Chpt 4-6 Terms Flashcards
Transduction
Conversion of external stimulus to action potential. Specific sense receptors transduce specific stimuli.
Psychophysics
Study of how stimuli are perceived
Sensory Adaptation
Activation of senses is most when stimuli are first detected. Then, the response proceeds to decline.
Takes place on a sense receptor level. The decrease in reaction of the receptor conserves energy and attentional resources.
Absolute Threshold
Longest level of stimulus needed for NS to detect a change 50% of the time when no stimulus of that type is present.
Human error increases as stimulus magnitude decreases, moreover, sensitivity of NS
Just Noticeable Difference (JND)
Smallest detectable change in stimulus, helping to distinguish smaller and weaker stimuli.
Weber’s Law: Relationship between JND and original stimulus intensity is linear
Stimulus increases as the change in stimulus magnitude in order for it to be noticeable, increases
Signal Detection Theory
How we detect stimuli under certain conditions e.g. background noise
Signal-to-noise ratio: having to speak louder
Response Biases: Tendency to guess when in doubt of stimuli
Cross-modal Processing
Specific Nerve Energies:
- Sensation is determined by native of sense receptors, not stimuli.
- Regardless of distinct stimuli energies
- Synesthesia: a condition where people experience cross-modal sensations.
- Alternate Explanation: A single brain region serves multiple functions
Synesthesia
A condition where people experience cross-modal sensations.
Mirror-touch: A person experiences the same sensation that another person experiences, such as touch
Lexical-gustatory Synesthesia: Words are associated with specific states or textures
Chromesthesia: Sounds trigger the experience of colour; in cases of misophonia, sounds trigger emotions
Personification: Numbers, letters, or days of the week that are attributed personality characteristics or appearance
Number-form Synesthesia: Numbers are imagined as mental maps
Spatial sequence Synesthesia: Cenain sequence of numbers, dates, or months are perceived as closer or farther in space
Selective Attention
The ability to focus on one stimulus and tune out others, controlled by the Reticular Activating System and Forebrain
Filter Theory of Attention: mental filter allowing us to attend to important stimuli
Dichotic Listening: People hear 2 different messages in each ear
Cocktail Party Effect: Ability to pick out important info from conversation not involving us
Inattention Blindness
Poor capability of detecting stimuli in plain sight when our attention is elsewhere.
Change Blindness: Failure to detect obvious change in the environment
Hue
Colour of light
Additive Colour Mixing vs. Subtractive Colour Mixing
Additive: mixing primary colours red, green, blue, producing white light
Subtractive: Mixing cyan, magenta, and yellow to produce dark colours
Iris
Coloured part of the eye that controls the amount of light entering
Pupil
Hole where light enters the eye
- Pupillary reflection: closing of pupils decreases the amount of light entering the eye
- Dilation: Expansion of pupil when processing complex information or due to physical attraction
Lens
Accommodates to see close/far objects
Flat: seeing distant objects
Fat: seeing close objects
Shape of eye
Myopia: causes nearsightedness due to the cornea being too steep or the eyes being too long
Hyperopia: Farsightedness due to the cornea being too flat or the eyes being too short
Presbyopia: Loss of flexibility in lens due to aging
Retina
Converts sensory info to neural info
Fovea
Part of retina with no rods or cones, where light is focused
Rods and Cones
Rodes: Help see shapes and low levels of light, assist in Dark Adaption
- Photopigments - chemicals that change from light exposure e.g. Rhodopsin
Cones: Help us see colour, but are sensitive to detail
Optic Nerve
Ganglion cells attatching the retina to the brain.
- Half the cells cross the optic Chiasm and the nerves enter the brain, turning into optic tracks
- Optic Tracks: Send majority of axons to the visual part of the Thalamus, then the Primary Visual Cortex V1 (primary route of visual perception).
The rest go to the midbrain, then the superior colliculus, which plays a role in reflexes.
Route of visual info
- Visual info from retina > Visual thalamus > Primary Visual Cortex V1 > Parietal lobe V2 (depth perception)
- Visual info from retina > Visual thalamus > Primary Visual Cortex V1 > Temporal lobe V2 (processes visual info and colour)
Blind Spot
Where the optic nerve connects to the retina
- no rodes or sense receptors because the gangion occupies its space
Feature Detection
Ability to identify objects with minimal patterns
Simple cells: Display yes-no responses to specific light orientations in specific locations
Complex Cells: Respond to specific light orientations with less restriction of location
Trichromatic Colour Perception Theory
3 kinds of cones (blue, green, red) are maximally sensitive to different wavelengths of light.
