Central action of substance P: possible role in reward

A series of studies had revealed a dualistic role of post-trial injections of substance P in affecting avoidance behavior depending on the site of the brain in which it is applied. Based on these data, the hypothesis was formulated that substance P has brain site-dependent rewarding and punishing properties, a possibility which was assessed in rats trained on a modified T-maze task. Injections of substance P into the medial forebrain bundle (100 ng) or medial septal nucleus (500 ng) served as a positive reinforcer for conditioned place preference learning in the T maze. Injections into the amygdala (50 ng) or substantia nigra (100 ng) did not have such reinforcing properties.     

The role of motor simulation in action perception: a neuropsychological case study

Research on embodied cognition stresses that bodily and motor processes constrain how we perceive others. Regarding action perception the most prominent hypothesis is that observed actions are matched to the observer’s own motor representations. Previous findings demonstrate that the motor laws that constrain one’s performance also constrain one’s perception of others’ actions. The present neuropsychological case study asked whether neurological impairments affect a person’s performance and action perception in the same way. The results showed that patient DS, who suffers from a frontal brain lesion, not only ignored target size when performing movements but also when asked to judge whether others can perform the same movements. In other words DS showed the same violation of Fitts’s law when performing and observing actions. These results further support the assumption of close perception action links and the assumption that these links recruit predictive mechanisms residing in the motor system.     

Converging on a new role for analogy in problem solving and retrieval: when two problems are better than one

People often fail to retrieve examples analogous to a current problem or situation. There is good evidence that comparing structurally matching cases facilitates subsequent analogical access. However, current approaches offer little at the time of memory search to promote retrieval of a routinely encoded analogous source. We adapted Gick and Holyoak's (1980, 1983) classic paradigm to investigate whether comparing two unsolved problems at test promotes retrieval of a single previously studied analogue. In Experiment 1, comparison of test problems facilitated analogical problem solving. Experiment 2 showed that comparison is the critical factor since solving two test problems separately proved ineffective. In Experiment 3, comparing two problems led to greater success for participants who read a prior analogous story than those who did not, demonstrating specifically that comparison facilitates retrieval. The three studies show that analogical access is powerfully determined by problem encoding. Implications for psychological theory and real-world applications are discussed.     

Trapped in a tight spot: Scaling effects occur when,according to the action-specific account,they should not,and fail to occur when they should

The action-specific account of perception claims that what we see is perceptually scaled according to our action capacity. However, it has been argued that this account relies on an overly confirmatory research strategy—predicting the presence of, and then finding, an effect (Firestone & Scholl, 2014). A comprehensive approach should also test disconfirmatory predictions, in which no effect is expected. In two experiments, we tested one such prediction based on the action-specific account, namely that scaling effects should occur only when participants intend to act (Witt, Proffitt, & Epstein, 2005). All participants wore asymmetric gloves in which one glove was padded with extra material, so that one hand was wider than the other. Participants visually estimated the width of apertures. The action-specific account predicts that the apertures should be estimated as being narrower for the wider hand, but only when participants intend to act. We found this scaling effect when it should not have occurred (Exp. 1, for participants who did not intend to act), as well as no effect when it should have occurred (Exp. 2, for participants who intended to act but were given a cover story for the visibility and position of their hands). Thus, the cover story used in Experiment 2 eliminated the scaling effect found in Experiment 1. We suggest that the scaling effect observed in Experiment 1 likely resulted from demand characteristics associated with using a salient, unexplained manipulation (e.g., telling people which hand to use to do the task). Our results suggest that the action-specific account lacks predictive power.     

Preferences for different questions when testing hypotheses in an abstract task: Positivity does play a role, asymmetry does not

Previous studies on hypothesis-testing behaviour have reported systematic preferences for posing positive questions (i.e., inquiries about features that are consistent with the truth of the hypothesis) and different types of asymmetric questions (i.e., questions where the hypothesis confirming and the hypothesis disconfirming responses have different evidential strength). Both tendencies can contribute - in some circumstances - to confirmation biases (i.e., the improper acceptance or maintenance of an incorrect hypothesis). The empirical support for asymmetric testing is, however, scarce and partly contradictory, and the relative strength of positive testing and asymmetric testing has not been empirically compared. In four studies where subjects were asked to select (Experiment 1) or evaluate (Experiments 2-4) questions for controlling an abstract hypothesis, we orthogonally balanced the positivity/negativity of questions by their symmetry/asymmetry (Experiments 1-3), or by the type of asymmetry (confirmatory vs disconfirmatory; Experiment 4). In all Experiments participants strongly preferred positive to negative questions. Their choices were on the other hand mostly unaffected by symmetry and asymmetry in general, or - more specifically - by different types of asymmetry. Other results indicated that participants were sensitive to the diagnosticity of the questions (Experiments 1-3), and that they preferred testing features with a high probability under the focal hypothesis (Experiment 4). In the discussion we argue that recourse to asymmetric testing - observed in some previous studies using more contextualized problems - probably depends on context-related motivations and prior knowledge. In abstract tasks, where that knowledge is not available, more simple strategies - such as positive testing - are prevalent.     

