When "It" becomes "Mine": attentional biases triggered by object ownership.

Abstract Previous research has demonstrated that higher-order cognitive processes associated with the allocation of selective attention are engaged when highly familiar self-relevant items are encountered, such as one's name, face, personal possessions and the like. The goal of our study was to determine whether these effects on attentional processing are triggered on-line at the moment self-relevance is established. In a pair of experiments, we recorded ERPs as participants viewed common objects (e.g., apple, socks, and ketchup) in the context of an “ownership” paradigm, where the presentation of each object was followed by a cue indicating whether the object nominally belonged either to the participant (a “self” cue) or the experimenter (an “other” cue). In Experiment 1, we found that “self” ownership cues were associated with increased attentional processing, as measured via the P300 component. In Experiment 2, we replicated this effect while demonstrating that at a visual–perceptual level, spatial attention became more narrowly focused on objects owned by self, as measured via the lateral occipital P1 ERP component. Taken together, our findings indicate that self-relevant attention effects are triggered by the act of taking ownership of objects associated with both perceptual and postperceptual processing in cortex.</jats:p

Differential Synchronization in Default and Task-Specific Networks of the Human Brain

On a regional scale the brain is organized into dynamic functional networks. The activity within one of these, the default network, can be dissociated from that in other task-specific networks. All brain networks are connected structurally but evidently are only transiently connected functionally. One hypothesis as to how such transient functional coupling occurs is that network formation and dissolution is mediated by increases and decreases in oscillatory synchronization between constituent brain regions. If so, then we should be able to find transient differences in intra-network synchronization between the default network and a task-specific network. In order to investigate this hypothesis we conducted two experiments in which subjects engaged in a Sustained Attention to Response Task while having brain activity recorded via high-density electroencephalography (EEG). We found that during periods when attention was focused internally (mind wandering) there was significantly more neural phase synchronization between brain regions associated with the default network, whereas during periods when subjects were focused on performing the visual task there was significantly more neural phase synchrony within a task-specific brain network that shared some of the same brain regions. These differences in network synchrony occurred in each of theta, alpha, and gamma frequency bands. A similar pattern of differential oscillatory power changes, indicating modulation of local synchronization by attention state, was also found. These results provide further evidence that the human brain is intrinsically organized into default and task-specific brain networks, and confirm that oscillatory synchronization is a potential mechanism for functional coupling within these networks

Dehorning the Darwinian Dilemma for Normative Realism

Normative realists tend to consider evolutionary debunking arguments as posing epistemological challenges to their view. By understanding Sharon Street's 'Darwinian dilemma' argument in this way, they have overlooked and left unanswered her unique scientific challenge to normative realism. This paper counters Street's scientific challenge and shows that normative realism is compatible with evolutionary views of human evaluative judgment. After presenting several problems that her Adaptive Link Account (ALA) of evaluative judgments faces, I outline and defend an evolutionary byproduct perspective on evaluative judgment. I then argue that a consideration of levels of analysis in biological-behavioral explanation suggests that the realist who adopts the byproduct perspective I outline is not at a prima facie disadvantage to the normative anti-realist on grounds of parsimony. This perspective, I suggest, can enable normative realists to answer evolutionary challenges to their view

Brain responses to biological relevance

Abstract &amp; This study examines whether orienting attention to biologically based social cues engages neural mechanisms distinct from those engaged by orienting to nonbiologically based nonsocial cues. Participants viewed a perceptually ambiguous stimulus presented centrally while performing a target detection task. By having participants alternate between viewing this stimulus as an eye in profile or an arrowhead, we were able to directly compare the neural mechanisms of attentional orienting to social and nonsocial cues while holding the physical stimulus constant. The functional magnetic resonance imaging results indicated that attentional orienting to both eye gaze and arrow cues engaged extensive dorsal and ventral frontoparietal networks. Eye gaze cues, however, more vigorously engaged two regions in the ventral frontal cortex associated with attentional reorienting to salient or meaningful stimuli, as well as lateral occipital regions. An event-related potential study demonstrated that this enhanced occipital response was attributable to a higher-amplitude sensory gain effect for targets appearing at locations cued by eye gaze than for those cued by an arrowhead. These results endorse the hypothesis that differences in attention to social and nonsocial cues are quantitative rather than qualitative, running counter to current models that assume enhanced processing for social stimuli reflects the involvement of a unique network of brain regions

