Sensation, Thresholds, and Psychophysics (6A) Practice Test

In an absolute threshold study relevant to tactile feedback in prosthetics, participants received brief electrical stimulation on the forearm at varying current levels and reported “felt” or “not felt.” The threshold was defined as the current detected on 50% of trials. Which design change would most directly improve confidence that the measured value reflects sensory threshold rather than predictable responding?

A signal detection task is used to study vigilance in air-traffic communication. Controllers listen to radio chatter (noise) and occasionally a critical call sign (signal) appears. During a high-workload block, controllers show fewer hits and more misses, with no clear change in false alarms. Which interpretation is most consistent with signal detection theory?