Human and Monkey Studies of Attentional Control Networks

University Of California-Davis, Davis CA

Investigators

Abstract

Visual selective attention is a core cognitive ability that enables humans and animals to focus on behaviorally relevant stimuli while minimizing interference from irrelevant and/or distracting events. Several current theoretical models have proposed that cortical brain regions interact with subcortical brain structures to form a control network for voluntary attention. This control network exerts modulatory influences over the transmission of the visual signals in the sensory pathways that result in attentional filtering of visual inputs. In particular, the pulvinar, a subcortical thalamic structure, has been implicated as a key part of the attentional control network, but relatively little is known about the neurophysiological mechanisms involved. With support from the National Science Foundation, Dr. George R. Mangun and Dr. W. Martin Usrey of the University of California at Davis will explore the neural mechanisms of attentional control, especially with respect to the role of the subcortical pulvinar nuclei of the thalamus. This project will combine studies in humans and monkeys. In healthy human volunteers, brain scanning using functional and structural magnetic resonance imaging will be used to identify the neuroanatomical systems involved in attentional processing and to assess the role of the pulvinar in attentional control. In awake monkeys, electrical recordings from the pulvinar and early visual cortical areas will be used to investigate the mechanisms of attentional processing at the level of single brain cells and small networks of neurons. Whether driving a car, listening to safety instructions, or concentrating on correctly preparing tax returns, attention supports successful performance. How the brain enables attention is of central interest for understanding how humans and animals function in a complex, and often demanding, environment. This research will test a specific hypothesis about the brain mechanisms that support successful attention. The research will capitalize on combining investigations in different related species (humans and monkeys) and will therefore permit different levels of analysis to be integrated. The activity of single neurons, which cannot easily be studied in humans, will be investigated in monkeys, while widespread human brain networks will be studied using brain imaging in humans. Because the humans and monkeys will be required to perform the same tasks while their brains are being studied, the resulting data from each species and method will be able to be integrated and considered in a common analytical and theoretical framework. The information from this research will provide a basic understanding of an essential ability in human thought and action, and will also provide information that can be used in ameliorating disorders of attention and improving attentional abilities in patients and healthy individuals.