Beyond awesome | 越而胜己

This note is taken from Prof. Judith McLaughlin's PSYCH 101 lecture at the University of Washington, Winter 2017.

## History of Psychology and Psychological Perspectives

### Major issues in psychology

#### Nature vs Nurture

• Are behavioral difference due to biology or environment?
• Consensus: All behavior depends on both.
• Genetics -> Potential
• Environment -> Outcome

#### Mind vs Brain

• How are the mind and the brain related?
• Does the brain produce the mind?
• Does the mind control the brain?
• Rene Descartes: Interactionism, Seperate, but they interact. Physical change <-> Mental change.
• Franz Gall: all mental faculties reside in the brain; these faculties are revealed thru contours of the skull. Founder of phrenology (reading personality from the bumps of skull).
• Current view:
• The mind is not just the brain.
• The mind is not independent from the brain.

#### Stability vs Change

• How stable are our behaviors and traits?
• Goal: Identify the factors that influence change?
• Age effects
• Situational effects

### History and Perspectives

#### Structuralism (Wilhelm Wundt)

• Goals / Emphasis
• Discover the laws and principles that explain conscious experience.
• Identify simplest essential unites of the mind.
• Introspection: report experience w/o interpretation. Problem: too subjective.

#### Functionalism (William James)

• Goals / Emphasis
• Discover how the mind functions to help us adapt to our environment.
• To study phenomena in real life situation.

#### Behavioral Perspective (Watson / Skinner)

• Goals / Emphasis
• Study observable responses and their relation to observable stimuli.
• Focus on env factors that cause behavior (i.e., rewards, punishments, etc.)
• Stimulus -> ? -> Response

#### Gestalt Perspective (Wertheimer)

• Goals / Emphasis
• Must analyze the whole of behavior, not just its elements.
• Emphasize the role that organizational processes play in perception, thinking and learning.
• The relationships among the elements as a whole play an important role in determining our experience.

#### Psychodynamic (psychoanalytic) Perspective (Freud)

• Goals / Emphasis
• Unconscious mental processes and conflict influence behavior.
• Childhood experiences determine adult personality and behavior.

#### Humanistic Perspective (Rogers / Maslow)

• Goals / Emphasis
• Subjective human experience.
• Individuals have free will and must take responsibility for their choices.
• Understand each person as a whole and hlep each person reach his/her fullest potential.

#### Cognitive Perspective

• Goals / Emphasis
• Examine internal mental processes and how they influence behavior.
• Study how people perceive, learn, remember, speak, think and solve problems.

#### Neuroscience Perspective

• Goals / Emphasis
• Every behavior, emotion and thought is caused by a physical event in the brain or nervous system.
• Understand the functioning of the brain and nervous system and how they affect behavior.

## Research Methods

### Steps in the scientific process

1. Identify a question of interest.
2. Gather information and form a hypothesis (statement that attempts to describe or explain a behavior).
3. Test the hypothesis by conducting research.
4. Analyze data, draw tentative conclusions and report findings.
5. Build a body of knowledge
• Generate new hypotheses
• Build on existing theories
• Develop new theories

### Descriptive methods

#### Naturalistic observation

Observe behavior in its natural setting w/o attempting to influence or control it. (Hidden cameras, two-sided mirrors, etc.)

• Strength
• Study behavior in normal setting
• Behavior is natural and spontaneous
• The only way to study some phenomena
• Weaknesses
• Time consuming
• Can't control the situation
• Can't determine causation
• Observer effect: People behave differently when they know they're being watched
• Observer bias: Researchers' expectations can cause them to see what they expect to see

#### Survey method

The use of questionnaires and interviews to gather information about people's experiences and attitudes.

• Strengths
• Can gather a lot of information in a short amount of time
• Useful for collecting data that can't be directly observed

Representative sample: a group of participants that accurately represents the larger population that the researcher wishes to describe.

• Weaknesses
• Biased sample
• Can't determine causation
• People may not be truthful in their answers

### Correlational research

Determines the degree of relationship between two factors and how well each factor predicts the other.

Correlation coefficient: the sign indicates the direction, the number indicates the strength.

• Types of Correlations

• Positive correlation: variables vary in the same direction.
• Negative correlation: variables vary in the opposite direction.
• Zero correlation.
• Misinterpreting correlations

• Directionality problem: if a causal relationship between the two variables does exist, it could go in either direction.
• Third variable problem: a third factor could underlie the relationship of the two factors of interest.

### Experimental Method

Researchers deliberately manipulate certain factors and measure their effects. Experiments are designed to test hypotheses.

#### Variables in an experiment

A variable is any condition that can be manipulated, controlled, or measured.

