Neuroscience
Déjà vu is that creepy feeling that you're living through a moment for the second time, as if retreading the path of an earlier existence. Now Alan Brown and Elizabeth Marsh believe they've found a way to simulate the déjà vu sensation in the laboratory - a finding that could help us understand why the phenomenon occurs.
Twenty-four participants were presented with dozens of symbols that had been carefully chosen, with the help of a pilot study, to be either entirely novel, rarely encountered, or highly familiar (e.g. the division symbol). The participants' task was simply to state for each symbol whether they'd seen it prior to the experiment.
A vital twist was that some of the symbols were preceded by an exceedingly brief flash - too quick to be detected consciously - of the same or a different symbol.
The take-home finding was that a brief flash of an entirely novel symbol before its subsequent, longer presentation, significantly increased the likelihood that a participant would wrongly claim to have seen that symbol prior to the experiment. Indeed, novel symbols not preceded by a subliminal flash were judged to be familiar just three per cent of the time, compared with 15 per cent of the time when preceded by a subliminal flash of the same symbol.
The relevance of these findings to the déjà vu effect were highlighted by post-test questioning of the participants, in which 50 per cent of them reported having experienced déjà vu during the study and 79 per cent said they'd sometimes been confused about whether or not they'd seen a symbol before.
The researchers said their experimental paradigm was analogous to a person glancing fleetingly at an unfamiliar street scene, being distracted by a poster in a window, before returning their gaze to the street and experiencing a strange sense of having been there before. The experiment provides "a possible mechanism for common illusions of false recognition," they concluded.
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Brown, A., & Marsh, E. (2009). Creating Illusions of Past Encounter Through Brief Exposure. Psychological Science, 20 (5), 534-538. DOI: 10.1111/j.1467-9280.2009.02337.x
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Neuroscience
Simulating déjà vu in the lab
Déjà vu is that creepy feeling that you're living through a moment for the second time, as if retreading the path of an earlier existence. Now Alan Brown and Elizabeth Marsh believe they've found a way to simulate the déjà vu sensation in the laboratory - a finding that could help us understand why the phenomenon occurs.Twenty-four participants were presented with dozens of symbols that had been carefully chosen, with the help of a pilot study, to be either entirely novel, rarely encountered, or highly familiar (e.g. the division symbol). The participants' task was simply to state for each symbol whether they'd seen it prior to the experiment.
A vital twist was that some of the symbols were preceded by an exceedingly brief flash - too quick to be detected consciously - of the same or a different symbol.
The take-home finding was that a brief flash of an entirely novel symbol before its subsequent, longer presentation, significantly increased the likelihood that a participant would wrongly claim to have seen that symbol prior to the experiment. Indeed, novel symbols not preceded by a subliminal flash were judged to be familiar just three per cent of the time, compared with 15 per cent of the time when preceded by a subliminal flash of the same symbol.
The relevance of these findings to the déjà vu effect were highlighted by post-test questioning of the participants, in which 50 per cent of them reported having experienced déjà vu during the study and 79 per cent said they'd sometimes been confused about whether or not they'd seen a symbol before.
The researchers said their experimental paradigm was analogous to a person glancing fleetingly at an unfamiliar street scene, being distracted by a poster in a window, before returning their gaze to the street and experiencing a strange sense of having been there before. The experiment provides "a possible mechanism for common illusions of false recognition," they concluded.
_________________________________
Brown, A., & Marsh, E. (2009). Creating Illusions of Past Encounter Through Brief Exposure. Psychological Science, 20 (5), 534-538. DOI: 10.1111/j.1467-9280.2009.02337.xPost written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Solving cryptic crosswords impairs our subsequent ability to recognise faces, a finding that has obvious practical implications for the kind of activities eye-witnesses get up to prior to an identity parade. Michael Lewis at Cardiff University presented...
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A sedative drug that interferes with memory also has the contrasting effect of enhancing intuition – the ability to use one’s ‘gut feelings’ – according to researchers at the Universities of Arizona and Colorado. Michael Frank and colleagues...
- You Won't Forget This
Last year researchers reported they were able to use real-time images of a person’s brain activity to tell what version of an ambiguous shape they were looking at. Now Leun Otten and colleagues report that they can use measures of the brain’s surface...
- Déjà Vu, All Over Again
Today's Science Times in the New York Times has a piece about the phenomenon of déjà vu: Déjà Vu: If It All Seems Familiar, There May Be a Reason By BENEDICT CAREY Excerpt: ...But the point, psychologists who study memory say, is that...
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Imagine you're a mental representation. You are a computational symbol system, and your job is to contain knowledge that is about the world and that can help your organism interact with that world (Newell, 1980). The 'aboutness' thing is the...