Central systems involved in emotional behavior April 2004

Central Coordination between: Autonomic Functions & Ongoing Behavior N. of the solitary tract modulates the autonomic functions:  Visceral inputs from VII, IX & X (gustatory, vestibular).  Projections to brain stem and spinal autonomic reflexes, like the motor vagal n.  Projections to more complex behavioral & endocrine centers like the hypothalamus & parabrachial n.

+Central Coordination Visceral sensory distribution in CNS to preganglionic n. & forebrain n. Solitary track Vagal n. Parabrachial Periaqueductal g. Ventrolateral medula n. ambiguus Hypothalamus Amygdala Cortex

Central Coordination between: Autonomic Functions and Ongoing Behavior Parabrachial n.:  Visceral inputs from the solitary tract and descending inputs from the bellow mentioned projection targets.  Projections to hypothalamus, periaqueductal gray m., amygdala, visceral sensory thalamus, cortex.

Central Coordination between: Autonomic Functions and Ongoing Behavior Periaqueductal gray matter:  Visceral inputs from the solitary tract, the parabrachial n., hypothalamus.  Projections to medullary RF which produces behaviorally coordinated patterns of autonomic res. (redirects blood flow during f-or-f response).

+Central Coordination between: Autonomic Functions and Ongoing Behavior Amygdaloid complex regulates the autonomic components of the unconditioned & conditioned behavioral response:  Inputs from sensory thalamus and cortex to lateral and basal n. & inputs from central autonomic system to central n.  Divergent ascending and descending outputs.

Amygdala nuclei

Amygdala inputs/outputs Stria Terminalis: Hypothalamus, Accumbens. Amygdalofugal: Brain stem, Thalamus, Hippocampus, Cingulate, Orbitofrontal c.

Integrative amygdala response Highly divergent outputs from the amygdala

Central Coordination between: Autonomic Functions and Ongoing Behavior  Visceral parabrachial n. >to> Visceral sensory thalamus (ventroposterior parvocellular n.) >to> Visceral sensory cortex (anterior insular cortex – conscious appreciation of taste, hunger, abdominal fullness, etc.) >to> Anterior cingulate cortex (infralimbic a. – visceral motor region – stimulation of cause BP res., lesion of cause abulia – no emotional res. to external stim.).  Insular & infralimbic cortex projects to amygdala, hypothalamus, periaqueductal gray, parabrachial, n. solitary tract, medullary RF.

Central Coordination between: Autonomic Functions and Ongoing Behavior  Hypothalamus integrates somatic, visceral & behavior info. Controls BP & electrolyte composition by drinking & salt appetite, temp regulation, energy metabolism by feeding, emergency res. by stress hormones.  Inputs from visceral sensory system, olfactory and visual.  Internal sensory neurons sensing temp, glucose, sodium, & circulating hormones (angiotensin).  Compares sensory information with bio-set points (local temp with 37 C). Upon deviation activates autonomic, endocrine & behavioral res. To restore homeostasis.

+CNS control of autonomic preganglionic n. Also afferents from NE, E, 5-HT n. in brain stem.

+Emotion and feeling  Emotion = bodily state mediated by subcortical & peripheral autonomic, endocrine & skeletomotor res.  Feeling = conscious sensation mediated by cingulate & frontal cortex. Stimulus

Emotional state  Functions of peripheral aspects of emotion: preparatory - general and specific arousal such as in different motivation states. communicative - facial & postural expressions.  Optimal arousal enhances mental and physical performance.

+Theory of emotion: Relationship between cognition and physiological states Conscious emotional stimulus Reflexive autonomic response 19 th century Acts & bodily responses code for type & intensity of feeling Conscious explanation James-Lange theory

Ekman support for James-Lange Autonomic indices were measured while Ss held various emotional expressions. Some, but not all, emotions could be differentiated.

Parallel processing in hypothalamus & cortex Cannon-Bard criticism on James-Lange:  Emotional responses are too undifferentiated to convey specific state.  Hypothalamus integrates the emotional responses.  Cortex mediates the subjective feeling.  Emotion & feeling occur simultaneously.

+Cannon-Bard in opposition to James-Lange

+Cognition modulates the emotion Schachter extension of James-Lange:  Cortex constructs feelings which are the cognitive response to peripheral information consistent with the individual’s expectations and social context.  Ss were injected with epinephrine, were informed/not- informed about the autonomous side effects, and exposed to annoying/amusing conditions. Ss who had been warned about the side effects exhibited less strong feelings, they attributed the arousal to the drug.

+Emotion as a cognitive story Damasio:  Autonomous responses are not as uniform as Cannon has originally suggested (confirms James-Lange).  Emotional experience – the feeling state - is a story that the cortex constructs to explain the bodily reactions (confirms Schachter).

