Apparatus for Brief Visual Stimuli Presentation

The question asks to identify the apparatus used for presenting visual stimuli for very short durations.

Analyzing the Options

• Visual Cliff: This apparatus is designed to test depth perception, particularly in infants and young animals. It does not primarily serve to present stimuli for brief durations.
• Tachistoscope: This device is specifically engineered to display visual stimuli (like images, words, or patterns) for precisely controlled, very brief exposure times, often measured in milliseconds. This matches the question's requirement.
• EEG Apparatus: Electroencephalography (EEG) equipment measures and records brain wave activity. It is unrelated to displaying visual stimuli.
• Trapezoidal Window: This is often used in experiments exploring perceptual constancy, such as shape constancy, where the shape of an object is viewed through a trapezoidal window to alter the perceived shape. It is not primarily for brief stimulus presentation.

Conclusion

Based on the function described, the Tachistoscope is the correct apparatus for showing visual stimuli for very brief durations.