Templates for rejection: configuring attention to ignore task-irrelevant features

Theories of attention are compatible with the idea that we can bias attention to avoid selecting objects that have known nontarget features. Although this may underlie several existing phenomena, the explicit guidance of attention away from known nontargets has yet to be demonstrated. Here we show that observers can use feature cues (i.e., color) to bias attention away from nontarget items during visual search. These negative cues were used to quickly instantiate a template for rejection that reliably facilitated search across the cue-to-search stimulus onset asynchronies (SOAs), although negative cues were not as potent as cues that guide attention toward target features. Furthermore, by varying the search set size we show a template for rejection is increasingly effective in facilitating search as scene complexity increases. Our findings demonstrate that knowing what not to look for can be used to configure attention to avoid certain features, complimenting what is known about setting attention to select certain target features.     

Liking and identifying emotionally expressive music: age and gender differences

Adults and children 5, 8, and 11 years of age listened to short excerpts of unfamiliar music that sounded happy, scary, peaceful, or sad. Listeners initially rated how much they liked each excerpt. They subsequently made a forced-choice judgment about the emotion that each excerpt conveyed. Identification accuracy was higher for young girls than for young boys, but both genders reached adult-like levels by age 11. High-arousal emotions (happiness and fear) were better identified than low-arousal emotions (peacefulness and sadness), and this advantage was exaggerated among younger children. Whereas children of all ages preferred excerpts depicting high-arousal emotions, adults favored excerpts depicting positive emotions (happiness and peacefulness). A preference for positive emotions over negative emotions was also evident among females of all ages. As identification accuracy improved, liking for positively valenced music increased among 5- and 8-year-olds but decreased among 11-year-olds.     

Analysis of the US-preexposure effect in flavor acceptance conditioning

In three experiments, rats received exposure to a sucrose solution followed by conditioning with a neutral flavor as the conditioned stimulus (CS) and sucrose as the unconditioned stimulus (US). In Experiments 1 and 2, some rats were given both the preexposure and the conditioning phases in a highly familiar context (the homecage), whereas other animals received both phases in a novel and distinctive context. In both cases the magnitude of the conditioning effect was reduced by preexposure to the US. Experiment 3 directly assessed the possible role of contextual cues by changing the context between the exposure phase and the conditioning phase but found no loss of the US-preexposure effect in these conditions. These results lend no support to the blocking-by-context account of the US-preexposure effect; alternative interpretations are considered.     

Using spatial frequency adaptation to study word recognition

The study of spatial frequency is being used increasingly often to investigate processes underlying visual word recognition. However, research in this area has adopted techniques that require the physical deformation of word targets used in experiments (e.g., filtered images of words, words embedded in visual noise), and this approach may limit the inferences that can be made about the role of spatial frequencies in normal word recognition. Spatial frequency adaptation is described in this article as an additional technique for studying the role of spatial frequency information in word recognition. The advantage of this technique is that it alters participants' sensitivity to particular spatial frequencies and so allows the study of spatial frequency involvement in word recognition using normal images of word stimuli. The application of the adaptation technique to studies of word recognition is explained in detail and its potential is then demonstrated by an example word recognition experiment in which spatial frequency adaptation was used.     

Effects of absolute luminance and luminance contrast on visual search in low mesopic environments

Diverse adaptive visual processing mechanisms allow us to complete visual search tasks in a wide visual photopic range (>0.6 cd/m²). Whether search strategies or mechanisms known from this range extend below, in the mesopic and scotopic luminance spectra (<0.6 cd/m²), has yet to be addressed. Based on a study that addressed simple target discrimination in luminance environments using contrast-dependent behavioral efficiency functions, we assessed visual search in more complex-feature and conjunction-search paradigms. The results verify the previously reported deficiency windows defined by an interaction of base luminance and luminance contrast for more complex visual-search tasks. Based on significant regression analyses, a more precise definition of the magnitude of contribution of different contrast parameters. Characterized feature search patterns had approximately a 2.5:1 ratio of contribution from the Michelson contrast property relative to Weber contrast, whereas the ratio was approximately 1:1 in a serial-search condition. The results implicate near-complete magnocellular isolation in a visual-search paradigm that has yet to be demonstrated. Our analyses provide a new method of characterizing visual search and the first insight in its underlying mechanisms in luminance environments in the low mesopic and scotopic spectra.