Multistable syllables as enacted percepts: a source of an asymmetric bias in the verbal transformation effect

Perceptual changes are experienced during rapid and continuous repetition of a speech form, leading to an auditory illusion known as the verbal transformation effect. Although verbal transformations are considered to reflect mainly the perceptual organization and interpretation of speech, the present study was designed to test whether or not speech production constraints may participate in the emergence of verbal representations. With this goal in mind, we examined whether variations in the articulatory cohesion of repeated nonsense words--specifically, temporal relationships between articulatory events--could lead to perceptual asymmetries in verbal transformations. The first experiment displayed variations in timing relations between two consonantal gestures embedded in various nonsense syllables in a repetitive speech production task. In the second experiment, French participants repeatedly uttered these syllables while searching for verbal transformation. Syllable transformation frequencies followed the temporal clustering between consonantal gestures: The more synchronized the gestures, the more stable and attractive the syllable. In the third experiment, which involved a covert repetition mode, the pattern was maintained without external speech movements. However, when a purely perceptual condition was used in a fourth experiment, the previously observed perceptual asymmetries of verbal transformations disappeared. These experiments demonstrate the existence of an asymmetric bias in the verbal transformation effect linked to articulatory control constraints. The persistence of this effect from an overt to a covert repetition procedure provides evidence that articulatory stability constraints originating from the action system may be involved in auditory imagery. The absence of the asymmetric bias during a purely auditory procedure rules out perceptual mechanisms as a possible explanation of the observed asymmetries.     

Illusion of sense of self-agency: discrepancy between the predicted and actual sensory consequences of actions modulates the sense of self-agency, but not the sense of self-ownership

It is proposed that knowledge of motor commands is used to distinguish self-generated sensation from externally generated sensation. In this paper, we show that the sense of self-agency, that is the sense that I am the one who is generating an action, largely depends on the degree of discrepancy resulting from comparison between the predicted and actual sensory feedback. In Experiment 1, the sense of self-agency was reduced when the presentation of the tone was unpredictable in terms of timing and its frequency, although in fact the tone was self-produced. In Experiment 2, the opposite case was found to occur. That is, participants experienced illusionary sense of self-agency when the externally generated sensations happened to match the prediction made by forward model. In Experiment 3, the sense of self-agency was reduced when there was a discrepancy between the predicted and actual sensory consequences, regardless of presence or absence of a discrepancy between the intended and actual consequences of actions. In all the experiments, a discrepancy between the predicted and actual feedback had no effects on sense of self-ownership, that is the sense that I am the one who is undergoing an experience. These results may suggest that both senses of self are mutually independent.     

Selection of effective tests of motor ability in preschool children based on pass-or-fail criteria: examination of reliability, objectivity, and rate of passing

The purpose of this study was to select effective tests of motor ability based on pass-or-fail criteria for use with preschool children. 37 items selected by examining theoretical validity and the results of preliminary tests were administered to preschool children (3 yr.: M = 3.7 yr., SD = 0.28; 4 yr.: M = 4.7 yr., SD = 0.28; 5 yr.: M = 5.7 yr., SD = 0.28). A skilled tester and each child's homeroom teacher rated whether the child's performance passed certain criteria or not. With agreement on two trials as an index of test-retest reliability, the mean agreement among the three grades ranged from 69% to 99% for Locomotion, 59% to 95% for Manipulation; and 66% to 100% for Stability. Disagreement on two trials may reflect instability in movement, practice effects, and so on. With agreement between two testers as an index of objectivity for 37 items, 33 showed interrater agreement of 80% or more for all three grades. No significant increase in pass rate with age was found on 10 items. In examining the three conditions mentioned above 27 items were selected as tests of motor ability: 14 items for Locomotion, 7 items for Manipulation, and 6 items for Stability.     

