Recent Behavioral Experiments Research Articles

Cooperation transitions in social games induced by aspiration-driven players.

Cooperation and defection are social traits whose evolutionary origin is still unresolved. Recent behavioral experiments with humans suggested that strategy changes are driven mainly by the individuals' expectations and not by imitation. This work theoretically analyzes and numerically explores an aspiration-driven strategy updating in a well-mixed population playing games. The payoffs of the game matrix and the aspiration are condensed into just two parameters that allow a comprehensive description of the dynamics. We find continuous and abrupt transitions in the cooperation density with excellent agreement between theory and the Gillespie simulations. Under strong selection, the system can display several levels of steady cooperation or get trapped into absorbing states. These states are still relevant for experiments even when irrational choices are made due to their prolonged relaxation times. Finally, we show that for the particular case of the prisoner dilemma, where defection is the dominant strategy under imitation mechanisms, the self-evaluation update instead favors cooperation nonlinearly with the level of aspiration. Thus, our work provides insights into the distinct role between imitation and self-evaluation with no learning dynamics.

Oculomotor feature discrimination is cortically mediated.

Eye movements are often directed toward stimuli with specific features. Decades of neurophysiological research has determined that this behavior is subserved by a feature-reweighting of the neural activation encoding potential eye movements. Despite the considerable body of research examining feature-based target selection, no comprehensive theoretical account of the feature-reweighting mechanism has yet been proposed. Given that such a theory is fundamental to our understanding of the nature of oculomotor processing, we propose an oculomotor feature-reweighting mechanism here. We first summarize the considerable anatomical and functional evidence suggesting that oculomotor substrates that encode potential eye movements rely on the visual cortices for feature information. Next, we highlight the results from our recent behavioral experiments demonstrating that feature information manifests in the oculomotor system in order of featural complexity, regardless of whether the feature information is task-relevant. Based on the available evidence, we propose an oculomotor feature-reweighting mechanism whereby (1) visual information is projected into the oculomotor system only after a visual representation manifests in the highest stage of the cortical visual processing hierarchy necessary to represent the relevant features and (2) these dynamically recruited cortical module(s) then perform feature discrimination via shifting neural feature representations, while also maintaining parity between the feature representations in cortical and oculomotor substrates by dynamically reweighting oculomotor vectors. Finally, we discuss how our behavioral experiments may extend to other areas in vision science and its possible clinical applications.

Stopping the Rot - A Review of the Recent Behavioral Experiments on Corruption

Stopping the Rot - A Review of the Recent Behavioral Experiments on Corruption

Satisfied-defect, unsatisfied-cooperate: An evolutionary dynamics of cooperation led by aspiration

Evolutionary game theory has been widely used to study the evolution of cooperation in social dilemmas where imitation-led strategy updates are typically assumed. However, results of recent behavioral experiments are not compatible with the predictions based on the imitation dynamics, casting doubts on the assumption of the imitation-led updates and calling for alternative mechanisms of strategy updates. An aspiration-led update is often considered as an alternative to the imitation-led one. While details of update rules can have significant impacts on the evolutionary outcomes and many variations in imitation-led updates are thus studied, however, few variations exist in aspiration-led updates. We introduce an aspiration-led update mechanism ("Satisfied-Defect, Unsatisfied-Cooperate") that is psychologically intuitive and can yield a behavior richer than the conventional aspiration-led update does in Prisoner's Dilemma games. Using analytical and numerical methods, we study and link the stochastic dynamics of it in well-mixed finite populations and the deterministic dynamics of infinite populations.

Experimental Privacy Studies - An Initial Review of the Literature

While information technology has been advancing rapidly during the past years, the dawn of the information age has not only elevated the importance of privacy in theory and practice but also raised concerns about how to protect a users’ private information. Within the information systems literature, there exist multiple approaches for studying online privacy, but many of them do not focus on actual user behavior. The following literature review aims for synthesizing the findings of recent behavioral experiments in the field of information privacy. Relevant topics and milestones from previous studies are likewise identified and included. In particular, the review contributes to the analysis of determinants to self-disclosure and summarizes the findings on the attempts to comprehend the privacy paradox and privacy calculus.

The path to colour discrimination is S-shaped: behaviour determines the interpretation of colour models.

