What physiological functions does serotonin (5-HT) regulate, and how do SSRIs act in treating clinical depression?

Serotonin regulates mood, emotion, sleep-wake cycles, and appetite. Selective serotonin reuptake inhibitors (SSRIs) block the presynaptic serotonin transporter (SERT), increasing synaptic serotonin availability; clinical antidepressant effects typically emerge over several weeks via downstream receptor and neuroplastic adaptations.

What monocular depth cues allow humans to perceive depth in two-dimensional paintings or photographs?

Linear perspective, relative size, interposition (occlusion), texture gradient, light and shadow, and relative height.

Which sensory modality bypasses the thalamus on its direct pathway to the primary cortex?

Olfaction (the sense of smell), which projects directly to the olfactory bulb and piriform cortex.

What are endorphins, and how do they modulate nociceptive (pain) signaling?

Endogenous opioid neuropeptides (such as beta-endorphin) that bind mu-opioid receptors in the periaqueductal gray (PAG), brainstem, and spinal dorsal horn to activate descending pain inhibition and suppress presynaptic release of substance P and glutamate.

What is the core premise of Gestalt psychology regarding sensory perception?

The human brain organizes sensory elements into holistic, structured perceptions: 'The whole is other (or greater) than the sum of its parts.'

How do dopamine pathway alterations correlate with Parkinson's disease and schizophrenia?

Parkinson's disease motor symptoms result from degeneration of dopaminergic neurons in the substantia nigra pars compacta projecting to the striatum (nigrostriatal pathway). In schizophrenia, elevated dopamine signaling in the mesolimbic/striatal pathway (especially at D2 receptors) is linked to positive symptoms (hallucinations, delusions), whereas reduced mesocortical dopamine activity (alongside glutamate/NMDA dysfunction) is linked to negative and cognitive symptoms.

What is the primary neuroendocrine regulatory role of the hypothalamus?

Maintains physiological homeostasis (temperature, thirst, hunger, circadian rhythms) and controls the pituitary gland (the 4 F's: fighting, fleeing, feeding, and mating).

What four outcomes are analyzed in Signal Detection Theory, and what do d' and β represent?

Outcomes: Hit, Miss, False Alarm, Correct Rejection; d' represents the observer's sensory sensitivity, while β (or c) represents their cognitive decision response criterion.

Which neurotransmitter is critical for motor movement at neuromuscular junctions, parasympathetic function, and memory consolidation?

Acetylcholine (ACh); severe degeneration of cholinergic neurons in the basal forebrain is a hallmark of Alzheimer's disease.

What are the distinct emotional and cognitive functions of the amygdala versus the hippocampus?

The amygdala processes emotional significance, fear conditioning, and threat detection; the hippocampus supports spatial navigation (cognitive maps) and consolidates new explicit declarative memories into long-term cortical storage.

What is sensory adaptation?

The progressive reduction in sensory receptor sensitivity and neural firing frequency following prolonged, unchanging exposure to a constant stimulus.

What autonomic vital reflexes are coordinated by the medulla oblongata?

Heart rate, vascular vasomotor tone, respiratory rhythmicity, swallowing, coughing, sneezing, and vomiting reflexes.

What does the All-or-None Law state regarding neuronal action potentials?

Once the membrane threshold of excitation (~ -55 mV) is reached at the axon hillock, an action potential fires at full and constant amplitude; stronger stimuli increase firing frequency, not action potential size.

What is sensory transduction?

The physiological process by which sensory receptors convert physical or chemical stimulus energy (such as light, sound waves, mechanical pressure, or odorants) into graded electrical receptor potentials that initiate neural signaling (action potentials) in sensory pathways.

What functional deficits characterize Broca's aphasia versus Wernicke's aphasia?

Broca's (expressive) aphasia, typically from left inferior frontal damage, produces non-fluent, effortful, telegraphic speech with relatively preserved comprehension; Wernicke's (receptive) aphasia, typically from left posterior superior temporal damage, produces fluent but meaningless paraphasic speech ('word salad') with severely impaired comprehension.

What sensory structures provide vestibular information regarding balance, head orientation, and acceleration?

The semicircular canals (detecting rotational angular acceleration) and otolith organs (utricle and saccule, detecting linear acceleration and gravity).

What is the primary motor coordination role of the cerebellum?

Fine-tuning motor precision, timing, coordination of voluntary movement, posture, and motor procedural learning (e.g., riding a bicycle).

How do Place Theory and Frequency (Temporal) Theory explain pitch perception across different sound frequencies?

Place theory explains high-frequency pitch via tonotopic vibration along the basilar membrane (high frequencies peak near the stiff cochlear base; low frequencies near the flexible apex); Temporal/Frequency theory (and the Volley principle) explains low-frequency pitch via phase-locked firing rates of auditory nerve fibers, while intermediate frequencies use both mechanisms.

