Vocabulary

Absolute threshold: The smallest amount of stimulation needed for detection by a sense.
Action Potential: A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
Action potential: A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
A-fibers: Fast-conducting sensory nerves with myelinated axons. Larger diameter and thicker myelin sheaths increases conduction speed. Aβ-fibers conduct touch signals from low-threshold mechanoreceptors with a velocity of 80 m/s and a diameter of 10 μm; Aδ-fibers have a diameter of 2.5 μm and conduct cold, noxious, and thermal signals at 12 m/s. The third and fastest conducting A-fiber is the Aα, which conducts proprioceptive information with a velocity of 120 m/s and a diameter of 20 μm.
Agnosia: Loss of the ability to perceive stimuli.
Allodynia: Pain due to a stimulus that does not normally provoke pain, e.g., when a light, stroking touch feels painful.
Ambulatory assessment: An overarching term to describe methodologies that assess the behavior, physiology, experience, and environments of humans in naturalistic settings.
Analgesia: Pain relief.
Anecdotal evidence: A piece of biased evidence, usually drawn from personal experience, used to support a conclusion that may or may not be correct.
Anosmia: Loss of the ability to smell.
Audition: Ability to process auditory stimuli. Also called hearing.
Auditory canal: Tube running from the outer ear to the middle ear.
Auditory hair cells: Receptors in the cochlea that transduce sound into electrical potentials.
Axon: Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
Axon: Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
Behaviorism: The study of behavior.
Binocular advantage: Benefits from having two eyes as opposed to a single eye.
Binocular disparity: Difference is images processed by the left and right eyes.
Binocular vision: Our ability to perceive 3D and depth because of the difference between the images on each of our retinas.
Blood-oxygen-level-dependent (BOLD): The signal typically measured in fMRI that results from changes in the ratio of oxygenated hemoglobin to deoxygenated hemoglobin in the blood.
Bottom-up processing: Building up to perceptual experience from individual pieces.
Bouncing balls illusion: The tendency to perceive two circles as bouncing off each other if the moment of their contact is accompanied by an auditory stimulus.
Brain Stem: The “trunk” of the brain comprised of the medulla, pons, midbrain, and diencephalon.
Broca’s Area: An area in the frontal lobe of the left hemisphere. Implicated in language production.
Causality: In research, the determination that one variable causes—is responsible for—an effect.
Cell membrane: A bi-lipid layer of molecules that separates the cell from the surrounding extracellular fluid.
Central nervous system: The part of the nervous system that consists of the brain and spinal cord.
Central Nervous System: The portion of the nervous system that includes the brain and spinal cord.
Cerebellum: The distinctive structure at the back of the brain, Latin for “small brain.”
Cerebrum: Usually refers to the cerebral cortex and associated white matter, but in some texts includes the subcortical structures.
C-fibers: C-fibers: Slow-conducting unmyelinated thin sensory afferents with a diameter of 1 μm and a conduction velocity of approximately 1 m/s. C-pain fibers convey noxious, thermal, and heat signals; C-tactile fibers convey gentle touch, light stroking.
Chemical senses: Our ability to process the environmental stimuli of smell and taste.
Chronic pain: Persistent or recurrent pain, beyond usual course of acute illness or injury; sometimes present without observable tissue damage or clear cause.
Cochlea: Spiral bone structure in the inner ear containing auditory hair cells.
Cochlea: Snail-shell-shaped organ that transduces mechanical vibrations into neural signals.
Cognitive psychology: The study of mental processes.
Conditioned aversions and preferences: Likes and dislikes developed through associations with pleasurable or unpleasurable sensations.
Cones: Photoreceptors that operate in lighted environments and can encode fine visual details. There are three different kinds (S or blue, M or green and L or red) that are each sensitive to slightly different types of light. Combined, these three types of cones allow you to have color vision.
Cones: Photoreceptors of the retina sensitive to color. Located primarily in the fovea.
Consciousness: Awareness of ourselves and our environment.