Using smartphone accelerometry to assess the relationship between cognitive load and gait dynamics during outdoor walking

Abstract Research has demonstrated that an increase in cognitive load can result in increased gait variability and slower overall walking speed, both of which are indicators of gait instability. The external environment also imposes load on our cognitive systems; however, most gait research has been conducted in a laboratory setting and little work has demonstrated how load imposed by natural environments impact gait dynamics during outdoor walking. Across four experiments, young adults were exposed to varying levels of cognitive load while walking through indoor and outdoor environments. Gait dynamics were concurrently recorded using smartphone-based accelerometry. Results suggest that, during indoor walking, increased cognitive load impacted a range of gait parameters such as step time and step time variability. The impact of environmental load on gait, however, was not as pronounced, with increased load associated only with step time changes during outdoor walking. Overall, the present work shows that cognitive load is related to young adult gait during both indoor and outdoor walking, and importantly, smartphones can be used as gait assessment tools in environments where gait dynamics have traditionally been difficult to measure

Interictal Neurocognitive Processing of Visual Stimuli in Migraine: Evidence from Event-Related Potentials

Research has established decreased sensory habituation as a defining feature in migraine, while decreased cognitive habituation has only been found with regard to cognitive assessment of the relative probability of the occurrence of a stimulus event. Our study extended the investigation of interictal habituation in migraine to include cognitive processing when viewing of a series of visually-complex images, similar to those we encounter on the internet everyday. We examined interictal neurocognitive function in migraine from a habituation perspective, using a novel paradigm designed to assess how the response to a series of images changes over time. Two groups of participants--migraineurs (N = 25) and non-migraine controls (N = 25)--were asked to view a set of 232 unfamiliar logos in the context of a target identification task as their brain electrical responses were recorded via event-related potentials (ERPs). The set of logos was viewed serially in each of 10 separate trial blocks, with data analysis focusing on how the ERP responses to the logos in frontal electrodes from 200-600 ms changed across time within each group. For the controls, we found that the amplitude of the late positive potential (LPP) ERP component elicited by the logos had no significant change across trial blocks. In contrast, in migraineurs we found that the LPP significantly increased in amplitude across trial blocks, an effect consistent with a lack of habituation to visual stimuli seen in previous research. Our findings provide empirical support abnormal cognitive processing of complex visual images across time in migraineurs that goes beyond the sensory-level habituation found in previous research

Business travel - The social practices surrounding meetings

A considerable amount of travel domestically and internationally is undertaken by 'briefcase travellers' in the pursuit of business meetings. Such business travel is deemed costly to the economy. This paper examines the potential factors at work in the social construction of meetings and their associated travel. What are the different motivations and expectations in attending a meeting? What are the actual consequences (positive and negative) in attending? How can the organisation of a meeting impact upon the wider organisation of activity in time and space of the individuals involved? How does the process of meeting attendance, including travel, unfold? How might ICTs impact on the social practices associated with meetings? The paper offers a critical assessment of such issues that may underlie and influence the nature and extent of business travel. It goes on to define the notion of excess briefcase travel as a means to frame the challenge for policymakers, employers and employees in potentially reducing such travel and the associated research challenge to establish empirical understandings. The paper examines literatures from transport studies as well as other territories of social science including mobilities research. © 2013 Elsevier Ltd

