Conceptual Models Flashcards
General Adaptation Syndrome
Function – emotion, movement, & cognition
Location – autonomic nervous system (ANS) + hypothalamus
Chemicals - +ACTH, +epinephrine, +norepinephrine, +cortisol
Stages – Selye’s model of stress:
* (Initial) Alarm Reaction Stage- increased sympathetic nervous system & activated hypothalamus to release hormones from the pituitary and adrenal glands.
* (Persists) Resistance Stage- increased parasympathetic nervous system to return to normal functioning, but cortisol lingers leaving the body at high energy levels.
* (Prolonged) Exhaustion Stage- pituitary and adrenal glands can’t maintain hormone levels and physiological processes begin to breakdown.
McEwen’s Allostatic Load Model
Function – physiological & psychological stress are processed differently; allostasis varies based on genetics, resilience, and locus of control of the stressor.
* processes allow the body to achieve stability by adapting to change (allostasis).
* brief allostatic state is fine, but when extended due to chronic/repeated stress it wears on the body & brain (allostatic load).
* if stressor lasts for days, weeks, or longer, it becomes an allostatic overload which effects one’s physical & psychological health.
Location – amygdala, hippocampus, & prefrontal cortex
Stages of Sleep
Function – sleep; Eysenck’s theories: Recovery/Restoration views the purpose of sleeps to be repaired damage that occurs when awake; Adaptive/Evolutionary views the purpose of sleep to conserve energy.
Stages – each having different EEG patterns
* Stage 1: transitional stage between wakefulness & sleep; low frequency, high amplitude alpha waves (drowsy state) are replaced by low frequency, low amplitude theta waves
* Stage 2: theta waves continue but are interrupted by sleep spindles (sudden bursts of moderately fast waves) & K-complexes (large, slow waves)
* Stage 3: after being asleep for 20min, there are low frequency, high amplitude delta waves(slow-wave, deep sleep)
* Stage 4: delta waves continue at a higher amplitude (slow-wave, deep sleep)
* Stage 5: rapid eye movement (REM) after being asleep for 80-90min, similar EEG pattern to stage 1; paradoxical sleep since the brain is active + physiologically aroused while major muscle groups are nearly paralyzed
Lifespan Changes in Sleep
Function – sleep changes with age increase
Stages –
* Newborns sleep longest, spend most time in REM; start in active sleep, then go to quiet (non-REM) sleep
* 3mos of age, this pattern reverses with the four stages of non-REM evident by 6mos
* Total sleep time decreases from 14-16hrs to 8hrs in adulthood
* Older adults struggle to fall/sleep asleep + spend less time in stage 4 & develop circadian phase advance (sleeping earlier in the night, waking earlier in the morning)
Bottom-Up Processing
Function – data driven; processing begins with sensory input and continues upward to the brain where it is perceived, interpreted, & stored.
Top-Down Processing
Function – concept driven; processing begins in the brain with preexisting knowledge and expectations to interpret incoming sensory input.
Vision
Function – light waves absorbed in the retina by photoreceptors (cones & rods).
* Cones – work best in bright light, responsible for visual acuity, color perception
* Rods – no color, crucial for peripheral vision, most sensitive to light & responsible for vision in dim light
Theories of Color Vision –
* Trichromatic theory: retina contains 3 color receptors (red, blue, green); focused on initial retina processing.
* Opponent-process theory: opponent-process cells contain 3 types (red/green, blue/yellow, white/black); focused on beyond-retina processing & explains afterimages + colorblindness.
Color Blindness
Function – seeing the incorrect color
* red/green most common; due to genetic mutation (recessive gene on X- chromosome; most common in males because they inherit only one X-chromosome, so in female, both parents must have the mutated gene) or injury/disease (diabetes, MS).
* blue/yellow caused by autosomal (non-sex) dominant gene, affecting males/females equally.
Depth Perception
Function – perceive depth on a combination of binocular and monocular cues.
* Binocular cues (both eyes), perception of relative closeness; includes retinal disparity (closer the object, greater the disparity) & convergence (tendency for eyes to turn inward as an object gets closer & vice-versa)
* Monocular cues (one eye), used for greater distances; includes relative size, interposition (overlapping), linear perspective, texture, & relative motion (motion parallax)
Pain
Function – extreme negative sensory input; extreme temperatures, mechanical pressure, electrical stimulation; moderated by emotional state & past experiences with pain.
Theory –
* Gate control: major theory of pain perception; distinguishes between two spinal cord fibers, the small unmyelinated fibers (responsible for transmitting pain signal to the brain) open the gate to pain signals & white larger myelinated fibers (transmit other sensory signals) closes the gate using other sensory signals (ex: relieving pain through use of heat or cold, distractions, hypnosis).
Synesthesia
Function – sensations in one sensory modality spontaneously trigger as associated sensational in another modality; most seen as number or letters are associated with specific colors. Genetic component & is due to increased cross-activation & cross-connectivity between sensory areas.
Psychophysics
Function – study of the relationship between magnitude of physical stimuli & psychological sensations; Weber’s Law, Fechner’s Law, Steven’s power law, & signal detection theory.
Theories –
* Weber’s Law: just noticeable differences (JND) for a stimulus is at a constant proportion (ex: to notice a difference in weight, it is either 2% lighter or heavier).
* Fechner’s Law: (Fechner-Weber) the JND grows to an increasingly greater degree with each increment of intensity; more applicable than Weber’s.
* Steven’s Power Law: relationship between physical stimuli & psychological sensations differs for different stimuli; more accurate than Weber’s & Fechner’s.
* Signal Detection Theory (SDT): assumes that the signal of stimuli is the result of both sensory & decision-making processes & is always accompanied by uncertain (presence of background neural activity like motivation, fatigue, environmental distractions). decision-making is affected by sensitivity (ability to distinguish between stimulus & background noise) and decision criterion (decision bias & response bias; willingness to say the stimulus is present in ambiguous situations). The greater the sensitivity, the greater the accuracy, but the willingness to say a stimulus exists influences the decision being made.
Theories of Emotion
Function – theories of emotions include James-Lange, Cannon-Bard, Schachter & Singer Two-Factor, LeDoux’s Two-System Theory, & Lazarus Cognitive Appraisal.
James-Lange Theory of Emotion
Theory - emotions follow physiological arousal; facial feedback hypothesis supports this (ex: smiling makes us happy).
Cannon-Bard Theory of Emotion
Theory - emotions & physiological arousal occur simultaneously; the thalamus sends signals to the cerebral cortex & sympathetic nervous system simultaneously; all emotions involve similar physiological arousals thus emotional reactions cannot be attributed to differences in physiological arousal.