Contralateral: Literally “opposite side”; used to refer to the fact that the two hemispheres of the brain process sensory information and motor commands for the opposite side of the body (e.g., the left hemisphere controls the right side of the body).
Contrast: Relative difference in the amount and type of light coming from two nearby locations.
Contrast gain: Process where the sensitivity of your visual system can be tuned to be most sensitive to the levels of contrast that are most prevalent in the environment.
Corpus Callosum: The thick bundle of nerve cells that connect the two hemispheres of the brain and allow them to communicate.
Correlation: In statistics, the measure of relatedness of two or more variables.
C-pain or Aδ-fibers: C-pain fibers convey noxious, thermal, and heat signals
Crossmodal phenomena: Effects that concern the influence of the perception of one sensory modality on the perception of another.
Crossmodal receptive field: A receptive field that can be stimulated by a stimulus from more than one sensory modality.
Crossmodal stimulus: A stimulus with components in multiple sensory modalties that interact with each other.
C-tactile fibers: C-tactile fibers convey gentle touch, light stroking
Cutaneous senses: The senses of the skin: tactile, thermal, pruritic (itchy), painful, and pleasant.
Daily Diary method: A methodology where participants complete a questionnaire about their thoughts, feelings, and behavior of the day at the end of the day.
Dark adaptation: Adjustment of eye to low levels of light.
Dark adaptation: Process that allows you to become sensitive to very small levels of light, so that you can actually see in the near-absence of light.
Data (also called observations): In research, information systematically collected for analysis and interpretation.
Day reconstruction method (DRM): A methodology where participants describe their experiences and behavior of a given day retrospectively upon a systematic reconstruction on the following day.
Deductive reasoning: A form of reasoning in which a given premise determines the interpretation of specific observations (e.g., All birds have feathers; since a duck is a bird, it has feathers).
Dendrite: Part of a neuron that extends away from the cell body and is the main input to the neuron.
Dendrites: Part of a neuron that extends away from the cell body and is the main input to the neuron.
Deoxygenated hemoglobin: Hemoglobin not carrying oxygen.
Depolarization: A change in a cell’s membrane potential, making the inside of the cell more positive and increasing the chance of an action potential.
Descending pain modulatory system: A top-down pain-modulating system able to inhibit or facilitate pain. The pathway produces analgesia by the release of endogenous opioids. Several brain structures and nuclei are part of this circuit, such as the frontal lobe areas of the anterior cingulate cortex, orbitofrontal cortex, and insular cortex; and nuclei in the amygdala and the hypothalamus, which all project to a structure in the midbrain called the periaqueductal grey (PAG). The PAG then controls ascending pain transmission from the afferent pain system indirectly through the rostral ventromedial medulla (RVM) in the brainstem, which uses ON- and OFF-cells to inhibit or facilitate nociceptive signals at the spinal dorsal horn.
Differential threshold (or difference threshold): The smallest difference needed in order to differentiate two stimuli. (See Just Noticeable Difference (JND))
Diffuse Optical Imaging (DOI): A neuroimaging technique that infers brain activity by measuring changes in light as it is passed through the skull and surface of the brain.
Diffusion: The force on molecules to move from areas of high concentration to areas of low concentration.
Distribution: In statistics, the relative frequency that a particular value occurs for each possible value of a given variable.
Dorsal pathway: Pathway of visual processing. The “where” pathway.
Double flash illusion: The false perception of two visual flashes when a single flash is accompanied by two auditory beeps.
Ecological momentary assessment: An overarching term to describe methodologies that repeatedly sample participants’ real-world experiences, behavior, and physiology in real time.
Ecological validity: The degree to which a study finding has been obtained under conditions that are typical for what happens in everyday life.
Electroencephalography (EEG): A neuroimaging technique that measures electrical brain activity via multiple electrodes on the scalp.
Electronically activated recorder, or EAR: A methodology where participants wear a small, portable audio recorder that intermittently records snippets of ambient sounds around them.