Types: independent (manipulated) and dependent (measured). The DV (effect) depends on the IV (cause).

Operational Definition: Specify how variables are to be observed and measured. (Quantify)

#### Groups in an experiment

Experimental group: A group of participants who are exposed to different levels of the IV (treatment).

Control group: A group of participants, similar to the experimental group, who receives the zero value of the IV (not given the treatment).

Random assignment: Using chance procedures to make sure all participants have an equal chance of being assigned to a group.

#### Generalizing results

Can only generalize results to the population being represented in the experiment.
Must replicate experiment using different populations to apply findings to different groups.

#### Potential problems

• Confounding variables
• Selection bias (Random assignment minimizes the effects of selection bias)
• Experimenter expectancy effect: unintended changes in participants behavior due to cues inadvertently given by the experimenter (mitigation: double-blind procedure, neither the experimenter nor participants know who is in what group)
• Placebo effect: when a participant's response to a treatment is due to/her expectations about the treatment rather than to treatment itself (mitigation: placebo: an inert substance or fake treatment used as a control in an experiment)

## Brain and Behavior

### Cells of the Nervous System

#### Neurons

Basic building blocks of the nervous system.

Dendrites -> soma -> axon -> axon terminals.

#### Glia (Glial cells)

• Supply nutrients to neurons (astrocytes)
• Agents of the immune system (Microglia)
• Form myelin that aids neuronal transmission (Schwann cells and oligodendrocytes)

### Nerve Impulse

Nerve potential

• Resting potential +(outside) / -(inside), voltage ~70mV
• Action potential -(outside) / +(inside), sodium channel opens, Na+ come in; after, potassium channel opens, K+ go out.

Synapse 突触: gap between neurons, or neurons and muscles, in which one neuron releases a chemical that either excites or inhibits the next neuron.

Presynaptic neuron (synaptic vesicles 突触小泡) -> synapse -> postsynaptic neuron.

Two types of synapses:

• Excitatory synapse: the binding of the neurotransmitter (NT) to the receptor cause positively charge ions to enter the cell. Increases the likelihood of an action potential.
• Inhibitory synapse: the binding of the NT to the receptor causes negatively charged ions to enter the cell and positively charged ions to exit. Decreases the likelihood of an action potential.

A single neuron may receive input from many synapses.

NT reabsorption and deactivation.

• Reuptake: reabsorption of NTs by presynaptic neuron.
• Deactivation: enzymes break down remaining NTs.

### Major neurotransmitters

• Acetylcholine 乙酰胆碱: Found in the CNS and peripheral NS and is involved in: movement, learning and memory, Alzheimer's disease.
• Dopamine 多巴胺: Primary neurotransmitter involved in: reward circuits (food, sex, drugs), fine motor control (Parkinson's disease), cognition/emotion (Schizopherenia).
• Norepinephrine 去甲肾上腺素: Primary neurotransmitter involved in: "fight-or-flight" response.
• Serotonin 血清素: Neurotransmitter involved in: sleep and arousal, appetite regulation, pleasure and pain (too little -> depression).
• Endorphins 内啡肽: produced by pituitary gland and hypothalamus. Natural opiates that are released in response to pain and vigorous exercise.

How do drugs alter neurotransmitters? Neurotransmitters only bind to appropriate receptor.

Agonist: mimics/enhances the activity of a particular NT.
Antagonist: blocks the activity of a particular NT.

### Divisions of the Nervous System

• Central Nervous System 中枢神经系统 -- brain and spinal cord.
• Spinal cord -- nerve fibers that transmit info from sense organs, muscles and glands to the brain, and from the brain to the rest of the body.
• Brain -- body's main processing system for info.
• Peripheral Nervous system 边缘神经系统 -- nerves and ganglia.
• Somatic Nervous System 躯体神经系统 -- carries input from sense organs to the brain (input); from brain/spinal cord to the skeletal muscles (output).
• Autonomic Nervous System 自主神经系统 -- controls body's vital/automatic activities and the functioning of the internal organs.
• Sympathetic Nervous System 交感神经系统 -- responds to emergencies by activating bodily resources, such as "fight-or-flight response".
• Parasympathetic Nervous System 副交感神经系统 -- Controls normal body operation; calms body down after an emergency.

