Sensation & Perception
Sensation refers to the immediate experience generated by environmental stimuli
Perception refers to the organization and meaning that you impose on your basic sensation to attempt to interpret them.
Gives us information about shape, color, distance. Light is the environmental stimulus and vision is the psychological aspect.
Cornea - clear membrane, curved surface that helps bend light as it enters the eye
Iris - ring of muscles that contracts and dilates to control the light entering the eye. Sometimes changes in emotional state. Angry - contracts Happy - dilates
Pupil - opening in the center of iris. It is a hole in the center of the eye
Lens - changes shape to focus on objects that are close/far completes the bending process for the eye
Retina - responds to the light and converts it into patterns of action potential.
The image on the retina is then transformed into electrical signals in a process known as transduction. This allows the visual messages to be transmitted to the brain to be interpreted.
Receptor Cells of the Eye
Cones are responsible for color vision and respond the best in light. They are concentrated in the Fovea.
Rods don't code color, but are respond and are adjustable in dim light. They are concentrated out of the Fovea. Our night vision is better in peripheral vision because the rods are located in the outside of the fovea.
Ganglion cells all come together by their axons to create optic nerves.
The blind spot is where the retina meets the optic nerves. Sometimes what you're seeing is not actual reality. A lot of what you're experiencing might not be accurate.
- Trichromatic Theory of Color Vision
- 3 mains colors that we see. Dependent on cones. Three different types of cones that are sensitive by different wave lengths. This theory suggest three cones combine colors with the stimulation of multiple cones.
- Short cones - blue
- Medium cones - green and yellow
- Long cones - red
- Opponent Process Theory
- Ganglion cells increase activity when one color is present and decreases when another is present.
Chromatic Adaptation activation of color. One aspect of vision that may fool someone into observing a color-based optical illusion, such as the same color illusion.
Color deficiency - rare in women 5% of men have some sort of color deficiency. Researchers suggest that women have a larger vocabulary in colors.
- Perceptual organization
- Figure Ground Relationship
- Figure is what you're emphasizing while the ground is what you're de-emphasizing.
- Relationship is usually color. Perception is active in categorical process.
Gestalt Psychology (viewing the larger picture) the sum is greater than it's parts.
The figure has definite shape while the ground seems shapeless. Ground seems to continue behind the figure. Figure has a clear location in space.
Organizing Vision by Groups
- Principles of grouping
- Proximity - objects that are near one another tend to be perceived as a unit.
- Similarity - objects that are similar tend to be perceived as a unit
- Continuity - tend to perceive smooth continuous lines not discontinued fragments
- Principle of closure - relates to blind spot, brain sees something is bigger.
- Perceptual Constancy
- objects constant in size, shape and brightness. Despite change in retina, you perceive size, shape, brightness the same. Familiarity is in place as well and relativity for brightness.
Brain is automatically creating a 3D figure with depth.
- Automatic depth perception.
- Cross cultural psychologists found that cultures that don't live in urban areas were not affected by this illusion. This suggest that what we see depends on our culture.
Light Wave Lengths
Light travels in waves. Wave lengths help to determine color.
- Frequency - wave lengths
- Amplitude - brightness
Sound waves are tiny disturbances in air pressure that travel through the ear canal.
- Wave length frequency/ pitch
- Amplitude/ loudness
Eardrum - thin membrane that vibrates in sequence with sound waves
- Bones of the middle ear: Malleous, incus and stapes
- The bones compensate transmission from air to liquid.
- Cochlea - bony fluid filled coil contains hair cells. Hair cells are receptor cells. Pressure from stirrup causes waves in cochlea which makes hair cells move.
- Inside the cochlea are receptors called cilia or hair cells that are embedded in the basilar membrane. The basilar membrane runs along the whole length of the coiled cochlea. Vibrations that reach the inner ear cause the fluid in the cochlea to move in waves. These waves in turn make the hair cells move.
Basilar membrane - hair cells are embedded
Theories of Pitch Perception
Place Theory - each frequency produces a vibration at a particular place on the basilar membrane. Low tones causes the greatest vibration from far way of the stapes. While high tones cause high vibrations close to the stapes.
Frequency Theory - the entire basilar membrane causes vibration
- Place theory explains how people discriminate high-pitched sounds that have a frequency greater than 5000 Hz. Place theory states that sound waves of different frequencies trigger receptors at different places on the basilar membrane. The brain figures out the pitch of the sound by detecting the position of the hair cells that sent the neural signal.
- Frequency theory explains how people discriminate low-pitched sounds that have a frequency below 1000 Hz. According to frequency theory, sound waves of different frequencies make the whole basilar membrane vibrate at different rates and therefore cause neural impulses to be sent at different rates. Pitch is determined by how fast neural signals move along to the brain.
- The detection of moderately pitched sounds, with a frequency between 1000 and 5000 Hz, is explained by both place theory and frequency theory. To discriminate among these sounds, the brain uses a code based both on where the neural impulses originated and how quickly neural impulses move.
