Bottom-up processing

Features of current stimulation help drive what is detected and recognized.

Definition

Bottom-up processing is processing driven by incoming sensory information rather than primarily by existing expectations or knowledge.

How to understand it

The phrase identifies a direction of influence: characteristics of the current input contribute to perception. An edge, a sudden onset, or a changing sound can provide information that a person must interpret. It does not require the person to be wholly unfamiliar with the world, and it does not imply that the brain waits for a complete raw picture before doing anything else.

Bottom-up and top-down are most useful as comparisons within an account. Ask which part of a response changes when the input changes and which part changes when instructions or expectations change. Attention is relevant to both: a striking event may draw attention, while a goal can guide what is selected. Most everyday examples combine these influences rather than cleanly separating them.

Evidence: (Spielman et al., 2020); (Noba: Sensation and Perception, n.d.); (Attention, n.d.)

Inspecting a new symbol

Teaching scenario

An instructor invents a symbol with three straight strokes and one curve, then shows it without a label. Students describe visible features before suggesting a meaning. Later the instructor supplies a context and asks them to reconsider. The first activity foregrounds information available in the display; the second adds a deliberate contextual cue. Neither activity removes all prior experience from the students’ processing.

Constructed for learning. This scenario is not a report of an empirical finding or a diagnosis.

Common confusion: Top-down processing

Bottom-up emphasizes influence from current input; top-down emphasizes influence from knowledge, goals, and expectations.

Compare bottom-up and top-down processing

Evidence: (Spielman et al., 2020); (Noba: Sensation and Perception, n.d.); (Attention, n.d.)

Limits of the concept

Bottom-up does not mean perception occurs without any prior learning.
A vivid demonstration alone cannot quantify the contribution of each processing direction.

Evidence: (Spielman et al., 2020); (Noba: Sensation and Perception, n.d.); (Attention, n.d.)

Textbook connection

Direct coveragePsychology 2e: 5.1 Sensation versus Perception

Direct definition of stimulus-driven processing.

Supplementary concepts may extend beyond this section. The source notes below identify the evidence for those details.

Related concepts

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Sources and inspection notes

Checked October 21, 2026. An inspection date is not a source publication date. Definitions and scenarios on this page are original teaching explanations.

Attention. (n.d.). https://nobaproject.com/modules/attentionSelection, limited capacity, and interaction between goals and salient input.
Opened and inspected on 21 October 2026. Academic teaching synthesis; not a primary experiment.
Noba: Sensation and perception. (n.d.). https://nobaproject.com/modules/sensation-and-perceptionPsychophysics, probabilistic thresholds, and stimulus-driven versus knowledge-guided processing.
Opened and inspected on 21 October 2026. Academic teaching synthesis; not a primary experiment.
Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020). Psychology 2e. OpenStax. https://openstax.org/books/psychology-2e/pages/5-1-sensation-versus-perceptionCourse textbook section
Opened actual subsection on 21 October 2026; title and URL verified. Course textbook, not independent primary evidence.