Neurofunctional (re)organization underlying narrative discourse processing in aging: evidence from fNIRS

Relatively few studies have analyzed the mechanisms underlying the cognitive changes that affect language in the elderly, and fewer have done so for narrative discourse. The goal of this study was to explore the neurofunctional changes associated with aging for different components of narrative discourse. Functional near-infrared spectroscopy (fNIRS) and behavioral data on 10 younger adults and 10 healthy elderly participants were collected. Ten younger adults in a non-proficient second language condition were included to explore the possibility that the age-related neurofunctional reorganization partly expresses demanding resource allocation. Results show within- and across-hemispheric differences in the neurofunctional pattern of activation in the older participants with reference to the younger ones, partially shared with the low-proficiency young adults, providing support for the recognized mechanisms underlying neural reserve and compensation. fNIRS was shown to be appropriate for studying the age-related neurofunctional reorganization of complex cognitive abilities.     

Group cycling safety behaviours: A systematic review

BackgroundThe popularity of cycling in a group is longstanding and increasing. Compared to riding as an individual, many cyclists feel safer when riding in a group as they have better personal security, potential support in case of mishaps, safer wayfinding and are more visible to other road users. However, further to the safety challenges shared with individual cyclists, group cyclist safety is impacted by rider proximity, the larger space taken up on roadways, potentially higher speeds, and social norms that could increase risky behaviours. Despite these unique safety considerations, the practice of cycling in groups has received little academic attention and group cyclist safety behaviours have not been analysed by road safety researchers.ObjectiveTo identify, describe, categorise and conceptualise within a teamwork framework, safety related behaviours of groups of cyclists as mentioned in academic literature.MethodsThree academic databases (Google Scholar, Proquest, and Scopus) were searched for peer reviewed literature that mentioned safe or risky behaviours of groups of cyclists. A total of 32 papers met the inclusion criteria. Relevant group cyclist behaviours were described and categorised using a conceptual teamwork framework.ResultsGroup cyclists’ safety behaviours are governed by a comprehensive but informal and adaptable set of rules. These rules are safety critical and are often strictly controlled within groups. Many groups of cyclists may ride in a safer manner than individual cyclists due to teamwork factors, particularly shared mental models, team orientation, and adaptability.ConclusionGroup cyclists take safety seriously. Teamwork factors may make behavioural interventions to decrease risky behaviours easier to implement with group cyclists compared to individual cyclists. Investigation of group cycling safety behaviours may inform safe system interventions to increase road safety.     

Effects of product type and contextual cues on eliciting naive theories of popularity and exclusivity

This research shows in a series of studies that exposing consumers to functional products evokes the naive theory of popularity, whereas exposing them to self-expressive products induces belief in the naive theory of exclusivity. The research further demonstrates that when the naive theory elicited by product type is matched by the appropriate contextual purchasing cues regarding the interest of others, it results in greater purchase intentions than when those cues are mismatched. The research specifies that the matching effect for functional products is mediated by consumers' perceptions of product quality, whereas mediation for self-expressive products occurs through consumers' self-perceptions regarding the extent to which the product conveys uniqueness. Finally, the research illustrates that an explicit signal of product quality (e.g., a favorable rating in Consumer Reports) attenuates the effect associated with the contextual cues regarding the interest of others.     

Normative indications for Xhosa speaking unskilled workers on the Rey–Osterrieth Complex Figure Test

The aim of this study was to establish normative indications for the Rey-Osterrieth Complex Figure (RCF) copy, incidental recall and delayed recall tasks, administered in English on a non-clinical population of Xhosa, unskilled workers (N?=?33) (females n?=?21; males n?=?12), with a background of relatively disadvantaged quality of education up to Grades 11 and 12. The sample was stratified into two age groupings (18 – 29 years, n?=?17; 30 – 40 years, n?=?16), equally distributed for sex and level of education. Within group statistical analyses compared subgroup test performances for sex and age within the total sample. Between group analyses were used to compare the performance of the present sample with age equivalent data derived from a meta-analysis of US normative data on the RCF task. There was an age effect in favour of the younger group for both the immediate and delayed recall tasks. The local data for all RCF tasks were significantly lower than the US normative data, with the indication that higher levels and/or quality of formal school education might advantage performance on this complex visuoperceptual copy and recall task.     

Effects of motor intention on the perception of somatosensory events: A behavioural and functional magnetic resonance imaging study

The intention to execute a movement can modulate our perception of sensory events, and this modulation is observed ahead of both ocular and upper limb movements. However, theoretical accounts of these effects, and also the empirical data, are often contradictory. Accounts of “active touch”, and the premotor theory of attention, have emphasized how movement intention leads to enhanced perceptual processing at the target of a movement, or on the to-be-moved effector. By contrast, recent theories of motor control emphasize how internal “forward” model (FM) estimates may be used to cancel or attenuate sensory signals that arise as a result of self-generated movements. We used behavioural and functional brain imaging (functional magnetic resonance imaging, fMRI) to investigate how perception of a somatosensory stimulus differed according to whether it was delivered to a hand that was about to execute a reaching movement or the alternative, nonmoving, hand. The results of our study demonstrate that a somatosensory stimulus delivered to a hand that is being prepared for movement is perceived to have occurred later than when that same stimulus is delivered to a nonmoving hand. This result indicates that it takes longer for a tactile stimulus to be detected when it is delivered to a moving limb and may correspond to a change in perceptual threshold. Our behavioural results are paralleled by the results of our fMRI study that demonstrated that there were significantly reduced blood-oxygen-level-dependent (BOLD) responses within the parietal operculum and insula following somatosensory stimulation of the hand being prepared for movement, compared to when an identical stimulus was delivered to a nonmoving hand. These findings are consistent with the prediction of FM accounts of motor control that postulate that central sensory suppression of somatosensation accompanies self-generated limb movements, and with previous reports indicating that effects of sensory suppression are observed in higher order somatosensory regions.     