+Emotion before action Magda Arnold:  Emotion is the product of unconscious evaluation of a situation.  Feeling is the conscious reflection of the unconscious appraisal.  Feeling is therefore also a tendency to respond in a particular way, not necessarily the response itself. Thus, unlike James-Lange, autonomic response is not essential for emotional experience.  Emotional experience: Unconscious evaluation of a stimulus → action tendencies → peripheral res. → → conscious experience. Explains also the emotional response to subliminal stimuli.

Unconscious evaluation → action tendencies

Hypothalamus & emotional response Hess localized the James & Lange emotional response to the hypothalamus:  Modulates the visceral reflexes.  Stimulation in vivo provokes site-dependent autonomic states, i.e., anger ↑, BP↑, pupillary constriction, hair-erection, arching of the back.  Lateral lesions → animal placid. Medial lesions → animal aggressive.  Is not only motor n. for the ANS but rather integrates various inputs to ensure a coherent autonomic and somatic expression of emotional states.

Limbic system: interaction between emotions & feelings Limbic lobe is a ring of primitive cortex (Papez) enabling a reciprocal communication between the conscious & peripheral aspects of emotion:  From feeling to emotion: Neocortex→ Cingulate g. → → Parahippocampal gyrus→ Hippocampus→ Fornix→ Mammilary bodies→ Hypothalamus.  From emotion to feeling: Hypothalamus→ → Mammilary bodies→ Thalamus→ Cingulate g.

Expansion of the limbic system MacLean expanded the limbic system to include the septum, accumbens, amygdala, orbitofrontal cortex. Amygdala and not the hippocampus coordinates the activity of the hypothalamus with the cortex.

Temporal lobe Kluver-Bucy syndrome initially ascribed to temporal-limbic lesions, latter fractioned to symptoms/sites:  Emotionally tame, fearless, flat emotions: amygdala lesions.  Excessive mouth behavior & ill directed sexual drive: amygdala lesions.  Excessive reaction but no recognition of visual stim: lesions of visual association area of the inferior temporal cortex. Mammillary bodies, hippocampus, anterior thalamic n., are not considered nowadays as essential for emotion.

+Amygdala, rather than Papez’s hippocampus Electrical stim of human amygdala → triggers feeling and somatic expression of fear. Calcification of human amygdala (Urbach-Wiethe disease) → disrupts implicit processing of facial cues of fear but does not impair explicit recognition of faces/objects. Conscious feeling: Cingulate cortex Parahippocampal Prefrontal Amygdala Somatic emotion: Hypothalamus Brainstem nuclei

Amygdala & Hippocampus 11/5/04LeDoux confirms James-Lange:  Unconscious evaluation of the emotional significance of a stimulus precedes the conscious evaluation.  Amygdala stores the unconscious memories of emotional states.  Hippocampus stores the cognitive features of conscious feelings: where, when and context of the fear-provoking stimuli.  Hippocampus/Amygdala - Parallel to the explicit/implicit features in memory research?

Amygdala mediates inborn emotional responses Happy Fearful

Amygdala and face perception Amygdala responds to complex visual stimuli important for social cognition: Amygdala ???? Face stim → Thalamus → Occipital cortex → Inferior temporal cortex (facial features including direction of gaze) → Amygdala → Emotional expression.

Amygdala mediates acquired emotional responses Studied in context of classical conditioning: CS – US association and contingency (predictability). Amygdala→ Rapid Res. Tone CS→ Brainstem→ Thalamus Cortex→ Amygdala→ Slow Res. Somatosensory US→ Brainstem→ Thalamus→ Amygdala→ Rapid Res.

Amygdala: rapid evaluation followed by emotional output Cortex: slow evaluation followed by cognitive output

Auditory CS pathways

Amygdala & reward/pleasure? food taste ≠ after amygdala lesion Tone CS food look = spared after amygdala lesion (excessive mouth behavior in Kluver-Bucy Syndrome)

Amygdala & context conditioning? Context conditioning = ↑ presence in rewarding environment. Amygdala = place cues acquire valance values (implications for fMRI context). Hippocampus = construction of cognitive maps through relation learning, binding of spatial & temporal cues. Ongoing controversy = context conditioning in hippocampus but expression through the amygdala.

+Amygdala mediates the autonomic expression & cognitive experience of emotion Emotional autonomic states = reciprocal projections from amygdala to hypothalamus & autonomic n. Influence on conscious feeling:  Reciprocal projections from amygdala to hippocampus, cingulate, prefrontal & orbitofrontal cortex.  Somatic feedback to cingulate and prefrontal cortex.

Output of the central n. through the stria terminalis & v. amygdalofugal pathway

END OF CENTRAL EMOTIONAL SYSTEMS