Consciousness, Sensation, and Perception

Vocabulary flashcards reviewing core terms, theories, and concepts from the lectures on Consciousness and Sensation & Perception.

Consciousness

Our awareness of our own mental processes, such as our thoughts, feelings, and sensations.

Focused Awareness

A state of selective attention that enables directing attention to certain events or experiences while filtering out extraneous stimuli to achieve alert wakefulness.

Drifting Consciousness

A waking state characterized by daydreaming and mind-wandering to dreamy thoughts or fantasies, containing mundane everyday thoughts.

Divided Consciousness

A state occurring when simultaneously performing two different activities, each demanding some level of attention.

Altered States of Consciousness

States of awareness that differ from one's usual waking state, such as daydreaming, meditation, hypnosis, or mind-altering drug use.

Circadian Rhythm

A roughly 24-hour day and night cycle found virtually in all species that regulates sleep and wakefulness.

Suprachiasmatic Nucleus (SCN)

The circadian center located in the hypothalamus that regulates sleep and wakefulness on roughly a 24-hour cycle.

Jet Lag

A condition occurring when a change in local time conflicts with the internal body clock, associated with fatigue, irritability, and difficulty concentrating.

Beta Waves

Brain waves associated with ordinary wakefulness and normal alert consciousness, measuring $15\text{-}30\,Hz$.

Alpha Waves

Brain waves associated with relaxed wakefulness, calm, meditation, and creative visualization, measuring $9\text{-}14\,Hz$.

Theta Waves

Brain waves associated with deep relaxation, meditation, and problem solving, measuring $4\text{-}8\,Hz$.

Delta Waves

Large, slow brain waves associated with deep, dreamless sleep (slow-wave sleep), measuring $1\text{-}3\,Hz$.

REM Sleep

Stage of sleep occurring 50 to 90 minutes after falling asleep, characterized by heightened brain activity, dreams, and paradoxical sleep.

Paradoxical Sleep

A phenomenon during REM sleep characterized by a high level of brain activity while muscle activity is blocked.

Information-Processing Theory

Theory proposing that dreams function to sort out and understand the memories experienced during the day.

Activation-Synthesis Hypothesis

Hypothesis stating that dreams are the brain's attempt to make sense of random neural activity released by the brainstem during the night.

Freud's Wish-Fulfillment Theory

Theory stating that dreams are key to understanding hidden unconscious conflicts, consisting of manifest and latent content.

Manifest Content

According to Freud's wish-fulfillment theory, the actual events that occur within a dream.

Latent Content

According to Freud's wish-fulfillment theory, the underlying or hidden meaning of a dream.

Insomnia

Sleep disorder characterized by difficulty falling asleep, remaining asleep, or returning to sleep after nighttime awakenings.

Narcolepsy

Sleep disorder characterized by sudden unexplained daytime sleep attacks, often associated with cataplexy.

Sleep Apnea

Sleep disorder where a person temporarily stops breathing momentarily as many as 500 times during a night's sleep.

Nightmare Disorder

Sleep disorder involving frequent, disturbing, vivid, and intense storylike dreams containing threats to safety or life.

Night Terrors

Intense sleep disturbances occurring during delta sleep.

Sleepwalking

Disorder common in children (about 5%) occurring during deep dreamless sleep where the individual walks while soundly asleep with eyes open.

Rebound Effect

The experience of increased REM sleep following REM sleep deprivation.

Meditation

An altered state of consciousness induced by narrowing attention to a single object, word, thought, or repetitive ritual.

Hypnosis

An altered state of consciousness characterized by focused attention, deep relaxation, and heightened susceptibility to suggestion.

Hidden Observer

A detached part of consciousness in Neodissociation Theory that monitors everything happening during hypnosis.

Psychoactive Drugs

Chemical substances that act on the brain to affect emotional or mental states, mood, thought processes, perceptions, and behavior.

Physiological Dependence

A severe drug-related problem involving tolerance and withdrawal syndrome upon cessation of drug use.

Psychological Dependence

Reliance on a drug to attain feelings of well-being or to cope with problems and emotional stress.

