Looking young for your age: Perceptions of anti‐aging actions

Despite the potential benefits of looking young, we predicted that older adults who attempt to look younger than they are would threaten the distinctiveness of young adults' social identity and, for this reason, such “passers” would be evaluated negatively. In three experiments we found that both male and female young adults negatively evaluated older adults who attempt to look younger compared to older adults who do not attempt to do so. Both male and female targets who attempt to look younger were evaluated negatively (Experiment 2), and these negative evaluations were a function of experienced threat to young adults' social identities (Experiment 3). Older adults may attempt to look young to avoid age‐based prejudice or conform to existing standards, but doing so can result in negative evaluations by younger people. Copyright © 2010 John Wiley & Sons, Ltd.     

Plasticity associated with escalated operant ethanol self-administration during acute withdrawal in ethanol-dependent rats requires intact matrix metalloproteinase systems

Repeated cycles of ethanol intoxication and withdrawal associated with dependence induce neuroadaptations in a variety of brain systems. Withdrawal-induced negative emotional states can be ameliorated by ethanol consumption; a learned process termed negative reinforcement. Accordingly, a dependence-induced phenotype is escalated ethanol self-administration. Matrix metalloproteinases (MMPs) are proteolytic enzymes which degrade the extracellular matrix to allow for synaptic reorganization and plasticity. To test the hypothesis that an intact MMP system is required for animals to learn about the negative reinforcing effects of ethanol and display escalated self-administration during acute withdrawal when ethanol-dependent, male Wistar rats were trained to self-administer ethanol and then assigned to either acute or chronic MMP inhibition treatment groups. The chronic treatment group received intracerebroventricular (ICV) infusions of the broad spectrum MMP inhibitor FN-439 or artificial cerebrospinal fluid (aCSF) via osmotic minipumps during a 1 month ethanol dependence induction period and subsequent post-dependence induction self-administration sessions that occurred during acute withdrawal. The acute treatment group only received ICV FN-439 or aCSF on the day of self-administration sessions following dependence induction during acute withdrawal. The results showed that inhibition of MMPs attenuated escalated ethanol self-administration following chronic and acute exposure conditions. Furthermore, once learning (i.e., plasticity) had occurred, MMP inhibition had no impact on escalated response patterns and animals previously subjected to MMP inhibition that did not escalate evidenced normal escalations in operant ethanol self-administration once FN-439 treatments were terminated. Thus, the present data identified that an intact MMP system is required for the escalated responding that occurs during acute withdrawal in dependent animals and implicate such escalation as a learned response.     

Neural correlates of metonymy resolution

Metonymies are exemplary models for complex semantic association processes at the sentence level. We investigated processing of metonymies using event-related functional magnetic resonance imaging (fMRI).During an 1.5 Tesla fMRI scan, 14 healthy subjects (12 female) read 124 short German sentences with either literal (like “Africa is arid”), metonymic (“Africa is hungry”), or nonsense (“Africa is woollen”) content. Sentences were constructed so that they obey certain grammatical, semantic, and plausibility conditions and were matched for word frequency, semantic association, length and syntactic structure. We concentrated on metonymies that were not yet fossilised; we also examined a wide variety of metonymic readings.Reading metonymies relative to literal sentences revealed signal changes in a predominantly left-lateralised fronto-temporal network with maxima in the left and right inferior frontal as well as left middle temporal gyri. Left inferior frontal activation may reflect both inference processes and access to world knowledge during metonymy resolution.     

Obstacle crossing with lower visual field restriction: shifts in strategy

In this study, the authors investigated how restriction of the vertical viewing angle influences obstacle-crossing behavior. Twelve participants stepped over obstacles of different dimensions while wearing visual-field-restricting goggles. Using full-body motion capture, several kinematic measures were extracted and analyzed. Results indicate that both a 40° and 90° vertical viewing angle yielded increased step length and toe clearance as compared to an unrestricted view (i.e., 135°), whereas speed remained unaltered. A further decrease (to 25°) caused participants to slow down in addition to a further increase of step length and toe clearance. These results are discussed in terms of a change in priorities, from conservation of energy and time to safety.     

Multidimensional processing of dynamic sounds: more than meets the ear

Strong cross-modal interactions exist between visual and auditory processing. The relative contributions of perceptual versus decision-related processes to such interactions are only beginning to be understood. We used methodological and statistical approaches to control for potential decision-related contributions such as response interference, decisional criterion shift, and strategy selection. Participants were presented with rising-, falling-, and constant-amplitude sounds and were asked to detect change (increase or decrease) in sound amplitude while ignoring an irrelevant visual cue of a disk that grew, shrank, or stayed constant in size. Across two experiments, testing context was manipulated by varying the grouping of visual cues during testing, and cross-modal congruency showed independent perceptual and decision-related effects. Whereas a change in testing context greatly affected criterion shifts, cross-modal effects on perceptual sensitivity remained relatively consistent. In general, participants were more sensitive to increases in sound amplitude and less sensitive to sounds paired with dynamic visual cues. As compared with incongruent visual cues, congruent cues enhanced detection of amplitude decreases, but not increases. These findings suggest that the relative contributions of perceptual and decisional processing and the impacts of these processes on cross-modal interactions can vary significantly depending on asymmetries in within-modal processing, as well as consistencies in cross-modal dynamics.     

Perceptual adaptation to structure-from-motion depends on the size of adaptor and probe objects,but not on the similarity of their shapes

Perceptual adaptation destabilizes the phenomenal appearance of multistable visual displays. Prolonged dominance of a perceptual state fatigues the associated neural population, lowering the likelihood of renewed perception of the same appearance (Nawrot & Blake in Perception & Psychophysics, 49, 230–44, 1991). Here, we used a selective adaptation paradigm to investigate perceptual adaptation for the illusory rotation of ambiguous structure-from-motion (SFM) displays. Specifically, we generated SFM objects with different three-dimensional shapes and presented them in random order, separating successive objects by brief blank periods, which included a mask. To assess the specificity of perceptual adaptation to the shape of SFM objects, we established the probability that a perceived direction of rotation persisted between successive objects of similar or dissimilar shape. We found that the strength of negative aftereffects depended on the volume, but not the shape, of adaptor and probe objects. More voluminous objects were both more effective as adaptor objects and more sensitive as probe objects. Surprisingly, we found these volume effects to be completely independent, since any relationship between two shapes (such as overlap between volumes, similarity of shape, or similarity of velocity profiles) failed to modulate the negative aftereffect. This pattern of results was the opposite of that observed for sensory memory of SFM objects, which reflects similarity between objects, but not volume of individual objects (Pastukhov et al. in Attention, Perception & Psychophysics, 75, 1215–1229, 2013). The disparate specificities of perceptual adaptation and sensory memory for identical SFM objects suggest that the two aftereffects engage distinct neural representations, consistent with recent brain imaging results (Schwiedrzik et al. in Cerebral Cortex, 2012).     

Caring for Nature: From Fact to Value, from Respect to Reverence

Abstract. Despite the classical prohibition of moving from fact to value, encounter with the biodiversity and plenitude of being in evolutionary natural history moves us to respect life, even to reverence it. Darwinian accounts are value‐laden and necessary for understanding life at the same time that Darwinian theory fails to provide sufficient cause for the historically developing diversity and increasing complexity on Earth. Earth is a providing ground; matter and energy on Earth support life, but distinctive to life is information coded in the genetic molecules that superintends this matter‐energy. Life is generated and regenerated in struggle, persists in its perishing. Such life is also a gift; nature is grace. Biologists and theologians join in celebrating and conserving the genesis on Earth, awed in their encounter with this creativity that characterizes our home planet.