Context and competition in the capture of visual attention

Competition-based models of visual attention propose that perceptual ambiguity is resolved through inhibition, which is stronger when objects share a greater number of neural receptive fields (RFs). According to this theory, the misallocation of attention to a salient distractor--that is, the capture of attention--can be indexed in RF-scaled interference costs. We used this pattern to investigate distractor-related costs in visual search across several manipulations of temporal context. Distractor costs are generally larger under circumstances in which the distractor can be defined by features that have recently characterised the target, suggesting that capture occurs in these trials. However, our results show that search for a target in the presence of a salient distractor also produces RF-scaled costs when the features defining the target and distractor do not vary from trial to trial. Contextual differences in distractor costs appear to reflect something other than capture, perhaps a qualitative difference in the type of attentional mechanism deployed to the distractor.     

Affect in the abstract: Abstract mindsets promote sensitivity to affect

Affective information is a key element of abstract, gist-based representations. Given this central role of affect in abstract representations, the authors hypothesized that those in an abstract mindset may show more sensitivity to affective information when attending to, interpreting, or responding to external stimuli. Across 5 studies, the authors present consistent evidence that those who tend to view the world in more abstract versus concrete terms, or who have been experimentally induced into an abstract (versus concrete) mindset, had their attention automatically captured by highly-affective stimuli (Studies 1a, 1b, and 1c), automatically extracted the affective connotation of stimuli presented outside of awareness (Study 2), and behaved more consistently with their affective construal of stimuli (Study 3). These findings suggest that the numerous dispositional and situational factors that influence the level at which one construes the world may also have, heretofore overlooked, consequences for basic affective processing. The present research also emphasizes the interdependence of so-called affective and cognitive processes, bridging major literatures on construal and affect that have developed largely independently.     

Evidence and armchair access

In this paper, I shall discuss a problem that arises when you try to combine an attractive account of what constitutes evidence with an independently plausible account of the kind of access we have to our evidence. According to E = K, our evidence consists of what we know. According to the principle of armchair access, we can know from the armchair what our evidence is. Combined, these claims entail that we can have armchair knowledge of the external world. Because it seems that the principle of armchair access is supported by widely shared intuitions about epistemic rationality, it seems we ought to embrace an internalist conception of evidence. I shall argue that this response is mistaken. Because externalism about evidence can accommodate the relevant intuitions about epistemic rationality, the principle of armchair access is unmotivated. We also have independent reasons for preferring externalism about evidence to the principle of armchair access.     

Accommodation,prediction and replication: model selection in scale construction

In psychology, measurement instruments are constructed from scales, which are obtained on the grounds of exploratory and confirmatory factor analysis. Looking at the literature, one can find various recommendations regarding how these techniques should be used during the scale construction process. Some authors suggest to use exploratory factor analysis on the entire data set while others advice to perform an internal cross-validation by randomly splitting the data set in two and then either perform exploratory factor analysis on both parts or exploratory factor analysis on the first part and confirmatory factor analysis on the other. In spite of all these divergent recommendations, there is no consensus on which method yields the best result. In this paper, we analyze this issue in light of the prediction versus accommodation debate and argue that the answer to this question depends on one’s conception of the criteria that should be used to achieve the goals of the scientific enterprise.

     

Aging and the perception of depth and 3-D shape from motion parallax

The ability of younger and older observers to perceive 3-D shape and depth from motion parallax was investigated. In Experiment 1, the observers discriminated among differently curved 3-dimensional (3-D) surfaces in the presence of noise. In Experiment 2, the surfaces' shape was held constant and the amount of front-to-back depth was varied; the observers estimated the amount of depth they perceived. The effects of age were strongly task dependent. The younger observers' performance in Experiment 1 was almost 60% higher than that of the older observers. In contrast, no age effect was obtained in Experiment 2. Older observers can effectively perceive variations in depth from patterns of motion parallax, but their ability to discriminate 3-D shape is significantly compromised.     

Western scrub-jays (<Emphasis Type="Italic">Aphelocoma californica</Emphasis>) use cognitive strategies to protect their caches from thieving conspecifics

Food caching birds hide food and recover the caches when supplies are less abundant. There is, however, a risk to this strategy because the caches are susceptible to pilfering by others. Corvids use a number of different strategies to reduce possible cache theft. Scrub-jays with previous experience of pilfering other's caches cached worms in two visuospatially distinct caching trays either in private or in the presence of a conspecific. When these storers had cached in private, they subsequently observed both trays out of reach of a conspecific. When these storers had cached in the presence of a conspecific, they subsequently watched the observer pilfering from one of the trays while the other tray was placed in full view, but out of reach. The storers were then allowed to recover the remaining caches 3 h later. Jays cached more worms when they were observed during caching. At the time of recovery, they re-cached more than if they had cached in private, selectively re-caching outside of the trays in sites unbeknown to potential thieves. In addition, after a single pilfering trial, the jays switched their recovery strategy from predominantly checking their caches (i.e. returning to a cache site to see whether the food remained there) to predominantly eating them. Re-caching remained constant across the three trials. These results suggest that scrub-jays use flexible, cognitive caching and recovery strategies to aid in reducing potential future pilfering of caches by conspecifics.     

The effects of prefrontal lesions on working memory performance and theory

The effects of experimental lesions of the monkey prefrontal cortex have played a predominant role in current conceptualizations of the functional organization of the lateral prefrontal cortex, especially with regard to working memory. The loss or sparing of certain performance abilities has been shown to be attributable to differences in the specific requirements of behavioral testing (e.g., spatial vs. nonspatial memoranda) along with differences in the specific locations of applied ablations (e.g., dorsal vs. ventral prefrontal cortex). Such findings, which have accumulated now for over a century, have led to widespread acceptance that the dorsolateral and ventrolateral aspects of the prefrontal cortex may perform different, specialized roles in higher order cognition. Nonetheless, it remains unclear and controversial how the lateral prefrontal cortex is functionally organized. Two main views propose different types of functional specialization of the dorsal and ventral prefrontal cortex. The first contends that the lateral prefrontal cortex is segregated according to the processing of spatial and nonspatial domains of information. The second contends that domain specialization is not the key to the organization of the prefrontal cortex, but that instead, the dorsal and ventral prefrontal cortices perform qualitatively different operations. This report critically reviews all relevant monkey lesion studies that have served as the foundation for current theories regarding the functional organization of the prefrontal cortex. Our goals are to evaluate how well the existing lesion data support each theory and to enumerate caveats that must be considered when interpreting the relevant literature.