- This theory doesn’t account for afterimages caused by the visual cortex processing rods and cones
Colour Blindness
Caused due to an absence of cones or brain damage
Monochromats - only one type of cone is present, and all colour vision is lost
dichromates - two cones are present
trichromats - how humans see colour
Opponent Processing Colour Theory
Colour is seen in 3 pairs of opponent cells - red/green blue/yellow black/white
Afterimages appear in complimentary colours and illustrate opponent processing
Ganglion retina cells and cells in the visual area of the thalamus that respond to red or blue don’t respond to green or yellow.
Blindsight
Blind individuals are aware of there surroundings
Bliind individuals suffer V1 damage (primary visual cortex) > Info flows to the visual association cortex, bypassing V1 because the normal pathway to visual areas is blocked > This accounts for how blind people can somewhat navigate
Visual Agnosia
Deficit in object perception, inividuals can identify shape/colour but can’t recognize object names
Pitch
Frequency of wave
Pitch increases, Frequency increases
Younger individuals are more sensitive to higher-pitch
Amplitude
Height of sound wave corresponding to loudness
Timbre
Quality/Complexity of sound
e.g. instruments
Ossicles
Malleus, Incus, Stapes or Hammer, Anvil, Stirrup.
Cochlea
Part of the inner ear that converts mechanical vibrations to neural activity.
Inner cavity of the Cochlea is filled with a thick liquid that triggers cilia with pressure, sending action potentials.
Organ of Corti/Basilar Membrane: Hair cells embedded within them where transduction occurs
Pitch Theory: The primary auditory cortex processes different tones in different areas of the basilar membrane.
Cilia at the base of the membrane are excited by high-pitch, as the cilia at the top are excited by low-pitch
Low-Pitch Perception
- Frequency Theory: Rate of action potential faithfully reproduces pitch up to 100Hz (max action potential)
- Volley Theory: Variation of frequency theory works for 100-5000Hz, slightly out of sync with each other. Therefore the overall rates contribute to 5000Hz
Conductive Deafness
Malfunctioning of the ear
e.g. failure of eardrum or ossicles
Noise Induced Hearing Loss
- Accompanied by Tinitis
- Byproduct of loud noise is loss of sensory cells and degeneration of optic nerve
- Most people lose hearing with age
Gustation
Sense of taste
Papillae: bumps on the tongue containing numerous taste buds (sweet, salty, bitter, sour, umami) each separate from each other.
- Individual receptors are weakly concentrated in certain locations
- Any location on the tongue is slightly sensitive to all tastes
Gustation Process
Odours interact with sense receptors in nasal passage. > Relayes info to Limbic System and Olfactory Cortex. > Taste receptors follow a similar process > Smell and taste converge in orbitofrontal Cortex.
Olfaction
Sense of Smell
- Parts of the limbic system, such as the amygdala, distinguish pleasant and unpleasant smells.
Pheromones
Odourless chemicals that signal sexual behaviour.
Vomeronasal Organ
Located between the bone between the nose and mouth in some animals, that detects pheromones
Proprioception
Sense of the body position
Vestibular Sense
Sense of balance
Somatosensory System
Responds to stimuli applied to the skin e.g. touch, pressure, temperature, pain which are sensed by mechanoreceptors and free nerve endings
- Nerves are unevenly distributed throughout the body
- Touch travels faster than pain
- Touch informs immediate surroundings and urgent matter
- Pain signals to tend to injuries
Withdrawn Reflex: Triggered by pain e.g. pulling away from a hot stove
Circadian Rythem
Changes that occur every 24 hours in our biological processes
e.g. hormone release, brain waves, body temperature, drowsiness
Disruption in the biological clock increases risk of:
- injury/fatal accidents
- health problems
- obesity
- diabetes/heart disease
Importance of Sleep
- Learning and Long-term memory formation
- Remembering emotional memory-
- Immune system
- Plan, reason, and function to the best of our ability
- Conservation of energy to reduce food intake (evolutionary perspective)
Suprachiasmatic Nucleas
Location of 20,000 neurons in the hypothalamus makes us feel drowsiness at different times of the day/night.
Essentially triggers a sense of fatigue.
Recommended hours of sleep
Newborns: 16 hours
Post-secondary students: up to 9 hours
The majority of people need 7-10 hours.
