Training and the attentional blink: Raising the ceiling does not remove the limits

The attentional blink (AB) is a widely studied deficit in reporting the second of two sequentially presented targets when they occur within 500 milliseconds. The AB often is interpreted to index a structural limit in sequential visual processing. However, this interpretation is challenged by reports that the deficit can be reduced with several hundred trials of specific training (Braun in Nature, 393(6684), 424–425, 1998; Choi et al. in Proceedings of the National Academy of Sciences, 109(30), 12242–12247, 2012; Taatgen et al. in Cognitive Psychology, 59(1), 1–29, 2009) and other reports that some individuals experience very little or no deficit, even without specific training (Martens et al. in Journal of Cognitive Neuroscience, 18(9), 1423-1438, 2006). Yet neither of these claims has been studied when the artifact of ceiling effects has been removed. We sent a small number of participants (n = 5) home to practice an AB task on their mobile phones for 3,000-6,000 trials (Experiment 1) and trained a much larger number of participants (n = 48) in a similar way for 1,200-1,800 trials (Experiment 2). Both experiments used adaptive procedures to equate task difficulty throughout training to keep second-target accuracy below ceiling levels. The results showed strong training effects on the rate of processing sequential information. Despite this, there were (a) robust AB effects after training for most participants, (b) no benefit for training on difficult versus easy target tasks, and (c) substantial correlations between the magnitude of the AB before and after extensive training. These findings support the interpretation that the AB is an index of a structural limit in the ability to consciously process rapid visual sequences.     

The role of reversal frequency in learning noisy second order conditional sequences

The hallmark of implicit learning is that complex knowledge can be acquired unconsciously. The second order conditionals (SOCs) of Reed and Johnson (1994) were developed to be complex, and they are popular materials for implicit learning research. Recently, it was demonstrated that in a sequence made noisy (by combining two SOCs), shared features of the SOCs may be learned explicitly (Fu, Fu, & Dienes, 2008). What are these shared features? We hypothesized that low reversal frequency may play a significant role. We have varied reversal frequency, and discovered that reversal frequency affected response times, inclusion exclusion behavior, and recognition ratings. Not only does it appear to be important to distinguish implicit and explicit knowledge, but also to distinguish what the knowledge is of.     

The impact of the social context on resistance to persuasion: Effortful versus effortless responses to counter-attitudinal information

Past research has demonstrated that the presence of attitudinal diversity within a person’s social network increases his or her openness to attitude change. The current research explores whether this increased openness to attitude change is the result of relatively thoughtful or nonthoughtful processes. A nationally representative sample of US adults was exposed to a counter-attitudinal persuasive message that contained either strong or weak arguments. Attitudinal diversity within participants’ social networks was associated with greater argument quality differentiation: people embedded in networks that included a variety of views were more likely than those in attitudinally homogenous networks to carefully scrutinize attitude-relevant information, modifying their attitudes in response to strong but not weak arguments.     

A Tractarian Universe

In this paper we develop a reconstruction of the Tractatus ontology. The basic idea is that objects are unsaturated and that Sachlagen are like molecules. Bisimulation is used for the proper individuation of the Sachlagen. We show that the ordering of the Sachlagen is a complete distributive, lattice. It is atomistic, i.e., each Sachlage is the supremum of the Sachverhalte below it. We exhibit three normal forms for Sachlagen: the bisimulation collapse, the canonical unraveling and the canonical bisimulation collapse. The first of these forms is unique modulo isomorphism, the second and third are simply unique. The subset ordering on normal forms of the second and third kind reflects the ordering of the Sachlagen.     

Explicit Fixed Points in Interpretability Logic

The problem of Uniqueness and Explicit Definability of Fixed Points for Interpretability Logic is considered. It turns out that Uniqueness is an immediate corollary of a theorem of Smoryski.