382: Stress, Pleasure, & Addiction

PERCEPTION & STRESS

One of the biggest discoveries in stress research is that stress deeds on our perception.  So how then do we appraise the stressor? We think about this in different ways.  We may think that we will do well, or that there is no possible way that we will do well.  We could keep our focus simply on our studies, or we could keep in mind that when it is done we don't have to worry till the fall.  The basic idea is that different people have different strategies on how to deal with stressors.

COPING WITH STRESS

Outlets for frustration such as exercise, beat someone up, etc.  Social supports also help you cope; having good friends vs frenemies, and having a happy marriage.  Two key issues with coping include predictability and control.   These are the two strongest predictors of PTSD.  Predictability makes stressors less stressful and lets you know when not to worry.  Control is a belief of your own ability to control situations and make stressors less stressful.

WHEN PREDICTABILITY DOESN'T WORK

The basic idea is that if you don't have enough anxiety it is boring and you will perform poorly where if you have too much anxiety then you will also perform poorly.  Predictability doesn't help with rare or frequent stressors.  Timing is another that if something is to far away then it won't matter and if you have a pop test it won't matter because you can't do anything about it.  Predictability  really just helps with medium level stressors.

WHEN CONTROL DOESN'T WORK

If you believe you have control but you really don't and something bad happens you will be more stressed because of your perception of control.  Especially if you still think you have control because then you might think something is wrong with you.  There is something known as the internal locus of control which is this idea of thinking you can control something when you can't.

We can increase our stress response by: not having outlets, not taking time for relationships, perceiving things as only getting worse, not being good at predictability and control.  Perception is the key.

THE BRAIN AND PLEASURE

Key neurotransmitter on the test is Dopamine.  The dopamine kicks in not just as you are doing something exciting (cliff jumping) but the whole process of preparing to do the exciting thing will release dopamine.    In many ways dopamine is an anticipatory neurotransmitter.  This goes from the ventral segmental area to the nucleus accumbens and the amygdala.  Opioid peptides, natural endorphins, also kick into this process.  The frontal cortex, cingulate cortex, and the amygdala also play a role in if something is pleasurable or not.

In the striatum there is the densest area of dopamine centers.  There is actually a strong correlation between drug addiction and base jumping, those who are looking for that next big rush.

What is Pleasure
Pleasure is not the actual event.  Dopamine is highest for a base jumper right as she is starting to run.  So the anticipation is the most pleasurable and after it is over the dopamine levels decrease significantly.

Delay of Gratification
If you come from a high stress environment with little pleasure in your life then you don't delay gratification when the opportunity arises.  Those who do wait, however, have much more successful futures (marshmallow study).

Dopamine & Pleasure
Dopamine increases in the anticipation of pleasure.  It will energize you to respond to incentives.  It also is tied to infatuation however, it is not tied to mature love.

STRESS & REWARD

Uncertainty and context matter.  Sometimes a situation will be benign and sometimes it will be malevolent. Tickling is not something you want for a long period of time or it will become uncomfortable and it needs to come from someone you trust to be enjoyable.

GLUCOCORTICOIDS AND PLEASURE

Glucocorticoids lead to increased dopamine at least transiently in moderate amounts.

Adrenaline Junkies
Really this should be called glucocorticoid (cortisol) junkies.

ADDICTION

Dopamine in the ventral tegmentum nucleus acumbens pathway is a key area.  Cocaine and these other drugs increase this pleasure response from dopamine exponentially which is why it is so addictive.  Taking drugs while stressed will increases the likelihood of you becoming addicted and decreases (momentarily) CRH and glucocorticoids.  People fell less stressed and anxious when taking drugs (withdrawal effects).

PLEASURE AND MODERN ENVIRONMENT

We are overly stimulated in our modern environment (electronics).  We don't have to have quiet time because we can feel every second with something.  We rapidly habituate to novelty because the next novel experience could be right around the corner because of this.  We are not as impressed by new things anymore.  Even food is engineered to produce an addictive effect.  

370: Music Perception Pt1

IMPORTANCE OF MUSIC PERCEPTION

Music can affect your mood.  In class he gave the example of the opening scene in the movie "Up" and how it can go from happy to dramatic to sad and then back again.  His point was that, although the movie/picture that goes with the music is important you can still get the emotion from the song without the movie/pictures.

