6. PYC1501 - Glossary of all terms

Absolute refractory period

the process whereby a neuron does not respond to normal stimulation.

Action potential

A transient all‐or‐nothing transmission of impulse conducted down the axon when the membrane potential reaches the threshold of excitation.

Agonist

a drug that has chemical properties similar to a particular neurotransmitter and thus mimics the effects of that neurotransmitter.

Antagonist

is a drug that reduces or inhibits the normal effects of a neurotransmitter.

Autonomic nervous system

part of the peripheral nervous system that controls involuntary functions of the internal organs and glands.

Axon

a segmented neural fibre that sends the information to another neuron or to the muscles and glands.

Brainstem

part of the central nervous system that oversees a wide range of very basic life support functions for the body including breathing, digestion, and the heartbeat.

Central Nervous System

the part of the nervous system that includes the brain, the brainstem, and the spinal cord. This system performs mainly the information synthesising function.

Corpus callosum

the nerve fibre that connects the left and the right hemispheres of the brain.

Dendrites

Part of a neuron that extends away from the cell body and is the main input to the neuron.

Excitatory postsynaptic potential (EPSP)

a depolarising current that causes the membrane potential to become more positive and closer to the threshold of excitation and,

Frontal lobe

The part of the cerebrum, responsible for motor output, planning, language, judgment, and decision‐making.

Inhibitory postsynaptic potential (IPSP)

a hyperpolarising current that causes the membrane potential to become more negative and further away from the threshold of excitation.

Limbic system

part of the brain that consists of highly specialised neural structures that are involved inregulating emotions.

Myelin sheath

A fatty tissue that insulates the axon of the neuron which is necessary for conducting neural impulses.

Neuron

a building block in the nervous system that receives and transmits information using both electrical and chemical processes.

Neurotransmitter

a chemical that relays signal impulses across the synapses among neurons.

Occipital lobe

The back most (posterior) part of the brain involved in vision.

Parasympathetic nervous system

part of the peripheral nervous system that restores and calms down the physiological responses so as to maintain homeostasis.

Parietal lobe

The part of the brain involved in bodily sensations and integrating the senses.

Peripheral nervous system

part of the human nervous system that controls volitional (somatic nervous system) and non‐volitional (autonomic nervous system) behaviours using cranial and spinal nerves.

Refractory period

is a time during which a neuron is incapable of firing an impulse.

Relative refractory period

the process whereby a neuron responds only to a very intense stimulation.

Resting membrane potential

a state in which the interior of the neuron contains a greater number of negatively charged ions than the area outside the cell.

Retina

is a cell layer in the back of the eye containing photoreceptors.

Soma

a cell body of a neuron that contains the nucleus and genetic information and directs protein synthesis.

Somatic nervous system

it controls conscious and voluntary activities and it serves as a relay of sensory and motor information to and from the central nervous system.

Spinal cord

a section of the central nervous system that connects the brain and the brainstem to all major nerves in the body.

Sympathetic nervous system

part of the peripheral nervous system that is involved in preparing the body for stress related activities.

Synapse

a process whereby neurons use electrical and chemical messages to communicate with each other at the synaptic cleft.

Synaptic (gap) cleft

the small space between the presynaptic terminal button of one neuron and the postsynaptic dendrite of another adjacent neuron.

Temporal lobe

The part of the brain involved in auditory and olfactory processing.

Absolute threshold

the smallest amount of stimulation needed for detection by a sense.

Afterimage

is the continuation of a visual sensation after the removal of the stimulus.

Agnosia

a loss of the ability to perceive visual stimuli.

Auditory

the processing of auditory stimuli. Also called hearing.

Auditory canal

a tube‐like structure running from the outer ear to the middle ear.

hair cells

the receptors in the cochlea that convert sound into electrical signals.

Binocular disparity

difference in images processed by the left and right eyes.

Binocular vision

the ability to perceive 3‐dimennsional objects because of the differences between the images on each retina in the eyes.

Bottom‐up processing

refers to building up to perceptual experience from individual pieces of sensory input.

Chemical senses

part of sensory system that allows people to process the environmental stimuli of smell and taste.

Cochlea

Spiral bone ‐like structure in the inner ear containing auditory hair cells.

Cones

a type of photoreceptors in the eye that enable us to see colours and fine details in bright light.

Decibel (dB)

is a logarithmic unit of measurement of sound intensity.

Depth perception

it refers to an ability to perceive spatial relationships in three‐dimensional (3‐D) space.

Differential threshold

the smallest change in stimulation that a person can detect. (also known as just noticeable difference ‐ jnd).

