Psychology of Emotion Lecture 13-15

Autonomic Nervous System (ANS)

A division of the nervous system that controls involuntary bodily functions, including the emergency situations “fight or flight” and nonemergency situations “rest or digest” responses.

Sympathetic Nervous System (SNS)

• Part of the ANS responsible for preparing the body for fight or flight during emergency situations;

• increases heart and breathing rates

• release energy stores from fats, liver, etc.

• shuts down digestion, reproduction

• arousal indicators (sweating, piloerections, etc.)

sympathetic nervous system (SNS)

tend to act as a whole unitary response; but Shiota suggests that SNS can act in differentiated process

Parasympathetic Nervous System (PNS)

Part of the ANS that regulates bodily resources after stress, facilitating rest and digestion.

parasympathetic nervous system

• aids in recovering from sympathetic activity

  • calms arousal; facilitates relaxation

• activates digestion, reproduction, dilates blood vessels in extremities, etc;

• activated more specifically, NOT always in unitary fashion

electrocardiogram (ECG or EKG)

used to measure changes in electrical activity generated by heart muscle contraction

QRS complex

indicates contraction, relaxation of ventricles

heart rate

number of beats per minute

cardiac interbeat interval (IBI)

mean ms between beats over some time window; finer-grained measure of change

systolic blood pressure

pressure of blood on arteries while ventricles are contracting

diastolic blood pressure

pressure while ventricles are relaxed

mean arterial pressure

average pressure across systole, diastole

Fight or Flight Response

A physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival.

electrodermal activity

increase in the speed of electrical conductivity by the skin due to increased sweat

respiratory sinus arrhythmia (RSA)

difference in respiration rate while inhaling vs. exhaling, used to assess PNS influence on the heart

dendrites

brings information to the cell body and axons take information away from the cell body

neurons

communicate through an electrochemical process

brain stem

brain structure functions as breathing, heart rate, blood pressure, swallowing, etc.

brain stem

between the thalamus and spinal cord; responsible for basic life functions

subcortex

brain structure that allows more complex behaviors

hypothalamus

brain structure that controls body temperature, satiety, thirst

thalamus

brain structures that are sensory relay station

cerebral cortex

brain structure functions are thought, voluntary movement, language, reasoning, perception, self-control

corpus callosum

thick band of nerve fibers that connects right and left sides

frontal lobe

part of the brain that controls reasoning, planning, parts of speech and movement (motor cortex), emotions, and working memory etc.

prefrontal cortex

part of the brain that is highly developed in humans

occipital lobe

part of the brain that controls vision, highly developed in humans

parietal lobe

part of the brain that controls spatial learning, verbal processes, sensory processing (touch, pain, pressure); joins information from many parts of the brain

temporal lobe

part of the brain that controls hearing, higher-order visual processing and memory

-very invasive procedures

-lesion one part of the brain may affect a whole circuit or system

-”fibers of passage”

-most lesions (except in animal studies) are fairly crude, not just one structure is affected, but sometimes an area

limitations of lesion techniques

transcranial magnetic stimulation (rTMS)

pulsed magnetic field performed on human skulls

not perfect control, limited depth into brain

limitations of stimulation

magnetoencephalography (MEG)

very quick timing of firing of neurons in ms but not adequate spatial resolution to localize the functions

• excellent temporal resolution (in ms)

• not invasive

advantages of EEG/MEG

• poor spatial resolution (depends on the number of electrodes you can fit on a head)

• can only measure cortical function (we think)

  • hard to say where the exact source is…

  • but not impossible to make estimates

disadvantages of EEG/MEG

Positron Emission Tomography (PET)

functional Magnetic Resonance Imaging (fMRI)

brain imaging techniques

• even less invasive

• high spatial resolution, also subcortical (except around sinuses)

advantages of neuroimaging

• costly (hundreds/thousands $$ per use)!

• relative low temporal resolution compared to EEG

• need phsyics and stats to tease out effects

disadvantages of neuroimaging

mother-offspring bonds

the first emotion according to MacLean

MacLean’s Triune Theory of Emotion

emotions come from integration of sensory info and visceral information,

integration occurs in “visceral” or “limbic” brain

hippocampus

at center of visceral brain

emotions come from integration of sensory info and visceral information

MacLean’s Triune Theory of Emotion

• Reptilian Brain

• Mammalian Brain

• Neomammalian Brain

the three brain systems according to MacLean’s Triune Brain Theory

reptilian

oldest brain system according to MacLean

Homeostasis

The ability of the body to maintain a stable internal environment despite external changes.

