Definition: To what extent does the study allow us to draw conclusions about a causal effect between two or more constructs? Issues: Selection, maturation, history, mortality, testing, regression towrd the mean, selection by maturation, treatment by mortality, treatment by testing, measured treatment variables Increase: Eliminate the threats, above all do experimental manipulations, random assignment, and counterbalancing.

Reliability and validity

This is the first handbook where the world’s foremost “experts on expertise” review our scientific knowledge on expertise and expert performance and how experts may differ from non-experts in terms of their development, training, reasoning, knowledge, social support, and innate talent. Methods are described for the study of experts’ knowledge and their performance of representative tasks from their domain of expertise. The development of expertise is also studied by retrospective interviews and the daily lives of experts are studied with diaries. In 15 major domains of expertise, the leading researchers summarize our knowledge of the structure and acquisition of expert skill and knowledge and discuss future prospects. General issues that cut across most domains are reviewed in chapters on various aspects of expertise, such as general and practical intelligence, differences in brain activity, self-regulated learning, deliberate practice, aging, knowledge management, and creativity.

The Cambridge Handbook of Expertise and Expert Performance

Everyday, people flexibly perform different categorizations of common faces, objects and scenes. Intuition and scattered evidence suggest that these categorizations require the use of different visual information from the input. However, there is no unifying method, based on the categorization performance of subjects, that can isolate the information used. To this end, we developed Bubbles, a general technique that can assign the credit of human categorization performance to specific visual information. To illustrate the technique, we applied Bubbles on three categorization tasks (gender, expressive or not and identity) on the same set of faces, with human and ideal observers to compare the features they used.

Bubbles: A Technique to Reveal the Use of Information in Recognition Tasks EOA Report

The prefrontal cortex, Anatomy, physiology, and neuropsychology of the frontal lobe, J.M. Fuster. Raven Press, New York (1980), IX-222 pages

The Sound-Symbolic System of Japanese

Right hemisphere or valence hypothesis, or both? The processing of hybrid faces in the intact and callosotomized brain.

Hemispheric asymmetries and emotions : evidence from effective connectivity

In a high-resolution electroencephalographic study, participants evaluated the friendliness level of upright and inverted 'hybrid faces', i.e. facial photos containing a subliminal emotional core in the low spatial frequencies (< 6 cycles/image), superimposed on a neutral expression in the rest of the spatial frequencies. Upright happy and angry faces were judged as more friendly or less friendly than neutral faces, respectively. We observed the time course of cerebral correlates of these stimuli with event-related potentials (ERPs), confirming that hybrid faces elicited the posterior emotion-related and face-related components (P1, N170 and P2), previously shown to be engaged by non-subliminal emotional stimuli. In addition, these components were stronger in the right hemisphere and were both enhanced and delayed by face inversion. A frontal positivity (210-300 ms) was stronger for emotional than for neutral faces, and for upright than for inverted faces. Hence, hybrid faces represent an original approach in the study of subliminal emotions, which appears promising for investigating their electrophysiological correlates.

The cerebral correlates of subliminal emotions: an eleoencephalographic study with emotional hybrid faces.

OBJECTIVE Four main theories concerning hemispheric asymmetries for emotional processing have been proposed: the right hemisphere hypothesis (RHH; the right hemisphere is specialized in processing all emotions), the valence hypothesis (VH; the left and the right hemispheres are superior in positive and negative emotion processing, respectively), the modified VH (the right-hemispheric superiority at posterior sites is followed by a valence-specific activity at frontal sites), and the motivational model (the left and the right hemispheres are superior in approaching-related and avoidance-related emotions, respectively). METHOD In a divided visual field paradigm, we presented happy and angry faces to 16 healthy participants, either unilaterally or bilaterally, in order to test the aforementioned theories. RESULTS Behavioral results provided support for the VH and correlational analysis revealed that handedness influences the rightward bias for positive emotions. The amplitude of P1, N170, and P2 event-related potential components at parietal sites (selected by means of topographic maps) was larger in the right than in the left hemisphere, independently of the emotional expression of the stimuli, supporting the RHH. At frontal sites, no asymmetry was found in bilateral conditions, whereas in unilateral conditions, a mixed pattern of hemispheric asymmetries emerged. CONCLUSIONS We conclude that there is no correspondence between behavioral and electrophysiological results concerning asymmetries for emotion processing, and that the VH and the RHH are not mutually exclusive. (PsycINFO Database Record

Contrasting hemispheric asymmetries for emotional processing from event-related potentials and behavioral responses.

Healthy individuals tend to weigh in more the left than the right side of visual space in a variety of contexts, ranging from pseudoneglect to perceptual asymmetries for faces. Among the common explanations proposed for the attentional and perceptual advantages of the left visual field, a link with the prevalence of right-handedness in humans has never been suggested, although some evidence seems to converge in favor of a bias of spatial attention towards the region most likely coincident with another person’s right hand during a face-to-face interaction. Such a bias might imply an increased efficiency in monitoring both communicative and aggressive acts, the right limb being more used than the left in both types of behaviour. Although attentional and perceptual asymmetries could be linked to right-handedness at the level of phylogeny because of the evolutionarily advantage of directing attention towards the region where others’ dominant hand usually operates, it is also legitimate to question whether, at the ontogenetic level, frequent exposure to right-handed individuals may foster leftward biases. These views are discussed in the light of extant literature, and a number of tests are proposed in order to assess our hypotheses.

/pdf/perceptual-asymmetries-and-handedness-a-neglected-link-42mtkj7iiy.pdf

Giulia Prete

Papers

Right hemisphere or valence hypothesis, or both? The processing of hybrid faces in the intact and callosotomized brain.

Hemispheric asymmetries and emotions : evidence from effective connectivity

The cerebral correlates of subliminal emotions: an eleoencephalographic study with emotional hybrid faces.

Contrasting hemispheric asymmetries for emotional processing from event-related potentials and behavioral responses.

Perceptual asymmetries and handedness: a neglected link?