then instructed to indicate how vividly they had the capability to visualize it.
In the absence of the participant’s awareness, at the final stage of the experiment, an actual stimulus consisting of the same features to those the participant was imagining was slowly faded in to sight on the computer screen. The participants were then instructed to give a rating on how vividly they had imagined the stimulus and told to define if what they viewed was real or imagined.
The findings demonstrated that the imagined as well as the perceived stimuli became intermingled in the participants’ minds. The study team provided an example, of a real stimulus that was faded in, where participants held the view that the imagination, they had was simply elevated in vividness.
As they imagined with increased vividness, the participants had an increased chance to hold the view that they had witnessed a real stimulus. This occurred even with nothing being presented to them.
Lead author, Dr Nadine Dijkstra of the Wellcome Centre for Human Neuroimaging at UCL says “In daily life, we often imagine things that are not there. For example, if we are asked whether a cat’s ears are round or pointy, we might inspect a mental image in our mind’s eye to answer the question.”
Dr Dijkstra further indicated that neuroscience has found that imagination together with perception depend on overlapping brain circuits. they were interested in knowing if this overlap brings about confusion between the 2: given that the same circuits played a role how can we be certain in what is real versus what is not.
The scientists applied a computer model to determine if the pattern of the findings was consistent with the theory that individuals judge if something is real or imagined, based on the extent of vividness they had experience with it.
The researchers gave validation to this model applying neuroimaging, demonstrating that the brain encodes the strength or vividity of real and imagined stimuli in a similar way that confuses reality and imagination.
Dr Dijkstra, indicated that the findings point out that, counterintuitively, there is an absence of categorical variations between imagination and reality; instead, it is a difference in degree, not in kind. Senior author, Professor Stephen Fleming (UCL Psychology & Language Sciences, Wellcome Centre for Human Neuroimaging at UCL, and Max Planck UCL Centre for Computational Psychiatry & Ageing Research) says “Normally imagination is relatively weak, and so we don’t confuse it with reality. But if imagination becomes strong or vivid enough, it may get treated as real.”