Depressants

Drugs such as alcohol, barbiturates, tranquilizers, and opioids that reduce central nervous system activity and slow bodily processes.

Stimulants

Drugs such as amphetamines, cocaine, MDMA, nicotine, and caffeine that heighten central nervous system activity and produce a pleasurable high.

Hallucinogens

Psychedelic drugs such as LSD, mescaline, psilocybin, PCP, and marijuana that alter sensory perceptions and produce visual, auditory, or sensory distortions.

Sensation

Process by which sensory organs receive stimuli and transform them into neural impulses that the brain uses to create sensory experiences.

Sensory Receptors

Specialized cells that detect physical stimuli from the outside world such as light, sound, and odor.

Psychophysics

The study of how physical sources of stimulation relate to our psychological experience of these stimuli.

Absolute Threshold

The smallest amount of a stimulus that a person can reliably detect $50\%$ of the time.

Just-Noticeable Difference (jnd)

The minimal difference between two stimuli that a person can detect.

Weber's Law

Principle formulated by Ernst Weber stating that the just-noticeable difference between two stimuli is a constant proportion of the original stimulus.

Signal-Detection Theory

Theory stating that stimulus detection depends on stimulus properties, background stimulation, and the biological/psychological characteristics of the perceiver.

Sensory Adaptation

Process by which sensory systems adapt to constant stimuli by becoming less sensitive to them.

Rods

Approximately 120 million photoreceptors sensitive to light intensity that detect objects in low light and are responsible for peripheral vision.

Cones

Photoreceptors in the retina responsible for color vision and perceiving fine details in bright light.

Accommodation

The process by which the eye's lens changes its shape to adjust for object distance and focus a visual image onto the retina.

Blind Spot

The part of the retina where the optic nerve leaves the eye, containing no photoreceptors.

Fovea

The center of our visual gaze located on the retina.

Feature Detectors

Visual cortex neurons discovered by Hubel and Wiesel that respond specifically to particular stimulus features like line orientation.

Trichromatic Theory

Theory proposed by Thomas Young and Hermann von Helmholtz stating that color vision relies on three types of receptors sensitive to red, green, and blue-violet.

Opponent-Process Theory

Theory proposed by Ewald Herring (Hering) stating that color vision relies on pairs of opposing receptors, explaining afterimages.

Charles Bonnet Syndrome

Condition caused by eye disease or visual loss (like macular degeneration) where individuals experience vivid visual hallucinations.

Amplitude

The height of a sound wave, which measures the amount of energy in the wave.

Frequency

The number of complete sound waves or cycles per second.

Pitch

The perceived highness or lowness of a sound, corresponding to the frequency of the sound wave.

Place Theory

Theory stating that pitch is perceived according to the specific location along the basilar membrane that vibrates most.

Frequency Theory

Theory stating that pitch perception depends upon the overall frequency of vibration of the basilar membrane.

Volley Principle

Principle proposing that pitch experience is related to the alternating firing of groups of neurons along the basilar membrane.

Conduction Deafness

Hearing loss caused by damage to middle ear structures, such as a punctured eardrum or ossicles losing ability to vibrate.

Nerve Deafness

Hearing loss caused by damage to hair cells in the inner ear or the auditory nerve.

Pheromones

Chemical substances found in bodily secretions that play an important role in numerous behaviors.

Gate-Control Theory

Theory stating that a gating mechanism in the spinal cord regulates pain perception by blocking or passing pain signals, modulated by endorphins.

Kinesthetic Sense

Sense that keeps a person informed about the movement and relative position of body parts using receptors in joints, ligaments, and muscles.

Vestibular Sense

Sense monitored by hair-cell receptors in inner ear semicircular canals and vestibular sacs that tracks body position in space and maintains balance.

Perception

Process by which the brain interprets sensory information to transform it into meaningful representations of the world.

Selective Attention

The first step in perception involving attending to meaningful stimuli while filtering out irrelevant information.

Perceptual Set

The tendency of perceptions to be influenced by expectations or preconceptions ("seeing what you expect to see").

Bottom-Up Processing

Visual processing mode where the brain recognizes meaningful patterns by piecing together individual bits of sensory information.