Electrostatic pressure: The force on two ions with similar charge to repel each other; the force of two ions with opposite charge to attract to one another.
Empirical: Concerned with observation and/or the ability to verify a claim.
Empiricism: The belief that knowledge comes from experience.
Endorphin: An endogenous morphine-like peptide that binds to the opioid receptors in the brain and body; synthesized in the body’s nervous system.
Eugenics: The practice of selective breeding to promote desired traits.
Excitatory postsynaptic potentials: A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold of excitation.
Experience-sampling method: A methodology where participants report on their momentary thoughts, feelings, and behaviors at different points in time over the course of a day.
External validity: The degree to which a finding generalizes from the specific sample and context of a study to some larger population and broader settings.
Exteroception: The sense of the external world, of all stimulation originating from outside our own bodies.
Fact: Objective information about the world.
Falsify: In science, the ability of a claim to be tested and—possibly—refuted; a defining feature of science.
Flashbulb memory: A highly detailed and vivid memory of an emotionally significant event.
Flavor: The combination of smell and taste.
Frontal Lobe: The front most (anterior) part of the cerebrum; anterior to the central sulcus and responsible for motor output and planning, language, judgment, and decision-making.
Full-cycle psychology: A scientific approach whereby researchers start with an observational field study to identify an effect in the real world, follow up with laboratory experimentation to verify the effect and isolate the causal mechanisms, and return to field research to corroborate their experimental findings.
Functional Magnetic Resonance Imaging (fMRI): Functional magnetic resonance imaging (fMRI): A neuroimaging technique that infers brain activity by measuring changes in oxygen levels in the blood.
Functionalism: A school of American psychology that focused on the utility of consciousness.
Generalize: In research, the degree to which one can extend conclusions drawn from the findings of a study to other groups or situations not included in the study.
Generalize: Generalizing, in science, refers to the ability to arrive at broad conclusions based on a smaller sample of observations. For these conclusions to be true the sample should accurately represent the larger population from which it is drawn.
Gestalt psychology: An attempt to study the unity of experience.
Gustation: Ability to process gustatory stimuli. Also called taste.
Gustation: The action of tasting; the ability to taste.
Hemoglobin: The oxygen-carrying portion of a red blood cell.
Hyperpolarization: A change in a cell’s membrane potential, making the inside of the cell more negative and decreasing the chance of an action potential.
Hypothesis: A tentative explanation that is subject to testing.
Individual differences: Ways in which people differ in terms of their behavior, emotion, cognition, and development.
Induction: To draw general conclusions from specific observations.
Inductive reasoning: A form of reasoning in which a general conclusion is inferred from a set of observations (e.g., noting that “the driver in that car was texting; he just cut me off then ran a red light!” (a specific observation), which leads to the general conclusion that texting while driving is dangerous).
Inhibitory postsynaptic potentials: A hyperpolarizing postsynaptic current that causes the membrane potential to become more negative and move away from the threshold of excitation.
Integrated: The process by which the perceptual system combines information arising from more than one modality.
Interaural differences: Differences (usually in time or intensity) between the two ears.
Internal validity: The degree to which a cause-effect relationship between two variables has been unambiguously established.
Interoception: The sense of the physiological state of the body. Hunger, thirst, temperature, pain, and other sensations relevant to homeostasis. Visceral input such as heart rate, blood pressure, and digestive activity give rise to an experience of the body’s internal states and physiological reactions to external stimulation. This experience has been described as a representation of “the material me,” and it is hypothesized to be the foundation of subjective feelings, emotion, and self-awareness.
Introspection: A method of focusing on internal processes.
Invasive Procedure: A procedure that involves the skin being broken or an instrument or chemical being introduced into a body cavity.
Ion channels: Proteins that span the cell membrane, forming channels that specific ions can flow through between the intracellular and extracellular space.
Ionotropic receptor: Ion channel that opens to allow ions to permeate the cell membrane under specific conditions, such as the presence of a neurotransmitter or a specific membrane potential.
