Imagine a song comes on the radio
and from the opening notes you’re hit with a rush of familiarity. You know
you’ve heard this song somewhere before, possibly at your friend’s house, and
you know you don’t like it very much. You’re sure that you know what the song
is called, but you just can’t recall its name. Eventually you start to become
frustrated. Despite the nagging of peripheral memories, you can never seem to
fully remember the song. Finally, you pull over at a gas station, pull out your
phone, and open an app that identifies the song for you. A cascade of relief and recognition washes
over you, and you move on with your day, satisfied that you truly do know the
name of that awful song.
This situation is most likely a
familiar one. Many people report the experience of feelings or memories
associated with a central trigger, despite their inability to recognize the
trigger itself. This phenomenon, referred to as recognition without identification
(RWI), is thought to be connected with the mysterious experience of déjà vu, as
well as instinctual responses or ‘gut reactions.’ In the laboratory, RWI is
defined as the ability of individuals to “…discriminate between studied and
non-studied items when the items themselves cannot be identified.“ (Cleary
& Ryals, 2013). One approach to modeling RWI is to ask participants to
identify obscured stimuli. The effect of RWI is seen when participants are more
successful at recognizing obscured images they have studied before, or could
otherwise have identified. Current evidence indicates that a sense of
familiarity might precede the full identification of an item, and that this
sense may inform an individual’s reaction to items that are otherwise unidentifiable
(Cleary & Ryals, 2013). This ‘perceptive’ recognition can clearly occur in
the absence of full conscious recognition, and it may rely on the separate
assessment of different aspects of a stimuli. Visual stimuli, for instance,
require the brain to process color, depth, shape, and many other aspects of an
image in order to create a collective whole. In the absence of enough
information to fully identify an image, the features that are present may
trigger a scaled familiarity response. This response can be strong enough to
allow a person to identify an obscured image, word, or song, even when they
think they are only guessing (Cleary & Ryals, 2013).
In one study, participants reported
a higher familiarity when they were presented with famous faces or locations
that had been obscured using a monochromatic filter. Despite their inability to
identify, or even discern the features of the images they were looking at, participants
reliably reported higher familiarity with images they had seen more often before.
The same study also compared participant’s reactions to obscured images of
living and non-living objects that were either threatening or benign in nature.
Higher familiarity ratings were given to threatening living images than to any
of the other unidentifiable stimuli (Cleary & Ryals, 2013). It appears that
a familiarity response approaching full recognition can occur even when the
visual details required for identification are not present. Furthermore, the
effect seems to be strengthened in response to living and threatening images, which
makes sense, because these are the types of images that would have most
required a rapid response during much of human history. It certainly seems
possible that RWI is an adaptive ability, driven by the need for an informed
response to stimuli that are too obscured or immediate to allow full conscious recognition.
The debate is still ongoing
however, in regards to the neural mechanism through which RWI occurs. If RWI responses
to various forms of stimuli were all found to act through some common neural
mechanism, distinct from that of conscious recognition, the evidence would tilt
more strongly in favor of the argument that it is an adaptive capability. In
order to address this uncertainty, a recent study analyzed EEG recordings taken
from participants as they performed various tasks involving RWI. The memory
responses seen in their recordings were extremely similar between RWI of words and
images, but both were entirely distinct from responses seen when participants were
able to fully identify the stimuli. The recordings showed RWI to correspond with responses in the occipital lobes of the participant’s brains, while a
distinct form of activity was seen in their frontal lobes when they were able
to fully identify an image (Ko & Duda, 2013). This strongly
suggests that information gained through RWI results from a different
neurological process than that of conscious identification.
The question of whether RWI is the
result of evolutionary pressures remains, and it could still be the byproduct
of a normal identification process faced with inadequate information. What is
clear however is that RWI represents a distinct and surprisingly effective
method for information retrieval within the brain. It operates separately from
conscious remembrance, which may help to explain why, no matter how hard you try,
you can never force yourself to remember the name of that annoyingly familiar
song. So when you next find yourself struggling with something that’s on the
tip of your tongue, remember to just relax and guess, you might be surprised at
what’s going on in your unconscious mind.
Cleary, A. M.,
Ryals, A. J., Nomi, J. S. (2013). Intuitively detecting what is hidden within a
visual mask: Familiar-novel discrimination and threat detection for
unidentified stimuli. Memory and
Cognition. 41, 989-999.
Ko, P. C.,
Duda, B., Hussey, E. P., Ally, B. A. (2013). Electrophysiological distinctions
between recognition memory with and without awareness. Neuropsychologia. 51, 642-655.
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