Biomedical subjects

Rachel Robbins

Publications and source records attributed to Rachel Robbins.

4 recordsLinked to original sources

PubMed2006

The evidence rejects the expertise hypothesis: reply to Gauthier & Bukach.

In Robbins, R. & McKone, E. (2006). No face-like processing for object-of-expertise in three behavioural tasks. Cognition this issue, we showed face-like holistic/configural processing does not occur for objects-of-expertise on standard paradigms including inversion, part-whole, part-in-configurally-transformed-whole, and the standard composite task. In this reply to the discussion by Gauthier, I., & Bukach, C. (2006). Should we reject the expertise hypothesis? Cognition, this issue, we focus on several issues: the fact that they do not dispute our review of previous data; the strength of null effects obtained from multiple studies and paradigms; the evidence for domain-specificity of the neural substrate supporting face processing; the difference between the expertise hypothesis (as a theory about the origin of face processing) and studies of how experience affects object processing in general; and the problems with G&B's proposed alteration to the standard composite paradigm. We argue that overwhelming evidence suggests the expertise hypothesis should be put to rest so that researchers can focus on what the origin of "special" processing for faces actually is, and investigate the many interesting changes to object recognition that do occur with experience.

Face↗

PubMed2006

No face-like processing for objects-of-expertise in three behavioural tasks.

In the debate between expertise and domain-specific explanations of "special" processing for faces, a common belief is that behavioural studies support the expertise hypothesis. The present article refutes this view, via a combination of new data and review. We tested dog experts with confirmed good individuation of exemplars of their breed-of-expertise. In all experiments, standard results were confirmed for faces. However, dog experts showed no face-like processing for dogs on three behavioural tasks (inversion; the composite paradigm; and sensitivity to contrast reversal). The lack of holistic/configural processing, indicated in the first two of these tests, is shown by review to be consistent rather than inconsistent with previous studies of objects-of-expertise.

Adult↗

PubMed2005

IL-21 induces differentiation of human naive and memory B cells into antibody-secreting plasma cells.

IL-21 is a type I cytokine that influences the function of T cells, NK cells, and B cells. In this study, we report that IL-21 plays a major role in stimulating the differentiation of human B cells. When human B cells were stimulated through the BCR, IL-21 induced minimal proliferation, IgD down-modulation, and small numbers of plasma cells. In contrast, after CD40 engagement, IL-21 induced extensive proliferation, class switch recombination (CSR), and plasma cell differentiation. Upon cross-linking both BCR and CD40, IL-21 induced the largest numbers of plasma cells. IL-21 drove both postswitch memory cells as well as poorly responsive naive cord blood B cells to differentiate into plasma cells. The effect of IL-21 was more potent than the combination of IL-2 and IL-10, especially when responsiveness of cord blood B cells was examined. IL-21 costimulation potently induced the expression of both B lymphocyte-induced maturation protein-1 (BLIMP-1) and activation-induced cytidine deaminase as well as the production of large amounts of IgG from B cells. Despite the induction of activation-induced cytidine deaminase and CSR, IL-21 did not induce somatic hypermutation. Finally, IL-2 enhanced the effects of IL-21, whereas IL-4 inhibited IL-21-induced plasma cell differentiation. Taken together, our data show that IL-21 plays a central role in CSR and plasma cell differentiation during T cell-dependent B cell responses.

Antibody Formation↗

PubMed2003

Can holistic processing be learned for inverted faces?

The origin of "special" processing for upright faces has been a matter of ongoing debate. If it is due to generic expertise, as opposed to having some innate component, holistic processing should be learnable for stimuli other than upright faces. Here we assess inverted faces. We trained subjects to discriminate identical twins using up to 1100 exposures to each twin in different poses and images. In the upright orientation, twin discrimination was supported by holistic processing. Removal of a single face feature had no effect on performance, and a composite effect (Young, A. W., Hellawell, D., & Hay, D.C. (1987). Configurational information in face perception. Perception 16 (6), 747-759) was obtained. In the inverted orientation, however, above chance identification ability relied on (a) image specific learning, or (b) tiny local feature differences not noticed in the upright faces. The failure to learn holistic processing for inverted faces indicates that, in contrast to the situation for objects (Tarr, M.J., & Pinker, S. (1989). Mental rotation and orientation-dependence in shape recognition. Cognitive Psychology 21 (2), 233-282), orientation specificity of face processing is highly stable against practice.

Adolescent↗