Just noticeable difference (JND): The smallest difference needed in order to differentiate two stimuli. (see Differential Threshold)
Lateral inhibition: A signal produced by a neuron aimed at suppressing the response of nearby neurons.
Lesions: Abnormalities in the tissue of an organism usually caused by disease or trauma.
Levels of analysis: In science, there are complementary understandings and explanations of phenomena.
Light adaptation: Adjustment of eye to high levels of light.
Limbic System: Includes the subcortical structures of the amygdala and hippocampal formation as well as some cortical structures; responsible for aversion and gratification.
Linguistic inquiry and word count: A quantitative text analysis methodology that automatically extracts grammatical and psychological information from a text by counting word frequencies.
Lived day analysis: A methodology where a research team follows an individual around with a video camera to objectively document a person’s daily life as it is lived.
McGurk effect: An effect in which conflicting visual and auditory components of a speech stimulus result in an illusory percept.
Mechanoreceptors: Mechanical sensory receptors in the skin that response to tactile stimulation.
Multimodal: Of or pertaining to multiple sensory modalities.
Multimodal perception: The effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world.
Multimodal perception: The effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world.
Multimodal phenomena: Effects that concern the binding of inputs from multiple sensory modalities.
Multisensory convergence zones: Regions in the brain that receive input from multiple unimodal areas processing different sensory modalities.
Multisensory enhancement: See “superadditive effect of multisensory integration.”
Myelin sheath: Substance around the axon of a neuron that serves as insulation to allow the action potential to conduct rapidly toward the terminal buttons.
Myelin Sheath: Fatty tissue, that insulates the axons of the neurons; myelin is necessary for normal conduction of electrical impulses among neurons.
Nervous System: The body’s network for electrochemical communication. This system includes all the nerves cells in the body.
Neural impulse: An electro-chemical signal that enables neurons to communicate.
Neural plasticity: The ability of synapses and neural pathways to change over time and adapt to changes in neural process, behavior, or environment.
Neurons: Individual brain cells
Neuroscience methods: A research method that deals with the structure or function of the nervous system and brain.
Neurotransmitters: Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
Neurotransmitters: Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
Nociception: The neural process of encoding noxious stimuli, the sensory input from nociceptors. Not necessarily painful, and crucially not necessary for the experience of pain.
Nociception: Our ability to sense pain.
Nociceptors: High-threshold sensory receptors of the peripheral somatosensory nervous system that are capable of transducing and encoding noxious stimuli. Nociceptors send information about actual or impending tissue damage to the brain. These signals can often lead to pain, but nociception and pain are not the same.
Noninvasive procedure: A procedure that does not require the insertion of an instrument or chemical through the skin or into a body cavity.
Noxious stimulus: A stimulus that is damaging or threatens damage to normal tissues.
Nucleus: Collection of nerve cells found in the brain which typically serve a specific function.
Null-hypothesis significance testing (NHST): In statistics, a test created to determine the chances that an alternative hypothesis would produce a result as extreme as the one observed if the null hypothesis were actually true.
Objective: Being free of personal bias.
Occipital Lobe: The back most (posterior) part of the cerebrum; involved in vision.
Ocial touch hypothesis: Proposes that social touch is a distinct domain of touch. C-tactile afferents form a special pathway that distinguishes social touch from other types of touch by selectively firing in response to touch of social-affective relevance; thus sending affective information parallel to the discriminatory information from the Aβ-fibers. In this way, the socially relevant touch stands out from the rest as having special positive emotional value and is processed further in affect-related brain areas such as the insula.
Odorants: Chemicals transduced by olfactory receptors.
Olfaction: The sense of smell; the action of smelling; the ability to smell.
Olfaction: Ability to process olfactory stimuli. Also called smell.
Olfactory epithelium: Organ containing olfactory receptors.
Omnivore: A person or animal that is able to survive by eating a wide range of foods from plant or animal origin.
