"Although the details of human hopes are surely beyond the imagination of other creatures," writes Jaak Panksepp in Affective Neuroscience: The Foundations of Human and Animal Emotions (1998), "the evidence now clearly indicates that certain intrinsic aspirations of all mammalian minds, those of mice as well as men, are driven by the same ancient neurochemistries."
Panksepp describes the SEEKING system as follows:
- This emotional system is a coherently operating neuronal network that promotes a certain class of survival abilities. This system makes animals intensely interested in exploring their world and leads them to become excited when they are about to get what they desire. It eventually allows animals to find and eagerly anticipate the things they need for survival, including, of course, food, water, warmth, and their ultimate evolutionary survival need, sex. In other words, when fully aroused, it helps fill the mind with interest and motivates organisms to move their bodies effortlessly in search of the things they need, crave, and desire. In humans, this may be one of the main brain systems that generate and sustain curiosity, even for intellectual pursuits. This system is obviously quite efficient at facilitating learning, especially mastering information about where material resources are situated and the best way to obtain them. It also helps assure that our bodies will work in smoothly patterned and effective ways in such quests.
When the mesolimbic pathway from the dopamine-producing VTA to the nucleus accumbens is stimulated, SEEKING behavior ensues. Panksepp writes: "For instance, stimulated rats move about excitedly, sniffing vigorously, pausing at times to investigate various nooks and crannies of their environment. If one presents the animal with a manipulandum, a lever that controls the onset of brain stimulation, it will readily learn to press the lever and will eagerly continue to 'self-stimulate' for extended periods, until physical exhaustion and collapse set in. The outward behavior of the animal commonly appears as if it is trying to get something behind the lever."
The mesolimbic pathway is activated trans-synaptically by normal rewards (food, water, copulation) but it can also be activated directly by the induced rewards of intravenous drugs or electrical or chemical brain stimulation (Wise). 1 The mesolimbic pathway is one of the dopaminergic pathways in the brain that modulates behavioral responses to rewarding stimuli. It originates in the VTA and connects to the limbic system via the nucleus accumbens, the amygdala, and the medial prefrontal cortex. A number of drugs are rewarding when they are injected into the nucleus accumbens and act as mesolimbic dopamine terminals, 2 and the axons of the mesolimbic dopamine system have high thresholds for stimulation (Wise).
Panksepp points out that when animals are in an appetitive state, anticipating a reward such as food or sex with a receptive mate, dopamine levels increase. But once an appetitive state turns into a consummatory state, dopamine levels immediately begin to decrease. So increasing levels of dopamine are not associated with consummatory, pleasurable activity. Rather the opposite is true. Pleasure is associated with decreasing dopamine levels. This does not mean that "reward" circuitry does not exist. Panksepp writes: "Temporal and frontal cortices contain an abundance of neurons that fire only in response to stimuli that have acquired meaning by being predictably associated with rewards."
That just means that once someone gets a reward they are satisfied. Most types of reward increase the level of dopamine in the brain, however pleasure apparently decreases dopamine levels.
Since humans think less when they are dreaming, it makes sense that dreams are emotional and not logical. I could say that they are driven by their 'reward system' when they are dreaming - the higher intellectual functions of their brain are shut off. They retreat into a more simplistic emotional state where they turn normal daily activity into some sort of silly movie.
During dreams, connection to your voluntary muscles is disabled. However, the person you are in your dream can move and it is as if then you can move your muscles in your mind. - REM sleep, the stage of sleep during which dreaming occurs, is characterized by paralysis of the voluntary muscles. Why? The phenomenon is known as REM atonia and prevents you from acting out your dreams while you're asleep. Basically, because motor neurons are not stimulated, your body does not move.
While dreams are often heavily influenced by our personal experiences, researchers have found that certain themes are very common across different cultures. For example, people from all over the world frequently dream about being chased, being attacked or falling.
So not only are dreams emotional, they also have a physical presence. - In your dreams you are really there and you can feel what is happening to you. That is why dreams of being chased, attacked or falling are fun, because you can 'feel' those sensations.
So in your dreams, not only are you using your imagination to run or move around, you are using your imagination to create worlds to run and move around in. Furthermore, these generated worlds are mostly from life events that are easily recalled in memory or simply more emotional.
So why does your mind make the dreams it makes? Does it select more emotional things to dream about or things that are simply more fun to dream about? (Apparently it does both)
So dreams are more emotional, and I think they also achieve stimulation from a more basic, reward based brain chemistry. The nature of emotion is reward based and simplistic, so it makes sense that dreams are that way since you aren't thinking.