Large‐scale neurocognitive networks and distributed processing for attention, language, and memory

Abstract

Cognition and comportment are subserved by interconnected neural networks that allow high-level computational architectures including parallel distributed processing. Cognitive problems are not resolved by a sequential and hierarchical progression toward predetermined goals but instead by a simultaneous and interactive consideration of multiple possibilities and constraints until a satisfactory fit is achieved. The resultant texture of mental activity is characterized by almost infinite richness and flexibility. According to this model, complex behavior is mapped at the level of multifocal neural systems rather than specific anatomical sites, giving rise to brain-behavior relationships that are both localized and distributed. Each network contains anatomically addressed channels for transferring information content and chemically addressed pathways for modulating behavioral tone. This approach provides a blueprint for reexploring the neurological foundations of attention, language, memory, and frontal lobe function.

Electrophysiological response patterns of primary sensory cortices in migraine

“…When applied to EP findings in migraineurs this model would explain both the low first block amplitude for most EP components and lack of habituation on trial repetition. The preactivation level of cortical excitability depends on the so-called "state-setting, chemically addressed connections" that originate in the brainstem and involve serotonin and noradrenaline as transmitters [67,90]. Low interictal activity of these systems, especially of the raphe-cortical serotonergic pathway, could indeed be responsible in migraineurs for the observed electrophysiological abnormalities [91].…”

Selective deficits in verbal working memory associated with a known genetic etiology: The neuropsychological profile of Duchenne muscular dystrophy

“…Dystrophin products localized to neurons are only found in the soma and dendrites (not the axon) and tend to aggregate at the postsynaptic densities, suggesting a possible role in synaptic function (Dorbani-Mamine et al, 1998;Jancsik & Hajos, 1998;Kim et al, 1992;Lidov et al, 1990;Uchino et al, 1994a). Further, dystrophin products in the central nervous system are found more in the cerebral and cerebellar cortices than in lower brain structures (Gorecki et al, 1998(Gorecki et al, ,1992Kimura et al, 1997;Lidov et al, 1990;Tian et al, 1996;Uchino et al, 1994a,b), and various theories of the neuroanatomical basis of working memory and/or attention have localized these abilities to cortical areas (Baddeley, 1986;Goldman-Rakic, 1988;Mesulam, 1990;Posner & Peterson, 1990). Future neurobiological work examining the role of dystrophin in the development of the brain may offer greater insight into the neurological basis of verbal working memory.…”

Semantic disturbance in schizophrenia and its relationship to the cognitive neuroscience of attention

“…Shastri and Ajjanagadde, 1993). These networks in turn help form wide-scale neural computational systems of perception, memory, language and other higher-order cognitive modules in which the role of attention is to insure the fidelity of computational contents (Mesulam, 1990). Thus in this model, brain and attention are composed of constituent operations and processes that are supported by discrete local circuits that act in concert to form widely-distributed networks and large-scale systems.…”