Recent studies indicate that emotion enhances early vision, but the generality of this finding remains unknown. Do the benefits of emotion extend to all basic aspects of vision, or are they limited ...in scope? Our results show that the brief presentation of a fearful face, compared with a neutral face, enhances sensitivity for the orientation of subsequently presented low-spatial-frequency stimuli, but diminishes orientation sensitivity for high-spatial-frequency stimuli. This is the first demonstration that emotion not only improves but also impairs low-level vision. The selective low-spatial-frequency benefits are consistent with the idea that emotion enhances magnocellular processing. Additionally, we suggest that the high-spatial-frequency deficits are due to inhibitory interactions between magnocellular and parvocellular pathways. Our results suggest an emotion-induced tradeoff in visual processing, rather than a general improvement. This trade-off may benefit perceptual dimensions that are relevant for survival at the expense of those that are less relevant.
It is generally assumed that emotion facilitates human vision in order to promote adaptive responses to a potential threat in the environment. Surprisingly, we recently found that emotion in some ...cases impairs the perception of elementary visual features (Bocanegra & Zeelenberg, 2009b). Here, we demonstrate that emotion improves fast temporal vision at the expense of fine-grained spatial vision. We tested participants' threshold resolution with Landolt circles containing a small spatial or brief temporal discontinuity. The prior presentation of a fearful face cue, compared with a neutral face cue, impaired spatial resolution but improved temporal resolution. In addition, we show that these benefits and deficits were triggered selectively by the global configural properties of the faces, which were transmitted only through low spatial frequencies. Critically, the common locus of these opposite effects suggests a trade-off between magno- and parvocellular-type visual channels, which contradicts the common assumption that emotion invariably improves vision. We show that, rather than being a general "boost" for all visual features, affective neural circuits sacrifice the slower processing of small details for a coarser but faster visual signal. (Contains 7 figures, 1 table and 4 footnotes.)
In a recent letter, Plant (
2015
) reminded us that proper calibration of our laboratory experiments is important for the progress of psychological science. Therefore, carefully controlled laboratory ...studies are argued to be preferred over Web-based experimentation, in which timing is usually more imprecise. Here we argue that there are many situations in which the timing of Web-based experimentation is acceptable and that online experimentation provides a very useful and promising complementary toolbox to available lab-based approaches. We discuss examples in which stimulus calibration or calibration against response criteria is necessary and situations in which this is not critical. We also discuss how online labor markets, such as Amazon’s Mechanical Turk, allow researchers to acquire data in more diverse populations and to test theories along more psychological dimensions. Recent methodological advances that have produced more accurate browser-based stimulus presentation are also discussed. In our view, online experimentation is one of the most promising avenues to advance replicable psychological science in the near future.
Recent studies show that emotional stimuli impair performance to subsequently presented neutral stimuli. Here we show a cross-modal perceptual enhancement caused by emotional cues. Auditory cue words ...were followed by a visually presented neutral target word. Two-alternative forced-choice identification of the visual target was improved by emotional cues as compared to neutral cues. When the cue was presented visually we replicated the emotion-induced impairment found in other studies. Our results suggest emotional stimuli have a twofold effect on perception. They impair perception by reflexively attracting attention at the expense of competing stimuli. However, emotional stimuli also induce a nonspecific perceptual enhancement that carries over onto other stimuli when competition is reduced, for example, by presenting stimuli in different modalities.
In the present study, we demonstrated that the emotional significance of a spatial cue enhances the effect of covert attention on spatial and temporal resolution (i.e., our ability to discriminate ...small spatial details and fast temporal flicker). Our results indicated that fearful face cues, as compared with neutral face cues, enhanced the attentional benefits in spatial resolution but also enhanced the attentional deficits in temporal resolution. Furthermore, we observed that the overall magnitudes of individuals’ attentional effects correlated strongly with the magnitude of the emotion × attention interaction effect. Combined, these findings provide strong support for the idea that emotion enhances the strength of a cue’s attentional response.
In order to engage in goal-directed behavior, cognitive agents have to control the processing of task-relevant features in their environments. Although cognitive control is critical for performance ...in unpredictable task environments, it is currently unknown how it affects performance in highly structured and predictable environments. In the present study, we showed that, counterintuitively, top-down control can impair and interfere with the otherwise automatic integration of statistical information in a predictable task environment, and it can render behavior less efficient than it would have been without the attempt to control the flow of information. In other words, less can sometimes be more (in terms of cognitive control), especially if the environment provides sufficient information for the cognitive system to behave on autopilot based on automatic processes alone.