What are the primary functional zones of a neuron, and in what direction does an electrical nerve impulse travel?

Dendrites (receptive input) -> Soma (cell body) -> Axon Hillock (action potential trigger zone) -> Axon (conduction) -> Axon Terminals (synaptic output).

State Weber's Law of psychophysics and explain its significance.

Across intermediate stimulus intensities, the Just Noticeable Difference (JND / difference threshold, ΔI) between two stimuli is a constant proportion (k) of the baseline stimulus intensity: ΔI / I = k (which also forms the basis for Fechner's logarithmic law relating stimulus magnitude to perceived intensity).

Explain the Gate Control Theory of pain proposed by Melzack and Wall.

A neural 'gate' in the dorsal horn of the spinal cord modulates pain signals; non-painful tactile input via large A-beta fibers activates inhibitory interneurons to close the gate, reducing pain transmission from small A-delta and C fibers.

What vital homeostatic and protective roles do astrocytes play in the central nervous system?

They maintain extracellular ion balance (buffering K+), clear and recycle neurotransmitters (such as glutamate), provide metabolic support (e.g., lactate/glucose delivery), and support and regulate the blood-brain barrier (physically formed by capillary endothelial tight junctions) via perivascular end-feet.

Compare the distribution, lighting conditions, and visual acuity of retinal rods versus cones.

Rods: peripheral, scotopic (low-light/night), achromatic, high convergence (low acuity); Cones: concentrated in the fovea, photopic (bright light), trichromatic color vision, 1:1 wiring (high acuity).

Why is glutamate considered both essential for neuroplasticity and dangerous in acute brain injury?

Glutamate is the principal CNS excitatory neurotransmitter required for synaptic plasticity and Long-Term Potentiation (LTP) via AMPA/NMDA receptors; however, excessive release during ischemia or trauma causes excitotoxicity, driving excessive Ca2+ influx through NMDA receptors that triggers necrotic and apoptotic neuronal death.

How do the Young-Helmholtz Trichromatic Theory and Hering's Opponent-Process Theory together explain human color vision?

Trichromatic theory operates at the photoreceptor level via three cone classes sensitive to short (S, 'blue'), medium (M, 'green'), and long (L, 'red') wavelengths; Opponent-Process theory operates in downstream retinal ganglion cells, the lateral geniculate nucleus (LGN), and visual cortex via antagonistic channels (L vs. M / red–green, S vs. [L+M] / blue–yellow, and luminance / black–white).

What sensory structure within the inner ear contains the auditory receptor hair cells?

The Organ of Corti, situated on the basilar membrane within the cochlea.

What is the primary inhibitory neurotransmitter in the adult central nervous system, and what class of medications enhances its action?

GABA (gamma-aminobutyric acid); benzodiazepines and barbiturates act as positive allosteric modulators on GABA-A receptors to produce anxiolytic and sedative effects.

What did Roger Sperry and Michael Gazzaniga discover in split-brain patients whose corpus callosum was severed?

Hemispheric specialization: in most individuals (where speech production is lateralized to the left hemisphere), an image flashed briefly to the left visual field (processed by the right hemisphere) cannot be verbally named, yet the patient can select or draw the object with the left hand (controlled by the right hemisphere).

Define the Gestalt grouping principles of Proximity, Similarity, and Closure.

Proximity: objects close to one another are grouped together; Similarity: visually similar objects are grouped; Closure: the mind automatically fills in gaps to perceive an incomplete figure as complete.

What is the resting membrane potential of a neuron, and what primary mechanisms establish and maintain it?

Typically around −70 mV (range −60 to −70 mV); established primarily by K+ diffusion out through non-gated K+ leak channels down its concentration gradient, while the electrogenic Na+/K+ ATPase pump (3 Na+ out, 2 K+ in) maintains the transmembrane Na+ and K+ gradients.

Which brainstem network is essential for regulating sleep-wake transitions, alertness, and cortical arousal?

The Reticular Activating System (RAS), a diffuse network of nuclei and ascending projections within the brainstem reticular formation (spanning the medulla, pons, and midbrain).

What are the two primary binocular depth cues, and how do they operate?

Retinal Disparity: the brain calculates depth by comparing the slightly different horizontal images received by each eye; Convergence: the inward neuromuscular turning of the eyes when focusing on nearby objects.

Biological Foundations, Neurotransmitters, Sensation & Perception

Introduction to Psychology 101 (Myers): biological foundations of behavior, neural signaling and neurotransmitters, brain structures, sensory transduction, psychophysics, and perceptual organization.