Top-Down Processing

Visual processing mode where the brain recognizes patterns as unified meaningful wholes rather than piecemeal constructions.

Gestalt Principles

Perceptual laws of grouping formulated by Max Wertheimer, including proximity, similarity, continuity, closure, symmetry, and area.

Perceptual Constancy

The tendency to perceive the size, shape, color, and brightness of an object as remaining constant despite changes in the retinal image.

Retinal Disparity

A binocular depth cue based on the slight difference in the visual images formed on the left and right retinas.

Convergence

A binocular depth cue based on the degree of muscle tension required to turn both eyes inward to focus on an object.

Carpentered World Hypothesis

Hypothesis stating that people living in cultures where right-angled structures are rare are less prone to the Müller-Lyer illusion.

Consciousness

Our awareness of our own mental processes, such as our thoughts, feelings, and sensations.

Focused Awareness

The ability to direct our attention to certain events or experiences while filtering out extraneous stimuli, enabling a heightened state of alert wakefulness.

Drifting Consciousness

A waking state of consciousness, such as daydreaming, in which the mind wanders to dreamy thoughts or fantasies containing mundane thoughts of everyday life.

Divided Consciousness

A state of consciousness occurring when simultaneously performing two different activities, each demanding some level of attention.

Altered States of Consciousness

States of awareness that differ from one's usual waking state, which may occur during daydreaming, meditation, hypnosis, or the use of mind-altering drugs.

Circadian Rhythm

An internal body clock cycle of about $24\text{ hours}$ that regulates sleep and wakefulness, found virtually in all species.

Suprachiasmatic Nucleus (SCN)

A circadian center located in the hypothalamus that regulates sleep and wakefulness on roughly a $24\text{-hour}$ cycle.

Jet Lag

A condition occurring when a change in local time conflicts with the internal body clock, associated with irritability, fatigue, and difficulty concentrating.

Beta Waves

Brain waves ranging from $15\text{--}30\text{ Hz}$ characteristic of ordinary wakefulness and normal alert consciousness.

Alpha Waves

Brain waves ranging from $9\text{--}14\text{ Hz}$ associated with relaxed wakefulness, calm, meditation, and creative visualization.

Theta Waves

Brain waves ranging from $4\text{--}8\text{ Hz}$ associated with deep relaxation, meditation, and problem solving.

Delta Waves

Large, slow brain waves ranging from $1\text{--}3\text{ Hz}$ characteristic of deep, dreamless slow-wave sleep (SWS).

REM Sleep

A stage of sleep occurring $50\text{--}90\text{ minutes}$ after falling asleep, characterized by active dreaming, brain waves similar to wakefulness, and blocked muscle activity (paradoxical sleep).

Information-Processing Theory

The theory that dreams act to sort out and understand the memories experienced during the day.

Activation-Synthesis Hypothesis

The hypothesis that dreams are the brain's attempt to make sense of random neural activity released by the brainstem during sleep.

Freud's Wish-Fulfillment Theory

The theory that dreams are key to understanding hidden unconscious conflicts, consisting of manifest content and latent content.

Manifest Content

The actual events that occur within a dream, according to Freud's wish-fulfillment theory.

Latent Content

The hidden, underlying psychological meaning of a dream, according to Freud's wish-fulfillment theory.

Insomnia

A sleep disorder characterized by difficulty falling asleep, remaining asleep, or returning to sleep after nighttime awakenings.

Narcolepsy

A sleep disorder marked by sudden unexplained sleep attacks during daytime hours, often associated with cataplexy.

Sleep Apnea

A sleep disorder where a person temporarily stops breathing up to $500$ times per night due to upper airway blockages.

Nightmare Disorder

A sleep disorder involving frequent, disturbing, vivid, and intense storylike dreams containing threats to safety.

Night Terrors

Intense sleep disturbances that occur during deep delta sleep.

Rebound Effect

An effect experienced after REM deprivation, characterized by an increased amount of REM sleep.

Transcendental Meditation

An altered state of consciousness induced by narrowing attention to a single repeating word or phrase called a mantra.

Mindfulness Meditation

A meditation practice focusing on thoughts and physical sensations experienced on a moment-to-moment basis.