Dreaming may be significant for mental health
Dreaming is a significant phenomenon which has been surrounded by a great deal of conjecture about it's value for mental health. We often like to think of dreaming as a sort of mental catharsis which helps us to deal in a more stable manner with our life. It often appears that people who remember their dreams are calmer and happier, as if their dreams are helping them to resolve conflicts and confront the complexities of life with more composure.
Dreaming is still not well understood, reports the journal Neuropsychopharmacology. However, there are aggressive initiatives to better understand why we dream and what this may mean for our mental state. It has been observed that resting brain activity varies with dream recall frequency between subjects.
Neuropsychological studies reveal that lesions in the temporo-parietal junction (TPJ) and/or the white matter of the medial prefrontal cortex (MPFC) of the brain lead to the global cessation of dream reports. This suggests that these regions of the brain play key roles in the dreaming process. In order to test this hypothesis, the researchers measured regional cerebral blood flow (rCBF) using positron emission tomography in healthy subjects with high and low dream recall frequencies (DRF) during wakefulness, rest and sleep.
From their studies the researchers concluded increased activity in the TPJ and MPFC might promote the mental imagery and/or memory encoding of our dreams. Specifically, increased activity in TPJ might facilitate attention orienting towards external stimuli which may be associated with intra-sleep-wakefulness, which facilitates the encoding of the dreams in our memory.
Some people are observed to recall a dream every morning, whereas other people only rarely recall a dream, reports Inserm in a discussion of this research. Perrine Ruby, an Inserm Research Fellow at the Lyon Neuroscience Research Center, led a team of researchers who have studied the brain activity of these two types of dreamers in order to better understand the differences between them.
Their study showed that the temporo-parietal junction, which is an information-processing hub in the brain, is more active in people who are high dream recallers. It is believed that increased activity in this brain region might facilitate attention orienting toward external stimuli while promoting intrasleep wakefulness, and therefore facilitating the encoding of dreams in memory.
What the actual reason is for dreaming remains a mystery for the researchers who study the difference between “high dream recallers,” who recall dreams regularly, and “low dream recallers,” who only recall dreams rarely. Ruby observed that “high dream recallers” have twice as much time of wakefulness during sleep as “low dream recallers” and the brains of the “high dream recallers” are more reactive to auditory stimuli during sleep and wakefulness.
It appears this increased brain reactivity may promote awakenings during the night, and may therefore facilitate memorization of dreams during brief periods of wakefulness. The results have suggested that high and low dream recallers differ in dream memorization, but do not exclude that they seem to also differ in dream production. It is therefore possible that high dream recallers produce a larger amount of dreaming than low dream recallers.