Attempting to understand the ‘hard problem’ of conscious experience through the lens of attention requires a discussion of what we mean by visual attention. This can be challenging since there are many forms of attention that work on several levels, both within and outside of our conscious experience.
First of all, what do we mean by ‘visual attention’? Visual attention is a mechanism (or group of mechanisms) that selectively filters visual information and serves the purpose of helping an organism perform actions, such as navigating through space, finding food, finding mates, avoiding predators, and more complex things such as using tools. We need not be aware of this selective visual information processing—in fact, most of it happens outside of conscious awareness and there are many studies that provide support for that claim, at least in humans (there’s a good review by van Boxtel et al., 2010). [Note that this discussion of attention implicitly needs to address how it interacts with memory systems, but we can simply focus on attention for our purposes here. And while we only focus on visual attention, since it has been studied extensively, our claims also apply to other modalities and conceptual forms of attention.]
Visual attention comes in various forms. It can be feature-based (attention to specific features such as color, segment orientation, or motion), spatial (attention to the layout of features), or object-based (attention to things that display object-like properties, such as cohesive set of features with a ‘common fate’). This is a rudimentary way to categorize the types of information that visual attention can process and operate upon. It becomes more complicated when you look at cross-modal attention (information from auditory, visual, or haptic sources), as this requires a ‘workspace’ where the different forms of attention within and across modalities can be unified as belonging to the same object or event.
Another way to talk about attention is that it can be deployed automatically (bottom-up) or more deliberately (top-down). But this distinction isn’t always so clear cut—some tasks that require a lot of top-down attention at first can become automatic and ‘effortless’. Think about when first learning to type or play the piano—eventually those complex and deliberate tasks can become effortless to perform and can produce a sense of ‘flow’ that requires very little conscious visual information processing (or other forms of focused attention). Such cases further complicate our understanding of attention, since its relationship to conscious experience seems to change over time, and this change over time might be especially interesting to examine (see Bruya, 2010, for more on effortless attention).
Another characteristic of attention worth mentioning now (which we will describe in more detail in a subsequent post) is that attention can be described functionally—it serves the purpose of assisting an organism in its interactions with its environment, a function that is crucial for survival. Consequently, we can give an evolutionary story to the development of attentional systems, from basic feature processing mechanisms to more complex object-based representations. This evolutionary story is reflected by the organization of the visual system in the brain from more basic processing areas near the brain stem (like attention to features), to higher-level modulation of attention occurring in the cortex (like object-based attention). Surprisingly, there isn’t much work on elucidating the evolution of attention specifically, which is worthy of detailed study (but see Cosmides & Tooby, 2013, as they are some of the few researchers that address this topic). Important for this evolutionary story is the research on attentional systems present in the basic neural structures of insects. For example, some studies have identified the neural mechanisms of feature-based selective attention in dragonflies (e.g., Wiederman & O’Carroll, 2013). Furthermore, one can speculate that animals with capacities for episodic-like memory (like scrub jays) may enjoy feature recognition and event-based attention, but further empirical work is required to support such claims about attention.
This description of visual attention—as mechanisms that modulate visual information processing either automatically or deliberately—is the starting point for our understanding of attention’s relationship to consciousness. Given that attention can occur either with or without conscious awareness is what makes its study so difficult… and also so interesting. What are the decisive factors that determine what information enters awareness? Clearly, we often are aware of perceptual (and conceptual) information that is not helpful to the task at hand, so it seems attention is not a perfect system. Nevertheless, a better understanding of how attention works and how it is related to conscious awareness can ultimately lead to a better understanding of consciousness in general.
Our upcoming posts will describe what we mean by ‘consciousness’, evolutionary considerations for both attention and consciousness, and finally more discussion on the relationship between the two under the framework of conscious attention.
Bonus: Greg Dunn, who received his Ph.D. in Neuroscience from the University of Pennsylvania in 2011, explores that connection, painting images of the hippocampus, cortex, and neurons. But the result is not purely scientific – it is instead a stunning amalgamation of traditional Japanese Sumi-e ink wash painting and modern interpretation.
Bruya, B. (2010). Effortless Attention: A New Perspective in the Cognitive Science of Attention and Action. Cambridge, MA: MIT Press.
Cosmides, L., & Tooby, J. (2013). Evolutionary psychology: New perspectives on cognition and motivation. Annual Review of Psychology, 64, 201-229. doi: 10.1146/annurev.psych.121208.131628
van Boxtel, J., Tsuchiya, N., & Koch, C. (2010). Consciousness and attention: On sufficiency and necessity. Frontiers in Psychology, 1(217). doi: 10.3389/fpsyg.2010.00217
Wiederman, S., & O’Carroll, D. (2013). Selective attention in an insect visual neuron. Current Biology, 23(2), 156-161. doi: 10.1016/j.cub.2012.11.048