Opponent Process Theory: Theory of color vision that assumes there are four different basic colors, organized into two pairs (red/green and blue/yellow) and proposes that colors in the world are encoded in terms of the opponency (or difference) between the colors in each pair. There is an additional black/white pair responsible for coding light contrast.
Opponent-process theory: Theory proposing color vision as influenced by cells responsive to pairs of colors.
Orthonasal olfaction: Perceiving scents/smells introduced via the nostrils.
Ossicles: A collection of three small bones in the middle ear that vibrate against the tympanic membrane.
Oxygenated hemoglobin: Hemoglobin carrying oxygen.
Pain: Defined as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage,” according to the International Association for the Study of Pain.
Parasympathetic nervous system (PNS): One of the two major divisions of the autonomic nervous system, responsible for stimulation of “rest and digest” activities.
Parietal Lobe: The part of the cerebrum between the frontal and occipital lobes; involved in bodily sensations, visual attention, and integrating the senses.
Perception: The psychological process of interpreting sensory information.
Peripheral nervous system: The part of the nervous system that is outside the brain and spinal cord.
Peripheral Nervous System: All of the nerve cells that connect the central nervous system to all the other parts of the body.
Phantom limb: The perception that a missing limb still exists.
Phantom limb pain: Pain in a limb that no longer exists.
Phantom pain: Pain that appears to originate in an amputated limb.
Photoactivation: A photochemical reaction that occurs when light hits photoreceptors, producing a neural signal.
Pinna: Visible part of the outer ear.
Pinna: Outermost portion of the ear.
Placebo effect: Effects from a treatment that are not caused by the physical properties of a treatment but by the meaning ascribed to it. These effects reflect the brain’s own activation of modulatory systems, which is triggered by positive expectation or desire for a successful treatment. Placebo analgesia is the most well-studied placebo effect and has been shown to depend, to a large degree, on opioid mechanisms. Placebo analgesia can be reversed by the pharmacological blocking of  opioid receptors. The word “placebo” is probably derived from the Latin word “placebit” (“it will please”).
Population: In research, all the people belonging to a particular group (e.g., the population of left handed people).
Positron: A particle having the same mass and numerically equal but positive charge as an electron.
Positron Emission Tomography (PET): A neuroimaging technique that measures brain activity by detecting the presence of a radioactive substance in the brain that is initially injected into the bloodstream and then pulled in by active brain tissue.
Practitioner-Scholar Model: A model of training of professional psychologists that emphasizes clinical practice.
Primary auditory cortex: Area of the cortex involved in processing auditory stimuli.
Primary auditory cortex: A region of the cortex devoted to the processing of simple auditory information.
Primary somatosensory cortex: Area of the cortex involved in processing somatosensory stimuli.
Primary visual cortex: A region of the cortex devoted to the processing of simple visual information.
Primary visual cortex: Area of the cortex involved in processing visual stimuli.
Primary visual cortex (V1): Brain region located in the occipital cortex (toward the back of the head) responsible for processing basic visual information like the detection, thickness, and orientation of simple lines, color, and small-scale motion.
Principle of Inverse Effectiveness: The finding that, in general, for a multimodal stimulus, if the response to each unimodal component (on its own) is weak, then the opportunity for multisensory enhancement is very large. However, if one component—by itself—is sufficient to evoke a strong response, then the effect on the response gained by simultaneously processing the other components of the stimulus will be relatively small.
Principle of inverse effectiveness: The finding that, in general, for a multimodal stimulus, if the response to each unimodal component (on its own) is weak, then the opportunity for multisensory enhancement is very large. However, if one component—by itself—is sufficient to evoke a strong response, then the effect on the response gained by simultaneously processing the other components of the stimulus will be relatively small.
Probability: A measure of the degree of certainty of the occurrence of an event.
Probability values: In statistics, the established threshold for determining whether a given value occurs by chance.
