The Deep History of Ourselves: The Four-Billion-Year Story of How We Got Conscious Brains

Knowledge Graph: The Deep History of Ourselves: The Four-Billion-Year Story of How We Got Conscious Brains (Joseph LeDoux, 2019)

Editorial spotlight: ↑ survival circuits first — consciousness emerged late

Concepts

• LeDoux survival circuits (importance 5): Non-conscious neural systems managing threat detection, energy regulation, homeostasis — evolved long before consciousness or feelings. The deep continuity across all nervous systems.. Source: (from training memory of book).
• LeDoux amygdala-centered fear circuit (importance 5): Threat detection system bypassing cortex. Automatic freezing, escape, autonomic arousal — the non-conscious core of defensive behavior.. Source: (from training memory of book).
• prokaryote behavioral repertoire (importance 4): Single-cell organisms exhibit approach/withdrawal, chemical sensing, membrane receptors — behavioral primitives without neurons.. Source: (from training memory of book).
• bilaterian cephalization (importance 4): Concentration of sensory organs and neurons at the front end — the origin of heads and brains.. Source: (from training memory of book).
• vertebrate brain bauplan (importance 4): Basic three-part structure: forebrain, midbrain, hindbrain. Shared across fish, amphibians, reptiles, birds, mammals.. Source: (from training memory of book).
• brainstem survival functions (importance 4): Hindbrain and midbrain control breathing, heart rate, sleep-wake, basic reflexes. Ancient, conserved, non-conscious.. Source: (from training memory of book).
• mammalian neocortex (importance 4): Six-layered structure unique to mammals. Handles sensory integration, motor planning, memory, later cognitive functions.. Source: (from training memory of book).
• LeDoux 'hot cognition' (importance 4): Brain processes that integrate survival circuits with cognitive representations. Threats activate both ancient reflexes and modern appraisals.. Source: (from training memory of book).
• LeDoux working memory integration (importance 4): Prefrontal cortex holds sensory, mnemonic, and body-state information online. Creates the 'now' of conscious experience.. Source: (from training memory of book).
• human language capacity (importance 4): Recursive syntax, symbolic reference, cultural transmission. Enables narrative self-models and extended consciousness.. Source: (from training memory of book).
• LeDoux higher-order theory adaptation (importance 4): Consciousness arises when cortical circuits re-represent survival-circuit states. First-order circuits remain non-conscious.. Source: (from training memory of book).
• LeDoux nerve net (importance 3): Decentralized neural architecture in cnidarians. No brain, but coordinated reflexes via chemical and electrical signaling.. Source: (from training memory of book).
• homeostatic regulation (pre-nervous) (importance 3): Energy balance, osmotic regulation, pH control existed in single-cell organisms. Nervous systems later coordinated these.. Source: (from training memory of book).
• LeDoux schema networks (importance 3): Cortical representations that integrate past experiences, survival relevance, context. Shape conscious appraisals of situations.. Source: (from training memory of book).
• LeDoux reflective self-awareness (importance 3): Ability to model oneself as an object of thought. Requires prefrontal-cortex monitoring of body and mental states.. Source: (from training memory of book).
• chemical synapse evolution (importance 3): Specialized junctions for neuron-to-neuron signaling. Appeared with first neurons. Enabled complex circuits.. Source: (from training memory of book).
• Hox gene body plans (importance 3): Master regulatory genes specifying anterior-posterior axis. Shared across bilaterians. Small mutations = large body-plan changes.. Source: (from training memory of book).
• episodic memory (hippocampus) (importance 3): Spatiotemporal memory of specific events. Hippocampus-dependent. Enables mental time travel and conscious recollection.. Source: (from training memory of book).
• theory of mind (ToM) (importance 3): Representing others' mental states. Requires prefrontal and temporal cortex. Likely unique to great apes and possibly corvids.. Source: (from training memory of book).
• fight-flight-freeze responses (importance 3): Universal defensive behaviors across vertebrates. Brainstem and amygdala coordination. Non-conscious, automatic.. Source: (from training memory of book).
• LeDoux body-feedback loop (importance 3): Survival circuits trigger bodily changes (heart rate, hormones). Insula and cingulate re-represent these as feelings.. Source: (from training memory of book).
• LeDoux cognitive appraisal integration (importance 3): Prefrontal cortex interprets survival-circuit activations using schemas, memories, language. Creates subjective emotional experience.. Source: (from training memory of book).
