Thu, 21 Aug 2008 11:00:21 BST CiteULike: oamgs Morris http://www.citeulike.org/user/oamg/author/Morris CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/oamg/article/1479628 <i>Neuropsychologia (13 June 2007)</i><br /><br />We investigated brain activity evoked by faces which were not consciously perceived by subjects. Subdural electrophysiological recordings and functional neuroimaging studies have each demonstrated face-specific processing in the fusiform gyrus (FFG) of humans. Using pattern masks, a stimulus can be presented but not consciously perceived, and thus can be used to assay obligatory or automatic processes. Here, using event-related functional magnetic resonance imaging and pattern masking, we observed that masked faces but not masked objects activated the right FFG. Other regions activated by consciously perceived unmasked faces were not activated when faces were masked. These data provide strong evidence for an automatic face-processing region in the right FFG. Face processing without awareness in the right fusiform gyrus. James P Morris Kevin A Pelphrey Gregory McCarthy doi:10.1016/j.neuropsychologia.2007.05.020 Neuropsychologia (13 June 2007) 2007-07-25T00:38:25-00:00 2007 Neuropsychologia 0028-3932 face fusiform_gyrus http://www.citeulike.org/user/oamg/article/1224444 <i>J Cogn Neurosci, Vol. 16, No. 10. (December 2004), pp. 1706-1716.</i><br /><br />An explication of the neural substrates for social perception is an important component in the emerging field of social cognitive neuroscience and is relevant to the field of cognitive neuroscience as a whole. Prior studies from our laboratory have demonstrated that passive viewing of biological motion (Pelphrey, Mitchell, et al., 2003; Puce et al., 1998) activates the posterior superior temporal sulcus (STS ) region. Furthermore, recent evidence has shown that the perceived context of observed gaze shifts (Pelphrey, Singerman, et al., 2003; Pelphrey et al., 2004) modulates STS activity. Here, using event-related functional magnetic resonance imaging at 4 T, we investigated brain activity in response to passive viewing of goal- and nongoal-directed reaching-to-grasp movements. Participants viewed an animated character making reaching-to-grasp movements either toward (correct) or away (incorrect) from a blinking dial. Both conditions evoked significant posterior STS activity that was strongly right lateralized. By examining the time course of the blood oxygenation level-dependent response from areas of activation, we observed a functional dissociation. Incorrect trials evoked significantly greater activity in the STS than did correct trials, while an area posterior and inferior to the STS (likely corresponding to the MT/ V5 complex) responded equally to correct and incorrect movements. Parietal cortical regions, including the superior parietal lobule and the anterior intraparietal sulcus, also responded equally to correct and incorrect movements, but showed evidence for differential responding based on the hand and arm (left or right) of the animated character used to make the reaching-to-grasp movement. The results of this study further suggest that a region of the right posterior STS is involved in analyzing the intentions of other people's actions and that activity in this region is sensitive to the context of observed biological motions. Grasping the intentions of others: the perceived intentionality of an action influences activity in the superior temporal sulcus during social perception. KA Pelphrey JP Morris G McCarthy doi:10.1162/0898929042947900 J Cogn Neurosci, Vol. 16, No. 10. (December 2004), pp. 1706-1716. 2007-04-13T17:43:18-00:00 2004 J Cogn Neurosci 0898-929X 16 10 1706 1716 biological_motion cause_and_effect intention social_perception superior_temporal_sulcus http://www.citeulike.org/user/oamg/article/215765 <i>Neuron, Vol. 43, No. 1. (8 July 2004), pp. 133-143.</i><br /><br />Midbrain dopamine and striatal tonically active neurons (TANs, presumed acetylcholine interneurons) signal behavioral significance of environmental events. Since striatal dopamine and acetylcholine affect plasticity of cortico-striatal transmission and are both crucial to learning, they may serve as teachers in the basal ganglia circuits. We recorded from both neuronal populations in monkeys performing a probabilistic instrumental conditioning task. Both neuronal types respond robustly to reward-related events. Although different events yielded responses with different latencies, the responses of the two populations coincided, indicating integration at the target level. Yet, while the dopamine neurons' response reflects mismatch between expectation and outcome in the positive domain, the TANs are invariant to reward predictability. Finally, TAN pairs are synchronized, compared to a minority of dopamine neuron pairs. We conclude that the striatal cholinergic and dopaminergic systems carry distinct messages by different means, which can be integrated differently to shape the basal ganglia responses to reward-related events. Coincident but distinct messages of midbrain dopamine and striatal tonically active neurons. G Morris D Arkadir A Nevet E Vaadia H Bergman doi:10.1016/j.neuron.2004.06.012 Neuron, Vol. 43, No. 1. (8 July 2004), pp. 133-143. 2005-06-01T15:22:14-00:00 2004 Neuron 0896-6273 43 1 133 143 counterfactual_learning dopamine substantia_nigra_pars_compacta