Tags

Type your tag names separated by a space and hit enter

Spatial working memory in heavy cannabis users: a functional magnetic resonance imaging study.
Psychopharmacology (Berl). 2004 Nov; 176(3-4):239-47.P

Abstract

RATIONALE

Many neuropsychological studies have documented deficits in working memory among recent heavy cannabis users. However, little is known about the effects of cannabis on brain activity.

OBJECTIVE

We assessed brain function among recent heavy cannabis users while they performed a working memory task.

METHODS

Functional magnetic resonance imaging was used to examine brain activity in 12 long-term heavy cannabis users, 6-36 h after last use, and in 10 control subjects while they performed a spatial working memory task. Regional brain activation was analyzed and compared using statistical parametric mapping techniques.

RESULTS

Compared with controls, cannabis users exhibited increased activation of brain regions typically used for spatial working memory tasks (such as prefrontal cortex and anterior cingulate). Users also recruited additional regions not typically used for spatial working memory (such as regions in the basal ganglia). These findings remained essentially unchanged when re-analyzed using subjects' ages as a covariate. Brain activation showed little or no significant correlation with subjects' years of education, verbal IQ, lifetime episodes of cannabis use, or urinary cannabinoid levels at the time of scanning.

CONCLUSIONS

Recent cannabis users displayed greater and more widespread brain activation than normal subjects when attempting to perform a spatial working memory task. This observation suggests that recent cannabis users may experience subtle neurophysiological deficits, and that they compensate for these deficits by "working harder"-calling upon additional brain regions to meet the demands of the task.

Authors+Show Affiliations

Cognitive Neuroimaging Laboratory, Brain Imaging Center, McLean Hospital/Harvard Medical School, 115 Mill St., Belmont, MA 02478, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Trial
Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15205869

Citation

Kanayama, Gen, et al. "Spatial Working Memory in Heavy Cannabis Users: a Functional Magnetic Resonance Imaging Study." Psychopharmacology, vol. 176, no. 3-4, 2004, pp. 239-47.
Kanayama G, Rogowska J, Pope HG, et al. Spatial working memory in heavy cannabis users: a functional magnetic resonance imaging study. Psychopharmacology (Berl). 2004;176(3-4):239-47.
Kanayama, G., Rogowska, J., Pope, H. G., Gruber, S. A., & Yurgelun-Todd, D. A. (2004). Spatial working memory in heavy cannabis users: a functional magnetic resonance imaging study. Psychopharmacology, 176(3-4), 239-47.
Kanayama G, et al. Spatial Working Memory in Heavy Cannabis Users: a Functional Magnetic Resonance Imaging Study. Psychopharmacology (Berl). 2004;176(3-4):239-47. PubMed PMID: 15205869.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Spatial working memory in heavy cannabis users: a functional magnetic resonance imaging study. AU - Kanayama,Gen, AU - Rogowska,Jadwiga, AU - Pope,Harrison G, AU - Gruber,Staci A, AU - Yurgelun-Todd,Deborah A, Y1 - 2004/06/16/ PY - 2003/03/26/received PY - 2004/03/19/accepted PY - 2004/6/19/pubmed PY - 2005/3/2/medline PY - 2004/6/19/entrez SP - 239 EP - 47 JF - Psychopharmacology JO - Psychopharmacology (Berl.) VL - 176 IS - 3-4 N2 - RATIONALE: Many neuropsychological studies have documented deficits in working memory among recent heavy cannabis users. However, little is known about the effects of cannabis on brain activity. OBJECTIVE: We assessed brain function among recent heavy cannabis users while they performed a working memory task. METHODS: Functional magnetic resonance imaging was used to examine brain activity in 12 long-term heavy cannabis users, 6-36 h after last use, and in 10 control subjects while they performed a spatial working memory task. Regional brain activation was analyzed and compared using statistical parametric mapping techniques. RESULTS: Compared with controls, cannabis users exhibited increased activation of brain regions typically used for spatial working memory tasks (such as prefrontal cortex and anterior cingulate). Users also recruited additional regions not typically used for spatial working memory (such as regions in the basal ganglia). These findings remained essentially unchanged when re-analyzed using subjects' ages as a covariate. Brain activation showed little or no significant correlation with subjects' years of education, verbal IQ, lifetime episodes of cannabis use, or urinary cannabinoid levels at the time of scanning. CONCLUSIONS: Recent cannabis users displayed greater and more widespread brain activation than normal subjects when attempting to perform a spatial working memory task. This observation suggests that recent cannabis users may experience subtle neurophysiological deficits, and that they compensate for these deficits by "working harder"-calling upon additional brain regions to meet the demands of the task. SN - 0033-3158 UR - https://www.unboundmedicine.com/medline/citation/15205869/Spatial_working_memory_in_heavy_cannabis_users:_a_functional_magnetic_resonance_imaging_study_ L2 - https://dx.doi.org/10.1007/s00213-004-1885-8 DB - PRIME DP - Unbound Medicine ER -