• LeDoux narrative self-model (importance 3): Language-based autobiographical story of who we are. Constantly updated. Gives continuity to conscious experience.. Source: (from training memory of book).
• LeDoux attention as gateway (importance 3): Working memory has limited capacity. Attention selects what enters consciousness from parallel non-conscious processing.. Source: (from training memory of book).
• LeDoux low-road threat pathway (importance 3): Thalamus → amygdala direct route bypasses cortex. Enables sub-100ms defensive responses to crude threat features.. Source: (from training memory of book).
• LeDoux high-road appraisal pathway (importance 3): Thalamus → cortex → amygdala slower route. Provides detailed perceptual analysis, context, memory before defensive response.. Source: (from training memory of book).
• fish lateral line system (importance 2): Mechanosensory organs detect water pressure changes. Ancient sensory modality shared across aquatic vertebrates.. Source: (from training memory of book).
• reptilian pallium (importance 2): Early cortex-like structure in reptiles. Three-layered, handles spatial and sensory integration.. Source: (from training memory of book).
• action potential mechanism (importance 2): All-or-none electrical spike propagating down axons. Universal signaling code across all neurons.. Source: (from training memory of book).
• myelin sheath (vertebrate) (importance 2): Glial insulation speeding signal transmission. Enabled larger vertebrate bodies and faster reflexes.. Source: (from training memory of book).
• global workspace theory (Baars) (importance 2): Consciousness = broadcasting information to multiple brain systems. LeDoux adapts this: broadcast includes survival-circuit states.. Source: (from training memory of book).
• chronic stress effects (importance 2): Prolonged cortisol damages hippocampus, shrinks prefrontal cortex. Modern mismatch: ancient circuits face novel stressors.. Source: (from training memory of book).
• extinction (fear reduction) (importance 2): New learning that threat is no longer present. Prefrontal cortex inhibits amygdala. Basis for exposure therapy.. Source: (from training memory of book).
• memory reconsolidation (importance 2): Retrieved memories become temporarily labile and can be modified. Window for therapeutic intervention in fear memories.. Source: (from training memory of book).
• default mode network (DMN) (importance 2): Brain regions active during rest, mind-wandering, self-referential thought. Includes medial prefrontal, posterior cingulate.. Source: (from training memory of book).
• mammalian parental care circuits (importance 2): Hypothalamic and limbic systems driving nursing, protection, attachment. Enabled by internal gestation and lactation.. Source: (from training memory of book).
• social brain hypothesis (Dunbar) (importance 2): Primate brain size correlates with social group size. Managing relationships drove cognitive expansion.. Source: (from training memory of book).
• visual cortex feature hierarchy (importance 2): V1 detects edges, V2 corners, V4 shapes, IT objects. Feedforward and feedback integration. Illustrates cortical processing strategy.. Source: (from training memory of book).
• predictive coding (Friston) (importance 2): Cortex generates top-down predictions; only prediction errors propagate upward. Efficient coding scheme, possibly for all cortex.. Source: (from training memory of book).
• habit formation (basal ganglia) (importance 2): Repeated actions shift from cortical (deliberate) to striatal (automatic) control. Survival-efficient but inflexible.. Source: (from training memory of book).
• brainstem arousal systems (importance 2): Norepinephrine, serotonin, acetylcholine, histamine nuclei modulate cortex. Set global brain states (sleep, wake, attention).. Source: (from training memory of book).
• REM sleep (memory consolidation) (importance 2): Rapid-eye-movement sleep stage. Hippocampal replay strengthens memories. Dreams may reflect survival-circuit activations.. Source: (from training memory of book).
• metacognition (thinking about thinking) (importance 2): Monitoring one's own knowledge and confidence. Requires prefrontal cortex. May be uniquely human or shared with great apes.. Source: (from training memory of book).
• emotional contagion (rats) (importance 1): Rodents freeze when cagemate receives shock. Suggests primitive empathy or shared survival-circuit activation.. Source: (from training memory of book).
• bat echolocation (importance 1): Auditory cortex maps 3D space from time delays. Shows sensory modality plasticity — cortex adapts to input type.. Source: (from training memory of book).
• circadian rhythm (SCN) (importance 1): Suprachiasmatic nucleus sets 24-hour cycle. Found in all animals. Synchronizes physiology to light-dark cycle.. Source: (from training memory of book).

