When you go to the market, your senses encounter a staggering amount of stimulation. You are focused on the watermelon stand, at the far end of your purview. However, while making your way there, you have to filter out the pungent fish, assorted cuts of beef, spice racks, and aromatic displays of breads and cheeses. In this crowded environment, you also mind your personal space but ignore the endless chatter of throng of shoppers and loud shouts of merchants advertising their goods, all of which are irrelevant to your present goal: picking a watermelon that looks, weighs and sounds right1. Your ability to select the things you care about and ignore distractions is a crowning achievement of human cognition, called Attention.
Most research on attention investigates how sensory responses are affected by attention and thus takes into account the organizing principles of the brain areas devoted to each sensory modality. In the visual system, investigations often emphasize the effect of spatial attention on topographically organized cortices. These principles have been useful when studying attentional modulation of perception within a given modality. However, emphasizing principles unique to different brain systems may limit our accounts of mechanisms that coordinate information processing in different brain systems, a primary role for attention.
The objective of my research is to go beyond modality based description of attention and identify canonical principles of attention that are domain-general. My hypothesis is that temporal structure -- the unfolding of cognitive functions over time -- provides a domain independent organizing principle in the guidance and allocation of attention. My lab uses a variety of approaches (psychophysics, physiology, eye tracking, and individual differences) to describe the temporal structure of attention in different domains. We hypothesize that temporal properties of attention form an organizing, domain-general, principle.
In recent studies[1, 2], I have shown that a rhythmic temporal structure guides attention in the visual spatial domain. The cognitive system samples relevant objects at a rate of eight times a second (8 Hz). When attention is distributed between two competing objects, each of these objects is sampled in alternation, four times a second. I labeled this phenomenon “attentional sampling”. My research program seeks to uncover domain-general principles that govern and coordinate the guidance of attention. The discovery of attentional sampling in vision provides a paradigm for investigating domain-general attentional sampling within and between modalities which my group will pursue in the coming years.
Systems neuroscience research has shown that rhythmic temporal structure in neural responses promotes and organizes communication between brain regions. In an analogous manner to the efforts of understanding coordinated neural responses , I investigate how attentional sampling provides a domain-general code for coordinating cognitive functions engaging different systems. Uncovering this code will provide a connection between attention at the market place and attention in the lab. In addition to shedding light on the way that attentional processes unfold in healthy individuals, this research program will also contribute to our understanding of pathologies impacting attention (e.g., attention disorder deficits, hemi-spatial neglect) and inform interventions inspired by the unraveled architecture of attention.