Scientific Understanding of Consciousness
Prefrontal regions are reciprocally connected with temporal, parietal, and occipital cortices, where they receive higher-level visual, auditory, and somatosensory information. (Miller; Human Frontal Lobes, 49)
Prefrontal regions have strong connections with limbic structures such as the hippocampus and amygdala, which mediate processes such as learning and memory, emotional and affective tone, autonomic regulation, drive, and motivation. (Miller; Human Frontal Lobes, 49)
Dopamine in Prefrontal Cortex
Prefrontal cortex receives a rich supply of axons containing dopamine. (LeDoux; Synaptic Self, 189)
Dopamine cell bodies are located in the ventral tegmental area of the brain stem. Axons of these cells branch extensively into the forebrain where the terminals release dopamine. (LeDoux; Synaptic Self, 189)
Dopamine receptors located on the spines and shafts of dendrites of excitatory cells seem to reduce the transfer of excitation from the dendrites to the cell bodies, allowing only especially strong excitatory inputs to elicit excitation. (LeDoux; Synaptic Self, 189)
Dopamine participates in working memory by biasing cells to mainly respond to strong inputs and thereby focusing attention on active current goals and away from distracting stimuli. (LeDoux; Synaptic Self, 189)
(paraphrase of Eichenbaum, Cognitive Neuroscience of Memory, 313ff)
Anatomy of the prefrontal cortex
The assignment of the central executive function to the prefrontal cortex is supported by substantial anatomical data. The phenomenal expansion of the prefrontal area in primates and especially humans is impressively associated with the evolution of cognitive capacities. The prefrontal cortex in humans is a diverse area, composed of several distinct subdivisions. There is considerable consensus on correspondences in monkeys with identified areas in the human prefrontal cortex. Although several anatomical areas have been characterized based on morphological appearance, most of the functional evidence has been related to four general regions. These include the medial, dorsolateral, ventrolateral, and orbital areas. Most of the attention with regard to working memory functions in monkeys and humans has focused on the dorsolateral and ventrolateral areas, and these areas are partially distinct in their connections with more posterior parts of the cerebral cortex. Each of the subdivisions receives input from a diverse set of rostral and causal cortical areas, and each has a distinctive input pattern.
In addition, prefrontal areas are characterized by considerable associative connections with other prefrontal areas. Nevertheless, despite this diversity and associativity with the prefrontal cortex, a few generalities have emerged about distinctions among prefrontal areas with regard to their inputs from posterior cortical areas. Thus, in general, the dorsolateral prefrontal area receives inputs mainly from medially and dorsolaterally located cortical areas that preferentially represent somatosensory and visuospatial information. Conversely, in general, the lateral prefrontal areas receive inputs mainly from ventrolateral and ventromedial cortical areas that represent auditory and visual pattern information. In particular, the differentiation of visuospatial input to the dorsolateral prefrontal area, and visual pattern input to the lateral prefrontal area has received considerable attention in studies on distinct working memory systems.
(end of paraphrase)