A new study has found that conscious experience can be altered retrospectively, so that experience of visual information can be changed almost half a second later by manipulating where our attention is drawn.
The research, led by cognitive scientist Claire Sergent, involved asking people to stare at a centre point of a screen with two empty circles either side.
At some point, one of the two circles would fill with randomly oriented stripes for just 50ms (one twentieth of a second) and afterwards the participants were asked to say which direction the stripes were pointing in.
Crucially however, each time this happened, one of the two circles would dim either before or after the stripes appeared.
This would happen at different times – from 400ms before the stripes appeared, up to 400ms after the stripes appeared, and the dimmed circle might appear on the matching side to the stripes or on the opposite side.
Dimming one of the circles grabs your attention. It makes you instantly focus more on whichever side of space it happens.
For example, if the left-hand circle dims, it grabs your attention, and if the stripes then appear on the left, you’re more likely to make a correct judgement about which direction they’re pointing because you’re already focused on this area. But if the stripes subsequently appear on the other side, you’re distracted and you do worse.
The key discovery from this experiment was that this also happens if the dimmed circle appears after the stripes. Up to 400ms seconds after.
In other words, you perceive the original visual details that would otherwise have escaped consciousness if your attention is drawn to the area after the picture disappears. It’s like a retrospective editing of consciousness by post-event attention.
This suggests that consciousness isn’t ‘filtered’ sensory information, but an active ‘conclusion’ drawn from information distributed across senses, space and time.
Link to locked scientific study.
Link to open-access commentary from same journal.
Mind Hacks 
Not that surprising, I believe we do the same with memories of events as well. Experiences following an event in life affect how we notice the details prior. Not quite the same, but it is really.
Dan @ ZenPresence.com
This makes me think that if our memory can be seen, like film, as frames stored in a sequence, then the capture window of a frame (to continue the analogy, the shutter speed of the mind), is ~800ms, or to round off, about a second.
To fully capture a “moment”, our brains need at least one second of material in which to form a memory/opinion/construction of what it thinks it experienced in that moment.
In short, we buffer our memories for at least half a second. Interesting…
Sure but was it a Stalinesque or Orwellian process 🙂
Good question, Dan
so did it alter the participants prior consciousness or just make them forget it?
Spinoza : Ethics II, 26.
This is fascinating!
Sometimes, when I’m in a crowded, noisy place, I’ll overhear my name in another conversation – one I’m not listening to. Even when my name’s spoken at the end, I can recall the entire sentence as if I *had* been listening. This has happened often enough that I’ve noticed this effect, and it does feel very much like my awareness has been altered after the fact. This study seems to confirm my subjective experience.
If there were a group of conspiracy theorists who thought that the passage of time was a human construct, this could be the cornerstone of their argument.
Darn, it’s too bad they don’t exist.
..should the tests be carried out with a set of participants who were ambidextrous, might the results differ?
In tests involving Optical Ilusions, I’ve always seen bot, at once! A simple experience that most of everybody I know do not seem to quite experience – for them, ’tis always one-at-a-time and cannot fathom “seeing” both at the same time. I am uncertain if I should attribute this to being ambidextrous, but I am curious if the study might try to include a second category of participants to evaluate if this could lead to further theories, although the point already made in authenticating the proces of retrospective editing in this study.
Who knows where this’ll go if ’twere also conducted with persons with synesthesia.
Good information, but it concerns sensation and perception, not consciousness.
Although the theory of retrospective editing is validated in the study above, the actual extent of “filtering” and more importantly post-event attraction/attention has yet to be understood.
..I wonder if the results may differ should they include ambidextrous participants in the same study in an isolated category to see if there were any differences observed in the field of perception in ‘active’ conclusion.
I cannot say for sure that being ambidextrous has lend a hand in how I tend to see both images at once in an Optical Illusion Test – an experience I only realised later in life has rarely to never happened to anyone I’ve come across. People I’ve met usually seem to only see one image at a time and many have told me they cannot fathom seeing both images at once – their focus on the negative-space versus positive-space seems to take precedance in leading their perception of the implied images viewed. I don’t know if Í should attribute my two-at-once experience to being ambidextrous but it would be interesting if they included a separate group of participants who were ambi-dex when conducting the study again, as well as persons with different spectrums of synesthesia!
Somehow watching the anamorphic art from your recent spike activity post reminded me of this post. You could think of the shift in attention (in this post) and the hearing of the name (in the comment) as similar to the little lens near the sculptures that brings all the scattered pieces together. More broadly, anamorphic art may be a nice metaphor for the brain/mind’s activity in general. Except that there are many viewpoints where the pieces come together ‘sensibly’. And there are viewpoints where the pieces come together sensibly for some, but the majority rejects these viewpoints.
Is it possible that retinal afterimages may persist at least 400 ms and be accessible to the visual cortex, even if the direction of gaze changes slightly? If so, that would eliminate the need for afterediting.