Introspective duration estimation of reactive and proactive motor responses

The metajudgment of motor responses refers to our ability to evaluate the accuracy of our own actions. Can humans metajudge the duration of their Reaction Times (RTs) to a light-flash and the accuracy of their reproduction of a reference time interval bounded by two light flashes (Anticipatory Response Time, ART)? A series of four distinct experiments shows that RT_Meta and ART_Metajudgments are possible but with accuracies about ×2.4 and ×3 poorer than the corresponding RT and ART ones. In order to reveal the origin of this drop in performance, we ask whether a visual feedback synchronous with subjects’ key-presses could improve performance. We show that overall the presence of a visual feedback does not significantly improve metajudgment accuracy although such a trend is noticeable in ART_Meta. We then compare these performances with the passive perceptual estimation of the played back (Pb) RT and ART time intervals when bounded by two (RT_Pb) and three (ART_Pb) light flashes. We show that RT_Meta and RT_Pb accuracies are close to equal, but that ART_Meta is about ×2 less accurate than ART_Pb which in turn is ×1.5 less accurate than ART. The latter observation fails however to reach statistical significance hence not sustaining proposals that active time estimation is more reliable than passive one. The whole dataset is accounted for by a clock-type model where duration estimation performance is limited by four noise sources (visual, clock-count, motor and proprioceptive + efference copy) plus one proper to ART_Meta task. It is proposed that the latter reflects the impossibility for the time-counting system to use the same time origin more than once.     

Day by day,hour by hour: Naturalistic language input to infants

Measurements of infants’ quotidian experiences provide critical information about early development. However, the role of sampling methods in providing these measurements is rarely examined. Here we directly compare language input from hour‐long video‐recordings and daylong audio‐recordings within the same group of 44 infants at 6 and 7 months. We compared 12 measures of language quantity and lexical diversity, talker variability, utterance‐type, and object presence, finding moderate correlations across recording‐types. However, video‐recordings generally featured far denser noun input across these measures compared to the daylong audio‐recordings, more akin to ‘peak’ audio hours (though not as high in talkers and word‐types). Although audio‐recordings captured ~10 times more awake‐time than videos, the noun input in them was only 2–4 times greater. Notably, whether we compared videos to daylong audio‐recordings or peak audio times, videos featured relatively fewer declaratives and more questions; furthermore, the most common video‐recorded nouns were less consistent across families than the top audio‐recording nouns were. Thus, hour‐long videos and daylong audio‐recordings revealed fairly divergent pictures of the language infants hear and learn from in their daily lives. We suggest that short video‐recordings provide a dense and somewhat different sample of infants’ language experiences, rather than a typical one, and should be used cautiously for extrapolation about common words, talkers, utterance‐types, and contexts at larger timescales. If theories of language development are to be held accountable to ‘facts on the ground’ from observational data, greater care is needed to unpack the ramifications of sampling methods of early language input.     

Guest editorial preface: special issue on pantheism and panentheism

International Journal for Philosophy of Religion -     

Preschool children's use of cues to generic meaning

Sentences that refer to categories - generic sentences (e.g., "Dogs are friendly") - are frequent in speech addressed to young children and constitute an important means of knowledge transmission. However, detecting generic meaning may be challenging for young children, since it requires attention to a multitude of morphosyntactic, semantic, and pragmatic cues. The first three experiments tested whether 3- and 4-year-olds use (a) the immediate linguistic context, (b) their previous knowledge, and (c) the social context to determine whether an utterance with ambiguous scope (e.g., "They are afraid of mice", spoken while pointing to 2 birds) is generic. Four-year-olds were able to take advantage of all the cues provided, but 3-year-olds were sensitive only to the first two. In Experiment 4, we tested the relative strength of linguistic-context cues and previous-knowledge cues by putting them in conflict; in this task, 4-year-olds, but not 3-year-olds, preferred to base their interpretations on the explicit noun phrase cues from the linguistic context. These studies indicate that, from early on, children can use contextual and semantic information to construe sentences as generic, thus taking advantage of the category knowledge conveyed in these sentences.     

