5-STAGE NEURAL ARC

How a Visual Impulse Travels Through Your Brain

From photons striking retinal photoreceptors to motor end-plate acetylcholine release.

1. Retinal Phototransduction

~20–40 milliseconds

Light photons hit rod and cone photoreceptors in the retina, triggering a biochemical cascade (rhodopsin bleaching) that generates electrical action potentials in ganglion cells.

↓ OPTIC NERVE TRANSMISSION

2. Optic Tract & Lateral Geniculate Nucleus

~15–25 milliseconds

Action potentials travel down optic nerve fibers, cross the optic chiasm, and synapse in the thalamus (LGN) before relaying directly to the primary visual cortex (V1).

↓ PRIMARY VISUAL CORTEX PROCESSING

3. Cortical Processing & Cognitive Recognition

~60–100 milliseconds

Visual cortex V1-V4 decodes color, motion, and edge signals. The frontal cortex evaluates intent and dispatches motor plans via the supplementary motor area (SMA).

↓ EFFERENT MOTOR COMMAND

4. Spinal Cord Conduction

~15–25 milliseconds

Upper motor neurons send electrical impulses down the corticospinal tract, descending through the cervical spine to synapse with alpha motor neurons.

↓ PERIPHERAL NERVE PULSE

5. Neuromuscular Junction & Motor Action

~10–20 milliseconds

Acetylcholine is released at the motor end-plate of finger flexor muscles, initiating sarcoplasmic reticulum calcium release and muscle contraction.

MODALITY LATENCY GAP

Visual vs. Auditory Reaction Time Speed

Why auditory impulses bypass cortical visual processing and react 40–50ms faster.

Visual Processing Pathway

Photons → Retina → Thalamus → Visual Cortex → Motor Cortex

~190 – 240 ms

Photoreceptor transduction requires complex G-protein enzymatic amplification, adding 20–40ms of retinal delay before neural signals reach the brain.

NEURAL CIRCUIT

Retina → Optic Chiasm → LGN (Thalamus) → V1 Visual Cortex → SMA Motor Cortex → Corticospinal Tract

Auditory Processing Pathway

Sound Wave → Cochlea → Auditory Nerve → Brainstem → Motor Response

~140 – 170 ms

Cochlear hair cell mechanical deflection converts acoustic pressure directly into electrical signals, reaching the brainstem in just 8–10ms.

NEURAL CIRCUIT

Cochlea → Cochlear Nucleus → Superior Olive → Inferior Colliculus → MGN → Primary Auditory Cortex → Motor Cortex

SPATIAL REACTION MATHEMATICS

Fitts's Law & Spatial Target Latency

Predicting Human Spatial Reaction Speed

In target-tracking tests (like our Aim Reaction Test), movement time (MT) is a logarithmic function of distance (D) and target width (W):

MT = a + b · log₂ (2D / W)

Higher Index of Difficulty (ID) increases motor planning overhead in the motor cortex, explaining why smaller targets slow spatial reaction time.

Test Your Spatial Aim Speed →

ACADEMIC CITATIONS

Peer-Reviewed Neurobiology Research

Key scientific literature establishing human reaction time benchmarks and neural mechanisms.

Human Visual Reaction Time Limits

Luce, R. D. (1986). Response Times: Their Role in Inferring Elementary Mental Organization. Oxford University Press.

Biological Reaction Floor

Auditory vs Visual Reaction Times

Jain, A. et al. (2015). Comparative study of visual and auditory reaction times in young adults. International Journal of Applied Research.

Modality Speed Differences

Circadian & Sleep Effects on Reflexes

Dinges, D. F. et al. (1997). Cumulative sleep sleepiness and performance deficits during sleep restriction. Sleep Research.

Sleep Deprivation Latency

Esports Athlete Neural Speed

Blickensderfer, E. et al. (2021). Perceptual-Motor Reflexes in Elite Competitive Esports Players. Journal of Electronic Gaming & Esports.

Pro Gamer Benchmarks

Hardware Polling Rate & Input Lag

Kaaresoj, T. et al. (2014). Touchscreen Latency and Perceived Quality in Interactive Devices. ACM Transactions on Computer-Human Interaction.

Display & Input Latency

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