Cognitive interpretation of subjective feelings
Interpretation of physiological symptoms (chills, increased HR)
E.g., anger, sadness, fear
Can occur unconsciously and influence behavior
Motivation: What we do with emotions
Goal directed behaviour
Can result from emotions. Feel stressed so study.
Subjective; can occur without awareness. Ex: Eat without thinking
Neuroanatomy of emotion and motivation: Structures implicated=
What Causes Behaviour?
Is it free will?
Possible explanation: brain needs stimulation? Experience world through
senses and engage in motor behavior to deal with it.
Subject is allowed only restricted sensory input: No sight, sound or
Low tolerance for deprivation and may even display hallucinations
If brain not receive stimulation , may produce it on its own
Hebb and Heron (1950s)
After about 4 to 8 hours, subjects became quite distressed; few
subjects lasted more than 24 hours
Brain has an inherent need for stimulation; one reason that we
engage in behavior is to stimulate the brain
Similar studies with rhesus monkeys: Do tricks to look through window
(stimulation) when deprived.
Drives and Behavior
Hypothetical state of arousal that motivates an organism to engage in
a particular behavior
Hungry-hunger drive-look for food
Drive theories of motivation assume the brain is storing energy for behavior
Flush model: Empty reservoir fills up over time, when full, engage in behavior to
empty reservoir again
Once a behavior is started, it will continue until all the energy
in its reservoir is gone
There are separate stores of energy for different behaviors
Later proved wrong, particularly when looking at non-biological drives
Neural Circuits and Behavior
Researchers have not been able to link drives and brain activity. Brain
during drive state no different than not in drive state.
Behavioral change correlates with changes in hormones and cellular activity
Example: A mans frequency of copulation is correlated with his levels
of male hormones, called androgens (male hormones related to level
of sexual interest). More of these hormones= have more sex.
Stimulating brain cells activated by androgens, induces sexual
behaviour. Motivational states correlated with brain activity.
Conclude: neuronal activity responsible for behaviour, not drives
Evolutionary Influences on Behavior
Innate Releasing Mechanism (IRM): Hypothetical mechanism that detects
specific sensory stimuli and directs an organism to take a particular action
Innate (part of genome); releasing (trigger behaviours)
Cats do attack behavior when shown Halloween cat image. Smile at
babies, they smile back (mimick). Blind kids show same facial
The brain must have a set of norms against which it can match stimuli
so as to trigger an appropriate response
Although IRMs are prewired into the brain, they can be modified with
Sexual stimuli not affect us when little but as we age, they have a different
Evolutionary Influences on Behavior (2)
Discipline that seeks to apply principles of natural selection to
understand the causes of human behavior
Behaviors exist because the neural circuits producing them have been
favored through natural selection E.g., homicide exists today because related to past adaptive
The Chemical Senses
Play a central role in motivated and emotional behaviour
Smell: mark territories, identify group members (urine; sweat)
Taste: identify foods ( food from non food, avoid poisons)
Stimulus: Odorants (volatile chemicals), something that enters air and can
exist in air molecule. Ex: Cant smell a desk, its not volatile
Organ: Olfactory epithelium *OE+(retina of the nose)
Contains receptor cells (olfactory sensory neurons) and support cells
Receptor cells send cilia into the olfactory mucosa
Airborne chemicals dissolve in the olfactory mucosa and interact with the
Activation of metabotropic receptors leads to the opening of sodium
channels and subsequent change in membrane potential
Smell things, enter OE, receptor cells detect volatile odorants with
cilia 9receptors on cilia specific to detect specific odorants), causes
change in membrane potential by opening sodium channels. Go to
olfactory bulb (extension of our brain?)
Olfactory cells project to the olfactory bulb, ending in tufts of dendrites
In the olfactory bulbs, synapses are formed with mitral cells, which then
project to several areas of the forebrain
Olfactory nerve goes to areas of limbic system: Pyriform cortex, entorhinal
cortex, amygdala, hypothalamus, thalamus, and the orbitofrontal cortex
Smell is very emotional sense. Ex: Cinnamon, popcorn. May trigger strong
emotional reactions. Olfactory memory very compelling.
Note: no connection through thalamus for amygdala and pyriform cortex!
Project there directly. Why such a strong emotional component to smell.
Taste and smell= flavour
Accessory Olfactory System
Pheromone: Animals use as signalling mechanism Odorant biochemical released by one animal that acts as a
chemosignal and can affect the physiology or behavior of another
animal, same or different species
Usually studied in rodents. Often released urine.
If female mouse pregnant, another male other than father enters
territory, female spontaneously aborts fetus to carry child of new
(thus dominant) male
Mclintock: Women living together, cycle together. Something
released in sweat?
Strippers earn more tips when ovulating. Men detecting something in
Vomeronasal Organ: Detects pheremones, activated by presence of
pheremones. Not in humans.
Special olfactory receptor, made up of small group of receptors that
are connected by a duct to the nasal passage and detect
pheromones; projects to the amygdala and hypothalamus
Human Olfactory Processing
We can identify our own odors, odors of kin vs. non-kin, friends vs.
Little language for odours
Lundstrom and colleagues (2008)
The brain analyzes common odors and body odors differently
Body odors activate structures also activated by visually emotional
Smelling a strangers odor activates structures also activated by
fearful visual stimuli
Birth control blocks MHC detection?
Taste receptors are found within taste buds located throughout the mouth
Taste buds organized in papilla
Five different taste-receptor types
Sweet, sour, salty, bitter, and umami (meaty)
Gustatory stimuli interact with microvilli, located on the tips of receptors, to
open ion channels and alter the membrane potential
Taste all tastes all over tongue. Properties of food stimulate receptor
Sense of salt learned? Eat more salt, crave more salt. Eat less, crave less.