Claims

• LeDoux's 4-billion-year continuity thesis (importance 5): Life's behavioral solutions trace back to single-cell organisms. Nervous systems refined ancient survival mechanisms, not invented them.. Source: (from training memory of book).
• LeDoux consciousness-as-latecomer (importance 5): Consciousness and subjective feelings are recent additions to survival circuits. Most brain function remains non-conscious.. Source: (from training memory of book).
• LeDoux two-track brain thesis (importance 5): Non-conscious survival circuits run in parallel with conscious cognitive processes. Most behavior guided by the former.. Source: (from training memory of book).
• LeDoux integrative model of self (importance 5): Human selfhood = survival circuits (4 billion years) + mammalian cortex (200 mya) + primate cognition (30 mya) + language (100 kya). Layered, not unified.. Source: (from training memory of book).
• LeDoux feelings ≠ emotions distinction (importance 4): Emotions (behavioral/physiological patterns) are non-conscious survival responses. Feelings (conscious experiences) require additional cortical integration.. Source: (from training memory of book).
• LeDoux behavior-first principle (importance 4): Evolution selected for survival behaviors, not subjective experiences. Feelings are byproducts of cortical re-representation.. Source: (from training memory of book).
• LeDoux minimal consciousness thesis (importance 4): Core consciousness requires working memory holding survival-circuit states + cortical re-representation. Likely limited to mammals.. Source: (from training memory of book).
• neurotransmitter deep conservation (importance 3): Glutamate, GABA, acetylcholine, serotonin used across all animals with neurons. Chemical signaling predates nervous systems.. Source: (from training memory of book).
• LeDoux language-dependent self (importance 3): Human narrative self-concept requires linguistic labeling and autobiographical memory. Non-linguistic animals lack this layer.. Source: (from training memory of book).
• LeDoux anxiety ≠ fear distinction (importance 3): Fear = immediate threat response (amygdala-driven). Anxiety = sustained worry state requiring cortical elaboration of potential threats.. Source: (from training memory of book).
• LeDoux therapy insight (importance 3): Treating anxiety requires targeting both non-conscious survival circuits (extinction) and conscious appraisals (cognitive therapy).. Source: (from training memory of book).
• LeDoux wanting ≠ liking split (importance 3): Dopamine drives 'wanting' (approach), not 'liking' (pleasure). Pleasure requires cortical re-representation of reward states.. Source: (from training memory of book).
• LeDoux cultural transmission advantage (importance 3): Human language enables non-genetic inheritance of survival strategies. Culture accelerates adaptation faster than genes.. Source: (from training memory of book).
• LeDoux psychiatric disorder framework (importance 3): Anxiety, depression, PTSD arise from dysregulated survival circuits + maladaptive cortical appraisals. Two-system treatment needed.. Source: (from training memory of book).
• LeDoux predictive survival circuits (importance 3): Survival circuits anticipate threats based on past experience. Prediction errors update defensive responses. Cortex adds symbolic predictions.. Source: (from training memory of book).
• LeDoux dual self (implicit + explicit) (importance 3): Implicit self = survival-circuit driven behavior. Explicit self = narrative self-concept. Usually aligned, sometimes in conflict.. Source: (from training memory of book).
• LeDoux consciousness distribution (importance 3): Core consciousness likely in mammals, possibly birds. Fish, reptiles, invertebrates have survival circuits but lack cortical re-representation.. Source: (from training memory of book).
• LeDoux constrained free will (importance 2): Survival circuits limit choices non-consciously. Conscious deliberation operates within biologically-set boundaries.. Source: (from training memory of book).
• LeDoux subjective temporality (importance 2): Conscious experience of 'now' spans ~3 seconds. Working memory integrates recent sensory, mnemonic, bodily states into unified moment.. Source: (from training memory of book).
• LeDoux continuity as construction (importance 2): Sense of continuous self is retroactive narrative. Gaps filled by confabulation. Self is a process, not a thing.. Source: (from training memory of book).
• LeDoux modern anxiety mismatch (importance 2): Survival circuits evolved for physical predators. Modern threats (social, economic, existential) trigger same circuits maladaptively.. Source: (from training memory of book).