Pseudoscience: Beliefs or practices that are presented as being scientific, or which are mistaken for being scientific, but which are not scientific (e.g., astrology, the use of celestial bodies to make predictions about human behaviors, and which presents itself as founded in astronomy, the actual scientific study of celestial objects. Astrology is a pseudoscience unable to be falsified, whereas astronomy is a legitimate scientific discipline).
Psychophysics: Study of the relationships between physical stimuli and the perception of those stimuli.
Psychophysiological methods: Any research method in which the dependent variable is a physiological measure and the independent variable is behavioral or mental (such as memory).
Realism: A point of view that emphasizes the importance of the senses in providing knowledge of the external world.
Receptive field: The portion of the world to which a neuron will respond if an appropriate stimulus is present there.
Representative: In research, the degree to which a sample is a typical example of the population from which it is drawn.
Resting membrane potential: The voltage inside the cell relative to the voltage outside the cell while the cell is a rest (approximately -70 mV).
Retina: Cell layer in the back of the eye containing photoreceptors.
Retronasal olfaction: Perceiving scents/smells introduced via the mouth/palate.
Rods: Photoreceptors that are very sensitive to light and are mostly responsible for night vision.
Rods: Photoreceptors of the retina sensitive to low levels of light. Located around the fovea.
Rubber hand illusion: The false perception of a fake hand as belonging to a perceiver, due to multimodal sensory information.
Sample: In research, a number of people selected from a population to serve as an example of that population.
Scientific theory: An explanation for observed phenomena that is empirically well-supported, consistent, and fruitful (predictive).
Scientist-practitioner model: A model of training of professional psychologists that emphasizes the development of both research and clinical skills.
Sensation: The physical processing of environmental stimuli by the sense organs.
Sensitization: Increased responsiveness of nociceptive neurons to their normal input and/or recruitment of a response to normally subthreshold inputs. Clinically, sensitization may only be inferred indirectly from phenomena such as hyperalgesia or allodynia. Sensitization can occur in the central nervous system (central sensitization) or in the periphery (peripheral sensitization).
Sensory adaptation: Decrease in sensitivity of a receptor to a stimulus after constant stimulation.
Sensory modalities: A type of sense; for example, vision or audition.
Shape theory of olfaction: Theory proposing that odorants of different size and shape correspond to different smells.
Signal detection: Method for studying the ability to correctly identify sensory stimuli.
Social touch hypothesis: Proposes that social touch is a distinct domain of touch. C-tactile afferents form a special pathway that distinguishes social touch from other types of touch by selectively firing in response to touch of social-affective relevance; thus sending affective information parallel to the discriminatory information from the Aβ-fibers. In this way, the socially relevant touch stands out from the rest as having special positive emotional value and is processed further in affect-related brain areas such as the insula.
Sodium-potassium pump: An ion channel that uses the neuron’s energy (adenosine triphosphate, ATP) to pump three Na+ ions outside the cell in exchange for bringing two K+ ions inside the cell.
Soma: Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis.
Soma: Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis.
Somatosensation: Ability to sense touch, pain and temperature.
Somatosensory cortex: Consists of primary sensory cortex (S1) in the postcentral gyrus in the parietal lobes and secondary somatosensory cortex (S2), which is defined functionally and found in the upper bank of the lateral sulcus, called the parietal operculum. Somatosensory cortex also includes parts of the insular cortex.
Somatotopic map: Organization of the primary somatosensory cortex maintaining a representation of the arrangement of the body.
Somatotopically organized: When the parts of the body that are represented in a particular brain region are organized topographically according to their physical location in the body (see Figure 2 illustration).
Sound waves: Changes in air pressure. The physical stimulus for audition.
Spatial principle of multisensory integration: The finding that the superadditive effects of multisensory integration are observed when the sources of stimulation are spatially related to one another.
Spatial resolution: The degree to which one can separate a single object in space from another.
Spatial Resolution: A term that refers to how small the elements of an image are; high spatial resolution means the device or technique can resolve very small elements; in neuroscience it describes how small of a structure in the brain can be imaged.