Insufficient sleep can cause short-term effects of irritability and loss of concentration.
Long-term effects can lead to “sleep debt” (requires several nights of sleeping a few extra hours to pay off), brief hallucinations, weight gain, high blood pressure, diabetes/heart problems, lower immune system
Kleine-Levin Syndrome
Excessive sleep disorder
Stages of Sleep
Each cycle lasts about 90 minutes
- Lasts 5-10 minutes. Our brain produces Theta Waves, due to the 50% lowered activity.
Theta Waves: occur 4-7 times per minute
Hypnagogic Imagery: experiences as we drift deeper into sleep and become more relaxed. Dream-like images that flit in and out of consciousness and sudden jerks of limbs are experienced.
- Brain waves further slow down and sleep spindles (intense bursts of electrical energy) and K-complexes (sharply rising and falling waves) are apparent under EEG.
- brain activity decelerates
- heart rate slows
- body temperature decreases
- muscles further relax
- eye movement stops
-65% of sleep is in stage 2
3 & 4. Occurs after 10-30 minutes, where deeper slow-wave sleep begins. Delta Waves are present.
Delta Wave: slower waves that appear 20-50% of the time in stage 3 and more than half the time in stage 4
- After 15-20 minutes we return to stage 2 before transitioning to REM sleep.
REM Sleep: high-frequency, low-amplitude waves, resembling those of being awake. Eyes are rigorously moving, our body is paralyzed while our brain is active.
During rem sleep, heart rate and blood pressure increase, and breathing is irregular. Rem is 20-25% of a night’s sleep. After 10-20 minutes of REM, the cycle repeats.
REM vs NREM Dreams
REM: emotional and illogical
NREM: often shorter, repetitive and thought-like
REM-Rebound
Amount and intensity of REM increases when deprived. Moreover, indicating REM’s importance in biological function
Middle Ear Muscle Activity
A phenomenon that occurs during REM, in which muscles of the middle ear become active, almost as theyr’e assisting us to hear sounds in the dream.
Lucid Dreams
Being aware that one is dreaming due to parts of the cerebral cortex associated with self-perception rev up with activity.
REM Behaviour Disorder
Brain and body are active during REM, an early indicator of dementia or Parkinsons’ disease
Sleeping Disorders
- Insomnia
- Narcolepsy
- Sleep Apnea
- Night Terrors
- Sleep Walking
Insomnia
- Trouble falling asleep
- Walking up too early
- Waking up in the middle of the night and struggling to fall back asleep
Experienced by individuals who suffer from depression, continual pain, or other medical conditions.
Other causes include stress, relationship problems, caffeine, or day-napping
Rebound Insomnia
A phenomenon of more difficulty sleeping due to long-term use of sleeping pills.
Narcolepsy
Episodes of sudden sleep lasting a few seconds/minutes. Episodes are often accompanied by vivid hallucinations
Cataplexy: Experienced by some people with narcolepsy, there is a complete loss of muscle tone, causing people to fall. Cataplexy is experienced by healthy people in REM, but while still alert in those with narcolepsy.
Orexin: a hormone that triggers sudden attacks of sudden sleepiness, those with narcolepsy have brain cells that produce insufficient orexin
Sleep Apnea
Blockage of the airway during sleep, causing insufficient supply of O2
- Loud snoring
- Short stops of breathing, waking individual up
- No awareness of these multiple wakings
- night sweats
- weight gain
- hearing loss
- irregular heartbeat
- risk of cognitive impairments (e.g. dementia)
Night Terrors
Screaming and crying for a few minutes followed by falling into a deep sleep.
Almost exclusive to children.
Sleepwalking
Happens with sleep deprivation and involves minimal activity.
Occurs during REM.
Purpose of dreaming
- processing emotional memories
- integrating new experiences with established memories to create a mental model of the world
- learning new strategies and ways of doing things
- stimulating threatening events so we can better cope
- reorganizing memories
Freud’s Dream Protection Theory
Dreams are guardians of sleep. During sleep, the ego (acts as a mental censor) is less able to keep sexual and aggressive instincts repressed.
Dream-work disguises and contains sexual and aggressive impulses by transforming them into symbols that represent wish fulfillment - how we wish things could be. This is why dreams must be deciphered and interpreted.
