Dharana, Dhyana, Samadhi: The Three Internal Limbs and Contemplative Neuroscience

The Inner Journey Begins

Patanjali’s eight-limbed path divides into two arcs. The first five limbs — Yama, Niyama, Asana, Pranayama, Pratyahara — are bahiranga (external) practices that prepare the body and senses. The final three limbs — Dharana (concentration), Dhyana (meditation), and Samadhi (absorption) — are antaranga (internal) practices that constitute the journey of consciousness into itself.

These three limbs are not separate practices but a continuum. Patanjali describes them as a progression: Dharana is the binding of attention to a single point. When Dharana is sustained without interruption, it becomes Dhyana. When Dhyana deepens to the point where the meditator loses awareness of the act of meditating — when the subject-object distinction dissolves — it becomes Samadhi. Together, the three are called Samyama — the integrated practice of concentration, meditation, and absorption (Yoga Sutras 3.4).

What makes this progression remarkable from a neuroscience perspective is that each stage corresponds to a distinct, measurable brain state with characteristic EEG signatures, network dynamics, and phenomenological qualities. The yogic map and the neuroscientific map converge with striking precision.

Dharana: Concentration and the Dorsal Attention Network

The Practice

Dharana (from the root “dhri” — to hold, to maintain) is defined in Sutra 3.1: “Dharana is the binding of the mind to one place.” The “place” may be external (a candle flame, a point on the wall) or internal (the breath, a chakra, a mantra, a mental image). The essential quality is single-pointedness — ekagrata — the mind resting on one thing without distraction.

This sounds simple. It is the most demanding thing a human being can do. The untrained mind sustains focused attention for approximately 8-12 seconds before a saccade of thought carries it away (Killingsworth & Gilbert, 2010). Dharana is the systematic training to extend this window — from seconds to minutes to the sustained concentration that opens into Dhyana.

The Neural Substrate

Concentrated attention is subserved by the dorsal attention network (DAN), which includes:

• Intraparietal sulcus (IPS): Maintains the spatial representation of the attention target
• Frontal eye fields (FEF): Controls voluntary gaze direction and attentional spotlight
• Superior parietal lobule: Integrates sensory information relevant to the attention target

The DAN operates in constant competition with the default mode network (DMN), which generates spontaneous thought, mind-wandering, and self-referential processing. During Dharana, the DAN must suppress the DMN — every wandering thought represents a DMN intrusion that the DAN must override.

The anterior cingulate cortex (ACC) serves as the conflict monitor — detecting the moment when DMN activity begins to override DAN control (the moment of distraction). The ACC signals the dorsolateral prefrontal cortex (dlPFC), which re-engages the DAN and suppresses the DMN. This cycle — focus, distraction, detection, re-engagement — is the fundamental exercise of Dharana.

Lutz et al. (2004) studied experienced meditators during focused attention practice and found:

• Increased gamma-band oscillations (25-42 Hz) — the EEG signature of intense, coherent neural processing. Gamma activity was not merely elevated during meditation but was significantly higher than in matched controls even at rest, suggesting a trait change in baseline neural coherence.
• Long-range gamma synchrony — simultaneous gamma oscillations across distant brain regions, indicating large-scale neural integration. This was unprecedented in the neuroscience literature — the degree of gamma synchrony observed in the most experienced meditators had never been recorded in any other context.

The Noradrenergic System

Sustained attention depends on the locus coeruleus — a small nucleus in the brainstem that is the brain’s primary source of norepinephrine. The locus coeruleus operates in two modes:

1. Tonic mode: Steady, moderate norepinephrine release that maintains sustained attention on the current task
2. Phasic mode: Burst-like norepinephrine release in response to novel or salient stimuli, which triggers attentional reorienting

Dharana trains the locus coeruleus to maintain tonic mode — steady alertness without the phasic bursts that produce distractibility. Jha et al. (2007) demonstrated that mindfulness training (which includes Dharana-like focused attention) modified the subsystems of attention, improving alerting (tonic readiness) and orienting (efficient shifting to targets) efficiency.

