Scientific foundations of psychology 1-19 and perceptions 1-54

Wilhelm Wundt

• set up the first psychological laboratory in an apartment near the university at LEIPZIG, Germany

• Trained subjects in introspection. Subjects were asked to accurately recorded their cognitive reactions to simple stimuli

• Established the Theory of Structuralism, which attempted to study thinking using the technique of introspection

• Considered the “Father of Scientific Psychology”

Introspection

• Technique used by Wilhelm Wundt who asked subjects to accurately record their cognitive reactions to simple stimuli

• Through this process, Wundt hopes to examine basic mental processes

William James

• Published The Principals of Psychology, the sciences first textbook

• Established the Theory of Functionalism: how mental processes function in our lives

• Brought psychology to the United States

Functionalism

• Theory described by William James

• Examine how the mental processes described by Wilhelm Wundt function in our lives

Positive Psychology

• A modern movement in psychological research that focuses on what makes life satisfying and meaningful

• These psychologists focus on both individual and group well-being

• Builds on the earlier Humanistic Psychology Perspective, with an increased emphasis on empirical research

Sigmund Freud

• Believed he discovered the unconscious mind - a part of the mind over which we dont have conscious control and which determines, in part, how we think and behave

• Proposed that we must examine the unconscious mind through dream analysis, word association, and other psychoanalytic therapy techniques if we are to truly understand human thought and behaviour

• Has been critiqued for being unscientific and creating unverifiable theories

Margaret Floy Washburn

• First women to earn a Ph.D in psychology

• Known for her experimental work involving animal behavior and sensation/perception processes

John Watson

• Decleared that psychology must limit itself to observable phenomena, not unobservable concepts like the unconscious mind, if it is be considered a science

• Wanted to establish behavioralism as the dominant paradigm of psychology

• Behaviorists maintain that psychologists should only look at behavior and causes of behavior-stimuli (environmental events) and responses (physical reactions) - and not concern themselves with describing elements of consciousness

Ivan Pavlov

• Performed pioneering conditioning experiments on dogs

• These experiments led to the development of the classical conditioning model of learning

B.F. Skinner

• Expanded the basic ideas f behaviorism to include the idea of reinforcement and punishment - environment stimuli that either encourage or discourage certain responses

• Helped stabling and popularize the operant conditioning model of learning

• His intellectual influence lasted for decades

Mary Whiton Calvin’s

• Student of William James

• Became president of the American Psychological Association

• Completed her doctoral studies but Harvard refused to award her Ph.D because, at the time, they did not grant doctoral degrees to women

Humanist Perspective

• Theorists Abraham Maslow and Carl Rogers, stressed individual choice and free will. This contrasts with the deterministic behaviorists who theorized that all behaviorists are caused by past conditioning

• Believe that we choose most of our behaviors and that these choices are guides by physiological, emotional, or spiritual needs

Psychoanalytic Perspective

• Described by Sigmund Freud

• Believe that the unconscious mind - a part of the mind that we do not have conscious control over or access to- controls much of our thoughts and actions

• Look for impulses or memories pushed into the unctuous mind through repression

• Think we must examine the unconscious mind through dream analysis, word association, and other psychoanalytic therapy techniques in order to understand human thought and behavior

Bio psychology (or Neuroscience) Perspective

• Explain human thought and behavior strictly in terms of biological processes

• Neuroscientists believe that human cognition and reactions might be caused by effects of our genes, hormones, and neurotransmitters in the brain or by a combination of all three

Evolutionary (or Darwinian) Perspective

• examine human thoughts and actions in terms of natural selection

• Natural selection in this context refers to the idea that some psychological traits might be advantageous for survival and that these traits would be passed down from the parents to the next generation

• Similar to the Biopsychology Perspective

Behavior Genetics

• Closely related to the Evolutionary Perspective

• Research how genetics and environmental influences interact to influence why individuals differ

• How are rules of attraction influenced by our cultural/environmental experiences and genetic factors?

Behavioral Genetics

• Explain human thought and behavior in terms of conditioning (learning)

• Look strictly at observable behaviors and what reaction organisms get in response to specific behaviors

• Dominant school of thought in psychology from the 1920s through the 1960s

Cognitive Perspective

• Examine human thought and behavior in terms of how we interpret, process, and remember environmental events

• Believes that the rules or methods we use to view the world are important to understand why we think and behave the way we do

Social-cultural (or Sociocultural) Perspective

• Look for how our thoughts and behaviors vary from people living in other cultures

• Emphasize the influence culture has on the way we think and act

Transduction

• The translation of incoming stimuli into neural signals

• Neural impulses from the sense travel first to the thalamus and then on to different cortices of the brain

