Yes/no recognition, forced-choice recognition, and the human hippocampus

Area of Science:

• Cognitive Neuroscience
• Neuropsychology

Background:

• Previous research indicated hippocampal lesions disproportionately impair yes/no recognition over forced-choice recognition for similar items.
• This was interpreted as evidence that yes/no tests rely more on recollection, a process selectively supported by the hippocampus.

Purpose of the Study:

• To re-evaluate the impact of hippocampal lesions on yes/no versus forced-choice recognition.
• To determine if the format of recognition testing, rather than recollection dependence, explains differential impairment.

Main Methods:

• Five patients with hippocampal lesions and 15 controls completed recognition memory tests using identical stimulus materials.
• Participants studied object images and were tested using either a 12-item forced-choice or a 60-item yes/no format.

Main Results:

• Patients showed impairment on both test formats but performed worse on the yes/no test initially.
• When the yes/no test was limited to 24 items (matching the forced-choice scope), patient performance was identical across both formats.
• Patient scores declined over the course of the longer yes/no test, suggesting fatigue or interference effects.

Conclusions:

• The hippocampus does not selectively support recollection over other recognition processes.
• Differences in performance between yes/no and forced-choice tests are likely attributable to test length, study-test delay, and interference, not inherent differences in cognitive demands.
• Hippocampal lesions impair both recognition formats to a similar extent.