In Patanjali’s terms, the trained locus coeruleus produces the quality described in Sutra 1.14: “Practice becomes established when cultivated for a long time, without interruption, and with devotion (dirgha kala nairantarya satkara).” The neural substrate of this steadiness is the locus coeruleus in sustained tonic mode.

Dhyana: Meditation and the Shift to Open Monitoring

The Transition

The transition from Dharana to Dhyana is described as the point where concentration becomes effortless — where the practitioner no longer needs to actively maintain attention on the object because the attention rests there naturally. Patanjali defines Dhyana in Sutra 3.2: “The continuous flow of cognition toward that object is Dhyana.”

This transition has a precise neurological correlate. In the early stages of focused attention (Dharana), the DAN is effortfully activated and the DMN is effortfully suppressed. The prefrontal cortex is working hard — metabolic neuroimaging shows elevated glucose consumption in the prefrontal regions during effortful concentration.

As concentration deepens, the prefrontal metabolic demand decreases. The attention sustains itself without prefrontal effort — like a flywheel that has been spun up and now rotates on its own momentum. This is the transition from effortful to effortless attention, and it corresponds to a shift in the EEG from beta/gamma dominance (effortful processing) to alpha/theta predominance (effortless, absorptive processing).

Simultaneously, the rigid suppression of the DMN relaxes. In Dhyana, the DMN is not suppressed (as in Dharana) but modulated — it operates at reduced amplitude, generating minimal self-referential content, while the DAN maintains a gentle, non-effortful focus. The two networks are no longer in competition; they are in a state of dynamic equilibrium.

The EEG Signature

The EEG of Dhyana shows:

• Increased frontal midline theta (4-7 Hz): This theta activity, generated in the anterior cingulate cortex and medial prefrontal cortex, is the signature of internalized attention and reduced cognitive processing. It is distinct from the theta of drowsiness (which is more diffuse and accompanied by reduced alpha).
• Maintained posterior alpha (8-12 Hz): Indicating preserved awareness — the practitioner is not falling asleep but is in a state of wakeful inner absorption.
• Reduced beta activity: Indicating disengagement of the analytical, discursive mind.
• Possible increased gamma coherence: In experienced practitioners, sustained gamma coherence may persist from the Dharana phase, indicating maintained neural integration without the effortful quality.

Cahn and Polich (2006) reviewed the EEG literature on meditation and confirmed that the theta-alpha profile is characteristic of meditation states across traditions, while the gamma enhancement is more specific to expert practitioners.

The DMN in Dhyana

Brewer et al. (2011) conducted a landmark study comparing experienced meditators with novices during meditation. Key findings:

• Experienced meditators showed reduced DMN activity during meditation — particularly in the medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC), the two main DMN hubs.
• Even more remarkably, experienced meditators showed reduced DMN activity at rest — when not meditating — compared to novices. This suggests a trait change: the baseline level of self-referential mental activity is permanently reduced in experienced meditators.
• Experienced meditators showed increased connectivity between the PCC and the dorsolateral prefrontal cortex — suggesting that the DMN is more effectively regulated by the prefrontal cortex, even at rest.

These findings correspond precisely to the yogic description of Dhyana as a state where mental fluctuations (chitta vritti) are progressively stilled. The “mental fluctuations” that Patanjali describes are the spontaneous activity of the DMN — the constant stream of memories, plans, fantasies, worries, and self-referential narratives that constitute the ordinary experience of having a mind. Dhyana stills this stream — first during practice, then progressively at rest.

Samadhi: Absorption and the Dissolution of Subject-Object Boundaries

The Nature of Samadhi

Samadhi (Sutra 3.3) occurs when Dhyana deepens to the point where “only the meaning of the object of meditation shines forth, as if devoid of its own form.” The meditator loses awareness of themselves as a meditator. The subject-object distinction — the fundamental division between “I” who is aware and “that” which I am aware of — dissolves. What remains is pure awareness — awareness without an object, or equivalently, awareness that has become its own object.

Patanjali distinguishes multiple levels of Samadhi:

Savitarka Samadhi (with examination): Absorption in which the gross form of the object is still perceived, along with its name and meaning. The object, its name, and its meaning are fused in consciousness.

Nirvitarka Samadhi (without examination): Absorption in which the name and meaning drop away, and only the pure perception of the object remains — perception without conceptual overlay.