Most of our current understanding on colour discrimination by animal observers is built on models. These typically set strict limits on the capacity of an animal to discriminate between colour stimuli imposed by physiological characteristics of the visual system and different assumptions about the underlying mechanisms of colour processing by the brain. Such physiologically driven models were not designed to accommodate sigmoidal-type discrimination functions as those observed in recent behavioural experiments. Unfortunately, many of the fundamental assumptions on which commonly used colour models are based have been tested against empirical data for very few species and many colour vision studies solely rely on physiological measurements of these species for predicting colour discrimination processes. Here, we test the assumption of a universal principle of colour discrimination only mediated by physiological parameters using behavioural data from four closely related hymenopteran species, considering two frequently used models. Results indicate that there is not a unique function describing colour discrimination by closely related bee species, and that this process is independent of specific model assumptions; in fact, different models produce comparable results for specific test species if calibrated against behavioural data.

Bilateral Rolandic operculum processing underlying heartbeat awareness reflects changes in bodily self-consciousness.

Exteroceptive bodily signals (including tactile, proprioceptive and visual signals) are important information contributing to self-consciousness. Moreover, prominent theories proposed that visceral signals about internal bodily states are equally or even more important for self-consciousness. Neuroimaging studies have described several brain regions which process signals related to bodily self-consciousness (BSC) based on the integration of exteroceptive signals (e.g. premotor cortex, angular gyrus, supramarginal gyrus and extrastriate body area), and that another brain region, the insula/operculum which is involved in interoception and interoceptive awareness, processes signals critical for self-awareness. Providing evidence for the integration of exteroceptive and interoceptive bodily signals, recent behavioral experiments have demonstrated that the manipulation of interoceptive (e.g. cardiac) signals, coupled with exteroceptive (e.g. visual) signals, also modulates BSC. Does this integration occur within or outside the structures described above? To this end, we adapted a recently designed protocol that uses cardio-visual stimulation to induce altered states of BSC to fMRI. Additionally, we measured neural activity in a classical interoceptive task. We found six brain regions (bilateral Rolandic operculum, bilateral supramarginal gyrus, right frontal inferior operculum and left temporal superior gyrus) that were activated differently during the interoception task as opposed to a control task. The brain regions which showed the highest selectivity for BSC based on our cardio-visual manipulation were found in the bilateral Rolandic operculum. Given our findings, we propose that the Rolandic operculum processes integrated exteroceptive-interoceptive signals that are necessary for interoceptive awareness as well as BSC.

Effects of Prior Knowledge on Memory: Implications for Education

ABSTRACTThe encoding, consolidation, and retrieval of events and facts form the basis for acquiring new skills and knowledge. Prior knowledge can enhance those memory processes considerably and thus foster knowledge acquisition. But prior knowledge can also hinder knowledge acquisition, in particular when the to‐be‐learned information is inconsistent with the presuppositions of the learner. Therefore, taking students' prior knowledge into account and knowing about the way it affects memory processes is important for optimization of students' learning. Recent behavioral and neuroimaging experiments have shed new light on the neural mechanisms through which prior knowledge affects memory. However, relatively little is known about developmental differences in the ability to make efficient use of one's knowledge base for memory purposes. In this article, we review and integrate recent empirical evidence from developmental psychology and cognitive neuroscience about the effects of prior knowledge on memory processes. In particular, this may entail an extended shift from processing in the medial temporal lobes of the brain toward processing in the neocortex. Such findings have implications for students as developing individuals. Therefore, we highlight recent insights from cognitive neuroscience that call for further investigation in educational settings, discussing to what extent these novel insights may inform teaching in the classroom.

Selective improvement of anosognosia for hemiplegia during transcranial direct current stimulation: A case report

