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STRESS DISSONANCE and DENIAL Agnosia & anosognosia

STRESS DISSONANCE and DENIAL Agnosia & anosognosia. Ethology & Sociobiology November 28, 2011. REVIEW. INPUT – INTEGRATION – OUTPUT FLOW kept in balance by negative and positive feedback INTEGRATION : COGNITION (“memory, thought, selective perception and action”) MOTIVATION (“NEEDS”)

rhonda-winters
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STRESS DISSONANCE and DENIAL Agnosia & anosognosia

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  1. STRESSDISSONANCE and DENIAL Agnosia & anosognosia Ethology & Sociobiology November 28, 2011

  2. REVIEW • INPUT – INTEGRATION – OUTPUT • FLOW kept in balance by negative and positive feedback • INTEGRATION: • COGNITION (“memory, thought, selective perception and action”) • MOTIVATION (“NEEDS”) • AFFECT (positive or negative emotions), motivation (“needs”)

  3. STRESS forces the BIAS that reduces cognitive dissonance SUBCLINCAL STRESSis evoked by modest challenges to homeostasis, including COGNITIVE DISSONANCE, an apparent mismatch between internal perceptions and external reality; challenges to the narrative that confers biologically valuable confidence.

  4. OVERVIEW: STRESS SUBCLINICAL STRESS Evoked by real or perceived challenge to meeting real or perceived needs WITHIN ADAPTIVE SCOPE (“comfort range”) Fine-tunes physiological and behavioral coping responses without evoking clinically challenging syndrome CLINICAL STRESS Attempts to “adapt” – the stress responses cope with real or perceived challenges to the organism’s real or perceived ability to meet more-or-less urgent NEEDS. If sustained can lead to “diseases of adaptation”

  5. REVIEW of COPING RESPONSES • Sympathoadrenomedullary (SAMS) response (adrenal medullary /chromaffin response to sympathetic activation: EPI & NOREPI) • Hypothalamic-pituitary-adrenal (HPA) axis activation(CRF, ACTH, adrenal glucocorticoids) • Opioids(endorphin, enkephalin; affects perception of pain and reproductive axis) • Prolactin (affects reproductive axis)

  6. REVIEW: stress-sensitive behavior • Detection, Arousal and Attention(steroids affect sensory thresholds, EPI intensifies; acute CS enhances salience) • Activity(CRF facilitates in familiar habitat, inhibits in unfamiliar habitat) • Exploration(CRF and ACTH enhances effects of novelty, CS facilitates) • Learning and memory( EPI, CRF, MSH facilitate acquisition) • Cognition( catecholamine modulation; taking prefrontal cortex “offline” (Arnsten))

  7. SURVEY: stress-sensitive behavior • Feeding( CS stimulates or inhibits depending on circulating levels) • Aggression(ACTH suppresses, CS increases or decreases depending on circulating levels) • Social Dominance(CS increases submissiveness) • Reproduction( ACTH, CS, opiods, and prolactin impair HPG axis) • Dysfunctional behavior(stereotypies, neuroses, psychoses)

  8. An aside on subclincal stress Stresasors converge ... BUT an organism can avoid “chronic” or sustained stress” by allowing recovery time between episodes

  9. OVERVIEW: DENIAL DENIAL • “Vital Lies” (Golman) • Freudian denial (to preserve ego) • Resolves cognitive dissonance (Festinger) • Phantom function: signals from motor cortex go to parietal monitoring area AND to muscles (that no longer exist). In the absence of feedback from muscles parietal area prevails • Right hemisphere impairment could mute emotionality, flatten affect, and lead to apparent indifference • Anososognosia

  10. AGNOSIA Agnosia: a loss of ability to recognize objects, persons, sounds, shapes, or smells; no sensory deficit, no memory loss. A few of the many disorders of reception or recognition: • Simultanagnosia: inability to recognize more than one object or detail in their visual field at a time (common symptom of Balint's syndrome) • Prosopagnosia: (aka facial agnosia; TMWMWH)) • Anosognosia: denial or unawareness of handicap (assoc w/ damage to nondominant (usually rt) cerebral hemisphere ( “disorder of belief”)

  11. SOCIAL AGNOSIA SOCIAL-EMOTIONAL AGNOSIA • Evoked in lizards by striatal lesions (Greenberg 1983) shows how ancient mechanisms are • In Humans, right cerebral, or bilateral temporal and amygdala injury. An inability to correctly perceive or comprehend social-emotional nuances conveyed through voice, gesture, or facial expression (Joseph, 2000).

  12. ANOSOGNOSIA • from the Greek: A+nosos (disease) + gnosis (knowledge) --Described by Babinski in 1914 • “Unaware” of dysfunction • Diminished “insight” • “Ignorance or denial of the presence of disease • Most famously of paralysis in patients with non-dominant (usually right) parietal lobe damage -- patients deny their hemiparesis, & confabulate rationalizations • Impaired right hemisphere appears unable to detect discrepancies between internal model and sensory feedback requiring patient to improvise, “hallucinate,” or confabulate left-side function.

  13. An aside on compulsive story-telling: confabulation

  14. HOW IS BELIEF ESTABLISHED? • Empiricism and Reality-Testing • data-based, induction-driven • PERCEPT CORRESPONDS to reality • Rationalism and Story-Telling • theory-based, deduction-driven • PERCEPTS COHERE with each other

  15. BELIEF Belief is the psychological state in which an individual is more-or-less confident in the validity of a proposition. (confidence can translate into biological fitness) Validity can be more-or-less • internal (limited generalizability; eg, individual) or • external(broad generalizablity; eg, population)

  16. LEFT - RIGHT HEMISPHERE LATERALITY • When separated, EACH hemisphere is UNAWARE of the ipsilateral world • Yet neither is aware of being incomplete • Each functions as best it can with the information available

  17. DISORDERS of BELIEF? Acceptance of experience that doesn’t correspond to external reality:kinds of hallucinations, Bonnet’s Syndrome(filling in scotoma),dismorphic body (False positive (confident match with memories); Type I Error)) Denial of experience that corresponds to external reality: agnosias: eg, visual(left occip), associative, anasognosia(denial of dysfunction / right cerebral cortices), prosopagnosia(faces) (False negative (failure to match with memories); Type II Error))

  18. THE EVOLUTIONARY BIOLOGY of BELIEFtesting and organizing percepts The philosophical constructs of correspondence and coherence may have cerebral representation: there are neurobehavioral mechanisms to establish the validity of an experience by means of: REALITY TESTING confirming validity of a percept and ORGANIZING validated percepts into a narrative (“theorizing”) The mechanisms are emphasized in the RIGHT and LEFT hemispheres, respectively, and must work together to derive the fullest possible understanding.

  19. BASAL GANGLIA • Stereotyped behavior • Social Agnosia • AGNOSIA • Paths to knowledge: Correspondence and coherence components of knowledge • Anosognosia (acquired “lack of insight” can lead to denial) • BELIEF • How do we know? Disorders of belief

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