Sharon Corina, Joy Geng, Katherine MacLean, Ron Mangun, Jesse Bengson, Bong Walsh
Jane Couperus, Risa Sawaki

Selective attention is a core cognitive function. It is the capacity to attend to and efficiently process relevant inputs, thoughts, and actions while ignoring irrelevant, distracting information. It involves interactive neural mechanisms, including top-down and bottom-up processes. Top-down or “voluntary attention” mechanisms are those that are based on the goals and intentions of the individual. In general, these top-down attentional functions are referred to as attentional control or regulatory processes. Many current models propose that attention influences information processing by biasing activity in sensory, decision and response processes. Attentional biasing is the idea that selective attention influences the outcome of neural competition in neural networks at a variety of stages of information processing. Neural competition arises from the local and global network properties within populations of neurons involved in sensory, cognitive, or motor function, and models of attentional control propose that this competition can be biased in favor of attended inputs, thoughts, and actions in order to facilitate efficient behavior. The resultant biased processes and their outputs can be referred to as attentional selection -- that is, the effective selection of behaviorally relevant inputs, thoughts, and actions.

In contrast to top-down processes, bottom-up or “reflexive attention” mechanisms are triggered by the physical properties of stimuli themselves. Properties such as the saliency of stimuli can lead to attentional orienting that is not controlled directly by voluntary attention systems.  Bottom-up factors and top-down influences interact, sometimes competing for the control of neural processing and therefore behavior. Indeed, top-down attentional regulation is most relevant when goals and strategies are in competition with bottom-up stimulus-driven influences or prepotent response tendencies.

Our laboratory investigates attentional mechanisms using a cognitive neuroscience approach to understand the cognitive and neural mechanisms of voluntary and reflexive attention in humans. We bring to bear a variety of complementary tools to study attention, including behavioral and psychophysical methods, human electrophysiological measures, and functional neuroimaging. Behavioral and psychophysical methods permit us to analyze the properties of the human attention system and how attention influences perception. Recordings of the electroencephalogram (EEG) and evoked responses known as event-related potentials (ERPs) permit a fine-grained view of the temporal properties of attentional control and selection. This is done by placing more than 100 electrodes on the scalp and recording the electrical activity of populations of neurons as the human subjects participate in carefully controlled attention tasks. Finally, functional magnetic resonance imaging (fMRI) is used to investigate the functional brain anatomy of the attention system and where in the brain attention influences various information processing transactions during perception and action.  This work continues with the support of the National Institute of Mental Health (NIMH).

In collaboration with colleagues working in non-human primates, we are investigating the neuronal and local circuit mechanisms of attentional processing in studies that are related to our human work. The research capitalizes on combining investigations in different related species (humans and monkeys) and therefore permits different levels of analysis to be integrated. The activity of single neurons, which cannot easily be studied in humans, can be investigated in monkeys, while widespread human brain networks can be studied using brain imaging in humans. Because the humans and monkeys in this work are required to perform the same tasks while their brains are being studied, the resulting data from each specie and method can be integrated and considered in a common analytical and theoretical framework. This work continues with support from the National Science Foundation (NSF).

Increasingly, the laboratory has developed  new interests in several translational neuroscience topics, including work in autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). In this work we intent to bring our two decades of basic science investigation to bear on issues that represent major mental health problems. Because selective attention is a core cognitive process, elucidating attentional mechanisms in humans remains a high priority in efforts to understand, diagnose and treat psychiatric conditions that involve deficits in attention, including ADHD, autism and schizophrenia. This work continues with the support of NIMH and private donations.