Empirical results

• eukaryote cellular complexity (importance 3): Nucleus, mitochondria, internal compartments enabled larger cells and multi-cellularity — preconditions for nervous systems.. Source: (from training memory of book).
• protostome-deuterostome divergence (importance 3): Two major branches of bilaterian evolution. Insects/mollusks (protostomes) vs vertebrates (deuterostomes). Independent brain elaborations.. Source: (from training memory of book).
• amniote egg revolution (importance 3): Reptiles, birds, mammals freed from water dependency. Enabled terrestrial radiation and larger brains.. Source: (from training memory of book).
• primate cortical expansion (importance 3): Primates have larger cortex-to-body ratios. Enhanced visual processing, social cognition, tool use.. Source: (from training memory of book).
• Cambrian explosion (~540 mya) (importance 3): Rapid diversification of animal body plans. First complex eyes, predators, armored prey. Sensory arms race drove brain evolution.. Source: (from training memory of book).
• human prefrontal expansion (importance 3): Humans have disproportionately large prefrontal cortex relative to other primates. Enables planning, abstract thought, self-regulation.. Source: (from training memory of book).
• avian cognitive complexity (importance 2): Birds evolved large brains independently. Corvids and parrots show tool use, social learning, future planning.. Source: (from training memory of book).
• octopus distributed nervous system (importance 2): Cephalopods have large brains among invertebrates. 2/3 of neurons in arms, not brain. Shows convergent complexity.. Source: (from training memory of book).
• honeybee spatial navigation (importance 2): Tiny insect brain computes sun angle, landmarks, distance. Waggle dance communicates location. Complex from ~1 million neurons.. Source: (from training memory of book).
• hippocampal place cells (O'Keefe) (importance 2): Neurons firing at specific spatial locations. Discovered in rats. Forms cognitive map of environment.. Source: (from training memory of book).
• great ape brain-body ratios (importance 2): Chimps, bonobos, orangutans, gorillas have large brains. Humans are extreme: 3× larger than expected for body size.. Source: (from training memory of book).
• prefrontal cortex late maturation (importance 2): Human prefrontal cortex develops into mid-20s. Explains adolescent risk-taking: survival circuits mature before executive control.. Source: (from training memory of book).
• Drosophila olfactory learning (importance 1): Fruit flies learn odor-shock associations. Mushroom body circuit parallels mammalian amygdala function. Convergent mechanisms.. Source: (from training memory of book).
• songbird vocal learning (importance 1): Zebra finches require tutor. Basal ganglia-cortical loop parallels human language circuits. Convergent vocal learning.. Source: (from training memory of book).
• blindsight (Weiskrantz) (importance 1): V1-damaged patients deny seeing but can 'guess' location. Demonstrates non-conscious visual processing via subcortical routes.. Source: (from training memory of book).
• split-brain patients (Gazzaniga) (importance 1): Severed corpus callosum separates hemispheres. Left hemisphere narrates, right hemisphere acts. Shows self is not unitary.. Source: (from training memory of book).

Methods

• mirror self-recognition test (importance 2): Mark on animal's face; does it touch the mark when seeing mirror? Passes in great apes, dolphins, elephants, magpies.. Source: (from training memory of book).
• Pavlovian fear conditioning (importance 2): Pair neutral stimulus with shock. Amygdala learns association. Model for studying survival-circuit plasticity.. Source: (from training memory of book).

