Human dorsal and ventral auditory streams subserve rehearsal-based and echoic processes during verbal working memory.
To hear a sequence of words and repeat them requires sensory-motor processing and something more-temporary storage. We investigated neural mechanisms of verbal memory by using fMRI and a task designed to tease apart perceptually based ("echoic") memory from phonological-articulatory memory. Sets of two- or three-word pairs were presented bimodally, followed by a cue indicating from which modality (auditory or visual) items were to be retrieved and rehearsed over a delay. Although delay-period activation in the planum temporale (PT) was insensible to the source modality and showed sustained delay-period activity, the superior temporal gyrus (STG) activated more vigorously when the retrieved items had arrived to the auditory modality and showed transient delay-period activity. Functional connectivity analysis revealed two topographically distinct fronto-temporal circuits, with STG co-activating more strongly with ventrolateral prefrontal cortex and PT co-activating more strongly with dorsolateral prefrontal cortex. These argue for separate contributions of ventral and dorsal auditory streams in verbal working memory.
Buchsbaum
Bradley R
BR
National Institute of Mental Health, National Institutes of Health, Intramural Research Program, Department of Health and Human Services, Bethesda, Maryland 20892, USA. buchsbab@intra.nimh.nih.gov
Olsen
Rosanna K
RK
Koch
Paul
P
Berman
Karen Faith
KF
D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008570:Memory, Short-Term / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D011214:Practice, Psychological; D011930:Reaction Time; D013702:Temporal Lobe / Q000502:physiology; D014705:Verbal Behavior / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*