Cognitive contributions of the ventral parietal cortex: an integrative theoretical account

Although ventral parietal cortex (VPC) activations can be found in a variety of cognitive domains, these activations have been typically attributed to cognitive operations specific to each domain. In this article, we propose a hypothesis that can account for VPC activations across all the cognitive domains reviewed. We first review VPC activations in the domains of perceptual and motor reorienting, episodic memory retrieval, language and number processing, theory of mind, and episodic memory encoding. Then, we consider the localization of VPC activations across domains and conclude that they are largely overlapping with some differences around the edges. Finally, we assess how well four different hypotheses of VPC function can explain findings in various domains and conclude that a bottom-up attention hypothesis provides the most complete and parsimonious account.     

Exploring the role of primary and supplementary motor areas in simple motor tasks with fNIRS

Studies employing functional magnetic resonance imaging (fMRI) have highlighted a covariation between the amplitude of hemodynamic responses recorded in primary and supplementary motor areas (M1 and SMA) and the duration of a motor task. A subset of these studies have hinted to a possible functional dissociation between processing carried out in these areas, with SMA primarily involved in action preparation, while M1 involved in action execution. This proposed functional dissociation was explored in the present study using a different technique--functional near-infrared spectroscopy--which enabled a finer-grained monitoring of the temporal characteristics of the hemodynamic response compared to fMRI. Here, hemodynamic responses in M1 and SMA were recorded in 7 participants during a right-finger-tapping task of short (1 s) or long (3 s) duration. Hemodynamic responses of larger amplitude were recorded from both contralateral M1 and SMA during long-duration than short-duration tapping. Furthermore, the analysis of the temporal profiles of these responses revealed a more sustained and prolonged activity for long-duration versus short-duration tapping in M1, but not in SMA. Rather than functionally dissociable areas, the present results are more compatible with the hypothesis that M1 and SMA subserve different, though strongly interacting, functional subroutines subtended in motor task preparation and execution.     

EEG source imaging during two Qigong meditations

Experienced Qigong meditators who regularly perform the exercises "Thinking of Nothing" and "Qigong" were studied with multichannel EEG source imaging during their meditations. The intracerebral localization of brain electric activity during the two meditation conditions was compared using sLORETA functional EEG tomography. Differences between conditions were assessed using t statistics (corrected for multiple testing) on the normalized and log-transformed current density values of the sLORETA images. In the EEG alpha-2 frequency, 125 voxels differed significantly; all were more active during "Qigong" than "Thinking of Nothing," forming a single cluster in parietal Brodmann areas 5, 7, 31, and 40, all in the right hemisphere. In the EEG beta-1 frequency, 37 voxels differed significantly; all were more active during "Thinking of Nothing" than "Qigong," forming a single cluster in prefrontal Brodmann areas 6, 8, and 9, all in the left hemisphere. Compared to combined initial-final no-task resting, "Qigong" showed activation in posterior areas whereas "Thinking of Nothing" showed activation in anterior areas. The stronger activity of posterior (right) parietal areas during "Qigong" and anterior (left) prefrontal areas during "Thinking of Nothing" may reflect a predominance of self-reference, attention and input-centered processing in the "Qigong" meditation, and of control-centered processing in the "Thinking of Nothing" meditation.     

Imagination and society: the role of visual sociology

The paper presents the field of Visual Sociology as an approach that makes use of photographs, films, documentaries, videos, to capture and assess aspects of social life and social signals. It overviews some relevant works in the field, it deals with methodological and epistemological issues, by raising the question of the relation between the observer and the observed, and makes reference to some methods of analysis, such as those proposed by the Grounded Theory, and to some connected tools for automatic qualitative analysis, like NVivo. The relevance of visual sociology to the study of social signals lies in the fact that it can validly integrate the information, introducing a multi-modal approach in the analysis of social signals.     

Imagination and society: the role of visual sociology

The paper presents the field of Visual Sociology as an approach that makes use of photographs, films, documentaries, videos, to capture and assess aspects of social life and social signals. It overviews some relevant works in the field, it deals with methodological and epistemological issues, by raising the question of the relation between the observer and the observed, and makes reference to some methods of analysis, such as those proposed by the Grounded Theory, and to some connected tools for automatic qualitative analysis, like NVivo. The relevance of visual sociology to the study of social signals lies in the fact that it can validly integrate the information, introducing a multi-modal approach in the analysis of social signals.     

Confirming expectations in asymmetric and symmetric social hypothesis testing

This article examines individuals' expectations in a social hypothesis testing task. Participants selected questions from a list to investigate the presence of personality traits in a target individual. They also identified the responses that they expected to receive and the likelihood of the expected responses. The results of two studies indicated that when people asked questions inquiring about the hypothesized traits that did not entail strong a priori beliefs, they expected to find evidence confirming the hypothesis under investigation. These confirming expectations were more pronounced for symmetric questions, in which the diagnosticity and frequency of the expected evidence did not conflict. When the search for information was asymmetric, confirming expectations were diminished, likely as a consequence of either the rareness or low diagnosticity of the hypothesis-confirming outcome. We also discuss the implications of these findings for confirmation bias.     

Some varieties of shadow illusions: split shadows, occluded shadows, stolen shadows, and shadows of shadows

Shadows are visual objects and as such are subject to preference rules for segmenting the visual scene (such as Gestalt laws). These rules govern shadows along two dimensions: their general unity and individuation (eg they describe a certain area as a unitary shadow as opposed to a set of two distinct shadows), and their being the shadow of a given object, as opposed to being the shadow of any other object in the scene (the shadow correspondence problem Mamassian, 2004 Perception 33 1279-1290). I describe a few phenomena that indicate the interplay of preferences in determining the final visual aspect of scenes in which shadows are present.     

Just an anger synonym? Moral context influences predictors of disgust word use

Are verbal reports of disgust in moral situations specific indicators of the concept of disgust, or are they used metaphorically to refer to anger? In this experiment, participants read scenarios describing a violation of a norm either about the use of the body (bodily moral) or about harm and rights (socio-moral). They then expressed disgust and anger on verbal scales, and through facial expression endorsement measures. The use of disgust words in the socio-moral condition was largely predicted by anger words and only secondarily by disgust faces, whereas in the bodily moral condition the use of disgust words was predicted to a similar extent by disgust faces and anger words. Angry faces, however, never predicted disgust words independently of anger words. These results support a middle-ground position in which disgust words concerning socio-moral violations are not entirely a metaphor for anger, but bear some relationship to other representations of disgust. In the case of socio-moral violations, however, the use of disgust language is more strongly related to anger language, and less strongly to facial representations of disgust than in the case of bodily moral violations.     

GOOD or BAD responder? Behavioural and neuroanatomical markers of clinical response to donepezil in dementia

We explored the neuropsychological and neuromorphometrical differences between probable Alzheimer's disease patients showing a good or a bad response to nine months treatment with donepezil. Before treatment, the neuropsychological profile of the two patient groups was perfectly matched. By the ninth month after treatment, the BAD-responders showed a decline of the MMSE score together with a progressive impairment of executive functions. A voxel-based morphometry investigation (VBM), at the time of the second neuropsychological assessment, showed that the BAD-responders had larger grey and white matter atrophies involving the substantia innominata of Meynert bilaterally, the ventral part of caudate nuclei and the left uncinate fasciculus, brain areas belonging to the cholinergic pathways. A more widespread degeneration of the central cholinergic pathways may explain the lack of donepezil efficacy in those patients not responding to a treatment that operates on the grounds that some degree of endogeneous release of acetylcholine is still available.