spatial summation: meaning, definition, pronunciation and examples
LowTechnical/Scientific
Quick answer
What does “spatial summation” mean?
A neurophysiological process where the combined effect of multiple stimuli, arriving at different points on a neuron at the same time, triggers an action potential that would not occur from a single stimulus.
Audio
Pronunciation
Definition
Meaning and Definition
A neurophysiological process where the combined effect of multiple stimuli, arriving at different points on a neuron at the same time, triggers an action potential that would not occur from a single stimulus.
In broader terms, it describes the additive effect or cumulative integration of separate inputs occurring in space to produce a total effect greater than any individual component. This concept is sometimes metaphorically extended in other fields (e.g., design, planning) to describe the accumulation of small, spatially distributed elements into a significant whole.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling of related words (e.g., 'neuron' vs. 'neurone') may follow regional conventions, but the compound term itself is invariant.
Connotations
Identical technical connotations in both varieties.
Frequency
Equally low frequency and highly specialized in both dialects.
Grammar
How to Use “spatial summation” in a Sentence
Spatial summation of [inputs/stimuli] results in [an action potential/a response].The neuron exhibited spatial summation.Researchers investigated the role of spatial summation in [a specific neural circuit].Vocabulary
Collocations
Examples
Examples of “spatial summation” in a Sentence
verb
British English
- The inputs from various dendrites must summate spatially to reach threshold.
- The neuron failed to summate the spatially separated EPSPs.
American English
- Signals from different synapses must summate spatially to initiate firing.
- The cell was unable to spatially summate the subthreshold inputs.
adverb
British English
- The potentials added together spatially, not temporally.
- The inputs were integrated summatively in a spatial manner.
American English
- Inputs are combined spatially to trigger a response.
- The neuron processes information summatively across space.
adjective
British English
- The spatial-summation properties of the motoneurone were characterised.
- They observed a clear spatial-summation effect.
American English
- The spatial summation mechanism is critical for synaptic integration.
- They measured the neuron's spatial summation capacity.
Usage
Meaning in Context
Business
Not applicable. Highly improbable in this context.
Academic
Standard term in neuroscience, physiology, and psychology textbooks and research papers.
Everyday
Virtually never used.
Technical
Core concept in neurophysiology and biophysics for describing neuronal integration.
Vocabulary
Synonyms of “spatial summation”
Neutral
Weak
Vocabulary
Antonyms of “spatial summation”
Watch out
Common Mistakes When Using “spatial summation”
- Misspelling as 'special summation'.
- Using it as a verb (e.g., 'The signals spatial summate'). The correct verb form is 'summate' spatially.
- Confusing it with 'temporal summation'. A common error is stating 'spatial summation occurs over time'—this is contradictory; spatial summation is about simultaneous inputs from different locations.
FAQ
Frequently Asked Questions
No. While often discussed regarding excitatory postsynaptic potentials (EPSPs), inhibitory postsynaptic potentials (IPSPs) can also summate spatially to prevent a neuron from reaching its firing threshold.
Yes. In real neurons, these processes are not mutually exclusive. Multiple inputs can arrive from different locations (spatial) and over a short period (temporal), and their combined effects are integrated to determine whether the neuron fires.
Spatial summation primarily occurs at the axon hillock (the trigger zone), where voltages from all the spatially distributed synaptic inputs on the dendrites and cell body converge and are summed.
Extremely rarely. It is a highly specialised neurophysiological term. On occasion, it might be used metaphorically in fields like sensory design or architecture to describe the cumulative effect of distributed elements, but this is not standard.
A neurophysiological process where the combined effect of multiple stimuli, arriving at different points on a neuron at the same time, triggers an action potential that would not occur from a single stimulus.
Spatial summation is usually technical/scientific in register.
Spatial summation: in British English it is pronounced /ˌspeɪ.ʃəl sʌˈmeɪ.ʃən/, and in American English it is pronounced /ˌspeɪ.ʃəl səˈmeɪ.ʃən/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think of 'spatial' as SPACE. Multiple mail carriers (stimuli) arriving at DIFFERENT DOORS (spatial locations) of a post office (neuron) at the SAME TIME. Only if they deliver enough letters (combined input) together will the post office decide to send out a truck (fire an action potential).
Conceptual Metaphor
A voting system where many people (stimuli) in different districts (spatial locations) vote at the same time; a proposition passes only if the total 'yes' votes from all districts exceed a threshold.
Practice
Quiz
What is the primary factor that distinguishes spatial summation from temporal summation?