But what about this book in particular? Well, it should really be called "The Complete" rather than "The Essential Epicurus;" I don't know why the publishers decided to sell themselves short and imply this is just a sampling of his surviving fragments, because they're all here. So if you're looking to start at the beginning, with the founding documents of Epicureanism (or at least what's left of them, since only a few scraps survived the low Middle Ages), this is the right book for you. But for anybody just looking to get a handle on this ancient school of philosophy, I would really recommend Lucretius instead. There's very little Epicurus says here that Lucretius didn't say more eloquently, more persuasively, more coherently and in greater detail in his poem De Rerum Natura. So go read that if you haven't already.
From: Letter to Menoeceus (p64), in: The Essential Epicurus, Prometheus Books, Amherst, USAInformation sources: The importance of hedonic regulation of food intake is perhaps best illustrated in experiments where rats had electrodes implanted in their brain, at different anatomical locations, and could self-administer electrical stimulation by pressing a lever. In the experimental environment, food supply was kept at a distant from the lever that provided electrical stimulation (you either eat or you stimulate electrically). This experimental setup is referred to as brain-stimulation-reward (BSR) and one of its distinguished pioneers is James Olds (see references below). Repeated self-stimulation was observed with electrodes that reached the medial forebrain bundle, the midbrain extension of the MFB, the orbitofrontal cortex, nucleus accumbens (NAc), lateral hypothalamus (or lateral hypothalamic area, LHA), ventral tegmental area (VTA) and brainstem structures (collectively referred to as the “brain pleasure areas”. For anatomical location see figure 2a and 2b). Brain-stimulated-reward experiments provided first evidence that reward circuitry is subdivided along functional and anatomical lines. Importantly, self-stimulation of the lateral hypothalamus was shown to generate a powerful grip on feeding behaviour as 16 out of 19 rats preferred to go without food or drink, even after days, in order to maintain contact with the manipulator. Rats stimulated in other brain areas were more reasonable and although initially intrigued by the electrical stimulus, 15 out of 19 chose for food after one day testing (G Spies, 1965). From these and other brain-stimulation-reward experiments emerged the idea that the electrical stimulation tapped into the neural circuitry sub serving natural rewards, such as food and water. In other words, food procures a certain pleasure but this sensation can be replaced by electrical stimulation of appropriate areas of the brain.