Level: basic
Languages: en → en
Cards: 32
Markdown: Biological Foundations, Neurotransmitters, Sensation & Perception (.md)

Flashcards (32)

#	Front (Term / Question)	Back (Definition / Answer)
1	What physiological functions does serotonin (5-HT) regulate, and how do SSRIs act in treating clinical depression?	Serotonin regulates mood, emotion, sleep-wake cycles, and appetite. Selective serotonin reuptake inhibitors (SSRIs) block the presynaptic serotonin transporter (SERT), increasing synaptic serotonin availability; clinical antidepressant effects typically emerge over several weeks via downstream receptor and neuroplastic adaptations.
2	What monocular depth cues allow humans to perceive depth in two-dimensional paintings or photographs?	Linear perspective, relative size, interposition (occlusion), texture gradient, light and shadow, and relative height.
3	Which sensory modality bypasses the thalamus on its direct pathway to the primary cortex?	Olfaction (the sense of smell), which projects directly to the olfactory bulb and piriform cortex.
4	What are endorphins, and how do they modulate nociceptive (pain) signaling?	Endogenous opioid neuropeptides (such as beta-endorphin) that bind mu-opioid receptors in the periaqueductal gray (PAG), brainstem, and spinal dorsal horn to activate descending pain inhibition and suppress presynaptic release of substance P and glutamate.
5	What is the core premise of Gestalt psychology regarding sensory perception?	The human brain organizes sensory elements into holistic, structured perceptions: 'The whole is other (or greater) than the sum of its parts.'
6	How do dopamine pathway alterations correlate with Parkinson's disease and schizophrenia?	Parkinson's disease motor symptoms result from degeneration of dopaminergic neurons in the substantia nigra pars compacta projecting to the striatum (nigrostriatal pathway). In schizophrenia, elevated dopamine signaling in the mesolimbic/striatal pathway (especially at D2 receptors) is linked to positive symptoms (hallucinations, delusions), whereas reduced mesocortical dopamine activity (alongside glutamate/NMDA dysfunction) is linked to negative and cognitive symptoms.
7	What is the primary neuroendocrine regulatory role of the hypothalamus?	Maintains physiological homeostasis (temperature, thirst, hunger, circadian rhythms) and controls the pituitary gland (the 4 F's: fighting, fleeing, feeding, and mating).
8	What four outcomes are analyzed in Signal Detection Theory, and what do d' and β represent?	Outcomes: Hit, Miss, False Alarm, Correct Rejection; d' represents the observer's sensory sensitivity, while β (or c) represents their cognitive decision response criterion.
9	Which neurotransmitter is critical for motor movement at neuromuscular junctions, parasympathetic function, and memory consolidation?	Acetylcholine (ACh); severe degeneration of cholinergic neurons in the basal forebrain is a hallmark of Alzheimer's disease.
10	What are the distinct emotional and cognitive functions of the amygdala versus the hippocampus?	The amygdala processes emotional significance, fear conditioning, and threat detection; the hippocampus supports spatial navigation (cognitive maps) and consolidates new explicit declarative memories into long-term cortical storage.
11	What is sensory adaptation?	The progressive reduction in sensory receptor sensitivity and neural firing frequency following prolonged, unchanging exposure to a constant stimulus.
12	What autonomic vital reflexes are coordinated by the medulla oblongata?	Heart rate, vascular vasomotor tone, respiratory rhythmicity, swallowing, coughing, sneezing, and vomiting reflexes.
13	What does the All-or-None Law state regarding neuronal action potentials?	Once the membrane threshold of excitation (~ -55 mV) is reached at the axon hillock, an action potential fires at full and constant amplitude; stronger stimuli increase firing frequency, not action potential size.
14	What is sensory transduction?	The physiological process by which sensory receptors convert physical or chemical stimulus energy (such as light, sound waves, mechanical pressure, or odorants) into graded electrical receptor potentials that initiate neural signaling (action potentials) in sensory pathways.
15	What functional deficits characterize Broca's aphasia versus Wernicke's aphasia?	Broca's (expressive) aphasia, typically from left inferior frontal damage, produces non-fluent, effortful, telegraphic speech with relatively preserved comprehension; Wernicke's (receptive) aphasia, typically from left posterior superior temporal damage, produces fluent but meaningless paraphasic speech ('word salad') with severely impaired comprehension.
16	What sensory structures provide vestibular information regarding balance, head orientation, and acceleration?	The semicircular canals (detecting rotational angular acceleration) and otolith organs (utricle and saccule, detecting linear acceleration and gravity).
17	What is the primary motor coordination role of the cerebellum?	Fine-tuning motor precision, timing, coordination of voluntary movement, posture, and motor procedural learning (e.g., riding a bicycle).