Heart Rate Variability (HRV)

The variation in the time interval between heartbeats, used as a measure of autonomic nervous system function.

Ventral Striatum

A brain structure involved in the reward system and is significant for emotional processing.

emphasized importance of evolution across species, has a functional view of emotion

good thing about the complex interactions involving three layers, 3 “brains”

• limbic system not unified “seat” of emotion

• no characteristics set limbic apart from other areas

bad thing about MacLean Triune Theory

Amygdala

An almond-shaped set of neurons located deep in the brain's temporal lobe, key in processing emotions such as fear and pleasure.

accidentally discovered that a part of the subcortex was responsible for fear

Kluver and Bucy, 1938

• removed temporal lobe of rhesus monkeys

  • became more docile and fearless

  • hypersexual, very oral

  • psychic blindness (see objects but did not recognize)

• changes in emotional behavior result of amygdala damage

Kluver and Bucy’s rhesus monkey experiment

amygdala provides emotional significance (or meaning) to objects

discovery of amygdala from Weiskrantz (1950)

lateral amygdaloid complex

receives and evaluates complex info from cortex; computes affective significance of stimuli, classical conditional

basal amygdaloid complex

modifies affective significance; contextual conditioning: second-order conditioning

basolateral amygdaloid complex

self regulation; affective significance relayed to OFC to guide behavior and decision-making; facial expression processing

medial amygdaloid complex

caretaking, sexual behavior, olfaction

• oxytocin facilitates recognition of offspring/parent

• oxytocin release during orgasm

• affects aggression

central amygdaloid complex

• coordinates emotional responses

  • autonomic regulation

  • regulates somatic/voluntary action

  • attention regulation

discovered/confirmed amygdala’s role in emotion; low road vs. high road concept

LeDoux’s Contributions to Emotional Brain

• Once conditioned to tone

  • rats will fear

  • Heart rate will increase

  • Blood pressure will increase

  • cortisol released

• Lesion the amygdala

• Unable to learn pairing of tone and shock

LeDoux’s Method to Induce Fear

LeDoux's High and Low Roads refer to two different pathways through which emotional stimuli are processed in the brain. The High Road, or Cortical Pathway, is the longer and more complex route that involves processing through the sensory cortex, allowing for a more detailed and conscious interpretation of emotions. In contrast, the Low Road, or Subcortical Pathway, is the faster and more direct route that triggers immediate emotional responses.

LeDoux’s High and Low Roads

The High Road, or Cortical Pathway, is the longer and more complex route that involves processing through the sensory cortex, allowing for a more detailed and conscious interpretation of emotions.

LeDoux’s High Road

emotional stimulus enters sensory thalamus → sensory cortex →amygdala

LeDoux’s High Road

Subcortical Pathway, the faster and more direct route that triggers immediate emotional responses, bypassing the sensory cortex

LeDoux’s Low Road

emotional stimulus enters sensory thalamus → amygdala (emotional response)

LeDoux’s Low Road

Neurotransmitters

Chemical messengers in the brain that transmit signals across synapses from one neuron to another.

Electrodermal Activity

A measure of the skin's ability to conduct electricity, which increases with sweat gland activity, often used in studies of emotional arousal.

Respiratory Sinus Arrhythmia (RSA)

The natural variation in heart rate that occurs during breathing, which is influenced by parasympathetic activity.

LeDoux's Model of Emotion

A model that distinguishes between the low road (subcortical path) and high road (cortical path) of emotion processing.

Conditioned Response

A learned response to a previously neutral stimulus, typically brought about by classical conditioning.

Fear Conditioning

The process by which an organism learns to associate a neutral stimulus with an aversive event, eliciting fear responses.

Emotional Memory

The process by which emotions are linked with memories, influencing recall and recognition of those memories.

Prefrontal Cortex

The part of the frontal lobe associated with complex cognitive behavior, decision making, and moderating social behavior.

Limbic System

A complex system of nerves and networks in the brain, primarily associated with emotions and memory.

Hypothalamus

A region of the brain that controls various metabolic processes, including the autonomic nervous system and hormone release.

Cerebral Cortex

The outer layer of the brain, involved in higher brain functions such as thought and movement.

Dilation of Pupils

A physiological response regulated by the sympathetic nervous system, often associated with arousal or increase in attention.

Emotional Processing

The mental process of experiencing, interpreting, and reacting to emotions.

Piloerection

The contraction of tiny muscles at the base of hair follicles, causing hairs to stand upright, often a response to cold or fear.

Skin Conductance Response (SCR)

A measure of the electrical conductance of the skin, which increases with sweat gland activity as a response to arousal.