Impaired Learning and Motor Behavior in Heterozygous Pafah1b1 (Lis1) Mutant Mice

Heterozygous mutation or deletion of Pafah1b1 (LIS1) in humans is associated with syndromes with type 1 lissencephaly, a severe brain developmental disorder resulting from abnormal neuronal migration. We have created Lis1 heterozygous mutant mice by gene targeting. Heterozygous mutant mice are viable and fertile, but display global organizational brain defects as a result of impaired neuronal migration. To assess the functional impact of the mutation, Lis1 heterozygous mice and their wild-type littermates were evaluated on a wide variety of behavioral tests. Lis1 mutant mice displayed abnormal hindpaw clutching responses and were impaired on a rotarod test. Lis1 heterozygous mice were also impaired in the spatial learning version of the Morris water task. Impaired motor behavior and spatial learning and memory in Lis1 mutant mice indicates that impaired neuronal migration can have functional effects on complex behavioral responses. The behavioral findings also support the use of the Lis1 mutant mice as a model from human type 1 lissencephaly.     

Relative quantity judgment by Asian elephants (Elephas maximus)

This study investigated whether Asian elephants can make relative quantity judgment (RQJ), a dichotomous judgment of unequal quantities ordered in magnitude. In Experiment 1, elephants were simultaneously shown two baskets with differing quantities of bait (up to 6 items). In Experiment 2, elephants were sequentially presented with baits, which could not be seen by elephants in their total quantities. The task of elephants was to choose the larger quantity in both experiments. Results showed that the elephants chose the larger quantity with significantly greater frequency. Interestingly, the elephants did not exhibit disparity or magnitude effects, in which performance declines with a smaller difference between quantities in a two-choice task, or the total quantity increases, respectively. These findings appear to be inconsistent with the previous reports of RQJ in other animals, suggesting that elephants may be using a different mechanism to compare and represent quantities than previously suggested for other species.     

Evidence of means–end behavior in Asian elephants (<Emphasis Type="Italic">Elephas maximus</Emphasis>)

The present study explores to what extent Asian elephants show “means–end” behavior. We used captive Asian elephants (N = 2) to conduct four variations of the Piagetian “support” problem, which involves a goal object that is out of reach, but rests on a support within reach. In the first condition, elephants were simultaneously presented with two identical trays serving as the “support”, with the bait on one tray and the other tray left empty. In the next two conditions, the bait was placed on one tray, while additional bait was placed beside the other tray. In the last condition, both trays contained bait, but one of the trays had a small gap which prevented the elephants from reaching the reward. Subjects were required to choose and pull either tray with their trunk and to obtain the bait (i.e. goal). Results showed that one elephant performed all of the support problems significantly above chance after several sessions, suggesting that the elephant was capable of understanding that pulling the tray was the “means” for achieving the “end” of obtaining the bait. This study showed that elephants show means–end behavior when subjected to a Piagetian “support” task, and indicates that such goal-directed behavior occurs in species other than primates.     

Spontaneous facial mimicry in response to dynamic facial expressions

Based on previous neuroscientific evidence indicating activation of the mirror neuron system in response to dynamic facial actions, we hypothesized that facial mimicry would occur while subjects viewed dynamic facial expressions. To test this hypothesis, dynamic/static facial expressions of anger/happiness were presented using computer-morphing (Experiment 1) and videos (Experiment 2). The subjects' facial actions were unobtrusively videotaped and blindly coded using Facial Action Coding System [FACS; Ekman, P., & Friesen, W. V. (1978). Facial action coding system. Palo Alto, CA: Consulting Psychologist]. In the dynamic presentations common to both experiments, brow lowering, a prototypical action in angry expressions, occurred more frequently in response to angry expressions than to happy expressions. The pulling of lip corners, a prototypical action in happy expressions, occurred more frequently in response to happy expressions than to angry expressions in dynamic presentations. Additionally, the mean latency of these actions was less than 900 ms after the onset of dynamic changes in facial expression. Naive raters recognized the subjects' facial reactions as emotional expressions, with the valence corresponding to the dynamic facial expressions that the subjects were viewing. These results indicate that dynamic facial expressions elicit spontaneous and rapid facial mimicry, which functions both as a form of intra-individual processing and as inter-individual communication.