Music as a Therapy
There are many mental and physical health benefits.  Some of the physiological changes include serotonin levels rise, change in heart rate and muscle activity, etc.

So how do we perceive music?  To understand this you need to break music down into it's basic features so first, what are some of the basic features of music?  These include notes and pitch (pitch = frequency).  When we talk about pitch equalling frequency then the assumption is that closer pitches will be closer in pitch, however, we see that octaves seem to break this rule.  For example, 440 Hz is an A and 880 Hz is an A and even though there are notes between them in frequency these two sound more similar in pitch than any of those notes between these two A's.  So musical pitch has more to it.

MUSICAL PITCH

Musical pitch has tone height and tone chroma.  As you increase the frequency the tone height gets higher. Tone chroma is based off of octave relationships where doubling the frequency results in an octave where the two notes in the octave are perceived as the same note.  So why does tone chroma have this effect.  The answer could be in place coding and in temporal coding.

Place Coding
This is the audio map.  It is based on where the neurons are in the cochlea which tells us where that frequency is at.

Temporal Coding
This allows the neuron to fire at a different rate based on that frequency.  This does not work above 5000 Hz which makes octave relationships hard to discern and melodies are not perceptually organized as melodies at that level.

When it comes down to it we don't really know if place coding or temporal coding is the answer to tone chroma but they seem to be a piece of the puzzle.

Cultural Effects
Different scales use different number of notes between octaves.  The fewer notes there are between octaves then the more acceptable variation in frequency to create a note (e.g., 440 Hz is always an A in heptatonic scale.  Pentatonic or Javanese scales could play a note at 410 Hz and it would still be an A because there are fewer notes between scales).

How many notes we put between octaves, the octave relationship, is a learned behavior.  Infants can notice bad notes in either scale (heptatonic or Javanese) equally well.  Adults however seem to be more limited to detection of bad notes in the scale they are familiar with.

PUTTING PITCHES TOGETHER

Chords are three or more pitches played simultaneously.  You can have consonant chords or dissonant chords both of which are based on ratios consistent with chroma.  No matter what tone height you play a chord at you will have the same variation between notes.

MELODY PERCEPTION

Melodies can be perceived at a very young age.  Testing 7 and 8-month-old babies are behaviorally able to discriminate both simple and complex melodies that they've heard from new melodies.

So what is a melody exactly?  Perception scientists define it as a sequence of pitches that is perceived as one coherent stream or structure based on the pattern of rising and falling pitches, not the pitches themselves.  That is to say, the melody pattern is more important than the key that the melody is played in.  The pattern is dependent on pitch height, duration of pitches, speed at which sounds are presented (tempo), and durations relative to each other to create rhythm.

RHYTHM

Rhythm is not unique to music since many activities have rhythm.  We impose rhythm even when there isn't any.  Thomas Bolton did a study where he presented a series of evenly spaced, identical sounds and listeners reported sound groups of two, three, or four and even perceived an accent on the first note in their perceived groups.

Listeners expect a fairly constant beat such as the first note in a group will be accented and the accent will occur in a steady pattern.  Composers then use a technique called syncopation where the accents are varied to create more exciting rhythms.  

375: Problem Solving Pt1

WELL DEFINED vs ILL POSED PROBLEMS (TA taught this lesson and it sounded like he got a lot of his material from the book)

Ill posed problem involves the ambiguity of solving certain problems.

Well-defined Problem
Intial state is where you begin.  Like hunger before a meal.  Then you move on to your goal state and finally to the subgoals state.  The final state is also known as an operator.

Ill-posed Problem
Basically what makes a problem ill-posed is that there are no steps to reach your goal.  There are no set criteria to solve the problem.  You can come up with different ideas on how to solve the problem but really there are an infinite number of ways to solve the problem.

TYPES OF THINKING

There are two types of thinking; directed and undirected thinking.  Directed thinking is anything where we have a goal in our mind and we work towards that.  Undirected thinking is the opposite of that, it is more daydreaming and artistic thinking.  Another two types include reproductive and productive thinking. Reproductive thinking is using past knowledge to solve your new problem and productive thinking would be a completely novel idea (even though that doesn't really exist).

ALGORITHM vs HEURISTICS

Algorithms use a trial and error systematic search.  Heuristics work backwards using analogies and finding a means end analysis.