Topic
Perceptual decision research, explained
9 open-access perceptual decision studies, each with a flashcard deck and a quiz.
- Can brain scans predict if a person is feeling pain?
By analyzing patterns across multiple brain regions simultaneously, researchers could predict whether a person perceived a subtle stimulus as painful, even when the stimulus intensity remained constant.
- How does the brain switch between different ways of seeing?
Spontaneous flips in how we perceive ambiguous images are driven by bidirectional communication between visual and parietal brain regions, and the strength of bottom-up signals determines how long each view lasts.
- How the Brain Tracks Choices When Things Are Unclear
A brain wave signal tracks how uncertain we are during decisions, regardless of what we are looking at.
- Tracking Decision Making in the Brain Using fMRI
While many brain areas collect sensory evidence, only a specific network in the frontal cortex marks the exact moment a decision is made.
- Do two frontal regions play different roles in perceptual decisions?
Zapping the frontal eye field produced brain responses that changed with how close the person was to answering, while zapping ventral prefrontal cortex produced responses that changed with whether the answer would be right.
- Does zapping visual cortex at the right moment slow decisions?
Briefly disrupting the lateral occipital cortex 400 ms after a hard-to-see image appeared slowed people's face-or-car decisions, just as a prior brain-network model predicted.
- Why does seeing a small thing make the next one look 'large'?
The tendency to classify an item as the opposite of the previous one seems to come from the brain shifting its internal small/large boundary, not from the eye's sensory adaptation.
- How does the brain trade speed for accuracy when deciding?
When people are told to hurry, brain signals of evidence build-up reach the same peak as when they are careful, suggesting the brain turns up overall gain rather than simply lowering its decision threshold.
- How does the brain track fast-changing evidence during a decision?
Each new piece of visual evidence travelled through the brain in three stages, from visual to parietal to motor areas, with the posterior cingulate cortex involved throughout.