Visual Attention and Consciousness

Understanding conscious awareness through the research on visual attention

Posted Jul 01, 2015

We all have an intuitive understanding of what it means to pay attention to a particular visual scene or a conversation, and that it must be somehow related to our conscious awareness—but what exactly is meant by the term “attention” from a more scientific and experimental perspective? Our discussion will focus on visual attention, since there are a vast number of empirical studies on it and vision is a huge part of our conscious experience.

Generally speaking, 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 or mates, avoiding predators, and completing more complex tasks 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 on this topic by van Boxtel et al., 2010). [We should make the point here that discussions about attention and the information that it processes implicitly need to address how it interacts with memory systems—but we can just focus on attention for our purposes.]

There are many forms of visual attention that work on various levels, both within and outside of our conscious experience. They include:

  • feature-based attention, which is attention to specific features such as color, segment orientation, or motion;
  • spatial attention, which is attention to the layout of features or objects; and
  • object-based attention, which is attention to things that display object-like properties, such as a cohesive set of features with a “common fate”.

These are rudimentary—yet overlapping—categories to describe the types of information that visual attention can process and operate upon. It becomes more complicated when you look at cross-modal attention, where information from auditory, visual, or haptic sources are combined—this requires a “global workspace” where the different forms of attention within and across modalities can be unified as belonging to the same object or event (for a more in-depth review of the various forms of attention, see Haladjian & Montemayor, 2015, pp.598-605).

One can also characterize attention by describing the ways in which it can be deployed. Some forms of attention can occur automatically (also called “bottom-up attention”) while other forms of attention are more deliberate (called “top-down attention”). 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 monitoring of visual information processing (or other forms of focused attention). Such examples further complicate our understanding of attention, since its relationship to conscious experience seems to change over time, and examining this change over time might be especially informative to our understanding of consciousness (see Bruya, 2010, for more on effortless attention).

An important characteristic of the various forms of attention is that they can be described functionally—attention 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, to the multi-modal integration of sensory information. 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). See illustration below. Surprisingly, there isn’t much work on outlining the evolution of attention specifically (see Cosmides & Tooby, 2013, as they are some of the few researchers that address this topic). We will further discuss this evolutionary aspect of attention in a subsequent post.

 MIT Press.
The major areas associated with visual attention are labeled here, including the dorsal and ventral processing streams that support bottom-up attention. The flow of visual information moves from the retina, through the optic nerve to the superior colliculus (SC) and separately to the lateral geniculate nucleus (LGN) of the thalamus. From the LGN, information is relayed to the visual cortex (V1–V5) and then to higher cortical areas. In terms of feedback processes, these can occur from any higher to lower levels (e.g., from V3 to V2), with “executive” top-down control functions primarily originating within the frontal cortex. As a rough approximation, the evolutionarily newer areas of the brain include the frontal lobe with older systems closer to the brain stem.
Source: Montemayor & Haladjian (2015). "Consciousness, Attention, and Conscious Attention". Cambridge, MA: MIT Press.

This description of visual attention—as something that modulates visual information processing either automatically or deliberately—is the starting point for our understanding of the relationship between attention and consciousness. It's important to emphasize that attention can occur either with or without conscious awareness. The distinction between conscious and unconscious forms of attention makes the study of conscious awareness quite difficult, but also very interesting. What are the crucial factors that determine what information enters awareness? Clearly, we often are aware of perceptual (and conceptual) information that is irrelevant to the task at hand, and which is not clearly related to action or decision-making. Thus, it seems that attention is not a perfect analog for awareness, especially since there may be non-attentive based forms of awareness. Nevertheless, attention is perhaps the most natural entry into conscious awareness. A better understanding of how attention works and how it is related to conscious awareness can ultimately lead to a better understanding of consciousness. Our next post will present more distinctions and dissociations within the realm of the philosophical theories of conscious awareness.

- Harry Haladjian & Carlos Montemayor


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

Haladjian, H. H., & Montemayor, C. (2015). On the evolution of conscious attention. Psychonomic Bulletin & Review, 22(3), 595-613. doi: 10.3758/s13423-014-0718-y

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