Recruitment of lateral rostral prefrontal cortex in spontaneous and task-related thoughts

Behavioural and neuroimaging studies suggest that spontaneous and task-related thought processes share common cognitive mechanisms and neural bases. Lateral rostral prefrontal cortex (RPFC) is a brain region that has been implicated both in spontaneous thought and in high-level cognitive control processes, such as goal/subgoal integration and the manipulation of self-generated thoughts. We therefore propose that the recruitment of lateral RPFC may follow a U-shaped function of cognitive demand: relatively high in low-demand situations conducive to the emergence of spontaneous thought, and in high-demand situations depending on processes supported by this brain region. We used functional magnetic resonance imaging to investigate brain activity while healthy participants performed two tasks, each with three levels of cognitive demands, in a block design. The frequency of task-unrelated thoughts, measured by questionnaire, was highest in the low cognitive demand condition. Low and high cognitive demand conditions were each compared to the intermediate level. Lateral RPFC and superior parietal cortex were recruited in both comparisons, with additional activations specific to each contrast. These results suggest that RPFC is involved both when (a) task demands are low, and the mind wanders, and (b) the task requires goal/subgoal integration and manipulation of self-generated thoughts.     

Correspondence effects with torches: Grasping affordance or visual feature asymmetry?

Three experiments were conducted to determine whether an object-based correspondence effect for torch (flashlight) stimuli reported by Pellicano et al. [(2010 Pellicano, A., Iani, C., Borghi, A. M., Rubichi, S., & Nicoletti, R. (2010). Simon-like and functional affordance effects with tools: The effects of object perceptual discrimination and object action state. Quarterly Journal of Experimental Psychology, 63, 2190–2201. doi: 10.1080/17470218.2010.486903[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). Simon-like and functional affordance effects with tools: The effects of object perceptual discrimination and object action state. Quarterly Journal of Experimental Psychology, 63, 2190–2201] is due to a grasping affordance provided by the handle or asymmetry of feature markings on the torch. In Experiment 1 the stimuli were the same as those from Pellicano et al.'s Experiment 2, whereas in Experiments 2 and 3 the stimuli were modified versions with the graspable handle removed. Participants in all experiments performed upright/inverted orientation judgements on the torch stimuli. The results of Experiment 1 replicated those of Pellicano et al.: A small but significant object-based correspondence effect was evident, mainly when the torch was in an active state. With the handle of the torch removed in Experiment 2, making the barrel markings more asymmetric in the display, the correspondence effect was larger. Experiment 3 directly demonstrated an effect of barrel-marking asymmetry on the correspondence effect: When only the half of the markings nearest the light end of the torch was included, the correspondence effect reversed to favour the light end. The results are in agreement with a visual feature-asymmetry account and are difficult to reconcile with a grasping-affordance account.     

Altered topological patterns of large-scale brain functional networks during passive hyperthermia

In this study, we simulated environmental heat exposure to 18 participants, and obtained functional magnetic resonance image (fMRI) data during resting state. Brain functional networks were constructed over a wide range of sparsity threshold according to a prior atlas dividing the whole cerebrum into 90 regions. Results of graph theoretical approaches showed that although brain networks in both normal and hyperthermia conditions exhibited economical small-world property, significant alterations in both global and nodal network metrics were demonstrated during hyperthermia. Specifically, a lower clustering coefficient, maintained shortest path length, a lower small-worldness, a lower mean local efficiency were found, indicating a tendency shift to a randomized network. Additionally, significant alterations in nodal efficiency were found in bilateral gyrus rectus, bilateral parahippocampal gyrus, bilateral insula, right caudate nucleus, bilateral putamen, left temporal pole of middle temporal gyrus, right inferior temporal gyrus. In consideration of physiological system changes, we found that the alterations of normalized clustering coefficient, small-worldness, mean normalized local efficiency were significantly correlated with the rectal temperature alteration, but failed to obtain significant correlations with the weight loss. More importantly, behavioral attention network test (ANT) after MRI scanning showed that the ANT effects were altered and correlated with the alterations of some global metrics (normalized shortest path length and normalized global efficiency) and prefrontal nodal efficiency (right dorsolateral superior frontal gyrus, right middle frontal gyrus and left orbital inferior frontal gyrus), implying behavioral deficits in executive control effects and maintained alerting and orienting effects during passive hyperthermia. The present study provided the first evidence for human brain functional disorder during passive hyperthermia according to graph theoretical analysis using resting-state fMRI.