The role of joint attention in the development of infants' play with objects

Year-old infants' play was scored within and outside joint attention with mother and when alone for four levels of maturity: stereotypical, inappropriate relational, appropriate relational, functional. Maternal sensitivity within joint attention was rated on two measures: following infants' interests and scaffolding infants' activities. Infants' play was more advanced with mother than when alone. With mother, infants had more functional and appropriate relational play within joint attention and more stereotypical play outside joint attention, indicating more advanced play within joint attention and more immature play outside joint attention. Functional play within joint attention, but not outside joint attention, correlated with functional play when alone. Mothers' ability to scaffold infants' activities within joint attention may be particularly facilitative to infants' advanced play.     

You better play 7: mutual versus common knowledge of advice in a weak-link experiment

This paper presents the results of an experiment on mutual versus common knowledge of advice in a two-player weak-link game with random matching. Our experimental subjects play in pairs for thirteen rounds. After a brief learning phase common to all treatments, we vary the knowledge levels associated with external advice given in the form of a suggestion to pick the strategy supporting the payoff-dominant equilibrium. Our results are somewhat surprising and can be summarized as follows: in all our treatments both the choice of the efficiency-inducing action and the percentage of efficient equilibrium play are higher with respect to the control treatment, revealing that even a condition as weak as mutual knowledge of level 1 is sufficient to significantly increase the salience of the efficient equilibrium with respect to the absence of advice. Furthermore, and contrary to our hypothesis, mutual knowledge of level 2 induces, under suitable conditions, successful coordination more frequently than common knowledge.     

Perception in action: The impact of sensory information on sensorimotor synchronization in musicians and non-musicians

The present study aimed at investigating to what extent sensorimotor synchronization is related to (i) musical specialization, (ii) perceptual discrimination, and (iii) the movement’s trajectory. To this end, musicians with different musical expertise (drummers, professional pianists, amateur pianists, singers, and non-musicians) performed an auditory and visual synchronization and a cross-modal temporal discrimination task. During auditory synchronization drummers performed less variably than amateur pianists, singers and non-musicians. In the cross-modal discrimination task drummers showed superior discrimination abilities which were correlated with synchronization variability as well as with the trajectory. These data suggest that (i) the type of specialized musical instrument affects synchronization abilities and (ii) synchronization accuracy is related to perceptual discrimination abilities as well as to (iii) the movement’s trajectory. Since particularly synchronization variability was affected by musical expertise, the present data imply that the type of instrument improves accuracy of timekeeping mechanisms.     

Changing internal constraints on action: the role of backward inhibition

Flexible control of action requires the ability to disengage from previous goals or task sets. The authors tested the hypothesis that disengagement during intentional shifts between task sets is accompanied by inhibition of the previous task set ("backward inhibition"). As an expression of backward inhibition the authors predicted increased response times when shifting to a task set that had to be abandoned recently and, thus, suffers residual inhibition. The critical backward inhibition effect on the level of abstractly defined perceptual task sets was obtained across 6 different experiments. In addition, it was shown that backward inhibition can be differentiated from negative priming (Experiment 2), that it is tied to top-down sequential control (Experiment 3), that it can account at least partially for "residual shift costs" in set-shifting experiments (Experiment 4), and that it occurs even in the context of preplanned sequences of task sets (Experiment 5).     

What they think of us: Meta-beliefs and solidarity-based collective action among the advantaged

Collective action researchers have recently started investigating solidarity-based collective action by advantaged groups. This literature, however, has overlooked intergroup meta-beliefs (MBs, i.e., beliefs about the outgroup's beliefs), which we argue are crucial, since solidarity inherently involves protesting for the outgroup. In the context of racial inequality in the U.S., we focused on three MBs White Americans could hold: responsibility, inactivity, and allyship. In two studies (N_total = 648), we found that inactive and responsible MBs predicted higher collective action tendencies among low White identifiers via guilt and obligation to act. Conversely, we found that both predicted lower collective action tendencies among high White identifiers, via perceived unfairness. Finally, we found that ally MB was positively associated with collective action tendencies, regardless of identification. We highlight the importance of the meta-perspective in understanding solidarity-based collective action, and discuss conceptual and practical implications of these findings.     