Performing online behavioral research is gaining increased popularity among researchers in psychological and cognitive science. However, the currently available methods for conducting online reaction ...time experiments are often complicated and typically require advanced technical skills. In this article, we introduce the Qualtrics Reaction Time Engine (QRTEngine), an open-source JavaScript engine that can be embedded in the online survey development environment Qualtrics. The QRTEngine can be used to easily develop browser-based online reaction time experiments with accurate timing within current browser capabilities, and it requires only minimal programming skills. After introducing the QRTEngine, we briefly discuss how to create and distribute a Stroop task. Next, we describe a study in which we investigated the timing accuracy of the engine under different processor loads using external chronometry. Finally, we show that the QRTEngine can be used to reproduce classic behavioral effects in three reaction time paradigms: a Stroop task, an attentional blink task, and a masked-priming task. These findings demonstrate that QRTEngine can be used as a tool for conducting online behavioral research even when this requires accurate stimulus presentation times.
Natural carbon sources, such as those present in cane sugar molasses and grape juice, promote the synthesis of astaxanthin in different Phaffia rhodozyma yeasts. One of these, coconut milk, has a ...very rich nutrient composition. The aim of this work was to investigate the utility of coconut milk as sole source of energy for astaxanthin pigment production by P. rhodozyma strains. Currently, coconut pulp is widely used in industrial processes in Mexico for the production of shampoos, candies, food, etc. However, coconut milk is a waste product. We show that coconut milk enhances astaxanthin production. The fermentation yielded 850 microgram/g yeast with the NRRL-10921 wild-type strain and 1,850 microgram/g yeast with the mutated R1 strain. Production was better than reported results employing other natural carbon sources.
Orifices instead of needle capillaries can be used for electrospraying liquids in steady cone-jet mode. This novel device has been used for multiplexing cone-jet menisci anchored at the rim of ...orifices drilled on a slide. The stability and reliability of the electrospraying process from holes improve substantially when orifices are drilled in dielectric materials with hydrophobic surfaces. The manufacturing process of high compactness multi-electrospray atomizers becomes much easier and cheaper if holes instead of needles are used as emitters. Very cheap multi-hole electrospray atomizers, bearing up to 37 holes and with a compactness of up to 115 emitters per square centimeter, have been home-made and successfully operated. The current and droplet size distribution of the spray issued from these atomizers agreed quite well with those issued from a single source of electrospray, provided that the same flow rate was being electrosprayed throughout each one of the orifices of the multi-injector, and that this value was equal to that issued from the single electrospray source.
Membrane pores can significantly alter not only the permeation dynamics of biological membranes but also their elasticity. Large membrane pores able to transport macromolecular contents represent an ...interesting model to test theoretical predictions that assign active-like (non-equilibrium) behavior to the permeability contributions to the enhanced membrane fluctuations existing in permeable membranes Maneville et al. Phys. Rev. Lett. 82, 4356 (1999). Such high-amplitude active contributions arise from the forced transport of solvent and solutes through the open pores, which becomes even dominant at large permeability. In this paper, we present a detailed experimental analysis of the active shape fluctuations that appear in highly permeable lipid vesicles with large macromolecular pores inserted in the lipid membrane, which are a consequence of transport permeability events occurred in an osmotic gradient. The experimental results are found in quantitative agreement with theory, showing a remarkable dependence with the density of membrane pores and giving account of mechanical compliances and permeability rates that are compatible with the large size of the membrane pore considered. The presence of individual permeation events has been detected in the fluctuation time-series, from which a stochastic distribution of the permeation events compatible with a shot-noise has been deduced. The non-equilibrium character of the membrane fluctuations in a permeation field, even if the membrane pores are mere passive transporters, is clearly demonstrated. Finally, a bio-nano-technology outlook of the proposed synthetic concept is given on the context of prospective uses as active membrane DNA-pores exploitable in gen-delivery applications based on lipid vesicles.
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•Membrane pores alter the permeation dynamics of biological membranes and their elasticity.•DNA-translocating pores can be used to transport macromolecular contents across membranes.•They represent an interesting model to test theoretical predictions of active-like (non-equilibrium) behavior to membrane permeability•Individual permeation events have been detected in the time-series of the membrane fluctuations.•The membrane fluctuations in a permeation field are out-of-equilibrium
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