Child & Family Center, University of Oregon, Eugene, OR 97401, USA.
Behav Brain Res. 2010 Dec 20;215(1):45-57. doi: 10.1016/j.bbr.2010.06.023. Epub 2010 Jun 25.
Control of attention is a key mechanism underlying behavior regulation. In this study we detail the aspects of attention that covary with the chronic use of cannabis throughout adolescence. We compared performance and brain activation differences in tasks involving attention between young adults with a history of chronic cannabis use during adolescence and matched non-user control subjects. Two tasks were used to activate attention networks: the Attention Network Task (ANT) and the use generation task. In the ANT, chronic users (N=14) differed from controls (N=14) in showing poorer performance (longer reaction time and more errors) on tasks requiring processing of incongruent stimuli reflecting the executive attention network, but not in networks related to alerting or orienting components of attention. Functional MRI of brain activity showed stronger activation within the right prefrontal cortex in chronic users compared to the control group specifically on ANT trials requiring executive attention. The use generation task also revealed significantly stronger activation of the same right prefrontal area in users compared to controls. These results suggest that chronic cannabis users have less efficient executive attention in conflict resolution tasks, demanding more activation in the right prefrontal areas to resolve conflict.
注意控制是行为调节的关键机制。在这项研究中，我们详细描述了注意力的各个方面，这些方面与青少年时期长期使用大麻有关。我们比较了有青少年时期慢性大麻使用史的成年患者和匹配的非使用者对照组在涉及注意力的任务中的表现和大脑激活差异。使用了两个任务来激活注意力网络：注意网络任务（ANT）和使用生成任务。在 ANT 中，慢性使用者（N=14）与对照组（N=14）在处理反映执行注意力网络的不一致刺激的任务上表现出较差的表现（反应时间更长，错误更多），而在与警觉或定向注意力网络相关的任务上则没有差异。大脑活动的功能磁共振成像显示，在需要执行注意力的 ANT 试验中，慢性使用者的右侧前额叶皮层的激活强度明显高于对照组。使用生成任务也显示使用者的同一右侧前额叶区域的激活明显强于对照组。这些结果表明，慢性大麻使用者在解决冲突的任务中表现出较低的执行注意力效率，需要更多的右侧前额叶区域的激活来解决冲突。
