Within the depth-psychology and adjacent neuroscientific literature assembled in the Seba corpus, 'activation' operates across at least three distinct registers that frequently intersect without being fully reconciled. In the neurobiological register — represented most systematically by Kandel, Craig, and the trauma-neuroscience researchers — activation denotes measurable electrochemical or hemodynamic events: ion-channel gating, CREB phosphorylation, fMRI BOLD signal, and region-specific cortical engagement. In the clinical-somatic register — principally Levine and Ogden — activation names the mobilization of survival energy through the autonomic nervous system, a process that can become pathologically arrested in trauma and must be titrated for therapeutic discharge. In the psychopharmacological register — Rubia's ADHD studies — activation is the criterion variable against which drug normalization is assessed, revealing frontocingulate and striatal deficits that stimulants partially remediate. The central tension across these registers is ontological: activation as cellular mechanism versus activation as embodied physiological state versus activation as index of psychological capacity. For depth psychology, the clinically decisive question is not whether activation occurs but whether its energy completes its intended arc — fight, flight, social engagement — or becomes bound in symptomatic detour. This makes activation inseparable from concepts of discharge, regulation, dissociation, and autonomic hierarchy.
treatment must be approached differently according to which of these three systems is activated during sessions and which lie dormant.
Levine argues that therapeutic intervention must be dynamically calibrated to which polyvagal system is currently activated, making activation the primary diagnostic and procedural coordinate in trauma treatment.
, In an Unspoken Voice: How the Body Releases Trauma and Restores Goodness, 2010thesis
Activation in the anterior insula is present during each of the six primary emotional feelings of anger, sadness, happiness, surprise, disgust, and fear.
Craig establishes anterior insular activation as the universal neural correlate of subjective emotional feeling, grounding affective experience in a specific cortical substrate.
, How Do You Feel? An Interoceptive Moment with Your Neurobiological Self, 2014thesis
Repeated transmitter activation of a seven transmembrane receptor leads to the translocation of the kinase to the nucleus and to activation of transcription, producing a persistent synaptic action.
Kandel demonstrates that graded degrees of transmitter activation produce qualitatively different cellular outcomes, from millisecond ion-channel events to lasting gene transcription and synaptic growth.
, The Molecular Biology of Memory Storage: A Dialogue between Genes and Synapses, 2001thesis
No other region of the brain is activated during all feelings and all tasks. The only feature that is common to everything a human does is awareness of the moment.
Craig uses the universality of AIC activation to argue that this region is the neural seat of moment-to-moment awareness itself, not merely of specific emotional states.
, How Do You Feel? An Interoceptive Moment with Your Neurobiological Self, 2014thesis
being in shutdown (immobility/freezing/or collapse) or in sympathetic/hyperactivation (fight or flight) greatly diminishes a person's capacity to receive and incorporate empathy and support.
Levine articulates the polyvagal logic by which excessive or arrested activation forecloses the social engagement capacity essential to healing.
, In an Unspoken Voice: How the Body Releases Trauma and Restores Goodness, 2010thesis
Methylphenidate normalises activation and functional connectivity deficits in attention and motivation networks in medication-naïve children with ADHD during a rewarded continuous performance task
Rubia frames methylphenidate's therapeutic action as the normalization of deficient activation patterns in frontostriatal networks, making activation the key metric of ADHD pathology and remediation.
, Methylphenidate normalises activation and functional connectivity deficits in attention and motivation networks in medication-naïve children with ADHD during a rewarded continuous performance task, 2009thesis
basic emotions have unique central network signatures... generated by genetically programmed (but adaptable) patterns of activation in the central autonomic network, which is also the emotional motor network.
Craig proposes that distinct emotional states correspond to genetically encoded but experientially modifiable patterns of autonomic-network activation, linking evolution, genetics, and phenomenology.
, How Do You Feel? An Interoceptive Moment with Your Neurobiological Self, 2014supporting
the activation in the posterior insula on both sides increased almost monotonically during both the 9- and 18-second trials, and it consistently peaked just after the end of the tone.
Craig demonstrates that posterior insular activation tracks interoceptive input continuously over time, providing empirical grounding for the role of body-state monitoring in temporal and emotional awareness.
, How Do You Feel? An Interoceptive Moment with Your Neurobiological Self, 2015supporting
repeated learning trials required for sensitization are important because they send signals to the nucleus, telling it to activate regulatory genes that encode regulatory proteins.
Kandel shows that behavioral repetition translates into molecular activation cascades, revealing the mechanism by which experience becomes durably encoded at the synaptic level.
, In search of memory the emergence of a new science of mind, 2006supporting
cyclic AMP second-messenger signaling is also turned on by serotonin during sensitization... the increase in cyclic AMP lasts about as long as the slow synaptic potential.
Kandel traces how neurotransmitter binding initiates a timed intracellular activation sequence whose duration matches the behavioral window of sensitization.
, In search of memory the emergence of a new science of mind, 2006supporting
the increased activation in these brain regions in ADHD children under Methylphenidate may be a compensatory activation.
