Immunocytochemical Mapping of an RDL-Like GABA Receptor Subunit and of GABA in Brain Structures Related to Learning and Memory in the Cricket Acheta domesticus

The distribution of putative RDL-like GABA receptors and of γ-aminobutyric acid (GABA) in the brain of the adult house cricket Acheta domesticus was studied using specific antisera. Special attention was given to brain structures known to be related to learning and memory. The main immunostaining for the RDL-like GABA receptor was observed in mushroom bodies, in particular the upper part of mushroom body peduncle and the two arms of the posterior calyx. Weaker immunostaining was detected in the distal part of the peduncle and in the α and β lobes. The dorso- and ventrolateral protocerebrum neuropils appeared rich in RDL-like GABA receptors. Staining was also detected in the glomeruli of the antennal lobe, as well as in the ellipsoid body of the central complex. Many neurons clustered in groups exhibit GABA-like immunoreactivity. Tracts that were strongly immunostained innervated both the calyces and the lobes of mushroom bodies. The glomeruli of the antennal lobe, the ellipsoid body, as well as neuropils of the dorso- and ventrolateral protocerebrum were also rich in GABA-like immuno- reactivity. The data demonstrated a good correlation between the distribution of the GABA-like and of the RDL-like GABA receptor immunoreactivity. The prominent distribution of RDL-like GABA receptor subunits, in particular areas of mushroom bodies and antennal lobes, underlines the importance of inhibitory signals in information processing in these major integrative centers of the insect brain.     

Heidegger and the source(s) of intelligibility

Wittgensteinian readings of Being and Time, and of the source of the intelligibility of Dasein's world, in terms of language and the average everyday public practices of das Man are partly right and partly wrong. They are right in correcting overly individualist and existentialist readings of Heidegger. But they are wrong in making Heidegger into a proponent of language or everydayness as the final word on intelligibility and the way the world is disclosed to us. The everydayness of das Man and language are partial sources of intelligibility but only insofar as they are comprehended within the greater unitary structure of care and temporality. Care and temporality constitute the foundational underpinnings for disclosure and the intelligibility ofthat wherein Dasein dwells.     

Age trends in early behavioral predictors of serious antisocial behaviors

A risk group of disruptive boys (N=65) identified in kindergarten was assessed using the same procedures at ages 6–7, 8–9, and 10–11. Criteria used to define the predictors and criterion variable were the same at all assessment times. Severity was addressed by comparing different forms of behaviors, considering the extent of harmful consequences to others (aggressiveness was considered as most harmful, whereas inattention was considered as least harmful), manifestation in multiple settings, and extreme scores (manipulation of cutoff scores). Different assessment strategies (direct observations, ratings) and different informants (trained observers, mothers and teachers) were used. Aggressiveness as rated by mothers was highly stable from age 6 to age 11. Inattention as rated by teachers was stable only from age 6 to age 9, whereas no stability was found for observations of task inappropriate behaviors. Taskinappropriate behaviors observed in mother-child interactions and in multiple settings at age 6–7 were significant predictors of self-reported antisocial behaviors at age 12, but this prediction was not repeated at ages 8–9 and 10–11. Teacher ratings of inattention at ages 6–7 and 8–9 were also significant predictors of self-reported antisocial behaviors at age 12. The predictive power was much lower when mothers' ratings of aggressiveness were used. Findings from the present study support the hypothesis that some antisocial behavior precursors are age dependent, in that they are more characteristic of certain age groups than of others. Implications for the selection of assessment screening procedures are discussed.     

Isolating Unconscious Influences: The Neutral Parameter Procedure

Earlier demonstrations of unconscious learning have been regularly challenged. In this paper, we suggest that earlier demonstrations were not compelling due to certain properties of the experimental situations, and notably that conscious exploitation of explicit knowledge, if present, would coincide or conflict with the results of unconscious processing. We designed a method consisting of inducing a neutral behavioural change in the way subjects drew geometric figures. Two experiments showed that important and long-lasting modifications of drawing behaviour were obtained following specially devised practice, although these modifications could not be expected from deliberate adaptive strategies. In addition, we showed that subjects were unaware of the manipulation to which they had been exposed. The study provides striking evidence for unconscious learning and offers insights for the design of suitable new tools to investigate unconscious cognition.     