Authorship effects in the prediction of handwriting strokes: Evidence for action simulation during action perception

Does the action system contribute to action perception? Recent evidence suggests that actions are simulated while being observed. Given that the planning and simulating system are the same only when one observes one's own actions, it might be easier to predict the future outcomes of actions when one has carried them out oneself earlier on. In order to test this hypothesis, three experiments were conducted in which participants observed parts of earlier self- and other-produced trajectories and judged whether another stroke would follow or not. When the trajectories were produced without constraints, participants accomplished this task only for self-produced trajectories. When the trajectories were produced under narrow constraints, the predictions were equally accurate for self- and for other-generated trajectories. These results support the action simulation assumption. The more the actions that one observes resemble the way one would carry them out oneself, the more accurate the simulation.     

Understanding the architecture of language: the possible role of neurology

Culicover and Jackendoff have recently described an approach to language representation where semantic structure works, alongside syntax, as a generative system with its own structure and principles of composition. Well-known neurological observations support this view. They show that in the presence of a syntactic impairment, comprehension can take place but only if the sentence's semantic structure is rich enough. This would suggest the existence of syntax-independent semantic combinatorial mechanisms, as Culicover and Jackendoff's model proposes.     

Chimpanzees (Pan troglodytes) can wait,when they choose to: a study with the hybrid delay task

Self-control has been studied in nonhuman animals using a variety of tasks. The inter-temporal choice (ITC) task presents choices between smaller–sooner (SS) and larger–later (LL) options. Using food amounts as rewards, this presents two problems: (a) choices of the LL option could either reflect self-control or instead result from animals’ difficulty with pointing to smaller amounts of food; (b) there is no way to verify whether the subjects would not revert their choice for the LL option, if given the opportunity to do so during the ensuing delay. To address these problems, we have recently introduced a new protocol, the hybrid delay task, which combines an initial ITC with a subsequent accumulation phase in which selection of the SS option leads to its immediate delivery, but choice of the LL option then leads to one-by-one presentation of those items that continues only as long as the subject does not eat any of the accumulated items. The choice of the LL option therefore only reflects self-control when the number of items obtained from LL choices during the accumulation phase is higher than what could be received in the SS option. Previous research with capuchin monkeys demonstrated that their apparent self-control responses in the ITC task may have overestimated their general self-control abilities, given their poor performance in the hybrid delay task. Here, chimpanzees instead demonstrated that their choices for the LL option in the ITC phase of the hybrid delay task were confirmed by their ability to sustain long delays during accumulation of LL rewards.     

Enjoying goal-directed action: the role of regulatory fit

We propose that the fit between an action's strategic orientation and the actor's regulatory state can influence the amount of enjoyment the action provides. In two studies using different methods of manipulating regulatory states and of gauging action evaluations, high regulatory fit increased participants' anticipations of action enjoyability. In a third study, high regulatory fit increased participants' enjoyment of, perceived success at, and willingness to repeat a novel laboratory task, and these effects were independent of participants' actual success on the task. Across the three studies, participants in a regulatory state oriented toward accomplishment experienced eagerness-related actions more favorably than vigilance-related actions, whereas participants in a regulatory state oriented toward responsibility experienced vigilance-related actions more favorably than eagerness-related actions. These findings' implications for understanding task interest and motivation are discussed.     

Gender role socialization in toy play situations: Mothers and fathers with their sons and daughters

This study examined the interaction within and between 20 intact families. As in past research, when parents were separated and not influenced by their child (i.e., completing a toy desirability scale), traditional findings were supported; neutral toys are not specific to the gender of the child while feminine toys were preferred for girls and masculine toys were preferred for boys. However, when parents were actively engaged in play with their child this traditional pattern was not supported. In general, parents spent the least amount of time with feminine toys. Children eagerly accepted most of the toys presented by their parents and their enthusiasm was equal for the toys in all three categories. This research suggests a change in parents' perceptions of what is acceptable gender-typing behavior.     

Empirical metaphysics: the role of intuitions about possible cases in philosophy

Frank Jackson has argued that only if we have a priori knowledge of the extension-fixers for many of our terms can we vindicate the methodological practice of relying on intuitions to decide between philosophical theories. While there has been much discussion of Jackson’s claim that we have such knowledge, there has been comparatively little discussion of this most powerful argument for that claim. Here I defend an alternative explanation of our intuitions about possible cases, one that does not rely on a priori extension-fixers. This alternative explanation provides a vindication of our reliance on intuitions, while blocking Jackson’s abductive argument for a priori semantic knowledge. In brief, I argue that we should regard our armchair intuitions as providing an important, a priori source of evidence for hypotheses about the contents of our implicit referential policies with regard to our terms. But all such hypotheses have a potential falsifier that is only discoverable empirically. In other words, gold-standard evidence for such hypotheses is always empirical.