Savichara Samadhi (with reflection): Absorption on the subtle nature of the object — not its physical form but its energetic or causal quality.

Nirvichara Samadhi (without reflection): Absorption without any mental content — the mind is utterly still, transparent, empty. This is the threshold of the highest Samadhi.

Nirbija Samadhi (seedless absorption): The final state, in which even the subtle impressions (samskaras) that generate future mental activity are dissolved. This is liberation — the permanent cessation of the mental fluctuations that generate suffering.

The Neuroscience of Non-Dual Awareness

The most direct neuroscientific investigation of Samadhi-like states comes from Josipovic (2014), who studied non-dual awareness using fMRI. The key finding:

In ordinary consciousness, the DMN and the task-positive network (TPN, which includes the DAN) are anti-correlated — when one is active, the other is suppressed. This anti-correlation is a fundamental feature of normal brain function: you are either engaged with the external world (TPN active) or engaged with internal self-referential processing (DMN active), but not both simultaneously.

In non-dual awareness, this anti-correlation breaks down. Both networks operate simultaneously without competing. The brain is simultaneously internally aware (DMN) and externally engaged (TPN) — not alternating between the two but holding both in a unified field of awareness.

This is the neural signature of what the yogic tradition calls Samadhi — the state in which the distinction between inner and outer, subject and object, self and world dissolves. It is not confusion or psychosis (in which boundaries dissolve with distress and disorientation). It is integration — the highest level of neural organization, in which segregated brain networks achieve a new mode of coherent cooperation.

Travis and Shear (2010) placed this state in their taxonomy as “automatic self-transcending” — characterized by:

• Increased alpha1 coherence across the cortex, indicating large-scale cortical integration
• Reduced high-frequency activity, indicating the cessation of effortful processing
• The brain functioning as a unified whole rather than as specialized networks operating in competition

Gamma Synchrony: The Signature of Integration

Lutz et al. (2004) observed that long-term meditators (10,000-50,000 hours of practice) produced gamma oscillations (25-42 Hz) of unprecedented amplitude and inter-electrode coherence. Gamma oscillations are associated with:

• Perceptual binding: The integration of disparate sensory features (color, shape, motion) into a unified percept
• Consciousness: Gamma activity is correlated with conscious awareness and is absent during unconscious processing
• Large-scale neural integration: Gamma coherence across distant brain regions indicates that those regions are functioning as a unified system rather than as independent modules

The extreme gamma coherence observed in advanced meditators may be the neural correlate of Samadhi’s integrative quality — the mind operating as a unified whole rather than as a collection of competing networks and processes.

Clinical and Existential Implications

Dharana for ADHD and Cognitive Enhancement

Dharana practices directly target the attentional deficits that characterize ADHD:

• DAN strengthening improves sustained attention
• ACC training improves conflict monitoring and impulse control
• Locus coeruleus training stabilizes arousal and reduces distractibility
• DMN regulation reduces mind-wandering

MacLean et al. (2010) demonstrated that intensive meditation training improved sustained attention on the psychomotor vigilance task — a standard measure of attentional capacity — and that improvements were maintained at a 5-month follow-up.

Dhyana for Depression and Rumination

The DMN reduction produced by Dhyana practice directly addresses rumination — the repetitive, negative self-referential thought patterns that maintain depression. Rumination is DMN overactivity: the medial prefrontal cortex generates negative self-evaluations, the posterior cingulate cortex maintains the self-referential narrative, and the temporal poles contribute negative autobiographical memories.

By training the brain to reduce DMN activity — both during and outside of practice — Dhyana breaks the neural pattern that maintains depressive rumination.

Samadhi and Existential Well-Being

The dissolution of the subject-object boundary reported in Samadhi corresponds to what Abraham Maslow called “peak experiences” and what Csikszentmihalyi described as “flow” — states of total absorption in which self-consciousness disappears and performance is optimal.

These states are associated with lasting improvements in well-being, meaning, and life satisfaction. Yaden et al. (2017) reviewed the literature on self-transcendent experiences and found that they predict reduced fear of death, increased prosocial behavior, and enhanced psychological resilience.

