A typical scene contains many different objects that compete for neural representation due to the limited processing capacity of the visual system. At the neural level, competition among multiple stimuli is evidenced by the mutual suppression of their visually evoked responses and occurs most strongly at the level of the receptive field. The competition among multiple objects can be biased by both bottom-up sensory-driven mechanisms and top-down influences, such as selective attention. Functional brain imaging studies reveal that biasing signals due to selective attention can modulate neural activity in visual cortex not only in the presence but also in the absence of visual stimulation. Although the competition among stimuli for representation is ultimately resolved within visual cortex, the source of top-down biasing signals likely derives from a distributed network of areas in frontal and parietal cortex. This biased competition model of attention suggests that once attentional resources are depleted, no further processing is possible. Yet, existing data suggest that emotional stimuli activate brain regions """"""""automatically,"""""""" largely immune from attentional control. We tested the alternative possibility, namely, that the neural processing of stimuli with emotional content is not automatic and instead requires some degree of attention. Our results revealed that, contrary to the prevailing view, all brain regions responding differentially to emotional faces, including the amygdala, did so only when sufficient attentional resources were available to process the faces. Thus, similar to the processing of other stimulus categories, the processing of facial expression is under top-down control.
| Tootell, Roger B H; Devaney, Kathryn J; Young, Jeremy C et al. (2008) fMRI mapping of a morphed continuum of 3D shapes within inferior temporal cortex. Proc Natl Acad Sci U S A 105:3605-9 |
| Hadj-Bouziane, Fadila; Bell, Andrew H; Knusten, Tamara A et al. (2008) Perception of emotional expressions is independent of face selectivity in monkey inferior temporal cortex. Proc Natl Acad Sci U S A 105:5591-6 |
| Heekeren, Hauke R; Marrett, Sean; Ungerleider, Leslie G (2008) The neural systems that mediate human perceptual decision making. Nat Rev Neurosci 9:467-79 |
| Ungerleider, Leslie G; Galkin, Thelma W; Desimone, Robert et al. (2008) Cortical connections of area V4 in the macaque. Cereb Cortex 18:477-99 |
| Mukai, Ikuko; Kim, David; Fukunaga, Masaki et al. (2007) Activations in visual and attention-related areas predict and correlate with the degree of perceptual learning. J Neurosci 27:11401-11 |
| Siman-Tov, Tali; Mendelsohn, Avi; Schonberg, Tom et al. (2007) Bihemispheric leftward bias in a visuospatial attention-related network. J Neurosci 27:11271-8 |
| Rossi, Andrew F; Bichot, Narcisse P; Desimone, Robert et al. (2007) Top down attentional deficits in macaques with lesions of lateral prefrontal cortex. J Neurosci 27:11306-14 |
| Pessoa, Luiz; Japee, Shruti; Sturman, David et al. (2006) Target visibility and visual awareness modulate amygdala responses to fearful faces. Cereb Cortex 16:366-75 |
| Heekeren, H R; Marrett, S; Ruff, D A et al. (2006) Involvement of human left dorsolateral prefrontal cortex in perceptual decision making is independent of response modality. Proc Natl Acad Sci U S A 103:10023-8 |
| Pessoa, Luiz; Japee, Shruti; Ungerleider, Leslie G (2005) Visual awareness and the detection of fearful faces. Emotion 5:243-7 |
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