4.1. Mechanisms of Action
Our data would reject four possible cortical mechanisms (expectations, rhythmic movement, visual memories, and auditory memories) by which the subject might have self-stimulated his own reward system during J2. Several other pathways are possible that our experiment did not test. First, it is known that reciprocal connections exist between the NAc and the medial OFC, so that it might be possible to activate a feedback loop between the two. Under normal conditions, the feedback loop would be quickly interrupted by shifting attention to everchanging input from visual, auditory, or somatic senses, but these cortical areas have been downregulated, and attention may be tightly focused on reinforcing the feedback loop. The loop might be realized by creating a series of very short tasks that can each be completed successfully, allowing a new goal to be achieved and reward attained with each new moment. The classic meditation instructions for breathing would constitute such a task, wherein the student is instructed: “When that in-breath finishes, you know that moment. You see in your mind that last moment of the in-breath. You then see the next moment as a pause between breaths, and then many more moments of pause until the out-breath begins… We are aware only of the beautiful breath, without effort and for a very long time.” ( p.16).
Other possible mechanisms of action could comprise subcortical activations that might have reward characteristics. For example, shifting control of breathing from the voluntary motor cortex to the involuntary medullary rhythmicity area in the brain stem might be perceived as relaxing, as well as giving rise to a common altered experience of “feeling like I am being breathed, not in control.” Also, rhythmic movements might be maintained below the level of cortical control, since spinal reflexes are now known to mediate rhythmic movements as complex as coordinating leg movements related to walking.
Our results also shed light on the magnitude of the activation of the dopamine reward system. Subjective reports from the subject indicated extremely high magnitude of reward, comparing J1 (which was not recorded due to head movement) to continuous multiple orgasms, J2 to “opening a birthday gift and getting exactly what you most wished for,” and J3 to postcoital bliss. Yet the objective activation of the reward system in J2 was not extreme. The apparent mismatch between extreme subjective reports and moderate objective activation can be explained by the signal-to-noise ratio of the circuits. When most other cortical activity is reduced, as in this subject, a much smaller reward signal can be detected and will be perceived as more intense than when cortical “noise” from other sources is high, as in normal awareness. Indeed, during normal awareness it takes drug-induced hyperstimulation of the dopamine pathways to generate such extreme subjective reports. If this signal-to-noise view is correct, then jhana’s reduced sense awareness is not incidental to achieving extreme pleasure but is a contributing condition.
Despite the moderate level of activation, caution is advisable with any voluntary stimulation of the reward systems. Drugs of abuse can generate short-term bliss but can quickly increase tolerance, requiring ever greater doses of the drug to create the same level of pleasure. They can also create withdrawal symptoms during abstinence . In contrast to the drugs, jhana meditators report negative tolerance because they can achieve the same state more quickly with less effort over time, and no withdrawal symptoms have been reported when meditation is stopped. Nevertheless, Figure 3 shows that NAc activity dropped below normal resting consciousness in J5, which may be a sign of short-term tolerance and neurotransmitter depletion.
Our experiment is to our knowledge the first that compares brain states in five different meditations (AC and J2–J5), finding strong differences between AC meditation and jhana, and smaller but still significant differences between jhana states. These in turn differ from the Tibetan Buddhist compassion meditation reported by Lutz et al.  where EEG gamma frequencies were dominant and from the alpha dominance of Transcendental Meditation . Taken together, the multiplicity of brain states suggests that there may be a vast array of ASCs available through meditation, depending on which brain regions are given awareness and which are inhibited from awareness . If there are a large number of possible ASCs, it is likely that only some would have survival value. For example, the state of mystical union with all beings might be helpful in encouraging cooperation with all people in the tribe, so that evolution may have selected certain of these ASCs to be more easily learned and retained.
However, the same reasoning would suggest that the ability to self-stimulate the brain’s reward system would be dysfunctional in the struggle for survival and procreation because it could short-circuit the system that motivates survival actions. Organisms that are adept at self-stimulation would quickly die out if they fail to respond to environmental demands or to pass on their genes. This reasoning suggests caution in making autonomous self-stimulation more available, but we point out that the modern environment already allows unprecedented stimulation of the dopamine reward system with plentiful food and drugs of abuse. A meditation that stimulates the reward system without the harmful effects of obesity and environmental damage could be beneficial in the modern environment. On the other hand, a meditation that short-circuits the desire to get an education and work for long-term goals could become dysfunctional. Rather than simply stimulating the reward system in response to traditional goals of food and sex, it would be beneficial to regulate the system and focus it on long-term goals that are more adaptive.
This case study provides guidelines for larger studies on jhana meditation in several areas. First, it demonstrates that jhana is not so fragile that it can be destroyed by the presence of curious experimenters or by intrusive sounds of MRI scanners. Hence, it can be scientifically investigated. Second, the transition time to move from one jhana to another in a practiced subject is much shorter (between 5 and 20 seconds) than we expected, in line with other meditations that do not produce such extreme ASCs . With short transition times, it might be feasible to use better randomized designs that alternate control states with meditations (however, the short transition times here may be due to the subject’s internal knowledge of readiness to transition, and he may not be able to transit “on demand”). Third, the experiment could be shortened if interest is focused only on the reward system because only J2 shows strong self-activation of the NAc. Fourth, the simple “resting” condition used here could be replaced with better controls that have been demonstrated to increase happiness, such as “remembering a happy event in your life” or visualizing a loved one.
More potential subjects will become available as more English-speaking students are being trained in jhana meditation [9, 50]. How these meditators achieve periods of extreme joy without common negative side effects could contribute to the scientific “pursuit of happiness” and could pave the way for novel paradigms for rehabilitation and recovery from nervous system injury.
I wonder if more absorbed jhanalabhis can be found? But then, who'll remain to tap fingers to signal transition to the next attainment?
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