Psych 79 Week 2

Biofeedback: The body’s

impact on the brain

• Breathing

• Modulates activity in vagus nerve

• Increased Heart Rate Variability (HRV) means less stress

• When we are stressed, heart rate increases and gets less variable 

yes

Increased Heart Rate Variability (HRV) = Less Stress

• HRV is the variation in time between your heartbeats.

• Higher HRV usually means your body is more relaxed and better able to handle stress.

• Lower HRV can indicate stress, fatigue, or that your body is under strain.

• In simple terms: Higher HRV → better stress regulation → less stres

• Relaxing muscles

• Facial muscles

• Stretching

• Muscles are tense; your body feels ready to fight/fligth response, survival mode 

• Relax muscles to feel less stressed

 Relaxing muscles

• Facial muscles

• Stretching

• 
  

• 
  

• Muscles are tense; your body feels ready to fight/fligth response, survival mode 

• Relax muscles to feel less stressed

• Pain makes your muscles tense 

• Botox - paralyzed muscles, so sometimes emotions can’t be shown 

• I need Botox to feel less mad and worried 

• Relaxing my face, signal to my face I am relaxed, and therefore I will feel relaxed 

• Smiling enhances happiness, more positive habits. 

• Posture- 

• Standing with a confident or relaxed body, you can calm down 

• You have many emotions; focus on one positive emotion to enhance it over other emotion

GABA

• Primary inhibitory neurotransmitter

• Target of anti-anxiety medications (Valium, Xanax

• 🧠 Slows down brain activity

• 😌 Helps you feel calm and relaxed

• 😴 Can help with sleep

• ↓ Reduces anxiety and stress

• Think of GABA as the brain’s “brake pedal.”

Easy way to remember:
👉 GABA = “Go And Be At ease” → calms the brain.

• Study yoga good at modulating GABA 

• Inhibitory neurotransmitter less likely to fire another electrical pulse 

• Chemical GABA, 

• Have people do yoga can increase production of GABA

Yoga and GABA 

Streeter 2020 , 2010 

Participants did 60-minute sessions, three times a week, for 12 weeks.

The yoga group reported greater mood improvement and reduced anxiety compared with the walking group.

Changes in brain GABA levels were associated with improvements in mood and anxiet

The 2020 study examined a 12-week yoga and breathing intervention in people with major depressive disorder. Researchers found that depressive symptoms decreased and anxiety improved. The study also investigated changes in GABA levels in the thalamus, a brain region involved in relaying information

Case Study: Phineas Gage

and the Prefrontal Cortex

• Orbitofrontal cortex helps modulate goal- directed behavior

• Phineas Gage suffered from orbitofrontal cortex damage 

• Damage to OFC increases impulsivity

Before the accident, Gage was described as responsible and well-behaved. Afterward, his personality and behavior changed significantly. He became more impulsive, emotional, and socially inappropriate.

Observational Study: Gaming

Addiction

Weng 2013 

• Structural MRI

comparing people with

Online Gaming

Addiction (OGA) to

people without

• OGA individuals had

atrophy in orbitofrontal

Corte

• More severe gaming addiction was associated with less gray matter in the orbitofrontal cortex.

Two Basic Types of

Scientific Studies

Observational

• Researcher observes

subjects and measures

variables of interest

Experimental

• Researcher applies

intervention or treatment

and measures an outcome

variable of interest

• An experiment can reveal

mechanism (i.e. how the

variables are related)

• For example: Do people

who exercise more have

better sleep?

• We can see trends or correlations 

• Limiation - no causal relationship 

Exercise Improves Sleep 

• See that vigorous/more exercise: 67% had better sleep and no activity had  39% less sleep 

• From this study we can conclude that there not enough information, exercise improves sleep 

Exercise improves sleep 

Reid 2010

Aerobic exercise improves self reported and quality of life in older adults with insomnia 

Exercise group - end of the treatment, had significantly less insomnia issues 

Non-physical activity - more insomina

Experimental study

We can conclude now that exercise causes better sleep

Can you conclude that it works the same in college students? No, you cannot since there were only older adults; you cannot draw conclusions

Correlation does not causation 

• Ice cream  sales and violent crime are both up 

• There is a third confounding variable that causes both to go up; it's the  hot weather since people are out 

• Science is better had predicting what will happen to another grou/smilair group but not to one individual 

• Correlation does not mean causation/effect 

yes

Sleep Debt 

If you do not sleep enough, what are the consequences 

For example, falling asleep in lecture, missed information 

Study 

• People stay in bed for 

• First 3-4 days, not much difference 

• There is no difference into 6 daus or lter

• 2 weeks of good sleep, 4 days of bad sleep wont be muchof an effect

Sleep Architecture 

Progress from stage 1 light sleep to 2 to 3 and 4 (slow wave sleep) to REM 

• When first fall asleep, deeper into sleep electrical activity they get bigger 

• When you fall asleep, they start synchronizing, when there is many neurons doing with same thing, the waves get bigger

yes

2. Why do brain waves get bigger during deep sleep?

Your notes are describing synchronization.