• The sense of smell of the one exception to this rule

Sensory Adaptation

• Decreasing responsiveness to stimuli due to constant stimuliation

• For example, we eventually stop receiving a persistent scent in a room

Sensory Habituation (also called Perceptual Adaptation)

• Our perception of sensations is partially determined by how used to them we are

• For example, no longer hearing traffic from the nearby freeway after having lived in a place for years

• This happens in the brain

Cocktail-Party Phenomenon

• If you are talking with a friend and someone across the room says your name or something else of particular interest to you, your attention will probably involuntarily switch across the room

• An example of selective attention

Sensation

• Occurs when of our senses is activated by something in our environment

• Occurs before the processes of perception (the brain interpreting these sensations)

Perception

• The brains interpretation of sensory messages

• Occurs after the process of sensation

• The process of understanding and interpreting sensations

Energy Senses

• The senses of vision, hearing, and touch

• These senses gather energy in the form of light, sound waves, and pressure, respectively

Chemical Senses

• The senses of taste and smell

• These senses work by gathering chemicals

Vision

• Dominiant sense in human being. Sighted people use vision to gather information about their environment more than any other sense

• The process involves several steps

  1. Light is reflected off objects

  2. Enters the cornea and pupil

  3. Transduction occurred

  4. Impulses from the left side of each retina go to the left hemisphere of the brain

  5. The visual cortex receives the impulses and activates feature doctored for vertical lines, curves, and motion

Cornea

• protective covering on the front of the eye

• Helps focus the light

Pupil

• opening in the center of the eye

• Similar to the shutter of a camera

• Muscles that control the pupil open it to let more light in and also make it smaller to let less light in

Lens

• Focuses light that entrees the pupil

• Curved and flexible in order to focus the light

• As the light passes through the lens, the image is flipped upside down and inverted

• The focused inverted image projects on the retina

Retina

• As the light passes through the lens, the image is flipped upside down and projected on the retina

• Special neurons in the retina are activated by light and send impulses along the optic nerve to the occipital lobe of the brain

Optic Nerve

• Nerve leading from the retina that carries impulses to the occipital love of the brain

• The optic nerve is divided into two parts. Impulses from the left side of each retina go to the left hemisphere of the brain, and those from the left side of each retina go to the right hemisphere of the brain

Occipital Lobe

• Location of the visual cortex

• Part of the brain that processes vision sensations

• Receives impulses via the optic nerve

Feature Detectors

• Perception researchers Huber and Wiesel discovered that groups of neurons in the visual cortex respond to different types of visual images

• The visual cortex has feature detectors for vertical lines, curves, and motion, among others. What we perceive visually is a combination of these features

Visible Light

• Color is perceived due to a combination of different factors:

  • Light intensity - how much energy the light contains (the amplitude) determines how bright an object appears

  • Light wavelength - the length of the light waves determines the particular hue we see. We see different wavelengths within the visible light spectrum as different colors

Rods and Cones

• Special neurons in the retina that are activated by light

• Cones are activated by color

• Rods respond to black and white and motion

Fovea

• Indentation at the center of the retina where cones are concentrated

• When light is focused onto your fovea, you see it in color

• Your peripheral vision, especially at the extremes, relies on rods and is mostly in black and white

• Fovea vision, focusing light on the fovea, results in the sharpest and clearest visual perception

Blind Spot

• The spot on the retina where the optic nerve leave the retina and there are no rods or cones

• We cannot detect objects in our blind spot, but our brains and the movement of our eyes accommodate for the blind spot, so we usually don’t notice

Trichromatic Theory

• a theory of color vision

• Also called Young-Helmholtz theory

• Hypothesizes that we have three types of cones in the retina

• These cones are activated in different combinations to produce all the colors of the visible spectrum

Color Blindness

• Individuals with dichromatic color blindness cannot see either red/green shades or blue/yellow shades

• Those who have monochromatic color blindness see only shades of gray

Opponent-Process theory

• Theory of color vision

• States that sensory receptors arranged in the retina come in pairs

• If one sensor is stimulated, its pair is inhibited from firing. Explains afterimages And color blindness

Hearing

• Sounds waves, vibrations in the air, travel through the air, and are then collected by the ears

• Have amplitude and frequency

• Vibrations enter the ear and vibrate the eardrum

• Vibration is transferred to the oval window

• Oval window is attached to the cochlea where transduction occurs

Sounds Waves

• Vibrations in the air. They travel through the air and are collected by the ears

• Have amplitude and frequency

• Amplitude is the height of the wave and determines the loudness

• Frequency is measured is megahertz, determines pitch

Cochlea

• process of transduction occurs here

• Shaped like a snail’s shell and filled with fluid. As sound waves move the fluid, hair cells move. Neurons are activated by movement of the hair cells

• Neural messages are sent to the auditory cortex in the temporal lobe

Pitch Theories

• Place theory explains that the hair cells in the cochlea respond to different frequencies of sound based on where they are located in the cochlea

• Frequency Theory, place theory is right but not about the lower tones. The lower tones are senses by the rate at which the cells fire.

