Humans are inherently intrigued by the phenomenon of dreams, including their origins, the reasons for their manifestation, and their often intriguing connection to the real world. While the exact purpose of dreaming remains uncertain, researchers in the field of sleep continue to investigate the intricacies of what takes place in the realm of dreams during our sleeping periods.
Essentially, dreams are a variety of experiences that arise during sleep, such as ideas, feelings, and visions. It’s important to remember that all senses can contribute to the dream experience, even though visual imagery predominates in the majority of dreams. Especially, individuals with visual impairment often encounter heightened auditory, gustatory, and olfactory elements in their dreams.
Furthermore, the spectrum of dreaming encompasses perception, where some individuals experience vividly colored dreams, while others have black-and-white ones. Continuing to explore these different aspects of dreaming is an ongoing research endeavor that challenges us to unravel the mysteries of the human mind while we sleep at night.
Of all the fascinating and mysterious things that happen to us when we sleep, dream is the most prominent. The highly vivid dreams are remarkable reproductions of reality, fusing together seemingly unrelated items, activities, and senses to create incredibly complex hallucinations. All people dream, yet each person’s dream content and how it affects their sleep are notably different. Understanding the fundamentals of dreams and their purpose is beneficial, even when there isn’t a straightforward explanation for their meaning or purpose.
Since the hippocampus is closely linked to memory, it has long been suspected that it plays a role in dreaming. One estimate states that 50% of all dreams have at least one element that is derived from a specific experience the individual had while they were awake (Fosse et al., 2003).
Even while dreams are rarely an exact copy of a single memory, they can nevertheless be unique because they combine snippets of different current events with other recollections. Considering all of this, one may assume that the brain regions in charge of memory are the ones that make dreams. Nonetheless, research from as far back as 1960 suggests that individuals with hippocampal loss are nonetheless capable of dreaming, and, quite surprisingly, these patients may dream about recent events for which they have no conscious recall (Stickgold et al., 2000).
On average, most people dream for approximately two hours every night. Dreams may happen during any sleep stage, but they are most frequent and intense during the rapid eye movement (REM) state.
The many varieties of dreaming are explained by the significant increase in brain activity that occurs during the REM sleep cycle as opposed to the non-REM stages. Although they may contain elements of reality, dreams during rapid eye movement (REM) sleep are typically more vivid, whimsical, and/or odd. In contrast, more cohesive material involving thoughts or memories rooted in a particular location and time is typically present in non-REM dreams.
REM sleep is not evenly distributed throughout the night; the majority occurs in the latter half of a standard sleep cycle. As a result, the time just before waking up is when dreams are most concentrated.
A significant neurobiological theory about dreams is the “activation-synthesis hypothesis.” This theory suggests that dreams lack inherent meaning; instead, they result from electrical brain impulses that randomly retrieve thoughts and images from our memories. According to this concept, upon waking, humans instinctively strive to make sense of these random elements by constructing narrative stories in the form of dreams.
However, psychologists specializing in evolution have theorized that dreaming actually has a purpose given the abundance of data supporting the realistic characteristics of human dreaming as well as the oblique experimental evidence that other mammals, like cats, dream as well. Specifically, the ‘threat simulation theory’ argues that dreaming is an ancient biological defense mechanism that evolved to be advantageous because it can effectively replicate potentially dangerous events on a regular basis, strengthening the neuro-cognitive pathways necessary for effective threat detection and avoidance.
The cerebral cortex, the outer layer of the cerebrum, is where dreams are said to originate. These cells are what our minds and senses are made of. Known as pyramidal cells or pyramidal neurons, these are the largest type of cells. With dendrites—trunks, roots, and branches—they resemble trees. Through the eyes, hearing, and other sensory organs, the “roots” gather sensory stimuli when we are awake.
Dreams are unique and enigmatic stories that piece together fragments of our daily lives while we are asleep. Interestingly, our minds craft stories as dreams even without the involvement of the hippocampal region, which is thought to be connected to dreams. Dreams are complicated; they defy our understanding since they draw from our waking times. According to the Activation-Synthesis theory, dreams may lack a distinct meaning and instead result from haphazard brain signals that create narratives when a person wakes up. The genuine nature of dreams remains an intriguing puzzle concealed within the fabric of our minds, even as we continue to investigate this mysterious world.
Sources
- https://www.sleepfoundation.org/dreams
- https://elifesciences.org/articles/58874?gad_source=1
- https://elifesciences.org/articles/58874?gad_source=1
- https://www.scientificamerican.com/article/the-science-behind-dreaming/
- https://www.sciencenorway.no/brain-dreams-sleep/researchers-may-have-discovered-where-dreams-come-from/1793982
