Letter processing in the visual system: different activation patterns for single letters and strings

One would expect that a lifetime of experience recognizing letters would have an important influence on the visual system. Surprisingly, there is limited evidence of a specific neural response to letters over visual control stimuli. We measured brain activation during a sequential matching task using isolated characters (Roman letters, digits, and Chinese characters) and strings of characters. We localized the visual word form area (VWFA) by contrasting the response to pseudowords against that for letter strings, but this region did not show any other sign of visual specialization for letters. In addition, a left fusiform area posterior to the VWFA was selective for letter strings, whereas a more anterior left fusiform region showed selectivity for single letters. The results of different analyses using both large regions of interest and inspections of individual patterns of response reveal a dissociation between selectivity for letter strings and selectivity for single letters. The results suggest that reading experience fine-tunes visual representations at different levels of processing. An important conclusion is that the processing of nonpronounceable letter strings cannot be assumed to be equivalent to single-letter perception.     

Numerical-spatial representation affects spatial coding: binding errors across the numerical distance effect

Does numerical-spatial representation affect feature binding? Studies of visual attention show that poor spatial coding leads to illusory conjunctions (ICs). In numerical cognition, it has been shown that numbers and space are not totally dissociated. This association underlies the numerical distance effect (DE): faster responses as the distance between the compared digits becomes larger (2 7 vs. 2 4). We used the DE to test whether numerical-spatial representation is available to visual processes that rely on spatial coding, such as feature binding. Participants reported the larger of two colored numbers. Both numerical distance (distances 2 and 5) and number–space congruity (e.g., congruent pair, 1 3; incongruent pair, 3 1) were analyzed. Results showed a higher proportion of ICs for distance 2 than for distance 5, providing strong evidence that numerical-spatial representation (1) entails a strong location code and (2) is available to visual processes that rely on location information.     

Active inference, sensory attenuation and illusions

Active inference provides a simple and neurobiologically plausible account of how action and perception are coupled in producing (Bayes) optimal behaviour. This can be seen most easily as minimising prediction error: we can either change our predictions to explain sensory input through perception. Alternatively, we can actively change sensory input to fulfil our predictions. In active inference, this action is mediated by classical reflex arcs that minimise proprioceptive prediction error created by descending proprioceptive predictions. However, this creates a conflict between action and perception; in that, self-generated movements require predictions to override the sensory evidence that one is not actually moving. However, ignoring sensory evidence means that externally generated sensations will not be perceived. Conversely, attending to (proprioceptive and somatosensory) sensations enables the detection of externally generated events but precludes generation of actions. This conflict can be resolved by attenuating the precision of sensory evidence during movement or, equivalently, attending away from the consequences of self-made acts. We propose that this Bayes optimal withdrawal of precise sensory evidence during movement is the cause of psychophysical sensory attenuation. Furthermore, it explains the force-matching illusion and reproduces empirical results almost exactly. Finally, if attenuation is removed, the force-matching illusion disappears and false (delusional) inferences about agency emerge. This is important, given the negative correlation between sensory attenuation and delusional beliefs in normal subjects—and the reduction in the magnitude of the illusion in schizophrenia. Active inference therefore links the neuromodulatory optimisation of precision to sensory attenuation and illusory phenomena during the attribution of agency in normal subjects. It also provides a functional account of deficits in syndromes characterised by false inference and impaired movement—like schizophrenia and Parkinsonism—syndromes that implicate abnormal modulatory neurotransmission.     

Clinical Utility of the Bem Sex Role Inventory (BSRI) in the Spanish Transsexual and Nontranssexual Population

The aim of the study is to evaluate the usefulness of the Bem Sex Role Inventory (BSRI; Bem, 1974), an overall measurement of the cultural construct of masculinity and femininity, in the psychological assessment of Spanish transsexuals. Seventy male-to-female transsexuals (MF), 51 female-to-male transsexuals (FM), 77 control men, and 79 control women completed the Spanish version of the BSRI. Statistically significant differences between groups were only found on the femininity scale, on which MF transsexuals and control women scored significantly higher than FM transsexuals and control men. The results indicate that (a) only the femininity scale of the BSRI appears to be useful today for evaluating differences in the sex-role identification in Spanish controls and transsexuals; and (b) MF and FM transsexuals score as a function of their gender identity instead of their anatomical sex on the BSRI femininity scale.     