The emergence of explicit knowledge during the early phase of learning in sequential reaction time tasks

Five experiments investigated the formation of explicit knowledge of a repeating sequence in a sequential reaction time task. Reliable explicit knowledge was obtained even though various conditions prevented the selective improvement of RTs (Exps. 1–4). This knowledge emerged early during training. Participants were able to recognize segments of the sequence (Exps. 3 and 4) or correctly assess the probabilities of transition of the target between successive locations (Exp. 5) after only two blocks of training trials. These findings rule out an interpretation of sequence learning that posits that explicit knowledge emerges from implicit knowledge during the course of training. Although these findings are compatible with a framework centered around the notion of dissociation between implicit and explicit knowledge, they are also consonant with a questioning of the usefulness of the concept of implicit knowledge.     

Stereotyping and action tendencies attribution as a function of available emotional information

In three experiments, we addressed the role of stereotypes in the attribution of action tendencies in intergroup contexts. We hypothesized that stereotyping would affect the attribution of action tendencies to out‐group members. Participants were presented with a facial expression displayed by either an in‐group or an out‐group member, followed by the presentation of a label describing an action tendency. They were then asked whether the label corresponded to the feeling state of the expresser. Study 1 tested whether stereotypes influence the attribution of action tendencies to out‐group members. Study 2 tested whether stereotype application varies as a function of the emotional information contained in the facial stimuli (i.e. neutral vs. emotional). Finally, Study 3 tested whether stereotype activation is indirectly determined by a difference in morphology between in‐group and out‐group members or directly determined by the expresser's group membership. As predicted, an increase in attribution of stereotypic action tendencies was observed for out‐group expressers. The application of stereotypes was specifically observed when facial expressions were neutral as compared to emotional and was independent of morphological differences between in‐group and out‐group faces. Such biases in interpreting out‐group members feeling states may play a crucial role in the maintenance of intergroup prejudice. Copyright © 2005 John Wiley & Sons, Ltd.     

Two-month-old infants of depressed mothers show mild, delayed and persistent change in emotional state after non-contingent interaction

The aim of this study was to explore how early infants show different responses to non-contingent maternal behavior according to their past history of relations with their mother. Two groups of 2-month-olds interacted with their mother who was assessed as depressed (group 1) or non-depressed (group 2). Although they received a continuous image and voice of their mothers, the infants were presented either a 30-s contingent maternal communication (live episode 1) or a thirty second non-contingent episode (replay of prior maternal communication), or again a 30-s contingent live episode (live2). The lower percentage of negative facial expressions displayed during replay by infants of depressed mothers suggests on one hand that they are less sensitive to a non-contingent maternal behavior than infants of non-depressed mothers. However, within group comparisons demonstrate a notable difference: while infants of non-depressed mothers show a U curve of smile, infants of depressed mothers show decreasing smile throughout the three episodes. Taken together, these results plead in favour of an other profile of sensitivity displayed by infants of depressed mothers. Instead of the strong but short-term reaction of infants of non-depressed mothers, the response of infants of depressed mothers appeared to be a mild, delayed and more persistent change in emotional state. These findings are discussed in the light of possible cognitive and social incidence of passive avoidance of stressful events in infants of depressed mothers.     

Development of children's mental representations: effects of age, sex, and school experience

In the present study mental representations in drawings by 158 young children, ages 2 1/2 to 6 yr. old were analysed. The aim was to investigate whether the accuracy of mental representations increased with age and how this development progressed. Also tested were whether the inferred mental representations differed for boys and girls and whether preschool experience affected the drawings. As expected, mental representation increased in complexity with age as measured by Goodenough's score, and girls' mental representations (drawings) were significantly more elaborate than boys. Moreover, attending school early seemed to affect mental representations of the 3-yr.-olds but not the 4-yr.-olds. Results are discussed in terms of internal and external factors in mental representation in drawing a man.