### Structures of the brain

• Hindbrain 后脑 -- contains the brainstem and cerebellum.
• Medulla 延髓 -- controls heart rate, breathing, blood pressure, coughing and swallowing.
• Pons 脑桥 -- important in muscle control, sleep regulation, attention, and other vital functions.
• Cerebellum 小脑 -- controls motor coordination maintains posture, and plays a role in basic learning and memory.
• Reticular formation 网状结构 -- controls arousal and attention and screens messages entering the brain.
• Midbrain 中脑 -- contains areas involved in some sensory reflexes; helps regulate brain arousal and pain.
• Forebrain 前脑 -- contains the most advanced structures.
• Thalamus 丘脑 -- receives info from all senses (EXCEPT for smell) and relays it to other parts of the brain.
• Hypothalamus 下丘脑 -- controls release of some hormones, influences drive states, helps regulate emotion, body temperature, and sensations of pleasure.
• Amygdala 杏仁核 -- involved in emotion: aggression, rage and fear.
• Hippocampus 海马体 -- plays a role in memory formation. Damage causes inabilityto form NEW memory.
• Cerebral cortex 大脑皮质 -- perception and higher mental processes

### Cerebral Cortex

Responsible for higher brain functions

• sensation and perception
• voluntary muscle control
• complex thought
• reasons
• memory and language

Four lobes

• frontal lobe
• parietal lobe
• occipital lobe
• temporal lobe

#### Cortical organization

• Functional specialization: different areas of the cortex serve different functions.
• Contralateral connections: each hemisphere is responsible for sensory/motor control of the opposite side of the body. "Corpus Callosum": bundle of axons that connects the two hemispheres.
• Hemispheric laterization: the two hemispheres have slightly different functions.
• Right hemisphere: primarily processes visual spatial information, is involved in holistic processing, and in recognizing and expressing emotion.
• Left hemisphere: processes language, sequential logical thinking, concerned with details.

#### Lobes of the cerebral cortex

• Frontal lobe 额叶: involved in working memory, movement, speech and language production, judgment and planning, and personality.
• Motor cortex: at the back of the frontal lobe; controls fine motor movements; each part of the motor cortex controls a different part of the body.
• Broca's area: involved in language production; damage leads to Broca's aphasia (slow, effortful speech that is meaningful, but ungrammatical)
• Parietal lobe 顶叶: specializes in processing information from the body's senses (touch, pain, temperature, awareness of body in space, etc.); involved in attention
• Sensory cortex: at the front of the parietal lobe; contains neurons that are sentitive to touch in different parts of the body.
• Damage might cause unilateral neglect: the neglect of the opposite side of the body and the opposite side of the world. A problem with attention.
• Occipital lobe 枕叶: specializes in processing visual information; different areas of the occipital lobe contribute to different aspects of vision.
• Damage might cause motion blindness: inability to see motion.
• Temporal lobe 颞叶: involved processing auditory information, language comprehension, and complex aspects of vision.
• Primary auditory cortex: at the top of the temporal lobe.
• Wernicke's area: behind the primary auditory cortex; responsible for the semantic aspects of language; damage results in Wernicke's aphasia (inability to comprehend language).
• Visual Agnosia: set of disorders where patients can't interpret visual information correctly. Prosopagnosia: inability to recognize faces.

## Sensation and Perception

### Definitions

• Sensation: the process by which the senses detect sensory stimuli and transmit them to the brain.
• Perception: the process by which sensory information is actively organized and interpreted by the brain.

### How do sensory systems work?

• Transduction 转导
• The conversion of one energy form to another. Sensory stimulus -> neural impulse.
• Receptor cells: specialized cells that respond to a specific physical stimulus, and are responsible for transduction.
• The diminished sensitivity to prolonged stimulation.
• Adaptation of one stimulus can affect the perception of another.
• Allows us to shift our attention to what is important.
• Sensory Deprivation 感官剥夺
• The absence of normal external simulation for extended periods of time.

### Vision

Visual Pathway: light -> photoreceptors (rods/cones) -> bipolar cells 双极细胞 -> ganglion cells 神经节细胞 -> optic nerve (blind spot) -> thalamus 丘脑 -> visual cortex 视觉皮质 (occipital lobe 枕叶)

Differences between rods and cones:

• Shape (cylindrical vs short, fat, tapered at one end)
• Prevalence (90-95% vs 5-10%)
• Location (toward periphery vs toward the center)
• Fovea: Area near center of retina that contains only cones and is responsible for most detailed vision
• Perception of detail (weak vs strong)
• Sensitivity to color (no vs yes)
• Response to dim light (strong vs weak)
• Dark adaptation: eye's increasing ability to see in dim light. Due to pupil dilation and recombination of rhodopsin in the rods.

### Sensation: Color vision and audition

#### Color vision

Trichromatic theory 三色说: Color perception depends on 3 receptors, each senstive to different wavelengths:

1. Sensitive to short wavelengths (blue)
2. Sensitive to medium wavelengths (green)
3. Sensitive to long wavelengths (red)

Opponent process theory 对立过程说: Posits 6 primary colors that are complementary to one another. The color pairs are linked in the brain by 3 "opponent systems" (types of cells).