• When awake: Neurons often fire at different times, so their electrical signals do not add together as strongly.

• During deep sleep: Many neurons become active in a more coordinated pattern.

• The result: Their electrical signals add together, creating larger-amplitude, slower brain waves on an EE

Circadian Rhythms

• Daily fluctuations

• Melatonin

• Cortisol

• Body temperature

• Hypothalamus controls

internal clock

• Reset by light

Brain releases melatonin, which helps you fall asleep 

Cortisol in the morning - stress response is not bad 

These two processes interact: melatonin and cortisol 

Just because you feel sleepy in the afternoon, the circadian rhythms will make you more alert

Two Process Model of Sleep

Regulation

• Homeostatic process

• Driven by how long it’s been

since you last slept

• Linear’

• Circadian process

• Driven by your internal clock

• Cyclica

 main processes that drive process for sleep 

1. Homeostatic process - sleep is a need you have such as eating or drinking 

2. Circadian process: internal clock, cyclical, not linear, drives physiological responses

Sleep Hygiene

• “A variety of different practices and habits that are

necessary to have good nighttime sleep quality

and full daytime alertness” –Sleep Foundation

• Sleep hygiene - habits and practices to take care of your sleep 

• Get a lightbox or turn it off when it's nighttime; have a consistent sleep pattern when to release melatonin and cortisol at the right time 

Sleep Hygiene

• Regular bedtime

• And regular wake time

• Uninterrupted sleep

• Bright light during the day, and not at night

• Quiet and dark sleep environment

• Calming routine

• Reduce stress

• Avoid caffeine

• Don’t take naps

• Use your bedroom for sleep

• Don’t use alcohol as a regular sleep aid

• Exercise

yes

Sleep helps …

• Improve mood

• Reduce pain and stress

• Reduce reward response to

unhealthy behaviors

• Improve learning and cognitive

performance

• Boost immune system

PET imagr showing glucose metabolism after 24 hours of sleep deprivation - pet scan injects sugar radiation to the brain to see which neurons are most active, there is huge decreases in certain areas how active the brain is , the whole prefronal cortex is affected by sleep deprivation, limbic system and striciym system working fine

Sleep-Stress Cycle • Inadequate sleep increases stress • Increased stress disrupts sleep

• Feel more stress, more cortisol, disrupt ability to fall asleep and downward spiral 

• Insomnia study - they track cortisol levels of the day, cortisol levels suppose to be high in the morning 

• Blood levels of the stress hormone cortisol arelevatedin teh late evening in insomnia as compared with controls 

• In the morning - high cortisol (supposed to get you energized out of bed) and at night high cortisol levels for insomnia 

• Inability to fall asleep stresses them out 

• Observational studies cannot tell you about causation 

Sleep and

the Limbic System

• Sleep is important in

memory

consolidation

• Communication

between

hippocampus and

PFC during slow-

wave sleep

• Sleep reduces

amygdala reactivity

Yes

Disrupted Sleep and Pain

• Disrupted sleep increases pain

• Pain-reducing properties of sleep are likely mediated by endorphins (Campbell 2013

• Not all sleep is equal 

• Took 3 different groups in a study 

• Control One had 8 hours of sleep , no interruptions 

• FA restricted group got same total amount of sleep 6 houts but fo sleep in broken up fashion waking them then up , their pain scores go up and up 

• RSO- 6 hours of sleep, no interruptions, stays the same 

• Disrupted sleep increases pain 

• Naps are not good 

• Another study: one night all groups got sleep deprivation 

• They had a lot of pain, but in the control group there are not affected at all, 

• Have one night of all nighter is not bad 

Yes

Prefrontal Deficits in

Insomnia Altena 2008 

• Insomnia reduces

prefrontal activity

• These reductions are

improved by sleep

Therap

• MRI study (neural activity), subjects did task 

• Insomnia  reduces neural activity in some areas 

• Therapy effect: the deficient brain regions go back to normal 

• Brain regions involved 

• Task effect 

• Insomnia effect, th brain region looks different than without; treat those people with their insomnia over several weeks, the brain region is now getting boosted. 

• Association

Why is sleep restorative?

• Cleaning away metabolic junk via cerebrospinal fluid

(CSF

• Brains of rats injects dye to see their brain activity 

• The lymph system gets rid of the chemicals 

• Brain there is not enough space, how does the brain get ride of checmiasl 

• When yu fall asleep, little spaces channels open up round theblood vessels in the brain, the headis filled with CSF, as those channels open, CSF flows threw and qashes out chemicals breaking down that accumate during the day 

• Clear headed - the chemicals arent there trying to get in the way og neurotransmitters 

Sleep Hygiene

• Regular bedtime

• And regular wake time

• Uninterrupted sleep

• Bright light during the day,

and not at night

• Quiet and dark sleep

environment

• Calming routine

• Reduce stress

• Avoid caffeine

• Don’t take naps

• Use your bedroom for

sleep

• Don’t use alcohol as

regular sleep aid

• Exercise

Yes