Right brain damage patients may not complain of a left sided paralysis up to the point of denying it or even claiming of having just moved an otherwise paralyzed limb. This condition is known as anosognosia for hemiplegia (AHP). Recent behavioural experiments suggest that some residual intentionality might be preserved in patients with anosognosia and that the false belief of having moved originates from a failure to notice discrepancies between movement expectancies and the actual state of the motor system. This failure may be caused by a lack of afferent sensory information concerning the movement or alternatively by a direct dysfunction of the brain regions involved in actions' motor monitoring (i.e., the comparator system). Here we examined the effect of anodal transcranial direct current stimulation (tDCS) of the right premotor cortex in a patient with a bilateral lesion, involving predominantly the right hemisphere, and a dense unawareness for his left hemiplegia. During sham or anodal tDCS the patient was requested to judge his ability to perform simple motor actions (i) without actually executing the movement itself (“offline” condition) and after having performed a series of verbally cued finger opposition movements (“online” condition) with (i) eyes-closed or (ii) eyes-open. We found that anodal tDCS induces a significant remission of the false experience of movement only when the patient is requested to actually perform the movement with eyes open. Conversely, the patient's awareness does not improve in both the “offline” condition (in which the patient does not attempt to perform the movement) and in the “online” condition, when vision is precluded (“online” condition, eyes-closed). We conclude that the stimulation of the premotor cortex by tDCS activates brain regions involved in motor monitoring, temporary restoring the ability of the motor comparator system to correctly appreciate afferent information and build up a veridical motor awareness.

The fusion of mental imagery and sensation in the temporal association cortex.

It is well understood that the brain integrates information that is provided to our different senses to generate a coherent multisensory percept of the world around us (Stein and Stanford, 2008), but how does the brain handle concurrent sensory information from our mind and the external world? Recent behavioral experiments have found that mental imagery--the internal representation of sensory stimuli in one's mind--can also lead to integrated multisensory perception (Berger and Ehrsson, 2013); however, the neural mechanisms of this process have not yet been explored. Here, using functional magnetic resonance imaging and an adapted version of a well known multisensory illusion (i.e., the ventriloquist illusion; Howard and Templeton, 1966), we investigated the neural basis of mental imagery-induced multisensory perception in humans. We found that simultaneous visual mental imagery and auditory stimulation led to an illusory translocation of auditory stimuli and was associated with increased activity in the left superior temporal sulcus (L. STS), a key site for the integration of real audiovisual stimuli (Beauchamp et al., 2004a, 2010; Driver and Noesselt, 2008; Ghazanfar et al., 2008; Dahl et al., 2009). This imagery-induced ventriloquist illusion was also associated with increased effective connectivity between the L. STS and the auditory cortex. These findings suggest an important role of the temporal association cortex in integrating imagined visual stimuli with real auditory stimuli, and further suggest that connectivity between the STS and auditory cortex plays a modulatory role in spatially localizing auditory stimuli in the presence of imagined visual stimuli.

Stimulus-onset asynchrony can aid odor segregation

Insects have a remarkable ability to identify and track odor sources in multi-odor backgrounds. Recent behavioral experiments show that this ability relies on detecting millisecond stimulus asynchronies between odors that originate from different sources [1]. Honeybees are able to distinguish mixtures where both odors arrive at the same time (synchronous mixtures) from those where odor onsets are staggered (asynchronous mixtures) even if the delay is only a few milliseconds. On this poster we explore asynchronous mixture recognition in a model of the honeybee antennal lobe. We demonstrate how local neuronal processing can translate the small onset time difference into lasting differences in the response pattern in the antennal lobe and hypothesize that a mechanism of this kind could facilitate odor-background segregation in downstream circuits of the olfactory pathway. We present a detailed data-driven model of the bee antennal lobe that reproduces a large data set of experimentally observed odor responses [2] and demonstrate with this model that our hypothesis is consistent with the current knowledge of the olfactory circuits in the bee brain.

Do Emotions Play a Constitutive Role in Moral Cognition?

Recent behavioral experiments, along with imaging experiments and neuropsychological studies appear to support the hypothesis that emotions play a causal or constitutive role in moral judgment. Those who resist this hypothesis tend to suggest that affective mechanisms are better suited to play a modulatory role in moral cognition. But I argue that claims about the role of emotion in moral cognition frame the debate in ways that divert attention away from other plausible hypotheses. I suggest that the available data may be more plausibly explained by appeal to predictive and evaluative mechanisms, which are neither wholly affective nor straightforwardly cognitive. By recognizing this fact, we can begin to see why questions about the role of emotion in moral psychology are likely to be empirically misguided.

