Abstract
Finding a reliable and objective measure of individual differences in mental imagery across sensory modalities is difficult, with measures relying on self-report scales or focusing on one modality alone. Based on the idea that mental imagery involves multimodal sensorimotor simulations, a mental comparison task (MCT) was developed across three studies and tested on adults (n = 96, 345, and 448). Analyses examined: (a) the internal consistency of the MCT, (b) whether lexical features of the MCT stimuli (word length and frequency) predicted performance, (c) whether the MCT related to two widely used self-report scales, (d) response latencies and accuracies across the visual, auditory, and tactile modalities, and (e) whether MCT performance was independent of processing speed. The MCT showed evidence of reliability and validity. Responses were fastest and most accurate for the visual modality, followed by the auditory and tactile. However, consistent with the idea that self-report questionnaires index a different aspect of mental imagery, the MCT showed minimal correlations with self-report imagery. Finally, relations between MCT scales remained strong after controlling for processing speed. Findings are discussed in relation to current understanding and measurement of mental imagery.
What This Study Is About
Researchers wanted to find a way to measure the "mind’s eye" without just asking people to rate how vivid their thoughts are. They developed a new test to see if they could objectively measure mental imagery—the ability to "see," "hear," or "feel" things in your mind—by seeing how fast people can compare objects they are only imagining.
How They Studied It
Over 800 adults participated across three different studies. Instead of just filling out a survey, they completed a Mental Comparison Task (MCT).
Imagine someone asks you: *"Which is shinier: a toaster or a spoon?"* To answer, you have to "pull up" a mental image of both and compare them. The researchers tested three different senses:
- Visual: Comparing brightness or shininess.
- Auditory: Comparing how loud things are (like a doorbell vs. a whistle).
- Tactile: Comparing how things feel (like sandpaper vs. a cat’s tongue).
They measured how fast and accurate people were and compared those scores to traditional "self-report" surveys where people rate their own imagination from 1 to 10.
What They Found
The researchers discovered that our brains aren't equally fast at everything. People were fastest and most accurate at comparing mental pictures (visual), followed by sounds, and finally touch.
The most surprising part? How people *rated* their own imagination on surveys didn't really match how they *performed* on the test. It’s like someone saying they are a "10/10" at basketball but then missing every shot during a game. This suggests that "feeling" like you have a vivid imagination is a different skill than actually using those images to solve a problem.
What This Might Mean
This study suggests that mental imagery is "multimodal"—it involves many different parts of the brain working together. It also shows that we need better tools than just surveys to understand how the mind works.
For people with aphantasia (the inability to visualize anything at all), this test is exciting because it focuses on *doing* rather than *seeing*. However, since this study mostly looked at people with "typical" imagery, we can't be certain yet how someone with aphantasia would score. It suggests that even if you don't "see" a picture, your brain might still be processing the information in a different way.
One Interesting Detail
The researchers found that comparing how "scratchy" or "soft" two objects are takes much longer than comparing how "bright" they are. It’s as if our brain’s "computer" takes longer to load a touch-based memory than a visual one!