Effects of Multimodal Load on Spatial Monitoring as Revealed by ERPs

While the role of selective attention in filtering out irrelevant information has been extensively studied, its characteristics and neural underpinnings when multiple environmental stimuli have to be processed in parallel are much less known. Building upon a dual-task paradigm that induced spatial awareness deficits for contralesional hemispace in right hemisphere-damaged patients, we investigated the electrophysiological correlates of multimodal load during spatial monitoring in healthy participants. The position of appearance of briefly presented, lateralized targets had to be reported either in isolation (single task) or together with a concurrent task, visual or auditory, which recruited additional attentional resources (dual-task). This top-down manipulation of attentional load, without any change of the sensory stimulation, modulated the amplitude of the first positive ERP response (P1) and shifted its neural generators, with a suppression of the signal in the early visual areas during both visual and auditory dual tasks. Furthermore, later N2 contralateral components elicited by left targets were particularly influenced by the concurrent visual task and were related to increased activation of the supramarginal gyrus. These results suggest that the right hemisphere is particularly affected by load manipulations, and confirm its crucial role in subtending automatic orienting of spatial attention and in monitoring both hemispaces

The Impact of Aerobic Exercise on Fronto-Parietal Network Connectivity and Its Relation to Mobility: An Exploratory Analysis of a 6-Month Randomized Controlled Trial

Impaired mobility is a major concern for older adults and has significant consequences. While the widely accepted belief is that improved physical function underlies the effectiveness of targeted exercise training in improving mobility and reducing falls, recent evidence suggests cognitive and neural benefits gained through exercise may also play an important role in promoting mobility. However, the underlying neural mechanisms of this relationship are currently unclear. Thus, we hypothesize that 6 months of progressive aerobic exercise training would alter frontoparietal network (FPN) connectivity during a motor task among older adults with mild subcortical ischemic vascular cognitive impairment (SIVCI)—and exercise-induced changes in FPN connectivity would correlate with changes in mobility. We focused on the FPN as it is involved in top-down attentional control as well as motor planning and motor execution. Participants were randomized either to usual-care (CON), which included monthly educational materials about VCI and healthy diet; or thrice-weekly aerobic training (AT), which was walking outdoors with progressive intensity. Functional magnetic resonance imaging was acquired at baseline and trial completion, where the participants were instructed to perform bilateral finger tapping task. At trial completion, compared with AT, CON showed significantly increased FPN connectivity strength during right finger tapping (p &lt; 0.05). Across the participants, reduced FPN connectivity was associated with greater cardiovascular capacity (p = 0.05). In the AT group, reduced FPN connectivity was significantly associated with improved mobility performance, as measured by the Timed-Up-and-Go test (r = 0.67, p = 0.02). These results suggest progressive AT may improve mobility in older adults with SIVCI via maintaining intra-network connectivity of the FPN

Organic contaminants in western pond turtles in remote habitat in California

Remote aquatic ecosystems are exposed to an assortment of semivolatile organic compounds (SOCs) originating from current and historic uses, of local and global origin. Here, a representative suite of 57 current- and historic-use pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons were surveyed in the plasma of the western pond turtle (Emys marmorata) and their potential prey items and habitat. California study sites included Sequoia National Park, Whiskeytown National Recreation Area, and Six Rivers National Forest. Each was downstream of undeveloped watersheds and varied in distance from agricultural and urban pollution sources. SOCs were detected frequently in all sites with more found in turtle plasma and aquatic macroinvertebrates in the two sites closest to agricultural and urban sources. Summed PCBs were highest in Whiskeytown National Recreation Area turtle plasma (mean; 1.56&nbsp;ng/g ww) compared to plasma from Sequoia National Park (0.16&nbsp;ng/g&nbsp;ww; p&nbsp;=&nbsp;0.002) and Six Rivers National Forest (0.07&nbsp;ng/g ww; p&nbsp;=&nbsp;0.001). While no current-use pesticides were detected in turtle plasma at any site, both current- and historic-use pesticides were found prominently in sediment and macroinvertebrates at the Sequoia National Park site, which is immediately downwind of Central Valley agriculture. SOC classes associated with urban and industrial pollution were found more often and at higher concentrations at Whiskeytown National Recreation Area. These findings demonstrate a range of SOC exposure in a turtle species with current and proposed conservation status and shed additional light on the fate of environmental contaminants in remote watersheds