Sperling’s Iconic Memory Experiment
This example implements the classic partial report procedure developed by George Sperling (1960) to investigate the capacity and duration of iconic memory.
1. Background
Sperling found that when participants were shown a 3x3 grid of letters for a very short time (50ms), they could only recall about 4-5 items in a “Whole Report” condition. However, if they were cued to recall only a specific row immediately after the grid disappeared (“Partial Report”), they could recall almost all items from that row. This suggested that the entire grid was briefly available in a high-capacity but rapidly decaying sensory store (iconic memory).
2. Experimental Task
- Fixation: A central cross appears for 500ms.
- Stimulus: A 3x3 grid of random uppercase consonants is flashed for 50ms.
- Cue:
- In Partial Report trials, a tone sounds immediately after the stimulus offset:
- High Tone (1000 Hz): Recall the Top row.
- Medium Tone (500 Hz): Recall the Middle row.
- Low Tone (250 Hz): Recall the Bottom row.
- In Whole Report trials, no specific row tone is played (or a neutral prompt is given).
- Response: The participant types the letters they remember into a text input box.
3. Implementation Details
- Language: Go (using
goxpyriment framework).
- Graphics: 3x3 grid rendering with
stimuli.TextLine.
- Audio: Procedural sine wave tones generated with
stimuli.Tone.
- Input: User response collection with
stimuli.TextInput.
- Trial Balancing: 10 Whole Report trials and 30 Partial Report trials (10 per row) are shuffled.
4. Controls
- Keyboard: Use the letter keys to type your response and press ENTER to submit.
- ESC: Quit the experiment at any time.
5. How to Run
From the Memory-Iconic-Sperling directory:
go run main.go -d -s [subject_id]
Or from the repository root:
go run examples/Memory-Iconic-Sperling/main.go -d -s [subject_id]
- -d: Developer mode (windowed display).
- -s: Subject ID (for data logging).
References
- Sperling, G. (1960). The information available in brief visual presentations. Psychological Monographs: General and Applied, 74(11), 1-29.