• Red/Green cells, red increases & green decreases, vice versa.
• Yellow/Blue cells, yellow increases & blue decreases, vice versa.
• White/Black cells, white increases & black decreases, vice versa.

Color blindness: Color deficiency (affects men more than women)

1. Trichromats: People who can perceive all 3 primary colors and distinguish any hue (normal color vision)
2. Dichromats: People who can distinguish 2 of the 3 primary colors.
3. Monochromats: Total color blindness. Can't distinguish any color.

Ishihara test.

#### Audition

Auditory pathway: sound wave -> eardrum 鼓膜 -> ossicles 听小骨 -> cochlea 耳蜗 (basilar membrane 基膜, cilia/hair cells) -> auditory nerve -> thalamus 丘脑 -> auditory cortex (temporal lobe).

Pitch perception

• Place theory: pitch perception depends on the area of the basilar membrane that vibrates the most.
• Frequency theory: for low frequency tones, the basilar membrane vibrates at the same frequency as the original sound and sends that information to the brain.

Sound localization

• Interaural time difference: if a sound is to either side of center, sound waves reach one ear slightly before they reach the other ear.
• Inte-raural intensity difference: if a sound is to either side of the center, the sound will be perceived as louder for the ear nearest the sound origins.

#### Illusions: McGurk Effect

• Demonstrates the interaction between hearing and vision in speech perception.
• Illustrates that our perceptions of sensory input are not always accurate.

### Perception: Interpreting sensory information

• Perceptual Adaptation: in vision, this refers to our ability to adjust to an artificially displaced or inverted visual field.
• Perceptual Set: When our experiences, assumptions and expectations greatly influence what we perceive.
• Perceptual Habits: Learned patterns of attention and organization; knowing what to expect and where to look.

Perceptual Constancies: Perceptual constancies allow us to perceive objects as having stable properties.

• Size constancy: When the perceived size of an object stays the same even when there's a change in distance between object and viewer.
• Shape constancy: An object's perceived shape remains the same even though the object changes its orientation toward the viewer.
• Color constancy: An object's perceived color remains the same even when lighting conditions change.

#### Perceptual Organization

• Figure Ground Organization: The organization of visual info into object (figure) that stand out from the surrounding background.
• Gestalt Principles of Organization
• Proximity: Tendency to perceive objects that are close together as belonging together.
• Similarity: Tendency to perceive objects that resemble each other as forming a group.
• Continuity: Tendency to perceive smooth continuous lines instead of discontinuous fragments.
• Closure: Tendency to "fill in" elements that are missing from the outline of a figure.
• Contiguity: Tendency to perceive objects that are near in time and space as belonging together.
• Common Region: Objects that are found within a common region are grouped together.
• Common Fate: Tendency to perceive elements that move together as belonging together and forming a group.

#### Depth Perception and Visual Illusions

Depth Perception

• Binocular Depth Cues
• Convergence: Eyes turn inward when they focus on nearby objects. The closer the object, the greater the convergence.
• Retina Disparity: Slight difference between viewpoints of the two eyes. The closer the object, the greater the retinal disparity.
• Monocular Depth Cues
• Accommodation: The bending of the lens to focus on nearby objects.
• Pictorial Depth Cues:
• Linear Perspective: Parallel lines appear to converge at a distance.
• Relative Size: If two similar sized objects appear together, the one with the larger retinal image will be perceived as closer than the one with the smaller retinal image.
• Relative Height: We perceive objects that are near the horizon as being farther from the viewer.
• Light and Shadow: You can distinguish bulges from indentations by the shadows they cast.
• Interposition (overlap): When one object partly blocks your viewer of another, the one that is blocked is perceived as being farther away.
• Texture Gradient: Near objects appear to have sharply defined textures, whereas similar objects look smoother in the distance.
• Aerial Perspective: Distant objects often look hazy in the distance.
• Relative Motion (Motion Parallax): As we pass a scene objects closest to us seem to move in the opposite direction and faster than those farther away.

Optical Illusions

• Mueller-Lyer Illusion: >----< vs <---->.

• Architecture?
• This illusion may be culturally specific.
• Provides evidence that our exp and learning have a profound influence on perception.
• Ponzo Illusion:

• The retinal images of the two lines are the same size, but the distance cue tells you that the one on the top is larger.
• Linear perspective queue.
  / ----- \
/         \
/   -----   \
Ponzo Illusion.


In general , illusions result from the over-application of perceptual constancies in the face of conflicting distance cues.