PMID- 15351627
OWN - NLM
STAT- MEDLINE
DCOM- 20041230
LR  - 20220408
IS  - 0028-3932 (Print)
IS  - 0028-3932 (Linking)
VI  - 42
IP  - 13
DP  - 2004
TI  - Shared and distinct neurophysiological components of the digits forward and 
      backward tasks as revealed by functional neuroimaging.
PG  - 1781-7
AB  - The digits forward (DF) and backward (DB) tasks are widely used 
      neuropsychological measures believed to tap overlapping systems of phonological 
      processing and working memory. Studies of focal brain lesions have partially 
      elucidated the brain regions essential for these tasks; however relatively little 
      information exists on the underlying functional neuroanatomy in the intact brain. 
      We therefore examined the shared and separate neural systems of these tasks in 
      two positron emission tomography (PET) experiments. In Experiment 1, eight 
      healthy participants performed verbal DF, DB, and a sensorimotor control task 
      during measurement of regional cerebral blood flow (rCBF). DF and DB each 
      activated frontal, parietal, and cerebellar regions as well as prominently 
      activating medial occipital cortex. To eliminate possible visuospatial confounds, 
      Experiment 2 replicated the first experiment in six additional healthy 
      participants who were blindfolded during the study. No differences in activation 
      were found between the two experimental groups. Combined data from both 
      experiments demonstrate that DF and DB rely upon a largely overlapping functional 
      neural system associated with working memory, most notably right dorsolateral 
      prefrontal cortex (DLPFC) and bilateral inferior parietal lobule (IPL) as well as 
      the anterior cingulate, a region associated with attentional effort. The degree 
      of activation increased linearly with increasing task difficulty in DF. DB 
      additionally recruited bilateral DLPFC, left IPL, and Broca's area. Medial 
      occipital cortex (including higher and lower visual processing areas) was 
      robustly activated in both DF and DB and could not be attributed to visual 
      processing per se, suggesting a possible visual imagery strategy for these 
      aural-verbal tasks.
CI  - Copyright 2004 Elsevier Ltd.
FAU - Gerton, Brooke K
AU  - Gerton BK
AD  - Unit on Integrative Neuroimaging, Clinical Brain Disorders Branch, Intramural 
      Research Program, National Institute of Mental Health, NIH, Bethesda, MD 
      20892-1365, USA.
FAU - Brown, Timothy T
AU  - Brown TT
FAU - Meyer-Lindenberg, Andreas
AU  - Meyer-Lindenberg A
FAU - Kohn, Philip
AU  - Kohn P
FAU - Holt, John L
AU  - Holt JL
FAU - Olsen, Rosanna K
AU  - Olsen RK
FAU - Berman, Karen Faith
AU  - Berman KF
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - England
TA  - Neuropsychologia
JT  - Neuropsychologia
JID - 0020713
SB  - IM
MH  - Adolescent
MH  - Adult
MH  - Attention/physiology
MH  - Brain/anatomy & histology/*blood supply
MH  - Brain Mapping
MH  - Female
MH  - Humans
MH  - Image Processing, Computer-Assisted
MH  - Male
MH  - Memory, Short-Term/*physiology
MH  - Mental Recall/*physiology
MH  - Neuropsychological Tests
MH  - Psychomotor Performance/physiology
MH  - Regional Blood Flow/physiology
MH  - *Tomography, Emission-Computed
MH  - Verbal Learning/physiology
MH  - Visual Perception/physiology
EDAT- 2004/09/08 05:00
MHDA- 2004/12/31 09:00
CRDT- 2004/09/08 05:00
PHST- 2003/08/12 00:00 [received]
PHST- 2004/04/27 00:00 [revised]
PHST- 2004/04/30 00:00 [accepted]
PHST- 2004/09/08 05:00 [pubmed]
PHST- 2004/12/31 09:00 [medline]
PHST- 2004/09/08 05:00 [entrez]
AID - S0028393204000958 [pii]
AID - 10.1016/j.neuropsychologia.2004.04.023 [doi]
PST - ppublish
SO  - Neuropsychologia. 2004;42(13):1781-7. doi: 
      10.1016/j.neuropsychologia.2004.04.023.