Subthalamic Nucleus Local Field Potential Activity during the Eriksen Flanker Task Reveals a Novel Role for Theta Phase during Conflict Monitoring

The subthalamic nucleus (STN) is thought to play a central role in modulating responses during conflict. Computational models have suggested that the location of the STN in the basal ganglia, as well as its numerous connections to conflict-related cortical structures, allows it to be ideally situated to act as a global inhibitor during conflict. Additionally, recent behavioral experiments have shown that deep brain stimulation to the STN results in impulsivity during high-conflict situations. However, the precise mechanisms that mediate the "hold-your-horses" function of the STN remain unclear. We recorded from deep brain stimulation electrodes implanted bilaterally in the STN of 13 human subjects with Parkinson's disease while they performed a flanker task. The incongruent trials with the shortest reaction times showed no behavioral or electrophysiological differences from congruent trials, suggesting that the distracter stimuli were successfully ignored. In these trials, cue-locked STN theta band activity demonstrated phase alignment across trials and was followed by a periresponse increase in theta power. In contrast, incongruent trials with longer reaction times demonstrated a relative reduction in theta phase alignment followed by higher theta power. Theta phase alignment negatively correlated with subject reaction time, and theta power positively correlated with trial reaction time. Thus, when conflicting stimuli are not properly ignored, disruption of STN theta phase alignment may help operationalize the hold-your-horses role of the nucleus, whereas later increases in the amplitude of theta oscillations may help overcome this function.

Domestic dogs' (Canis familiaris) understanding of Projected Video Images of a Human Demonstrator in an Object‐choice Task

AbstractPresenting animals with artificial visual stimuli is a key element of many recent behavioral experiments largely because images are easier to control and manipulate than live demonstrations. Determining how animals process images is crucial for being able to correctly interpret subjects' reactions toward these stimuli. In this study, we aimed to use the framework proposed by Fagot et al. (2010) Proc. Natl. Acad. Sci. USA 107, 519 to classify how dogs perceive life‐sized projected videos. First, we tested whether dogs can use pre‐recorded and hence non‐interactive, video footage of a human to locate a hidden reward in a three‐way choice task. Secondly, we investigated whether dogs solve this task by means of referential understanding. To achieve this, we separated the location of the video projection from the location where dogs had to search for the hidden reward. Our results confirmed that dogs can reliably use pre‐recorded videos of a human as a source of information when the demonstration and the hiding locations are in the same room. However, they did not find the hidden object above the chance level when the hiding locations were in a separate room. Still, further analysis found a positive connection between the attention paid to the projection and the success rate of dogs. This finding suggests that the factor limiting dogs' performance was their attention and that with further training they might be able to master tasks involving referential understanding.

Data-driven honeybee antennal lobe model demonstrates how stimulus-onset asynchrony can aid odor segregation

Insects have a remarkable ability to identify and track odor sources in multi-odor backgrounds. Recent behavioral experiments show that this ability relies on detecting millisecond stimulus asynchronies between odors that originate from different sources [1]. Honeybees, Apis mellifera, are able to distinguish mixtures where both odors arrive at the same time (synchronous mixtures) from those where odor onsets are staggered (asynchronous mixtures). Surprisingly, this ability persists down to an onset delay of only 6 ms. On this poster we explore this surprising ability in a model of the honeybee antennal lobe. We hypothesize that a winner-take-all inhibitory network (see Figure ​Figure1)1) of local neurons (LNs) in the antennal lobe has a symmetry-breaking effect, such that the response pattern in projection neurons (PNs) to an asynchronous mixture is different from the response pattern to the corresponding synchronous mixture for an extended period of time beyond the initial odor onset where the two mixture conditions actually differ. The prolonged difference between response patterns to synchronous and asynchronous mixtures could facilitate odor-background segregation in downstream circuits of the olfactory pathway. Figure 1 A Anatomy of the olfactory system of the honeybee. Olfactory receptor neurons (ORNs) on the antenna are depicted as blue spheres, the glomeruli of the AL were derived from the 3D AL atlas [3] and each glomerulus for which we had sufficient data (transparent) ... We present a detailed data-driven model of the bee antennal lobe that reproduces a large data set of experimentally observed odor responses [2] and demonstrate with this model that our hypothesis is consistent with the current knowledge of the olfactory circuits in the bee brain.