18	How do Place Theory and Frequency (Temporal) Theory explain pitch perception across different sound frequencies?	Place theory explains high-frequency pitch via tonotopic vibration along the basilar membrane (high frequencies peak near the stiff cochlear base; low frequencies near the flexible apex); Temporal/Frequency theory (and the Volley principle) explains low-frequency pitch via phase-locked firing rates of auditory nerve fibers, while intermediate frequencies use both mechanisms.
19	What are the primary functional zones of a neuron, and in what direction does an electrical nerve impulse travel?	Dendrites (receptive input) -> Soma (cell body) -> Axon Hillock (action potential trigger zone) -> Axon (conduction) -> Axon Terminals (synaptic output).
20	State Weber's Law of psychophysics and explain its significance.	Across intermediate stimulus intensities, the Just Noticeable Difference (JND / difference threshold, ΔI) between two stimuli is a constant proportion (k) of the baseline stimulus intensity: ΔI / I = k (which also forms the basis for Fechner's logarithmic law relating stimulus magnitude to perceived intensity).
21	Explain the Gate Control Theory of pain proposed by Melzack and Wall.	A neural 'gate' in the dorsal horn of the spinal cord modulates pain signals; non-painful tactile input via large A-beta fibers activates inhibitory interneurons to close the gate, reducing pain transmission from small A-delta and C fibers.
22	What vital homeostatic and protective roles do astrocytes play in the central nervous system?	They maintain extracellular ion balance (buffering K+), clear and recycle neurotransmitters (such as glutamate), provide metabolic support (e.g., lactate/glucose delivery), and support and regulate the blood-brain barrier (physically formed by capillary endothelial tight junctions) via perivascular end-feet.
23	Compare the distribution, lighting conditions, and visual acuity of retinal rods versus cones.	Rods: peripheral, scotopic (low-light/night), achromatic, high convergence (low acuity); Cones: concentrated in the fovea, photopic (bright light), trichromatic color vision, 1:1 wiring (high acuity).
24	Why is glutamate considered both essential for neuroplasticity and dangerous in acute brain injury?	Glutamate is the principal CNS excitatory neurotransmitter required for synaptic plasticity and Long-Term Potentiation (LTP) via AMPA/NMDA receptors; however, excessive release during ischemia or trauma causes excitotoxicity, driving excessive Ca2+ influx through NMDA receptors that triggers necrotic and apoptotic neuronal death.
25	How do the Young-Helmholtz Trichromatic Theory and Hering's Opponent-Process Theory together explain human color vision?	Trichromatic theory operates at the photoreceptor level via three cone classes sensitive to short (S, 'blue'), medium (M, 'green'), and long (L, 'red') wavelengths; Opponent-Process theory operates in downstream retinal ganglion cells, the lateral geniculate nucleus (LGN), and visual cortex via antagonistic channels (L vs. M / red–green, S vs. [L+M] / blue–yellow, and luminance / black–white).
26	What sensory structure within the inner ear contains the auditory receptor hair cells?	The Organ of Corti, situated on the basilar membrane within the cochlea.
27	What is the primary inhibitory neurotransmitter in the adult central nervous system, and what class of medications enhances its action?	GABA (gamma-aminobutyric acid); benzodiazepines and barbiturates act as positive allosteric modulators on GABA-A receptors to produce anxiolytic and sedative effects.
28	What did Roger Sperry and Michael Gazzaniga discover in split-brain patients whose corpus callosum was severed?	Hemispheric specialization: in most individuals (where speech production is lateralized to the left hemisphere), an image flashed briefly to the left visual field (processed by the right hemisphere) cannot be verbally named, yet the patient can select or draw the object with the left hand (controlled by the right hemisphere).
29	Define the Gestalt grouping principles of Proximity, Similarity, and Closure.	Proximity: objects close to one another are grouped together; Similarity: visually similar objects are grouped; Closure: the mind automatically fills in gaps to perceive an incomplete figure as complete.
30	What is the resting membrane potential of a neuron, and what primary mechanisms establish and maintain it?	Typically around −70 mV (range −60 to −70 mV); established primarily by K+ diffusion out through non-gated K+ leak channels down its concentration gradient, while the electrogenic Na+/K+ ATPase pump (3 Na+ out, 2 K+ in) maintains the transmembrane Na+ and K+ gradients.
31	Which brainstem network is essential for regulating sleep-wake transitions, alertness, and cortical arousal?	The Reticular Activating System (RAS), a diffuse network of nuclei and ascending projections within the brainstem reticular formation (spanning the medulla, pons, and midbrain).
32	What are the two primary binocular depth cues, and how do they operate?	Retinal Disparity: the brain calculates depth by comparing the slightly different horizontal images received by each eye; Convergence: the inward neuromuscular turning of the eyes when focusing on nearby objects.