Hippocampal dampening during a relational memory task.
The hippocampus (HPC) has an essential role in relational memory. One task used to test relational memory is the transverse patterning (TP) problem (A+ B-, B+ C-, and C+ A-), which is sensitive to HPC damage across species. Using functional magnetic resonance imaging in humans, the authors observed activation maps and time course data indicating that the HPC is involved in this task, but it is paradoxically less active during the hippocampal-dependent relational memory phase relative to both a hippocampal-independent control memory phase and to a fixation control phase. This suggests that traditional assumptions suggesting that brain regions critical for a task must produce an increased blood oxygen level-dependent response during performance of that task are probably inaccurate and alternative explanations should be entertained.
Astur
Robert S
RS
Department of Diagnostic Radiology, Yale University, New Haven, CT 06106, USA. Robert.astur@yale.edu
Constable
R Todd
RT
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001245:Association Learning / Q000502:physiology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D002755:Choice Behavior / Q000502:physiology; D007839:Functional Laterality; D006624:Hippocampus / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008568:Memory / Q000502:physiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000378:metabolism; D011930:Reaction Time / Q000502:physiology; D013997:Time Factors
D010100:Oxygen