Data-driven honeybee antennal lobe model suggests how stimulus-onset asynchrony can aid odour segregation

Insects have a remarkable ability to identify and track odour sources in multi-odour backgrounds. Recent behavioural experiments show that this ability relies on detecting millisecond stimulus asynchronies between odourants that originate from different sources. Honeybees, Apis mellifera, are able to distinguish mixtures where both odourants arrive at the same time (synchronous mixtures) from those where odourant onsets are staggered (asynchronous mixtures) down to an onset delay of only 6ms. In this paper we explore this surprising ability in a model of the insects' primary olfactory brain area, the antennal lobe. We hypothesize that a winner-take-all inhibitory network of local neurons in the antennal lobe has a symmetry-breaking effect, such that the response pattern in projection neurons to an asynchronous mixture is different from the response pattern to the corresponding synchronous mixture for an extended period of time beyond the initial odourant onset where the two mixture conditions actually differ. The prolonged difference between response patterns to synchronous and asynchronous mixtures could facilitate odoursegregation in downstream circuits of the olfactory pathway. We present a detailed data-driven model of the bee antennal lobe that reproduces a large data set of experimentally observed physiological odour responses, successfully implements the hypothesised symmetry-breaking mechanism and so demonstrates that this mechanism is consistent with our current knowledge of the olfactory circuits in the bee brain.This article is part of a Special Issue entitled Neural Coding 2012.

Effects of anti-cocaine vaccine and viral gene transfer of cocaine hydrolase in mice on cocaine toxicity including motor strength and liver damage

In developing an vivo drug-interception therapy to treat cocaine abuse and hinder relapse into drug seeking provoked by re-encounter with cocaine, two promising agents are: (1) a cocaine hydrolase enzyme (CocH) derived from human butyrylcholinesterase and delivered by gene transfer; (2) an anti-cocaine antibody elicited by vaccination. Recent behavioral experiments showed that antibody and enzyme work in a complementary fashion to reduce cocaine-stimulated locomotor activity in rats and mice. Our present goal was to test protection against liver damage and muscle weakness in mice challenged with massive doses of cocaine at or near the LD50 level (100–120mg/kg, i.p.). We found that, when the interceptor proteins were combined at doses that were only modestly protective in isolation (enzyme, 1mg/kg; antibody, 8mg/kg), they provided complete protection of liver tissue and motor function. When the enzyme levels were ∼400-fold higher, after in vivo transduction by adeno-associated viral vector, similar protection was observed from CocH alone.

Neural Mechanisms Underlying Paradoxical Performance for Monetary Incentives Are Driven by Loss Aversion

SummaryEmployers often make payment contingent on performance in order to motivate workers. We used fMRI with a novel incentivized skill task to examine the neural processes underlying behavioral responses to performance-based pay. We found that individuals' performance increased with increasing incentives; however, very high incentive levels led to the paradoxical consequence of worse performance. Between initial incentive presentation and task execution, striatal activity rapidly switched between activation and deactivation in response to increasing incentives. Critically, decrements in performance and striatal deactivations were directly predicted by an independent measure of behavioral loss aversion. These results suggest that incentives associated with successful task performance are initially encoded as a potential gain; however, when actually performing a task, individuals encode the potential loss that would arise from failure.

A perspective on the study of cognition and sociality of cephalopod mollusks, a group of intelligent marine invertebrates1

AbstractCephalopod mollusks are found virtually everywhere throughout the world's oceans. They are highly mobile invertebrates that have evolved behavioral and morphological defenses against vertebrate predators. Unlike other mollusks, the coleoid cephalopods (octopus, cuttlefish, and squid) possess highly developed nervous systems with huge brains equivalent in size to some vertebrate brains. Cephalopod intelligence is also exhibited by their impressive memory and learning abilities. Why have cephalopods developed such huge brains and cognitive ability? One of the keys to answering this question lies in understanding the social interactions of cephalopods, which have thus far not been well documented. In this paper, I will outline our recent behavioral experiments using mirrors with some cephalopods and discuss these experiments in light of the diversity of social and cognitive behaviors of cephalopods.

Abstract or not? Insights from priming

AbstractCohen Kadosh & Walsh (CK&W) argue that numerical representation is primarily non-abstract. However, in their target article they failed to consider recent behavioral priming experiments. These priming experiments provide evidence for an abstract numerical representation under automatic conditions.