The Progressive Path: Why Sequence Matters

The sequence Dharana-Dhyana-Samadhi is not arbitrary. Each stage creates the neurological preconditions for the next:

1. Dharana strengthens the DAN and ACC, providing the attentional stability required for sustained meditation
2. Dhyana modulates the DMN, reducing the self-referential mental noise that prevents absorption
3. Samadhi integrates the DMN and TPN, achieving a level of neural coherence that requires both the attentional stability of Dharana and the DMN quieting of Dhyana

Attempting Samadhi without Dharana training is like attempting to run a marathon without cardiovascular conditioning. The neural infrastructure is not in place. The result is either frustration (the mind cannot sustain the practice) or distortion (altered states are achieved without the stability to integrate them — a condition recognized in both the yogic and psychiatric traditions as a significant risk).

The Four Directions Perspective

Dharana is the practice of the East — the rising sun of attention, the single point of light that illuminates the darkness. It is the beginning of the inner journey, the first step into the territory of consciousness.

Dhyana is the practice of the South — the warmth of sustained presence, the fire that burns without consuming, the steady flame of awareness that warms everything it touches.

Samadhi is the practice of the West — the sunset of the ego, the dissolution of the boundary between self and world, the return to the great ocean of consciousness from which the individual wave arose.

The North — wisdom — is what remains after Samadhi: the clear-eyed seeing that emerges when the mental noise has stilled and the subject-object boundary has thinned. The North is not a practice but a fruit — the wisdom that arises when the practices have done their work.

Testable Hypotheses

1. A Dharana-focused training protocol (12 weeks of daily trataka or breath concentration) will produce greater improvements in sustained attention (measured by psychomotor vigilance task) than a comparable period of open monitoring mindfulness.
2. Practitioners who report spontaneous Dhyana states (effortless meditation) will show reduced DMN-TPN anti-correlation on resting-state fMRI compared to practitioners who report only effortful concentration.
3. The gamma coherence observed by Lutz et al. (2004) will correlate with self-reported frequency of Samadhi-like states on a phenomenological questionnaire.

References

• Brewer, J. A., Worhunsky, P. D., Gray, J. R., Tang, Y. Y., Weber, J., & Kober, H. (2011). Meditation experience is associated with differences in default mode network activity and connectivity. Proceedings of the National Academy of Sciences, 108(50), 20254-20259.
• Cahn, B. R., & Polich, J. (2006). Meditation states and traits: EEG, ERP, and neuroimaging studies. Psychological Bulletin, 132(2), 180-211.
• Jha, A. P., Krompinger, J., & Baime, M. J. (2007). Mindfulness training modifies subsystems of attention. Cognitive, Affective, & Behavioral Neuroscience, 7(2), 109-119.
• Josipovic, Z. (2014). Neural correlates of nondual awareness in meditation. Annals of the New York Academy of Sciences, 1307(1), 9-18.
• Killingsworth, M. A., & Gilbert, D. T. (2010). A wandering mind is an unhappy mind. Science, 330(6006), 932.
• Lutz, A., Greischar, L. L., Rawlings, N. B., Ricard, M., & Davidson, R. J. (2004). Long-term meditators self-induce high-amplitude gamma synchrony during mental practice. Proceedings of the National Academy of Sciences, 101(46), 16369-16373.
• MacLean, K. A., Ferrer, E., Aichele, S. R., Bridwell, D. A., Zanesco, A. P., Jacobs, T. L., … & Saron, C. D. (2010). Intensive meditation training improves perceptual discrimination and sustained attention. Psychological Science, 21(6), 829-839.
• Patanjali. Yoga Sutras. Translation by Satchidananda, S. (1978). The Yoga Sutras of Patanjali. Integral Yoga Publications.
• Travis, F., & Shear, J. (2010). Focused attention, open monitoring and automatic self-transcending: categories to organize meditations from Vedic, Buddhist and Chinese traditions. Consciousness and Cognition, 19(4), 1110-1118.
• Yaden, D. B., Haidt, J., Hood, R. W., Vago, D. R., & Newberg, A. B. (2017). The varieties of self-transcendent experience. Review of General Psychology, 21(2), 143-160.