Touch

• activated when the skin in indented, pierced, or experiences a change in temperature

• Some nerve endings in the skin respond to pressure; others respond to temperature

• The brain interprets the amount of indentation (or temperature change) as the intensity of the touch, from a light tough to a hard blow

• We sense placement of the touch by the place on the body where the nerve ending fire

• Nerve ending are more concentrated in different parts of the body

Gate-Control theory

• explains how we experience pain

• Some pain messages how higher priority than others

• When high-priority message is sent, the gate swings open for it and shuts for low-priory messages

Taste (or Gustation)

• Nerves involved in the chemical senses response to chemicals rather than energy

• Taste buds on the tongue absorb chemicals from the food we eat

Smell (or Olfaction)

• Molecules of substances rise into the air and are drawn into the nose

• The molecules settle in a mucous membrane at the top of each nostril and are absorbed by receptor cells located there

• As many as 100 different types of smell receptors may exist

• Connect the brain to the amygdala and then to the hippocampus

Vestibular Sense

• tell us about how the body is oriented in space

• When the position of your head changes, the fluid moves in the canals, causing sensors in the canals to move

• The movement of these hair cells activate neurons, and their impulses go to the brain

Kinesthetic Sense

• Gives us feedback about the position and orientation of specific body parts

• Receptors in our uncles and joints send information to the brain about our limbs

• The information, combined with visual feedback, let us keep track of our bodies

Absolute Threshold

• Smallest amount of stimulus we can perceive

• Technical definition - the minimal amount of stimulus we can detect 50 percent of the time

Subliminal Messages

• Stimuli below the absolute threshold

• Research does not support the claim that subliminal messages affect out behaviors in overt ways

Difference Threshold (also just noticeable difference)

• smallest amount of change needed in a stimulus before we detect a change

• Computer by Weber’s law

• The change needed is proportional to the original intensity of the stimulus

Weber’s Law

• Describes the difference thresholds for different senses

• The change needed is proportional to the original intensity of the stimulus

Signal Detection Theory

• investigates the effects of the distraction and interferences we perceive while experiencing the world

• Takes into account how motivates we are to detect certain stimuli and what we expect to perceive.

• Tries to explain and predict the different perceptual mistakes we make

Top-Down processing

• we perceive by filling in gaps in what we sense

• Occurs when we use background knowledge to fill in gaps

• Our experiences create schemata, mental representation of how we expect the world to be

Perceptual Set

• Our experiences create schemata, mental representations of how we expect the world to be

• Schemata can creat a perceptual set, which is a predisposition to perceiving something in a certain way

Bottom-Up processing

• we only use features of the object itself to build a complete perception

Gestalt Rules

• the principals that govern how we perceive groups of objects

• Based on the observations that we normally perceive images as groups, not as isolated elements

• This process is believed to be innate and inevitable

Constancy

• every object we see changes minutes from moment to moment due to our changing angle of vision, variations in light, and so on

• Is out ability to maintain a constant perception of an object despite these changes

• Include size constancy, shape constancy, and brightness constancy

Size Constancy

• objects closer to our eyes will produce bigger images on our retinas, but we take distance into account in our estimations of size

• We keep a constant size in mind for an object and know that it does not grow or shrink in size as it moves closer or farther away

Shape constancy

• objects viewed from different angles will produce different shapes on our retinas but we know the shape on an object remain constant

Brightness constancy

• we perceive an object as being a constant color even as the light reflecting off the object changes

Depth Cues

• Researchers divides cues that we use to perceive depth into two categories

  • Monocular cues - depth cues that do not depend on having two eyes

  • Binocular cues - cues that depend on having two eyes

Sensory Interaction

• our senses often work together to create overall perception of the world

Sound Localization

• the ability to determine where sounds are coming from

• The brain is able to combine sounds as they arrive at both ears, use differences in intensity of sound and the time it took sounds to reach each ear to triangulate approximate location of origin

Phantom Limb

• the perception that body part exists even after it is removed

Kinesthesis

• The sense of movement/position of parts of the body

• With your eyes closed, you can perceive the location or movement of parts of your body because of this sense

Apparent Movement (Stroboscopic Movement, Phi Phenomenon, Autokinetic Effect)

• under certain conditions, stationary objects may appear to move

• When two objects are side by side are are rapidly illuminated one after another, the object will appear to move

• When staring at a stationary point of light in the dark, we may perceive that the light is moving because of eye fatigue and/or lack of reference points