Primates do not spontaneously use shape properties for object individuation: a competence or a performance problem?

Several recent studies have documented that non-human primates can individuate objects according to property and/or kind information in much the same way as human infants do from around one year of age when they begin to acquire language. Some studies suggest, however, that only some properties are used for the individuation of food items: color, but not shape. The present study investigated whether these findings reveal a true competence problem with shape properties in the food domain or whether they merely reveal a performance problem (e.g., lack of attention to shapes). We tested 25 great apes (chimpanzees, bonobos and gorillas) in two food individuation tasks. We manipulated subjects’ experience with differences in color and shape properties of food items. Results indicated (i) that all subjects, regardless of their prior experience, solved the color-based object individuation task and (ii) that only the group with previous experience with different shape properties succeeded in the shape-based individuation task. Great apes can thus be primed to take shape into account for individuating food objects, and this results clearly speaks in favor of a performance (rather than a competence) problem in using shape for object individuation of food items.     

The ontogeny of intent‐based normative judgments

When evaluating norm transgressions, children begin to show some sensitivity to the agent's intentionality around preschool age. However, the specific developmental trajectories of different forms of such intent‐based judgments and their cognitive underpinnings are still largely unclear. The current studies, therefore, systematically investigated the development of intent‐based normative judgments as a function of two crucial factors: (a) the type of the agent's mental state underlying a normative transgression, and (b) the type of norm transgressed (moral versus conventional). In Study 1, 5‐ and 7‐year‐old children as well as adults were presented with vignettes in which an agent transgressed either a moral or a conventional norm. Crucially, she did so either intentionally, accidentally (not intentionally at all) or unknowingly (intentionally, yet based on a false belief regarding the outcome). The results revealed two asymmetries in children's intent‐based judgments. First, all age groups showed greater sensitivity to mental state information for moral compared to conventional transgressions. Second, children's (but not adults') normative judgments were more sensitive to the agent's intention than to her belief. Two subsequent studies investigated this asymmetry in children more closely and found evidence that it is based on performance factors: children are able in principle to take into account an agent's false belief in much the same way as her intentions, yet do not make belief‐based judgments in many existing tasks (like that of Study 1) due to their inferential complexity. Taken together, these findings contribute to a more systematic understanding of the development of intent‐based normative judgment.     

HYPE: A System of Hyperintensional Logic (with an Application to Semantic Paradoxes)

Journal of Philosophical Logic - This article introduces, studies, and applies a new system of logic which is called ‘HYPE’. In HYPE, formulas are evaluated at states that may exhibit...     

Control over location-based response activation in the Simon task: behavioral and electrophysiological evidence

In 4 Simon experiments the authors examined control over 2 routes of sensorimotor processing: response priming in the unconditional route and response selection via the conditional route. The Simon effect diminished as the frequency of noncorresponding trials increased. Location-based response priming was observed only when the stimulus followed a corresponding event but not after a noncorresponding trial. Therefore, the unconditional route appears to be suppressed whenever the task context indicates priming as potentially disadvantageous. Moreover, the task-irrelevant stimulus location was used for response selection as a function of correspondence probability. Although exact repetitions of stimulus-response sequences caused a marked speed-up of responses, this 3rd mechanism is independent of unconditional route suppression and frequency-based adjustments in the conditional route.     

No Future

The difficulties with formalizing the intensional notions necessity, knowability and omniscience, and rational belief are well-known. If these notions are formalized as predicates applying to (codes of) sentences, then from apparently weak and uncontroversial logical principles governing these notions, outright contradictions can be derived. Tense logic is one of the best understood and most extensively developed branches of intensional logic. In tense logic, the temporal notions future and past are formalized as sentential operators rather than as predicates. The question therefore arises whether the notions that are investigated in tense logic can be consistently formalized as predicates. In this paper it is shown that the answer to this question is negative. The logical treatment of the notions of future and past as predicates gives rise to paradoxes due the specific interplay between both notions. For this reason, the tense paradoxes that will be presented are not identical to the paradoxes referred to above.     

Testing the race model inequality: An algorithm and computer programs

In divided-attention tasks, responses are faster when two target stimuli are presented, and thus one is redundant, than when only a single target stimulus is presented. Raab (1962) suggested an account of this redundant-targets effect in terms of a race model in which the response to redundant target stimuli is initiated by the faster of two separate target detection processes. Such models make a prediction about the probability distributions of reaction times that is often called the race model inequality, and it is often of interest to test this prediction. In this article, we describe a precise algorithm that can be used to test the race model inequality and present MATLAB routines and a Pascal program that implement this algorithm.     

The auditory redundant signals effect: An influence of number of stimuli or number of percepts?

In two experiments, we examined simple reaction times (RTs) for detection of the onsets and offsets of auditory stimuli. Both experiments assessed the redundant signals effect (RSE), which is traditionally defined as the reduction in RT associated with the presentation of two redundant stimuli, rather than a single stimulus. In Experiment 1, with two identical tones presented via headphones to the left ear, right ear, or both, no RSE was found in responding to tone onsets, but a large RSE was found in responding to their offsets. In Experiment 2, with a pure tone and white noise as the two stimulus alternatives, RSEs were found for responding to both onsets and offsets. The results support the notion that the occurrence of an RSE depends on the number of percepts, rather than the number of stimuli, and on the requirement to respond to stimulus onsets versus offsets. The parallel grains model (Miller & Ulrich, 2003) provides one possible account of this pattern of results.     

Done wrong or said wrong? Young children understand the normative directions of fit of different speech acts

Young children use and comprehend different kinds of speech acts from the beginning of their communicative development. But it is not clear how they understand the conventional and normative structure of such speech acts. In particular, imperative speech acts have a world-to-word direction of fit, such that their fulfillment means that the world must change to fit the word. In contrast, assertive speech acts have a word-to-world direction of fit, such that their fulfillment means that the word must fit the world truly. In the current study, 3-year-olds understood this difference explicitly, as they directed their criticisms selectively to actors when they did not follow the imperatives of the speaker, but to speakers when they did not describe an actor’s actions correctly. Two-year-olds criticized appropriately in the case of imperatives, but showed a more ambiguous pattern in the case of assertions. These findings identify another domain in which children’s normative understanding of human activity emerges around the third year of life.     

Blood and whole-body androgen levels of male swordtails correlated with aggression measures in a standard-opponent test

The scores of three aggression parameters in a standard-opponent test correlated significantly with individual androgen concentrations measured in tissue as well as in blood samples taken immediately after the test (bites: r = +.62/+.82, threats: r = + 0.75/+.70, latency: r = −.66/−.53). If the test was performed after 28 days of social isolation no correlations were found. There were also no correlations between behavioural measures and corticoids.