Manifest Content: details of the dream
Latent Content: true, hidden meaning of the dream
Issues with Freud’s Dream Protection Theory
- Most dreams are sexual in nature and account for 10% of dreams we remember
- Many dreams don’t appear to be disguised (everyday activities)
- Doesn’t account for individuals with trauma who experience repetitive nightmares
Activation-Synthesis Theory
Proposes dreams reflect the brain’s activation during sleep, rather than repressed unconscious wishes.
Activation:
- REM is turned on by neurotransmitter surges of acetylcholine, which activates neurons in the pons, while serotonin and norepinephrine are shut down.
- This decreases reflective thought, reasoning, attention, and memory.
- The activated Pons signals to the Lateral geniculate nucleus of the Thalamus a relay for sensory info to the forebrain.
Synthesis:
The forebrain then assembles a meaningful story.
The Net result of this change is the reason for dreams.
Neurocognitive Theory
Claims that dreams reflect more than just random neural impulses activated by the brain stem (pons). Dreams are supported by the brain’s default network and are a meaningful product of cognitive abilities.
Dream Continuity Hypothesis
Dreams mirror circumstances, there is continuity between sleeping and waking experiences.
Hallucinations
Realistic perceptual experiences in the absence of external stimuli.
Visual: occurs due to oxygen/sensory deprivation, epilepsy, fever, dementia, migraines
Auditory: occurs due to mistakenly attributing thoughts/inner speech to an external source
Auditory Verbal: psychotic individuals have more negative and less controlled hallucinations than nonpsychotic
Out-of-body Experience (OBE)
Extraordinary sense of consciousness leaving the body.
Occur with drug usage, meditation, migraines, seizures, or when extremely relaxed/stressed. OBE also occurs in NDE.
Explanation: When the senses of touch and vision are scrambled, there is a disruption of our physical body’s experience
Near-death Experiences (NDE)
OBE was reported by people who almost died.
Explanation: Changes in brain chemistry associated with cardiac arrest, anesthesia, and other physical trauma.
May result from massive release of endorphins in a dying brain as well as oxygen deprivation.
Mystical Experiences
Last only for a few moments but leaves a lasting, lifelong impression. A sense of unity or oneness with the world is experienced. This phenomenon is associated with spirituality and religion, or social isolation.
Hypnosis
Interpersonal situation in which imaginative suggestions are used to change consciousness.
Induction: the first step in hypnosis, that creates positive expectations for responses to the following suggestions.
Active-alert Induction: individuals are physically active while following relaxing hypnotic suggestions
Self-hypnosis: Suggestions are self-administered.
Hypnosis Myths
- Hypnosis produces a trance state where “amazing” things happen
- Hypnotic phenomena are unique (people can experience hypnotic phenomena without hypnosis)
- It is a sleep-like state
- People are unaware of their surroundings
- People forget what happened during hypnosis
- Memory enhancement
Past Life Regression Therapy
A therapeutic approach that hypnotizes and age-regresses patients to a previous life to identify the source of a present-day problem.
Hypnosis Explanations
Sociocognitive Theory:
Attitudes, beliefs, motivations, and expectations about hypnosis, as well as response to waking imaginative suggestions, shape response to hypnosis.
Disassociation Theory:
Division of consciousness, in which attention is carried out without awareness. This results in a separation between personality functions that are normally well-integrated.
Hidden Observer
during hypnosis, a separated consciousness is formed in an individual’s mind which is able to observe the individual
Classical Conditioning
Form of learning in which animals come to respond to a previously neutral stimulus that was associated with another stimulus that elicits an autonomic response.
Acquisition
Learning phase during which a conditioned response is established
Extinction
Gradual reduction and eventual elimination of the conditioned response after the conditioned stimulus is presented repeatedly without the uncontrolled stimulus.
Spontaneous Recovery
Sudden re-emergence of an extinct conditioned response after a delay following an extinction procedure.
Renewal Effect
Sudden re-emergence of a conditioned response following extinction when an animal is returned to the environment in which the conditioned response was acquired.
High-order Conditioning
Developing a conditioned response to a conditioned stimulus by virtue of its association with another conditioned stimulus
Latent Inhibition
Difficulty in establishing classical conditioning to a conditioned stimulus we’ve repeatedly experienced alone, that is, without the conditioned stimulus.
Operant Conditioning
Learning is controlled by the consequences of the organism’s behaviour
Law of Effect
Principle asserts that if a stimulus followed by a behaviour results in a reward, it is more likely to give rise to the behaviour in the future.
Latent Learning
Learning that is not directly observable.