Spines: Protrusions on the dendrite of a neuron that form synapses with terminal buttons of the presynaptic axon.
Spinothalamic tract: Runs through the spinal cord’s lateral column up to the thalamus. C-fibers enter the dorsal horn of the spinal cord and form a synapse with a neuron that then crosses over to the lateral column and becomes part of the spinothalamic tract.
Split-brain Patient: A patient who has had most or all of his or her corpus callosum severed.
Structuralism: A school of American psychology that sought to describe the elements of conscious experience.
Superadditive effect of multisensory integration: The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own.
Superadditive effect of multisensory integration: The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own.
Sympathetic nervous system (SNS): One of the two major divisions of the autonomic nervous system, responsible for stimulation of “fight or flight” activities.
Synapse: Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron.
Synapses: Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron.
Synaptic Gap: Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine, axon, or soma.
Synaptic gap: Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine, axon, or soma.
Synaptic vesicles: Groups of neurotransmitters packaged together and located within the terminal button.
Synesthesia: The blending of two or more sensory experiences, or the automatic activation of a secondary (indirect) sensory experience due to certain aspects of the primary (direct) sensory stimulation.
Tastants: Chemicals transduced by taste receptor cells.
Taste receptor cells: Receptors that transduce gustatory information.
Temporal Lobe: The part of the cerebrum in front of (anterior to) the occipital lobe and below the lateral fissure; involved in vision, auditory processing, memory, and integrating vision and audition.
Temporal Resolution: A term that refers to how small a unit of time can be measured; high temporal resolution means capable of resolving very small units of time; in neuroscience it describes how precisely in time a process can be measured in the brain.
Temporal resolution: The degree to which one can separate a single point in time from another.
Terminal button: The part of the end of the axon that form synapses with postsynaptic dendrite, axon, or soma.
Threshold of excitation: Specific membrane potential that the neuron must reach to initiate an action potential.
Tip-of-the-tongue phenomenon: The inability to pull a word from memory even though there is the sensation that that word is available.
Top-down processing: Experience influencing the perception of stimuli.
Transduction: The mechanisms that convert stimuli into electrical signals that can be transmitted and processed by the nervous system. Physical or chemical stimulation creates action potentials in a receptor cell in the peripheral nervous system, which is then conducted along the axon to the central nervous system.
Transduction: The conversion of one form of energy into another.
Trichromacy theory: Theory that proposes that all of your color perception is fundamentally based on the combination of three (not two, not four) different color signals.
Trichromatic theory: Theory proposing color vision as influenced by three different cones responding preferentially to red, green and blue.
Tympanic membrane: Ear drum, which separates the outer ear from the middle ear.
Tympanic membrane: Thin, stretched membrane in the middle ear that vibrates in response to sound. Also called the eardrum.
Type I error: In statistics, the error of rejecting the null hypothesis when it is true.
Type II error: In statistics, the error of failing to reject the null hypothesis when it is false.
Unimodal: Of or pertaining to a single sensory modality.
Unimodal components: The parts of a stimulus relevant to one sensory modality at a time.
Unimodal cortex: A region of the brain devoted to the processing of information from a single sensory modality.
Value: Belief about the way things should be.
Ventral pathway: Pathway of visual processing. The “what” pathway.
Vestibular system: Parts of the inner ear involved in balance.
Vestibulo-ocular reflex: Coordination of motion information with visual information that allows you to maintain your gaze on an object while you move.
Voltage: The difference in electric charge between two points.
Weber’s law: States that just noticeable difference is proportional to the magnitude of the initial stimulus.
What pathway: Pathway of neural processing in the brain that is responsible for your ability to recognize what is around you.
Where-and-How pathway: Pathway of neural processing in the brain that is responsible for you knowing where things are in the world and how to interact with them.
White coat hypertension: A phenomenon in which patients exhibit elevated blood pressure in the hospital or doctor’s office but not in their everyday lives.