Information learned from generic language becomes central to children’s biological concepts: Evidence from their open-ended explanations

Generic sentences (e.g., “Snakes have holes in their teeth”) convey that a property (e.g., having holes in one’s teeth) is true of a category (e.g., snakes). We test the hypothesis that, in addition to this basic aspect of their meaning, generic sentences also imply that the information they express is more conceptually central than the information conveyed in similar non-generic sentences (e.g., “This snake has holes in his teeth”). To test this hypothesis, we elicited 4- and 5-year-old children’s open-ended explanations for generic and non-generic versions of the same novel properties. Based on arguments in the categorization literature, we assumed that, relative to more peripheral properties, properties that are understood as conceptually central would be explained more often as causes and less often as effects of other features, behaviors, or processes. Two experiments confirmed the prediction that preschool-age children construe novel information learned from generics as more conceptually central than the same information learned from non-generics. Additionally, Experiment 2 suggested that the conceptual status of novel properties learned from generic sentences becomes similar to that of familiar properties that are already at the category core. These findings illustrate the power of generic language to shape children’s concepts.     

Agency,Consciousness, and Executive Control

On the Causal Theory of Action (CTA), internal proper parts of an agent such as desires and intentions are causally responsible for actions. CTA has increasingly come under attack for its alleged failure to account for agency. A recent version of this criticism due to François Schroeter proposes that CTA cannot provide an adequate account of either the executive control or the autonomous control involved in full-fledged agency. Schroeter offers as an alternative a revised understanding of the proper role of consciousness in agency. In this paper we criticize Schroeter’s analysis of the type of consciousness involved in executive control and examine the way in which the conscious self allegedly intervenes in action. We argue that Schroeter’s proposal should not be preferred over recent versions of CTA.     

Comparison of perceptual and motor latencies via anticipatory and reactive response times

To compare the timing of perceptual and motor decisions, distinct tasks have been designed, all of which have yielded systematic differences between these two moments. These observations have been taken as evidence of a sensorimotor dissociation. Inasmuch as the distinction between perceptual and motor decision moments is conceptually warranted, this conclusion remains debatable, since the observed differences may reflect the dissimilarity between the stimulations/tasks used to assess them. Here, we minimize such dissimilarities by comparing response time (RT) and anticipatory RT (ART), an alternative technique with which to infer the relative perceptual decision moments. Observers pressed a key either in synchrony with the third of a sequence of three stimuli appearing at a constant pace (ART) or in response to the onset of this third stimulus presented at a random interval after the second (RT). Hence, the two stimulation sequences were virtually identical. Both the mean and the variance of RT were affected by stimulus intensity about 1.5 times more than were the mean and the variance of ART. Within the framework of two simple integration-to-bound models, these findings are compatible with the hypothesis that perceptual and motor decisions operate on the same internal signal but are based on distinct criteria, with the perceptual criterion lower than the motor one.     

The effect of generic statements on children's causal attributions: questions of mechanism

Generic statements, or generics, express generalizations about entire kinds (e.g., "Girls are good at a game called 'tooki'"). In contrast, nongeneric statements express facts about specific (sets of) individuals (e.g., "Jane is good at tooki"). Aside from simply conveying information, generics and nongenerics also instill different causal perspectives on the facts expressed, implying that these facts stem from deep, inherent causes (e.g., talent) or from external, mechanistic causes (e.g., instruction), respectively. In the present research (with samples of 4- to 7-year-olds and undergraduates, N = 220), we proposed that children's causal attributions for the facts learned through these statements are determined not by the generic/nongeneric format of the statements themselves but rather by the generic/nongeneric format of the beliefs relevant to these statements. This proposal led to two specific predictions. First, the influence of the generic belief induced by a novel generic statement should be detected in any subsequent context that falls under its scope--even in circumstances that involve particular individuals. Confirming this prediction, participants often attributed a fact conveyed in a nongeneric statement (e.g., a particular girl's tooki ability) to deep, inherent causes if they had previously formed a relevant generic belief (e.g., by hearing that girls are good at tooki). Second, we predicted that nongeneric statements such as "Most girls are good at tooki" should also promote attributions to deep causes because they often ultimately give rise to generic beliefs, as suggested by recent evidence. This prediction was confirmed as well. These results clarify and expand our knowledge of the influence of language on children's understanding of the world.