Pre‐frontal‐insular‐cerebellar modifications correlate with disgust feeling blunting after subthalamic stimulation: A positron emission tomography study in Parkinson's disease

Subthalamic nucleus (STN) deep brain stimulation (DBS) has recently advanced our understanding of the major role played by this basal ganglion in human emotion. Research indicates that STN DBS can induce modifications in all components of emotion, and neuroimaging studies have shown that the metabolic modifications correlated with these emotional disturbances following surgery are both task‐ and sensory input‐dependent. Nevertheless, to date, these modifications have not been confirmed for all emotional components, notably subjective emotional experience, or feelings. To identify the neural network underlying the modification of feelings following STN DBS, we assessed 16 patients with Parkinson's disease before and after surgery, using both subjective assessments of emotional experience and ¹⁸[F]fluorodeoxyglucose positron emission tomography (¹⁸FDG‐PET). The patients viewed six film excerpts intended to elicit happy, angry, fearful, sad, disgusted, and neutral feelings, and they self‐rated the intensity of these feelings. After DBS, there was a significant reduction in the intensity of the disgust feeling. Correlations were observed between decreased disgust experience and cerebral glucose metabolism (FDG uptake) in the bilateral pre‐frontal cortices (orbitofrontal, dorsolateral, and inferior frontal gyri), bilateral insula, and right cerebellum. We suggest that the STN contributes to the synchronization process underlying the emergence of feelings.     

Action compatibility effects are hedonically marked and have incidental consequences on affective judgment

Recent results from Cannon, Hayes, and Tipper (2010) have established that the Action Compatibility Effect (ACE) is hedonically marked and elicits a genuine positive reaction. In this work, we aim to show that the hedonic marking of the ACE has incidental consequences on affective judgment. For this, we used the affective priming paradigm principle (for a review, see Musch & Klauer, 2003): participants have to respond, as quickly as they can, regarding the pleasantness or unpleasantness character of a target word. In the priming phase, we do not present an affective stimulus; however, we present two different graspable objects, one after the other. The handles of the graspable objects are shown either both on the same side (i.e., perceptual action compatibility) or not (i.e., perceptual action incompatibility). In addition, the orientation of the handles of the objects are either compatible (i.e., action compatibility) or not (i.e., action compatibility) with the response hand used for the word evaluation. Consistent with our hypothesis, participants responded faster to positive words after perceptual action compatibility and action compatibility (thus demonstrating the ACE) than after incompatibility conditions.     

The benefits and costs of comparisons in a novel object categorization task: Interactions with development

We investigated how children use within- or between-category comparisons to generalize novel names for novel objects on the basis of a nonsalient dimension (texture) rather than a salient one (shape). Previous studies have not experimentally addressed the costs associated with comparisons. We conjectured that increasing the number of stimuli to be compared (and thus, converging evidence in favor of the target texture-based generalization), might not necessarily be beneficial, especially in young children (3- to 4-year-olds vs. 5- to 6-year-olds). Our results showed that more evidence in favor of texture (i.e., more within-category exemplars sharing the same texture) did not linearly increase texture-based choices in the same way for younger and older children. They also revealed that between-category comparisons gave rise to texture-based generalizations in both age groups. Overall, our results show that even though within- and between-category comparisons contribute to generalizations based on texture, they also generate cognitive constraints that interact with age.     

Color perception involves color representations firstly at a semantic level and then at a lexical level

Studies and models have suggested that color perception first involves access to semantic representations of color. This result leads to two questions: (1) is knowledge able to influence the perception of color when associated with a color? and (2) can the perception of color really involve only semantic representations? We developed an experiment where participants have to discriminate the color of a patch (yellow vs. green). The target patch is preceded either by a black-and-white line drawing or by a word representing a natural object associated with the same or a different color (banana vs. frog). We expected a priming effect for pictures because, with a 350-ms SOA, they only involve access to semantic representations of color, whereas words seem only elicit an access to lexical representations. As expected, we found a priming effect for pictures, but also for words. Moreover, we found a general slowdown of response times in the word-prime-condition suggesting the need of an additional processing step to produce priming. In a second experiment, we manipulated the SOA in order to preclude a semantic access in the word-prime-condition that could explain the additional step of processing. We also found a priming effect, suggesting that interaction with perception occurs at a lexical level and the additional step occurs at a color perception level. In the discussion, we develop a new model of color perception assuming that color perception involves access to semantic representations and then access to lexical representations.     

