Perceptionof event

Physiologicalreactions

Feelingof Fear/Anxiety/Stress

Common Sense View

How are emotions and physiological responses linked?

Emotional Behaviors

I. _____________________(1884): A theory ofemotion that suggests that behaviors andphysiological responses are directly elicited bysituations and that feelings of emotions areproduced by feedback from these behaviorsand responses

Example: the sight of a bear elicits increases in several autonomic (heart rate, blood pressure, etc), endocrine (hormonal) and behavioral responses (running), which in turn produce the conscious feeling of fear.

Perceptionof bear

Physiologicalreactions

Feelingof Fear

II. ___________________ (1900s): The theory that emotional experience and emotional expression are parallel processes that have no direct causal relation

(i.e., autonomic and behavioral responsesare completely independent from “feelings”)

Perceptionof bear

Physiologicalreactions

Feelingof Fear

Strong predictions of these two theories:- James-Lange theory predicts that without

autonomic and somatic feedback, people wouldhave no emotions

- Cannon-Bard theory predicts just the opposite,that person does not need autonomic andsomatic feedback to be aware of emotions

Studies have indicatedthat both theories areright and wrong atthe same time

Antonio Damasio has recently suggested his _________________________ of emotion, whichsuggests that signals (markers) arising frominternal and external environment (emotionalstimuli) act to guide behavior and decisionmaking, usually in an unconscious process

III. Modern biopsychological view of emotions.

The limbic circuit (Papez, 1937) and emotion:Influential early neuroanatomical circuit ofseveral interconnected brain structures believedto be important for emotional expression andfeelings

Papez proposed that emotional __________ wasproduced by activity of the limbic circuit upon thehypothalamus, and that emotional __________ wasthe product of limbic activity upon the cortex(from the cingulate cortex)

The Kluver-Bucy (1939) syndrome: originallyobserved in monkeys sustaining bilateral anteriortemporal lobectomies (especially the amygdaloidcomplex)Behavioral outcome of this surgical procedure include the following:

- __________________- consumption of nearly everything edible;- increased, but inappropriate, sexual activity(often towards inanimate objects);

- tendency to repeatedly investigate same objects;- tendency to investigate objects with mouth;- _____________________________

This syndrome has been observed in patients sustaining bilateral removal of the amygdaloidcomplex and some types of encephalitis.

The Amygdala and Emotions

FEARThe feeling of fear produces a constellation ofendocrine, autonomic, and behavioral responsesthat are very characteristic. Examples: increasedheart rate, blood pressure, respiration, arousal,ulcers, urination, defecation, glucocorticoidsecretion, facial expression of fear, fight or flight response, etc

All these autonomic and behavioral reactions inresponse to fearful situations have been shown to be organized, integrated, and controlled by the________________________.- lesions of the amygdala in laboratory animalsnormally eliminate all these fear reactions

Example: Normal rats are very scared of cats,(natural predators of rodents), and rats do notnormally approach cats, even if the cat isanesthetized; however, rats with bilateral damageto the amygdala will climb all over anesthetizedcats and even pull their wiskers!!!

Amygdala & Fear Conditioning

Thalamus

Cortex

AmygdalaAssociativeProcesses

Hypothalamus Brainstem

PrefrontalCortex x

Sensory cue:Sight, smell,

sound etc

Endocrine, Sympathetic &Behavioral Responses

Possible clinical relevance for anxiety disorders, post-traumatic stress disorder (PTSD).

NoxiousStimulus

HUMAN FEARPatients evaluated for neurosurgery and subjectedto electrical brain stimulations show autonomicsigns of fear when stimulated in ______________but no reports of _____________________- however, ____________________ produces bothautonomic fear responses and experientialreports of fear

Finally, human subjects who participate in brainimaging experiments (PET or fMRI scans) andare shown __________________________ displayparticularly high brain activity levels of theamygdala bilaterally

Bilateral damage to the amygdala in humans alsoprevents the elicitation of several ___________________________________ in response to fearprovoking stimuli

Negatively charged stimuli which are fearful alsohelp remember details of the situation; peoplewith amygdala damage do not show thisfacilitating effect of negative emotions on memory

Miller et al., (2005) J. Neuropsychiatry Clin. Neurosci. 17:1-6

Masked fearful faces Masked angry faces

e.g. The amygdala is activated after seeing pictures of fearful or angry faces. It does not require conscious awareness of emotion to be activated.

Imaging studies e.g. functional magnetic resonance imaging (fMRI) which indirectly measures neuronal activation, also show that the amygdala is central to the fear respsonse.

Amygdala

fMRI is based on the facts that:1. active neurons use oxygen, so there will be increased

blood flow to the area.2. oxyhemoglobin and deoxyhemoglobin have different

magnetic properties