PT - JOURNAL ARTICLE AU - Sirawaj Itthipuripat AU - Javier O. Garcia AU - Nuttida Rungratsameetaweemana AU - Thomas C. Sprague AU - John T. Serences TI - Changing the Spatial Scope of Attention Alters Patterns of Neural Gain in Human Cortex AID - 10.1523/JNEUROSCI.3943-13.2014 DP - 2014 Jan 01 TA - The Journal of Neuroscience PG - 112--123 VI - 34 IP - 1 4099 - http://www.jneurosci.org/content/34/1/112.short 4100 - http://www.jneurosci.org/content/34/1/112.full SO - J. Neurosci.2014 Jan 01; 34 AB - Over the last several decades, spatial attention has been shown to influence the activity of neurons in visual cortex in various ways. These conflicting observations have inspired competing models to account for the influence of attention on perception and behavior. Here, we used electroencephalography (EEG) to assess steady-state visual evoked potentials (SSVEP) in human subjects and showed that highly focused spatial attention primarily enhanced neural responses to high-contrast stimuli (response gain), whereas distributed attention primarily enhanced responses to medium-contrast stimuli (contrast gain). Together, these data suggest that different patterns of neural modulation do not reflect fundamentally different neural mechanisms, but instead reflect changes in the spatial extent of attention.