Paying Awareness

Attention and awareness are actually two fundamentally different mental processes, and they often operate separately, says a new study.

Awareness. Not pictured: attention.

Certain parts of the brain – such as the primary visual cortex (V1) – are activated in response to attention but not to awareness; and for others, the reverse is the case. In short, the processes of attention and awareness either affect distinct networks of nerve cells, or they each affect cells in different ways – or perhaps some combination of those two ideas is closer to the truth.

But in any case, the verdict is in: in neurological terms, being aware and paying attention are two different things.

Awareness of a particular sensory stimulus or thought is usually described as the ability to be conscious of it. Attention, on the other hand, is the process of bringing that stimulus or thought into the focus of conscious awareness, at the expense of others.

Several studies, including this one published in June 2011, have found that not only can you be aware of something without paying attention to it – you can also pay attention to something without being aware it’s there.

For instance, when people are shown a pattern of colorful moving shapes in their left eye, and a static pattern of dots – most green, but one bright red – in their right, their visual attention will be directed to the red dot – even though they’ll report that they weren’t aware the dot was there! Pretty weird, huh?

But now, as the journal Science reports, two teams – one from the Max Planck Institute for Biological Cybernetics and one from the University of Tokyo – have taken this research another step further, by taking fMRI scans of volunteers’ brains as the subjects watched split-eye visuals similar to the ones I just mentioned.

What they discovered shocked them:

The visibility or invisibility of a visual target led to only nonsignificant blood oxygenation level–dependent (BOLD) effects in the human primary visual cortex (V1). Directing attention toward and away from the target had much larger and robust effects across all study participants.

In other words, awareness of a visible object triggers almost no activity in the primary visual cortex – but directing attention toward or away from that object causes flurries of activity across V1:

The difference in the lower-level limit of BOLD activation between attention and awareness illustrates dissociated neural correlates of the two processes. Our results agree with previously reported V1 BOLD effects on attention, while they invite a reconsideration of the functional role of V1 in visual awareness.

The researchers are understandably pumped about their breakthrough, but they also advise caution about drawing broad conclusions at this point – after all, this experiment focused only on the visual cortex, a relatively primitive part of the cerebrum. How attention and awareness are coupled or decoupled in more advanced processing areas remains to be seen – and the answers may not be nearly so straightforward.

Even so, it’s always cool to watch scientists take apart components of this deeply strange thing we call a “self,” and begin to understand how those components work together to create the moments of our conscious existence.

And though I can’t be aware of every new discovery, I’ll certainly be paying close attention to the ones I notice.

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