Entities

• cnidarians (jellyfish, hydra) (importance 4): First animals with neurons — nerve nets without centralization. Coordinate swimming, feeding, stinging.. Source: (from training memory of book).
• amygdala (importance 4): Subcortical structure processing threats and survival-relevant stimuli. Present in all vertebrates, elaborated in mammals.. Source: (from training memory of book).
• prefrontal cortex (importance 4): Front of mammalian cortex. Executive control, planning, self-awareness. Especially enlarged in primates.. Source: (from training memory of book).
• Urbilaterian ancestor (importance 3): Common ancestor of all bilaterally symmetric animals (~600 mya). Had simple brain, sensory organs, gut, basic body plan.. Source: (from training memory of book).
• hypothalamus (importance 3): Master regulator of hunger, thirst, temperature, hormones. Integrates survival needs below consciousness.. Source: (from training memory of book).
• hippocampus (importance 3): Medial temporal lobe structure. Spatial maps, episodic memory, contextual learning. Present in all mammals, simpler in reptiles.. Source: (from training memory of book).
• insular cortex (importance 3): Processes interoceptive signals (gut, heart, lungs). Creates conscious awareness of bodily states. Key for feelings.. Source: (from training memory of book).
• LUCA (Last Universal Common Ancestor) (importance 2): ~3.5 billion years ago. Single-cell organism ancestor of all life. Had DNA, proteins, metabolism — no nervous system.. Source: (from training memory of book).
• trilobite compound eyes (importance 2): Complex visual systems in early arthropods. Demonstrates sophistication of Cambrian sensory processing.. Source: (from training memory of book).
• GABA (inhibitory transmitter) (importance 2): Gamma-aminobutyric acid. Primary inhibitory neurotransmitter across all nervous systems. Evolutionary ancient.. Source: (from training memory of book).
• glutamate (excitatory transmitter) (importance 2): Primary excitatory neurotransmitter. Present in cnidarians through humans. Enables rapid signaling.. Source: (from training memory of book).
• Neanderthal brain size (importance 2): Similar or slightly larger than Homo sapiens. Complex tool use, burial practices. Language unclear.. Source: (from training memory of book).
• cortisol (stress hormone) (importance 2): Glucocorticoid released by adrenal glands. Mobilizes energy, suppresses immunity. Adaptive acutely, harmful chronically.. Source: (from training memory of book).
• dopamine (reward signaling) (importance 2): Neurotransmitter encoding reward prediction errors. Drives approach behavior, learning. Conserved across vertebrates.. Source: (from training memory of book).
• nucleus accumbens (importance 2): Ventral striatum region processing rewards. Receives dopamine projections. Mediates motivation and pleasure.. Source: (from training memory of book).
• anterior cingulate cortex (importance 2): Monitors conflict, errors, pain. Integrates emotion and cognition. Enlarged in primates.. Source: (from training memory of book).
• oxytocin (social bonding) (importance 2): Neuropeptide facilitating maternal care, pair bonding, trust. Ancient hormone co-opted for mammalian social behavior.. Source: (from training memory of book).
• thalamus (sensory relay) (importance 2): Subcortical hub routing sensory information to cortex. All senses except smell pass through thalamus first.. Source: (from training memory of book).
• cerebellum (importance 2): Contains 80% of brain's neurons. Coordinates movement, timing, sequence learning. Non-conscious motor memory.. Source: (from training memory of book).
• basal ganglia (importance 2): Subcortical nuclei for action selection, habit learning, reward processing. Includes striatum, substantia nigra.. Source: (from training memory of book).
• C. elegans (302-neuron worm) (importance 1): Nematode with fully-mapped connectome. Shows complex behavior from minimal circuit. Developmental biology model.. Source: (from training memory of book).