Exploring the perception of social characteristics in faces using the isolation effect

The age, sex, and distinctiveness of faces can be judged from objective and partially independent facial features. In contrast, the physical basis of other social judgements, such as attractiveness, intelligence, and trustworthiness is not as yet entirely understood, despite the consistency of these judgements from faces. The present set of experiments investigated the perception of social characteristics in faces, using an adaptation of the von Restorff/isolation paradigm to determine which social characteristics are spontaneously encoded from the face. The isolation effect involves enhanced memory for perceptually salient items in a list (items that are isolated in the sense that they are in numeric minority) and our results suggested that its locus is at the encoding stage of the recognition memory experiment. Isolation in the present experiments was achieved by manipulating the number of faces included in the sets on the basis of certain characteristics. Because the manipulation of the characteristics of faces in a set to be learnt was not mentioned in most of the experiments, any resulting memory increment for the isolated items could be taken as an index of spontaneous processing of the manipulated social characteristic. Age and sex were found to be spontaneously encoded from faces. Results for other characteristics were mixed, ranging from distinctiveness and attractiveness, for which there was some indication of spontaneous processing, to intelligence and trustworthiness, which did not seem to be spontaneously encoded from faces. For intelligence, an isolation effect was found only when the experiment required a judgement that led to activation of the appropriate stereotype.     

When intuition fails to align with data: A reply to Rossion (2013)

Holistic processing, a hallmark of face perception, is often measured in the so-called composite paradigm, in which participants are asked to match part of a stimulus while ignoring another part. In prior work, we recommended against the use of one version of the composite task we call the partial design, on the basis of confounds with response biases. Rossion wrote a lengthy piece that reviews the work that he has published using this design, raising a large number of criticisms, both about an alternative measure of holistic processing that we have used and advocated (which we call the complete design) and about our work in general. In this reply, we have limited our discussion to those issues that would be relevant to a researcher looking to decide which version of this composite paradigm to use, as we doubt a comprehensive reply would be of significant interest outside a very small circle.     

The phonological loop in task alternation and task repetition

It has recently been proposed that task repetition is easier than task alternation because the appropriate task settings are already present in working memory, whereas during task alternation task settings must be retrieved from long-term memory (Mayr & Kliegl, 2000). The present study tested whether the phonological loop is involved in keeping the relevant task settings active in working memory. It may then be expected that concurrent articulatory suppression would diminish the facilitation associated with task repetition because the phonological loop could no longer maintain the appropriate task settings active in working memory. Both during task repetition and task alternation the relevant task settings should then be retrieved from long-term memory. Three dual-task experiments were conducted. The results of Experiment 1 were in support of our prediction. Experiment 2 replicated the findings of Experiment 1 and showed that the task settings probably represent the adequate response mappings. Experiment 3 ruled out the involvement of the visuo-spatial sketchpad and more general coordination demands during dual tasking.     

Now you see it,now you don't: Explaining inconsistent evidence on gender stereotyping of newborns

Parental gender‐stereotyped perceptions of newborns—particularly their physical characteristics—have been discussed as important determinants of sex role socialization from birth on. However, corresponding empirical evidence is inconclusive. We propose that inconsistent findings on gender‐correlated perceptions are due to whether or not actual physical differences between newborn girls and boys are properly (statistically or experimentally) taken into account. In our study, 55 mother–father pairs rated both their own and two unknown newborns, labeled either female or male. Although we successfully replicated the typical gender‐correlated perceptions of own newborns' physical characteristics, all effects were explainable by actual physical sex differences in length and weight at birth. Similarly, no gender‐specific rating differences emerged as a function of labeled gender of unknown children matched in actual physical characteristics. Altogether, the findings demonstrate the vital importance of considering existing sex differences between newborn girls and boys for drawing valid conclusions on gender stereotyping of newborns.