Stim Files __exclusive__ Jun 2026

: They contain columns of numbers representing the onset times (in seconds) of different stimuli (e.g., "Image A appeared at 10.5s").

In a standard "task-based" fMRI experiment, the brain is constantly active. To find the specific "signal" related to a task, researchers must "model" the expected brain response. stim files

In scientific settings, systems like presentation software or neural stimulators generate .stim files. These files dictate the timing, intensity, and duration of a physical stimulus. : They contain columns of numbers representing the

Ensure they are properly trimmed to match the fMRI data. TTL_pulse ). |

| Limitation | Explanation | |------------|-------------| | | A typo in onset_ms (e.g., “2000x”) may crash the experiment or cause silent timing errors. | | Large file overhead | For thousands of trials with many columns, parsing overhead can increase latency (rarely critical for psychophysics, but noticeable in real‑time loops). | | Limited data types | Binary large objects (e.g., waveforms, movie frames) must be stored externally; the stim file only contains paths. | | No hierarchical structure | Block‑nested designs (e.g., run > block > trial) require redundant columns or multiple files. | | Timing precision | Onset/offset columns typically assume software timing; hardware‑synchronized events may need additional descriptors (e.g., TTL_pulse ). |