Mona Lisa Rasee is one of Marcel
Duchamp's variations on the Mona Lisa.
This is a black and white photograph of the original painting. The only difference between it and the
original is the caption. The caption "Mona Lisa Rasee" makes
us see the painting differently, since it invokes the visual image of the Mona Lisa
bearded and mustached.
Marcel Duchamp did create a bearded and mustached Mona Lisa before
creating "Mona Lisa Rasee".
People who knew this version may have formed a visual image of the Mona
Lisa with the specific beard and mustache that Duchamp painted on it.
What are mental images? According to Prof. Bence Nanay from Antwerp University, mental
imagery is perceptual
processing not triggered by corresponding sensory stimulation in the relevant
sense modality.
What does this mean? If the image is visual, for
instance, it is not identical with a visual stimulus that we may concurrently
see (we do not actually see the beard when we looked at the picture above and form
the image of the bearded Mona Lisa).
This definition implies that a
mental image is processed in the sensory processing systems. When we form a mental image
we activate the same brain areas that are activated when we process a
perceptual stimulus. When we form a
visual image, we activate brain areas that are activated during visual
processing. When we form an auditory
image, we activate brain areas that are activated during auditory processing,
and so on.
Mental images have five
features:
1. They can be formed in all modalities. There are auditory images, olfactory
images, flavor images tactile images. We
can play a song in our mind's ear, form an image of the scent of cinnamon or of
the touch of a feather.
2. They can be involuntary. A song we heard in the morning may
involuntarily replay itself in our mind's ears throughout the day. On a sadder note, people may have
involuntary flashbacks of traumatic events that they've been through.
3. They don't have to be placed in a specific spatial
place. If we see an apple in our
mind's eye, it won't necessarily be "placed" anywhere specific in
space. We can manipulate an image from
an egocentric
point of view (imagining taking a different perspective in space) or from an allocentric
point of view (mentally manipulating objects from a stationary point of view ).
4. Usually they don't generate a sense of presence. Usually we know that the mental image
does not exist in reality. But there are
forms of mental image that do have a sense of presence, like dreams.
5. They can be unconscious. As defined above, a mental image is a
perceptual process. Since perceptual
processes can be unconscious, mental images can also be unconscious. Some people have a condition called Aphantasia. These people can perform tasks that allegedly
require the formation of mental images, but they do not report experiencing mental
images. Researchers have differing views
on this: some say these people have
mental images that they are not aware of.
Others say they perform these tasks using other cognitive skills.
What cognitive tasks allegedly
require the formation of mental images?
Tasks like this one:
In this task, the person is asked to decide which of the four
stimuli on the right is identical to the stimulus on the left. People usually solve this kind of problem by
mental rotation – they mentally rotate the stimuli on the right until they are
parallel (or not) with the stimulus on the left.
Prof. Nanay argues that mental
images are an integral part of our perceptual processes. We cannot perceive (almost) any stimulus
without mental imagery taking a part in our perceptual process. Why?
It's easy to explain with visual images.
Look around you. Almost any
object you see occludes other objects which lie behind it, and also occludes
the back side of itself. Using mental
imagery we "complete" the background objects or the back side of
objects. Furthermore: we experience everything in more than one
sense modality. But usually we don't get
information about every object from all sense modalities. We represent the information we don't get from
our senses by forming multimodal mental images of objects. For example, I can form a mental image of the
tactile feeling of the tree trunk that is seen from my window. If the window is closed, I can form an
auditory image of the rustling of the tree's leaves in the wind. The tactile and the auditory images are
combined with the visual perception of the tree to create my experience of the
tree.
Are you familiar with the phenomenon, that when you read an email
written by someone you know, you read the message in that person's
"voice"? This is another
example of the way a mental (auditory) image is involved in perceptual
processes.
This is probably the reason visual processing (as a CHC ability) is defined this way: "The ability to make use of simulated
mental imagery (often in conjunction with currently perceived images) to solve
problems". Visual processing is what the mind does with
the information coming from the eyes, sometimes a long time after the
information arrived. Likewise is the
case with auditory processing. Auditory processing is what the
mind does with auditory information, sometimes a long time after it arrived. That's why Beethoven managed to write such
great music when he was already completely deaf. He used auditory imagery. And when he did that, he was engaged in
auditory processing.
Reference: video posts by
Prof. Bence Nanay