Obsessive-compulsive disorder patients display enhanced latent inhibition on a visual search task

Latent inhibition (LI) is a phenomenon that reflects the ability to ignore irrelevant stimuli. LI is attenuated in some schizophrenic patient groups and in high schizotypal normal participants. One study has found enhanced LI in patients with obsessive-compulsive disorder (OCD [Swerdlow, N. R., Hartston, H. J., & Hartman, P. L., 1999. Enhanced visual latent inhibition in obsessive-compulsive disorder. Biological Psychiatry, 45, 482-488]). The present experiment replicated this finding using a within-subject visual search LI task, with OCD patients displaying more LI than healthy controls. The contrasting LI effects in schizophrenia and OCD are discussed in terms of how these groups differentially process relevant and irrelevant stimuli, and how that outcome affects subsequent behavior.     

The development of features in object concepts

According to one productive and influential approach to cognition, categorization, object recognition, and higher level cognitive processes operate on a set of fixed features, which are the output of lower level perceptual processes. In many situations, however, it is the higher level cognitive process being executed that influences the lower level features that are created. Rather than viewing the repertoire of features as being fixed by low-level processes, we present a theory in which people create features to subserve the representation and categorization of objects. Two types of category learning should be distinguished. Fixed space category learning occurs when new categorizations are representable with the available feature set. Flexible space category learning occurs when new categorizations cannot be represented with the features available. Whether fixed or flexible, learning depends on the featural contrasts and similarities between the new category to be represented and the individuals existing concepts. Fixed feature approaches face one of two problems with tasks that call for new features: If the fixed features are fairly high level and directly useful for categorization, then they will not be flexible enough to represent all objects that might be relevant for a new task. If the fixed features are small, subsymbolic fragments (such as pixels), then regularities at the level of the functional features required to accomplish categorizations will not be captured by these primitives. We present evidence of flexible perceptual changes arising from category learning and theoretical arguments for the importance of this flexibility. We describe conditions that promote feature creation and argue against interpreting them in terms of fixed features. Finally, we discuss the implications of functional features for object categorization, conceptual development, chunking, constructive induction, and formal models of dimensionality reduction.     

Word‐to‐picture recognition is a function of motor components mappings at the stage of retrieval

Embodied approaches of cognition argue that retrieval involves the re‐enactment of both sensory and motor components of the desired remembering. In this study, we investigated the effect of motor action performed to produce the response in a recognition task when this action is compatible with the affordance of the objects that have to be recognised. In our experiment, participants were first asked to learn a list of words referring to graspable objects, and then told to make recognition judgements on pictures. The pictures represented objects where the graspable part was either pointing to the same or to the opposite side of the “Yes” response key. Results show a robust effect of compatibility between objects affordance and response hand. Moreover, this compatibility improves participants' ability of discrimination, suggesting that motor components are relevant cue for memory judgement at the stage of retrieval in a recognition task. More broadly, our data highlight that memory judgements are a function of motor components mappings at the stage of retrieval.     

Competition and cooperation between groups and between individuals

Groups and individuals were compared in two experiments. In the first, two same-sex individuals or two same-sex dyads played 10 trials of a Prisoner's Dilemma matrix game (PDG) for money. Play between individuals was more cooperative and less competitive than play between groups. In the second experiment subjects played 10 trials of either PDG or mutual-fate-control (MFC) matrices. For the MFC matrix the competitive choice, which reduces the opponent's outcomes, but has no effect on own outcomes, reflects a desire to increase one's relative advantage over the opponent. Although cooperation was greater for MFC, for both PDG and MFC matrices groups were more competitive and less cooperative than individuals. A large component of the groups-individuals effect is attributed to the greater desire of groups to “win” or avoid “losing” to the opponent, regardless of their absolute outcomes.     

Reactions of Participants and Observers to Modes of Adjudication1

An important aspect of conflict resolution by judgment of a third party is the extent to which participants and observers are satisfied that both the procedure and the outcome are fair and impartial. Male undergraduates participated in a business simulation, which resulted in a controversy placing them in the position of defendants in a trial. An examination was then made of the effects of adversary and nonadversary procedures, prior belief about guilt, and favorableness of the judgment on participant subjects’perceptions of the adjudication. Another group of subjects who had no prior information about the guilt or innocence of the defendent served as observers. Participant subjects viewed the adversary procedure as most fair and satisfying. They were also most satisfied with judgments resulting from the adversary procedure, independently of pretrial belief or favorableness of verdict. Participants also preferred innocent to guilty verdicts, regardless of their pretrial belief. Subjects who held a pretrial belief of innocence were particularly dissatisfied with guilty verdicts and with the nonadversary trial procedure. Observers also found the adversary procedure to be most fair, and expressed a preference for innocent verdicts.