Relations

• LUCA (Last Universal Common Ancestor) precedes prokaryote behavioral repertoire
• prokaryote behavioral repertoire precedes eukaryote cellular complexity
• prokaryote behavioral repertoire exemplifies homeostatic regulation (pre-nervous)
• eukaryote cellular complexity enables cnidarians (jellyfish, hydra)
• cnidarians (jellyfish, hydra) exemplifies LeDoux nerve net
• LeDoux nerve net requires chemical synapse evolution
• chemical synapse evolution evidences neurotransmitter deep conservation
• neurotransmitter deep conservation exemplifies GABA (inhibitory transmitter)
• neurotransmitter deep conservation exemplifies glutamate (excitatory transmitter)
• action potential mechanism enables chemical synapse evolution
• cnidarians (jellyfish, hydra) precedes Urbilaterian ancestor
• Urbilaterian ancestor exemplifies bilaterian cephalization
• bilaterian cephalization enables vertebrate brain bauplan
• Urbilaterian ancestor precedes protostome-deuterostome divergence
• protostome-deuterostome divergence precedes vertebrate brain bauplan
• Hox gene body plans enables bilaterian cephalization
• Cambrian explosion (~540 mya) motivates bilaterian cephalization
• Cambrian explosion (~540 mya) exemplifies trilobite compound eyes
• vertebrate brain bauplan exemplifies brainstem survival functions
• brainstem survival functions exemplifies LeDoux survival circuits
• homeostatic regulation (pre-nervous) precedes hypothalamus
• hypothalamus supports brainstem survival functions
• vertebrate brain bauplan precedes amniote egg revolution
• amniote egg revolution enables mammalian neocortex
• amniote egg revolution precedes reptilian pallium
• reptilian pallium precedes mammalian neocortex
• mammalian neocortex enables LeDoux two-track brain thesis
• LeDoux survival circuits supports LeDoux two-track brain thesis
• LeDoux two-track brain thesis supports LeDoux consciousness-as-latecomer
• vertebrate brain bauplan exemplifies amygdala
• amygdala exemplifies LeDoux amygdala-centered fear circuit
• LeDoux amygdala-centered fear circuit exemplifies LeDoux survival circuits
• LeDoux amygdala-centered fear circuit enables fight-flight-freeze responses
• fish lateral line system exemplifies vertebrate brain bauplan
• myelin sheath (vertebrate) enables action potential mechanism
• mammalian neocortex precedes primate cortical expansion
• primate cortical expansion exemplifies great ape brain-body ratios
• great ape brain-body ratios precedes human prefrontal expansion
• human prefrontal expansion exemplifies prefrontal cortex
• prefrontal cortex enables LeDoux working memory integration
• LeDoux working memory integration enables LeDoux higher-order theory adaptation
• LeDoux higher-order theory adaptation supports LeDoux consciousness-as-latecomer
• human language capacity enables LeDoux narrative self-model
• LeDoux narrative self-model supports LeDoux language-dependent self
• LeDoux language-dependent self supports LeDoux reflective self-awareness
• prefrontal cortex enables LeDoux reflective self-awareness
• LeDoux survival circuits evidences LeDoux's 4-billion-year continuity thesis
• prokaryote behavioral repertoire evidences LeDoux's 4-billion-year continuity thesis
• LeDoux amygdala-centered fear circuit supports LeDoux feelings ≠ emotions distinction
• LeDoux working memory integration supports LeDoux feelings ≠ emotions distinction
• LeDoux feelings ≠ emotions distinction supports LeDoux behavior-first principle
• mammalian neocortex enables LeDoux 'hot cognition'
• LeDoux survival circuits requires LeDoux 'hot cognition'
• LeDoux schema networks enables LeDoux 'hot cognition'
• hippocampus enables episodic memory (hippocampus)
• episodic memory (hippocampus) enables LeDoux narrative self-model
• hippocampal place cells (O'Keefe) evidences episodic memory (hippocampus)
• mirror self-recognition test evidences LeDoux reflective self-awareness
• theory of mind (ToM) requires LeDoux reflective self-awareness
• prefrontal cortex enables theory of mind (ToM)
• Neanderthal brain size precedes human prefrontal expansion
• global workspace theory (Baars) motivates LeDoux higher-order theory adaptation
• LeDoux anxiety ≠ fear distinction supports LeDoux feelings ≠ emotions distinction
• amygdala supports LeDoux anxiety ≠ fear distinction
• prefrontal cortex supports LeDoux anxiety ≠ fear distinction
• chronic stress effects exemplifies cortisol (stress hormone)
• cortisol (stress hormone) requires hypothalamus
• chronic stress effects refutes hippocampus
• Pavlovian fear conditioning evidences LeDoux amygdala-centered fear circuit
• extinction (fear reduction) requires prefrontal cortex
• extinction (fear reduction) supports LeDoux therapy insight
• LeDoux anxiety ≠ fear distinction supports LeDoux therapy insight
