Influence of lighting environment on social preferences in sticklebacks from two different photic habitats. II. shoaling and mate preferences of lab-bred fishes

Different environmental conditions may lead to diverse morphological, behavioral and physiological adaptations of different populations of the same species. Lighting conditions, for example, vary vastly especially between aquatic habitats, and have been shown to elicit adaptations. The availability of short-wave ultraviolet (UV) light is especially fluctuating, as UV wavelengths are attenuated strongly depending on water properties. The island of North Uist, Scotland, comprises two differential habitat types, tea-stained and clear-water lakes, varying considerably in UV transmission. In previous studies, wild-caught three-spined stickleback Gasterosteus aculeatus populations (three populations of each habitat type) were tested with respect to their shoaling and mate preferences for fish viewed under UV-present and UV-absent conditions. The results revealed a habitat-dependent preference of UV cues during shoal choice (tea-stained populations: preference for UV-absent condition in tea-stained water; clear-water populations: no preference in clear-water) but an overall preference for UV-present conditions during mate choice. To assess genetic influences on these behavioral patterns, similar experiments were conducted with lab-bred F1-generations of the same stickleback populations that were raised in a common environment (i.e. standardized clear-water conditions). Offspring of sticklebacks from tea-stained lakes tended to prefer shoals viewed under UV-absent conditions (only in tea-stained water), while sticklebacks from clear-water lakes showed a significant preference for the shoal viewed under UV-present conditions in clear-water but not in tea-stained water. Mate-preference experiments demonstrated that females from the tea-stained lakes significantly preferred and females from the clear-water lakes preferred by trend the male viewed under UV-present conditions in the clear-water treatment. The results for both shoaling- and mate-preference tests were largely similar for wild-caught and lab-bred sticklebacks, thus hinting at a genetic basis for the preference patterns.

Asymmetric developmental change regarding the effect of reward and punishment on response inhibition

Reward and punishment influence inhibitory performance, but developmental changes in these effects are not well understood. Our aim was to understand the effects of potential reward gains and losses (as indices of reward and punishment) on response inhibition among children and adolescents. We conducted financial and non-financial go/no-go tasks with 40 boys (8- to 15-year-olds). Participants gained or lost money depending on their performance on the financial task, and score rankings were compared to participants on the non-financial task. We found that adolescents’ inhibitory control, as reflected in their reaction times when they made inhibitory errors, was lower in the reward-present condition than in the reward-absent condition, although accuracy was higher when the reward was available for all participants. Additionally, inhibitory control, specifically among adolescents, was higher for financial feedback than for non-financial feedback. These results suggest that the effects of reward and feedback type on motor impulsivity differ as a function of developmental stage. We discuss the theoretical implications of the present findings in terms of the interaction between emotional feedback and response inhibition among children and adolescents.

Necessity of technicians for computerized neuropsychological assessment devices in multiple sclerosis

Objective: Determine the influence of technician supervision on computer-administered cognitive tests in multiple sclerosis (MS). Methods: Eighty MS patients underwent assessment using the CogState Brief Battery (CSBB) and the Cleveland Clinic Cognitive Battery (C3B). Each was administered twice, once with a technician guiding assessment, and once with technician-absent. Twenty-eight healthy controls were also evaluated. Results: The influence of technician guidance was not statistically significant for group means on either test. For CSBB, administration problems were more common in the technician-absent condition. Conclusion: In this MS sample, reliable and valid test results were obtained from computer-assisted cognitive testing without technician guidance.