Dorsal pathway

the ‘where’ pathway of visual processing.

Frequency

refers to the number of waves that pass a given point in a given period

Gustation (taste)

describes the detection of taste by chemoreceptors in the oral cavity, predominantly on the tongue.

Light intensity

refers to how much energy the light contains and it determines the brightness of the light.

Light wavelength

refers to the distance between the two successive crests or troughs of the light wave. The color we see depends mainly on light wavelength.

Mechanoreceptors

receptors in the skin that allow for the conversion of one kind of energy into a form that the brain can understand.

Olfaction (smell)

an ability to process smell stimuli.

Olfactory receptor cells

are found in a mucous membrane at the top of the nose and are topped with tentacle‐like protrusions that contain receptor proteins.

Opponent‐process theory

a theory proposing that colour vision as influenced by cells responsive to pairs of colours.

Ossicles

A collection of three small bones in the middle ear that vibrate against the tympanic

Perception

refers to the way sensory information is organised, interpreted, and consciously

Perceptual grouping

refers to the tendency to group stimuli in a pattern or shape that allows for

Photoreceptor

specialised cells in the retina that convert light into electrical signal.

Pinna

Outermost portion of the ear.

Primary auditory cortex

an area of the cortex involved in processing auditory stimuli.

Primary somatosensory cortex

an area of the cortex involved in processing somatosensory stimuli.

Primary visual cortex

an area of the cortex involved in processing visual stimuli.

Prosopagnosia

an inability to recognise faces.

Proprioception

the ability to sense the position and movement of body parts.

Retina

a cell layer in the back of the eye containing photoreceptors.

Rods

a type of photoreceptors that are primarily responsible for our ability to see in dim light

Sensation

the physical processing of environmental stimuli by the sense organs.

Sensory adaptation

a reduction in sensitivity to a stimulus after constant exposure to it.

Signal detection

is the process at which stimulus signal can be detected at any particular intensity by the sense organs.

Somatosensation

an ability to sense touch, pain and temperature.

Sound waves

pressure caused by the vibration of sound in a medium that transfers energy, like air.

Tactile stimuli

refers to stimuli associated with texture.

Timbre

is the purity of sound, affected by frequency, amplitude, and timing of sound waves.

Top‐down processing

the perceptions that begin with the most general and move toward the more specific.

Trichromatic theory

a theory proposing that colour vision as influenced by different cones responding preferentially to red, green and blue colours.

Tympanic membrane (eardrum)

a thin, stretched membrane in the ear that vibrates in response to sound waves.

Ventral pathway

the ‘what’ pathway of visual processing.

Vestibular system

Parts of the inner ear involved in balance.

Wave amplitude

is the height of a wave as measured from the highest point (peak) to the lowest point on the wave (trough).

Wavelength

refers to the length of a wave from one peak to the next.

Algorithms

a learned set of rules that always leads to the correct solution of a problem.

Analogy

involve finding similarities between two or more issues and using these similarities for reasoning or problem‐solving.

Cognition

the mental processes that take place inside a person’s mind in terms of thinking, reasoning, perceptions, and so on.

Cognitive universalism

the idea that concepts are universal and influence the development of language.

Collective monologue

a form of egocentric, unsocialized speech in which children talk among themselves without apparently communicating with each other in a meaningful way.

Concepts

are the categories of objects, events, or ideas that have common properties shared by the members of the category.

Confirmation bias

is the tendency to search for evidence that fits one’s beliefs, actions, or thinking while ignoring any evidence to the contrary.

Critical reasoning

a complex type of reasoning that involves thinking reflectively, productively and evaluating evidence.

Decision‐making

is a process of identifying alternative courses of action and choosing the best option.

Deductive reasoning

a type of formal reasoning that involves reasoning from the general to the specific.

Fallacies

are errors in thinking processes that use irrelevant premises to support a conclusion.

Formal (logical) reasoning

is the process of following a set of rigorous procedures to reach valid conclusions.

Formal concepts

the concepts that are defined by specific rules or features and are quite rigid.

Functional fixedness

a barrier to problem‐solving that involves thinking about objects only in terms of their typical use (literally fixed on the function).

Grammar

is the system of rules governing the structure and use of a language.

Heuristic (rule of thumb) method

a problem‐solving method that involves disregarding certain possible solutions to focus solely on the ones that are more likely to succeed.

Incubation

a period whereby the mind subconsciously keeps looking for a solution to a problem without an awareness of an individual.

Inductive reasoning

a type of informal reasoning that involves reasoning from the specific to the general. It consists of drawing conclusions about all members of a category based on observing only some members.