• memory reconsolidation supports LeDoux therapy insight
• dopamine (reward signaling) enables nucleus accumbens
• nucleus accumbens supports LeDoux wanting ≠ liking split
• LeDoux wanting ≠ liking split supports LeDoux feelings ≠ emotions distinction
• insular cortex enables LeDoux body-feedback loop
• anterior cingulate cortex enables LeDoux body-feedback loop
• LeDoux body-feedback loop supports LeDoux feelings ≠ emotions distinction
• LeDoux cognitive appraisal integration supports LeDoux feelings ≠ emotions distinction
• prefrontal cortex enables LeDoux cognitive appraisal integration
• LeDoux schema networks enables LeDoux cognitive appraisal integration
• default mode network (DMN) enables LeDoux narrative self-model
• oxytocin (social bonding) enables mammalian parental care circuits
• mammalian parental care circuits motivates social brain hypothesis (Dunbar)
• social brain hypothesis (Dunbar) supports primate cortical expansion
• LeDoux cultural transmission advantage requires human language capacity
• LeDoux cultural transmission advantage supports LeDoux's 4-billion-year continuity thesis
• prefrontal cortex late maturation exemplifies prefrontal cortex
• LeDoux psychiatric disorder framework supports LeDoux therapy insight
• LeDoux two-track brain thesis supports LeDoux psychiatric disorder framework
• LeDoux constrained free will requires LeDoux survival circuits
• LeDoux constrained free will requires prefrontal cortex
• LeDoux attention as gateway enables LeDoux working memory integration
• thalamus (sensory relay) enables LeDoux low-road threat pathway
• thalamus (sensory relay) enables LeDoux high-road appraisal pathway
• LeDoux low-road threat pathway enables amygdala
• LeDoux high-road appraisal pathway enables amygdala
• LeDoux low-road threat pathway exemplifies LeDoux two-track brain thesis
• LeDoux high-road appraisal pathway exemplifies LeDoux two-track brain thesis
• visual cortex feature hierarchy exemplifies mammalian neocortex
• predictive coding (Friston) motivates visual cortex feature hierarchy
• LeDoux predictive survival circuits builds-on predictive coding (Friston)
• LeDoux predictive survival circuits supports LeDoux survival circuits
• LeDoux integrative model of self supports LeDoux's 4-billion-year continuity thesis
• LeDoux integrative model of self supports LeDoux consciousness-as-latecomer
• LeDoux integrative model of self supports LeDoux two-track brain thesis
• LeDoux survival circuits supports LeDoux integrative model of self
• mammalian neocortex supports LeDoux integrative model of self
• primate cortical expansion supports LeDoux integrative model of self
• human language capacity supports LeDoux integrative model of self
• C. elegans (302-neuron worm) exemplifies LeDoux nerve net
• Drosophila olfactory learning builds-on LeDoux amygdala-centered fear circuit
• emotional contagion (rats) evidences LeDoux survival circuits
• avian cognitive complexity builds-on primate cortical expansion
• octopus distributed nervous system builds-on LeDoux nerve net
• honeybee spatial navigation builds-on prokaryote behavioral repertoire
• songbird vocal learning builds-on human language capacity
• bat echolocation builds-on visual cortex feature hierarchy
• blindsight (Weiskrantz) evidences LeDoux low-road threat pathway
• split-brain patients (Gazzaniga) evidences LeDoux dual self (implicit + explicit)
• LeDoux dual self (implicit + explicit) supports LeDoux two-track brain thesis
• cerebellum enables habit formation (basal ganglia)
• basal ganglia enables habit formation (basal ganglia)
• habit formation (basal ganglia) exemplifies LeDoux survival circuits
• LeDoux consciousness distribution requires mammalian neocortex
• LeDoux consciousness distribution supports LeDoux higher-order theory adaptation
• brainstem arousal systems exemplifies brainstem survival functions
• circadian rhythm (SCN) exemplifies homeostatic regulation (pre-nervous)
• REM sleep (memory consolidation) requires hippocampus
• REM sleep (memory consolidation) supports episodic memory (hippocampus)
• LeDoux subjective temporality requires LeDoux working memory integration
• LeDoux continuity as construction supports LeDoux narrative self-model
• metacognition (thinking about thinking) requires prefrontal cortex
• LeDoux modern anxiety mismatch exemplifies LeDoux survival circuits
• LeDoux modern anxiety mismatch supports LeDoux psychiatric disorder framework
• LeDoux minimal consciousness thesis requires LeDoux working memory integration
• LeDoux minimal consciousness thesis supports LeDoux higher-order theory adaptation
• LeDoux minimal consciousness thesis requires mammalian neocortex

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