Using mineral equilibria to estimate H2O activities in peridotites from the Western Gneiss Region of Norway

The Earth’s mantle is an important reservoir of H2O, and even a small amount of H2O has a significant influence on the physical properties of mantle rocks. Estimating the amount of H2O in rocks from the Earth’s mantle would, therefore, provide some insights into the physical properties of this volumetrically dominant portion of the Earth. The goal of this study is to use mineral equilibria to determine the activities of H2O (aH2O) in orogenic mantle peridotites from the Western Gneiss Region of Norway. An amphibole dehydration reaction yielded values of aH2O ranging from 0.1 to 0.4 for these samples. Values of fO2 of approximately 1 to 2 log units below the FMQ oxygen buffer were estimated from a fO2-buffering reaction between olivine, orthopyroxene, and spinel for these same samples. These results demonstrate that the presence of amphibole in the mantle does not require elevated values of aH2O (i.e., aH2O≈1) nor relatively oxidizing values of fO2 (i.e., >FMQ). It is possible to estimate a minimum value of aH2O by characterizing fluid speciation in C-O-H system for a given value of oxygen fugacity (fO2). Our results show that the estimates of aH2O obtained from the amphibole dehydration equilibrium are significantly lower than values of aH2O estimated from this combination of fO2 and C-O-H calculations. This suggests that fluid pressure (Pfluid) is less than lithostatic pressure (Plith) and, for metamorphic rocks, implies the absence of a free fluid phase. Fluid absent condition could be generated by amphibole growth during exhumation. If small amounts of H2O were added to these rocks, the formation of amphibole could yield low values of aH2O by consuming all available H2O. On the other hand, if the nominally anhydrous minerals (NAMs) contained significant H2O at conditions outside of the stability field of amphibole they might have served as a reservoir of H2O. In this case, NAMs could supply the OH necessary for amphibole growth once retrograde P-T conditions were consistent with amphibole stability. Thus, amphibole growth may effectively dehydrate coexisting NAMs and enhance the strength of rocks as long as the NAMs controlled the rheology of the rock.

Influence of Reward Expectation on Visuospatial Processing in Macaque Lateral Prefrontal Cortex

The lateral prefrontal cortex (LPFC) has been implicated in visuospatial processing, especially when it is required to hold spatial information during a delay period. It has also been reported that the LPFC receives information about expected reward outcome. However, the interaction between visuospatial processing and reward processing is still unclear because the two types of processing could not be dissociated in conventional delayed response tasks. To examine this, we used a memory-guided saccade task with an asymmetric reward schedule and recorded 228 LPFC neurons. The position of the target cue indicated the spatial location for the following saccade and the color of the target cue indicated the reward outcome for a correct saccade. Activity of LPFC was classified into three main types: S-type activity carried only spatial signals, R-type activity carried only reward signals, and SR-type activity carried both. Therefore only SR-type cells were potentially involved in both visuospatial processing and reward processing. SR-type activity was enhanced (SR+) or depressed (SR−) by the reward expectation. The spatial discriminability as expressed by the transmitted information was improved by reward expectation in SR+ type. In contrast, when reward information was coded by an increase of activity in the reward-absent condition (SR− type), it did not improve the spatial representation. This activity appeared to be involved in gaze fixation. These results extend previous findings suggesting that the LPFC exerts dual influences based on predicted reward outcome: improvement of memory-guided saccades (when reward is expected) and suppression of inappropriate behavior (when reward is not expected).

Attentional Effects with Superimposed Symbology: Implications for Head-up Displays (HUD)

Previous research has shown that the presence of head-up display (HUD) symbology containing altitude information improves altitude performance at the cost of terrain path performance, implying that these information sources may not be available for concurrent cognitive processing. In two flight simulation experiments, the influence of attentive field size on this concurrent processing limitation was evaluated. In Experiment 1, a superimposed digital altitude (i.e., HUD) indicator was presented at three distances from a flight-relevant ground track. A control condition eliminated the digital altitude indicator. Altitude symbology improved performance on the altitude maintenance task, but impaired performance on the ground track task only when directly superimposed. Experiment 2 tested a visual masking explanation of the performance trade-off. Irrelevant HUD information yielded identical results to the HUD absent condition, ruling out effects of visual masking. An explanation in which visual/spatial attention cannot be directed to both HUD information and terrain information simultaneously is proposed. The absence of a performance tradeoff when the HUD and the terrain information are not directly superimposed is attributed to a breaking of attentional tunneling on the HUD, possibly due to eye movements.