Olfaction & Gustation
Stimuli are qualitative descriptors. Odor descriptors are less accurate that assumed.
People are able to guess others individual smell more. Gender is also more identifiable. Mother's are also more aware of baby's sent.
Olfaction and gustation intermingle. Bumps on tongue lead down to taste buds located in tongue as a receptor cell.
Descriptions of taste qualities - sweet, salty, bitter, sour
5th taste described by that Japanese called Umami - Savory (MSG)
- Temperature allows you to sense changes. Two sensory receptors warm and cold.
- Cold receptors respond to cold and high temps -50 F/ +125 F
- When we feel a hot stimuli, both our cold and warm receptors are activating leading to a hot experience.
- Sense of Pain
- Pain is essential for survival.
- The Gate Control Theory
- Both psychological and physiological. We experience pain only when the pain messages pass through a gate in the spinal cord up to the brain. Automatic process, the brain can automatically close that gate if somehow it become beneficial for survival.
- Consciousness is our awareness of external and internal stimuli and also involves our plans for action and thinking. Guides plans, actions and thinking. It allows you to focus on certain stimuli than others.
- Waking Consciousness - examine a degree to which we are aware of our mental processes. We are aware of products, but the process is unaware. It is difficult to describe unless it's a creative thought process.
Thought suppression - deliberate removal of a though from consciousness. Thought replacement is successful in thought suppression.
- Information that is ignored is still processed.
- Cocktail Party Effect - Illustrates attention as being extremely divided.
- Average person sleeps 22 years of their life.
- Circadian rhythms (circa dias - about a day)
- Zeitgebers - (time givers) anything that imposes time
- Humans rely on a 25 hour schedule. Free running tendency.
- People tend to be more sterotypical during their off time and rational during their own time. Night owl/morning person
- EEG electro encentrograph/gram
- Action potential firing during sleep produces lines on the EEG. Measures the electrical activity in brain.
- Alpha waves - dense packed
- Theta waves X-complex
- Sleep spindles
Stage 3/4 Hardest to wake up from. An indicator for long sleep.
R.E.M. after being asleep for awhile an individual goes backward into the stages.
Rapid eye movement is similar to being awake in EEG patten. Physiological arousal are similar to being awake - blood pressure, breathing, etc.
During a typical night of sleep you go through several rem sessions.
Rem paradoxical sleep. Some argue that rem is a third state of consciousness. Most associated with dreaming. Dreams are usually bizarre and emotional. Non rem dreams are similar thoughts as to being awake.
Meaning of these stages
REM deprivation studies
deprived people from rem sleep. Hooked up to EEG with long alarm during rem.
Found that individuals were not psychologically rested. Denying rem sleep will force people into rem. Deep sleep deprivation - physically rejuvenated.
Theories of Dreaming
- Psychoanalytic Theory of Dreaming
- dreams provide access to unconscious mind. "Dreaming is the royal road to the subconscious." Believed that sexual/aggressive desires are revealed during dreaming. Psychoanalytical theory can help decipher dreams. Freud emphasized the symbolic nature of dreams.
- Cognitive Theory of Dreaming
- Suggest that when we are dreaming the mind is basically clearing house. Dreams function with memory. Dreams are used to modify and reorganize memories. Natural process of what's a permanent memory. Suggest that analyzing dreams isn't important.
- Neurobiological Theory of Dreaming Attempt to understand the brain is to compare it with a computer. Sleep is when the human brain debugs the human network. Dreams are the random neurons firing to clear memory of useless information.
Theories of Dreaming
- Activation Synthesis Theory of Dreaming
- Suggest that dreams involve our subjective awareness of the activation of our brain during sleep. When we're sleeping our brain internally generates signals in regions that are specialized in different things. Brain synthesizes the activation. Activation occurs with no sensory input it synthesizes (makes sense/opposes meaning.
- the activation-synthesis model proposed in the late 1970s by dream researchers J. Allan Hobson and Robert McCarley.
- According to this theory, it is the activities and physiological process of the brain that lead to dreaming. During REM sleep, circuits in the brain become activated. As a result, parts of the limbic system that are associated with sensations, memories, and emotions become active as well. Our dreams, this theory suggests, are the result of our brains trying to make sense out of all these signals and internal activities. Continue reading to learn more details about the activation-synthesis model of dreaming.
Extra sensory perception
- Ganzfeld procedure used to determine ESP
- Two individuals in two different rooms called the sender and receiver. Sender looks at different videos and receiver is usually without disturbances, white noise, blind folded and leaning back.
Meta analysis of 28 ESP experiments found 38% - File drawer effect (people only remember things that are interesting)
suggest 3 things exists, not, lies.
Freud would say don't engage in lucid dreaming because it will eclipse your path to the subconscious mind. Laberge would say lucid dreaming is a psychological benefit by becoming aware.