A learning rule that explains how rewards teach attention

Many theories propose that top-down attentional signals control processing in sensory cortices by modulating neural activity. But who controls the controller? Here we investigate how a biologically plausible neural reinforcement learning scheme can create higher order representations and top-down attentional signals. The learning scheme trains neural networks using two factors that gate Hebbian plasticity: (1) an attentional feedback signal from the response-selection stage to earlier processing levels; and (2) a globally available neuromodulator that encodes the reward prediction error. We demonstrate how the neural network learns to direct attention to one of two coloured stimuli that are arranged in a rank-order. Like monkeys trained on this task, the network develops units that are tuned to the rank-order of the colours and it generalizes this newly learned rule to previously unseen colour combinations. These results provide new insight into how individuals can learn to control attention as a function of reward contingency.     

Recombinative reading derived from pseudoword instruction in a miniature linguistic system

A miniature linguistic system was used to study acquisition of recombinative symbolic behavior. Three studies evaluated the teaching conditions of conditional discriminations with printed and spoken pseudowords that could potentially generate recombinative reading. Fifty-four college students across all studies learned to match 12 printed pseudowords to 12 spoken pseudowords. Some also matched pictures to the same spoken words. Each two-syllable pseudoword was formed by symbols from an arbitrarily created alphabet composed of four vowels and four consonants. Letters had univocal correspondence with phonemes. Recombinative receptive reading, comprehensive reading, and textual responding to pseudowords were periodically assessed. Experiment 1 (n = 20) showed that recombinative reading increased as the number of trained words composed of the same symbols increased. Experiment 2 (n = 14) showed that overtraining the same two words did not produce recombinative reading for most participants. Experiment 3 (n = 20), in which training with pictures was omitted, showed that elemental control by within-syllable units can develop even when the trained pseudowords are meaningless (not related to pictures). The present results support the utility of the miniature linguistic system methodology for identifying and controlling environmental determinants of rudimentary reading skills.     

Attentional factors in conceptual congruency

Conceptual congruency effects are biases induced by an irrelevant conceptual dimension of a task (e.g., location in vertical space) on the processing of another, relevant dimension (e.g., judging words' emotional evaluation). Such effects are a central empirical pillar for recent views about how the mind/brain represents concepts. In the present paper, we show how attentional cueing (both exogenous and endogenous) to each conceptual dimension succeeds in modifying both the manifestation and the symmetry of the effect. The theoretical implications of this finding are discussed.     

Computerized adaptive testing: the capitalization on chance problem

This paper describes several simulation studies that examine the effects of capitalization on chance in the selection of items and the ability estimation in CAT, employing the 3-parameter logistic model. In order to generate different estimation errors for the item parameters, the calibration sample size was manipulated (N = 500, 1000 and 2000 subjects) as was the ratio of item bank size to test length (banks of 197 and 788 items, test lengths of 20 and 40 items), both in a CAT and in a random test. Results show that capitalization on chance is particularly serious in CAT, as revealed by the large positive bias found in the small sample calibration conditions. For broad ranges of theta, the overestimation of the precision (asymptotic Se) reaches levels of 40%, something that does not occur with the RMSE (theta). The problem is greater as the item bank size to test length ratio increases. Potential solutions were tested in a second study, where two exposure control methods were incorporated into the item selection algorithm. Some alternative solutions are discussed.     

Brazilian-Portuguese empathy quotient: evidences of its construct validity and reliability

Empathy is the ability to read other's mind and understand their intentions. This paper examines the psychometric properties of the Brazilian-Portuguese version of a short form of the empathy quotient (EQ, 15 items). The EQ-15 was administered to 237 participants from the general population from Jo?o Pessoa, Brazil. Confirmatory factor analyses supported the tripartite model with cognitive, emotional and social empathy factors. In line with other studies, gender differences were only observed for the first two factors, with female participants scoring higher on both, which suggests that the social factor might not constitute a truly dimension of empathy. Strong evidence for convergent and discriminant validity was only observed for the cognitive factor. The poor psychometric parameters of the emotional and social factors are argued to reflect the complexity and contrasting ideas of their items. The possibility of elaborating specific items for the emotional and social factors is also discussed.     

Blocking with serial compound stimuli: The role of local context and second-order associations

Blocking was studied with rats in two serial conditioning experiments in which CS1 was followed by CS2 and then shock. Experiment 1 demonstrated that pretraining with CS1 was able to block conditioning to CS2 when the pretraining consisted of trace conditioning. But when serial conditioning was used for pretraining, with a third stimulus as the second element of the compound, then blocking was not detected during the subsequent phase. In Experiment 2 the effect of pretraining with CS2 on blocking with CS1 was examined. Blocking was effective, but only when steps were taken to minimize the growth of second-order associations resulting from the pairing of CS1 with CS2. These results are consistent with a principle stating that the ability of a pretrained stimulus to block the added stimulus in a compound depends on the relative contiguity of each stimulus to the US.     

Equivalent Stimuli are more Strongly Related after Training With Delayed Matching Than after Simultaneous Matching: A Study Using the Implicit Relational Assessment Procedure (IRAP)

The Psychological Record - Bortoloti and de Rose (2009) found evidence that the level of functional transfer is higher in equivalence classes generated by delayed matching to sample (DMTS) than in...