal neurons reflected the discrepancy between current and predicted risk.

John Duncan provides an excellent review of the role of the frontal and parietal cortex in higher level cognition.  He argues that they form a multiple-demand (MD) network.  Neurons in this MD network have multiple functions, flexibly adapting their coding to signal different things in different tasks.    Duncan argues that they play a critical role in subdividing complex problems and organizing a coherent sequence of focused parts or subgoals.  The MD network construction of these attentional episodes is thought to be a core function for complex cognition and this function is central to fluid intelligence.

Crowe et al recorded simultaneously from the prefrontal and parietal cortices during a visuospatial categorization task.  By examining simultaneous fluctuations in information, they provided evidence that the signals reflecting the rule-dependent categories were transmitted in a top-down fashion from the prefrontal to the parietal cortex.  The prefrontal cortex has long been thought to be the source of top-down “executive” signals.  However, until recently, direct evidence for this has been rare.  This study adds to a growing body of literature that has provided this evidence by using multiple-electrode recording to examine the temporal dynamics of neural signals (e.g., Buschman and Miller, 2007; Ibos et al, 2013).