Attention deployment in natural scenes: Higher-order scene statistics rather than semantics modulate the N2pc component.

Which properties of a natural scene affect visual search? We consider the alternative hypotheses that low-level statistics, higher-level statistics, semantics, or layout affect search difficulty in natural scenes. Across three experiments (n = 20 each), we used four different backgrounds that preserve distinct scene properties: (a) natural scenes (all experiments); (b) 1/f noise (pink noise, which preserves only low-level statistics and was used in Experiments 1 and 2); (c) textures that preserve low-level and higher-level statistics but not semantics or layout (Experiments 2 and 3); and (d) inverted (upside-down) scenes that preserve statistics and semantics but not layout (Experiment 2). We included "split scenes" that contained different backgrounds left and right of the midline (Experiment 1, natural/noise; Experiment 3, natural/texture).

Risk Factors and Outcomes of Late Posttraumatic Seizures in Combat-Related Traumatic Brain Injury.

Introduction: Post-traumatic seizures (PTSs) contribute to morbidity after traumatic brain injury (TBI). Early PTS are rare in combat casualties sustaining TBI, but the prevalence of late PTS is poorly described. We sought to define the prevalence and risk factors of late PTS in combat casualties with computed tomography evidence of TBI.

Attention in natural scenes: Affective-motivational factors guide gaze independently of visual salience.

In addition to low-level stimulus characteristics and current goals, our previous experience with stimuli can also guide attentional deployment. It remains unclear, however, if such effects act independently or whether they interact in guiding attention. In the current study, we presented natural scenes including every-day objects that differed in affective-motivational impact.

Competition with and without priority control: linking rivalry to attention through winner-take-all networks with memory.

Competition is ubiquitous in perception. For example, items in the visual field compete for processing resources, and attention controls their priority (biased competition). The inevitable ambiguity in the interpretation of sensory signals yields another form of competition: distinct perceptual interpretations compete for access to awareness.