Rubia distinguishes normative from compensatory activation, introducing the interpretive complexity that pharmacologically induced activation may reflect remediation rather than normalization.
, Methylphenidate normalises activation and functional connectivity deficits in attention and motivation networks in medication-naïve children with ADHD during a rewarded continuous performance task, 2009supporting
Almost all recent imaging studies of emotion report joint activation of the AIC and the ACC in subjects experiencing emotional feelings, including maternal and romantic love, anger, fear, sadness, happiness, sexual arousal, disgust.
Craig surveys the breadth of emotional conditions reliably producing co-activation of insular and cingulate cortices, establishing this dyad as the functional signature of conscious feeling.
, How Do You Feel — Now? The Anterior Insula and Human Awareness, 2009supporting
boys with ADHD showed reduced activation under placebo in bilateral IFC, reaching into left insula and putamen; SMA/ACC; and right DLPFC.
Rubia maps the topography of underactivation in ADHD, identifying a frontal-insular-striatal network whose deficient engagement defines the disorder's neurofunctional profile.
, Effects of Stimulants on Brain Function in Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysissupporting
differential activation may be attributable to the different nature and quality of a traumatic memory... differences in brain networks engaged in traumatic memory recall have been observed in subjects with PTSD who experienced flashbacks.
Ogden links asymmetric hemispheric activation patterns to the qualitative distinction between traumatic flashback and ordinary autobiographical recall, grounding clinical phenomenology in neuroimaging evidence.
, Trauma and the Body: A Sensorimotor Approach to Psychotherapy, 2006supporting
PKA and MAPK phosphorylate and activate the cAMP response element-binding (CREB) protein and remove the repressive action of CREB-2, an inhibitor of CREB-1.
Kandel details the molecular activation cascade — from kinase translocation to gene-regulatory protein engagement — that converts short-term synaptic change into long-term structural memory.
, The Molecular Biology of Memory Storage: A Dialogue between Genes and Synapses, 2001supporting
Joy, unlike other positive emotions, shows increased beta-adrenergic sympathetic activation, which is usually associated with motivational engagement, co-occurring with increased vagal activation.
Lench demonstrates that distinct positive emotions carry differentiated autonomic activation signatures, challenging undifferentiated accounts of positive affect and supporting emotion-specific physiological profiling.
, The Function of Emotions: When and Why Emotions Help Us, 2018supporting
During positive emotional conditions, there was strong activation in the left AIC, with no significant activation in the right AIC, in both women and men.
Craig documents valence-dependent lateralization of insular activation, providing a neuroanatomical basis for the asymmetric processing of positive versus negative affective states.
, How Do You Feel? An Interoceptive Moment with Your Neurobiological Self, 2014supporting
when these receptors recognize and bind a chemical messenger on the outside of the cell, they activate an enzyme within the cell called adenylyl cyclase, which makes cyclic AMP.
Kandel explains the metabotropic receptor mechanism by which extracellular signals produce amplified intracellular activation, foundational to understanding second-messenger contributions to memory and mood.
, In search of memory the emergence of a new science of mind, 2006supporting
the amygdala, the so-called fear or 'smoke detector,' lit up with electrical activity; at the same time, a region in the left cerebral cortex, called Broca's area, went dim.
Levine cites van der Kolk's neuroimaging evidence showing that trauma activates subcortical fear circuitry while simultaneously suppressing language-center function, producing the characteristic wordlessness of traumatic experience.
, In an Unspoken Voice: How the Body Releases Trauma and Restores Goodness, 2010supporting
gene function can be regulated up and down in response to environmental needs by signaling molecules from outside the cell... as well as from inside the cell (second messenger signals such as cyclic AMP).
Kandel establishes the bidirectional, environmentally responsive nature of gene activation, providing the epigenetic substrate for understanding how experience shapes lasting neurobiological change.
, In search of memory the emergence of a new science of mind, 2006supporting
one experiences waves of involuntary shaking and trembling, followed by spontaneous changes in breathing... to discharge the vast energy that, though mobilized to prepare the organism to fight, flee or otherwise self-protect, was not fully executed.
Levine describes the somatic phenomenology of activation release — trembling, breathing shifts — as the body's natural mechanism for completing the arousal cycle that trauma has interrupted.
, In an Unspoken Voice: How the Body Releases Trauma and Restores Goodness, 2010aside
stimulant users changed response options less as a function of varying error rates and were... significantly less influenced by the previous trial outcome.
Paulus links reduced neural activation in stimulant users to behavioral inflexibility, suggesting that blunted activation responses impair adaptive error-contingent learning.
, Reduced Behavioral and Neural Activation in Stimulant Users to Different Error Rates during Decision Makingaside
when the cell membrane is sufficiently stimulated, sodium ions move into the cell for about 1/1000 of a second, changing the internal voltage from −70 millivolts to +40 millivolts and producing the rise of the action potential.
Kandel describes membrane-level activation via the action potential, providing the electrophysiological foundation upon which all higher-order theories of neural and psychological activation rest.
, In search of memory the emergence of a new science of mind, 2006aside