View larger version: In this window In a new window Download as PowerPoint Slide Figure 1. It is interesting to note that, although expected stimuli have previously been reported to result in an attenuated neural response (e.g., Summerfield et al. 2008; Kok, Jehee, et al. 2012; Summerfield CrossRefMedlineWeb of ScienceGoogle Scholar ↵ Oostenveld R, Fries P, Maris E, Schoffelen J-M . 2011. A feature-integration theory of attention. http://ecoflashapps.com/cannot-locate/cannot-locate-field-definition-for-field-lotus-notes.html
Document information More support for: IBM Notes Templates Software version: 8.5.3 Operating system(s): Linux, OS X, Windows, iOS Software edition: All Editions Reference #: 1627550 Modified date: 18 November 2014 Site In this sense, some of the neural findings we report likely correspond to attentional processes. J Neurosci. 20:RC63. Resolving the problem NOTE: This is fixed in the 9.0 release.
CrossRefMedlineGoogle Scholar ↵ Lleras A, Rensink RA, Enns JT . 2005. Abstract/FREE Full Text ↵ Händel BF, Haarmeier T, Jensen O . 2011. Please try the request again.
Numbers correspond to the affiliation list which can be exposed by using the show more link. Second, the neural implementation of the biasing of visual search by prior information is unclear. This particular time window was chosen such that it did not include transient activity related to the processing of the previous display (which had its onset at −1.4 s). In other words, activity in these regions during processing of display n−1 was predictive of whether subjects responded fast or slow after stimulus display n.
Newbury Park, CA, USA: Sage Publications. Exploratory Whole-Brain Analysis For the analysis of our MEG results, we first examined specific and well-established neurophysiological signals: Lateralization of visuospatial alpha-band power (in relation to target location) and somatomotor beta-band A possible alternative explanation of the rapid resumption phenomenon could be that subjects have actually already identified the target on display n−1, yet consciously decide to wait until the next display The presence of anticipatory alpha modulation indicates an active preparation of the subjects' visual system for the upcoming target.
Provide UserB with the delegate access below to UserA's mail file. -> Read, create, edit and delete to -> Mail, Calendar, To Do and Contacts 3. Visual search has no memory. This modulation was only present for subsequent “fast” trials, that is, in trials where a perceptual prediction was generated. Each brain volume was divided into a grid of points spaced 8 mm apart, and warped to the template Montreal Neurological Institute (MNI) brain.
We found that for the later epochs, the sum of 2 Gaussians fitted the data significantly better than the single Gaussian (Wald F7,15 = 4.24, P = 0.045), while this was http://ecoflashapps.com/cannot-locate/lotus-notes-cannot-locate-field-definition.html CrossRefMedlineWeb of ScienceGoogle Scholar ↵ Kok P, Jehee JFM, de Lange FP . 2012. Effectively, this beamformer is sensitive to all frequencies—as opposed to the above analyses that focused on induced responses in the alpha and beta bands. Finally, neural activation in medial superior frontal cortex and right temporo-parietal junction (TPJ) appears to be involved in the generation of these sensory predictions that bias subsequent visual search.
First, what is the nature of the prediction? Crucially, this prestimulus beta-band modulation was markedly different for fast trials, compared with slow trials. Generated Tue, 08 Nov 2016 00:15:34 GMT by s_mf18 (squid/3.5.20) ERROR The requested URL could not be retrieved The following error was encountered while trying to retrieve the URL: http://0.0.0.9/ Connection Check This Out Subsequently, computed power values were averaged over grid points and orientations to get a single estimate per source cluster.
J Cogn Neurosci. 23:2494–2502. The frontal eye fields (FEFs) form the frontal node in the dorsal attentional network. Nat Rev Neurosci. 15:745–756.
CrossRefMedlineWeb of ScienceGoogle Scholar ↵ Horowitz TS, Wolfe JM . 1998. On other trials, a subthreshold signal reflecting the target's location and identity is perceived after the first (or a subsequent) display (the “activate” phase). The perceptual prediction contained information about the spatial location of the target. During the entire experiment, we recorded brain activity using MEG.
Nat Rev Neurosci. 3:201–215. It has previously been shown that lateralization of beta-band (16–30 Hz) oscillatory activity observed over motor areas is a sensitive marker of preparation of either the left or the right response The results of this control analysis did not differ qualitatively from those reported here, thus ruling out the duration of exposure to the stimulus array (over and above the effect of this contact form Long-term memory prepares neural activity for perception.
CrossRefMedlineGoogle Scholar ↵ Summerfield C, Trittschuh EH, Monti JM, Mesulam M-M, Egner T . 2008. Control of goal-directed and stimulus-driven attention in the brain. Looking for jobs... Plotted activity is masked with cluster-corrected P < 0.05.
CrossRefMedlineWeb of ScienceGoogle Scholar ↵ Nolte G . 2003. Stimuli and Experimental Design The experimental stimuli used consisted of a search display with 15 distracters (L-shape, rotated at random multiples of 90°) and 1 target (normal or inverted T-shape), which Nat Neurosci. 11:1004–1006.