PT  - JOURNAL ARTICLE
AU  - C. M. Portas
AU  - G. Rees
AU  - A. M. Howseman
AU  - O. Josephs
AU  - R. Turner
AU  - C. D. Frith
TI  - A Specific Role for the Thalamus in Mediating the Interaction of Attention and Arousal in Humans
AID  - 10.1523/JNEUROSCI.18-21-08979.1998
DP  - 1998 Nov 01
TA  - The Journal of Neuroscience
PG  - 8979--8989
VI  - 18
IP  - 21
4099  - http://www.jneurosci.org/content/18/21/8979.short
4100  - http://www.jneurosci.org/content/18/21/8979.full
SO  - J. Neurosci.1998 Nov 01; 18
AB  - The physiological basis for the interaction of selective attention and arousal is not clearly understood. Here we present evidence in humans that specifically implicates the thalamus in this interaction. We used functional magnetic resonance imaging to measure brain activity during the performance of an attentional task under different levels of arousal. Activity evoked in the ventrolateral thalamus by the attentional task changed as a function of arousal. The highest level of attention-related thalamic activity is seen under conditions of low arousal (secondary to sleep deprivation) compared with high arousal (secondary to caffeine administration). Other brain regions were also active during the attentional task, but these areas did not change their activity as a function of arousal. Control experiments establish that this pattern of changes in thalamic activity cannot be accounted for by nonspecific effects of arousal on cerebral hemodynamics. We conclude that the thalamus is involved in mediating the interaction of attention and arousal in humans.