Metalinguistic awareness and language development

Thirty-six 3- and 4-year-old children were given a battery of six metalinguistic tasks and two measures of language development: the Peabody Picture Vocabulary Test and a sentence comprehension test. The results clearly showed that the majority of preschoolers were able to make at least some metalinguistic judgments, and that metalinguistic performance improved with age. Furthermore, overall performance on the metalinguistic tasks was significantly correlated with each language measure when the effects of age were partialed out. In contrast, the correlation between age and metalinguistic performance was not significant once the effects of both language measures were partialed out. These data demonstrate that preschoolers' metalinguistic abilities are more extensive than has been previously acknowledged, and that they are closely tied to other aspects of language development at this time.     

Recognition models evaluated: A commentary on Keren and Baggen

In a recent paper (1981), Keren and Baggen proposed two new models for alphanumeric confusion data, based on Tversky’s (1977) feature model of similarity, and compared them with Luce’s (1963) biased choice model. On the basis of their data, they concluded that, although the choice model fit slightly better, their models were to be preferred on grounds of parsimony and interpretability. It is shown here that both of these models are special cases of the Luce model, so that the general Luce model will necessarily fit better. This leads to considerable reinterpretation of Keren and Baggen’s conclusions. Finally, better methods of estimating parameters and evaluating goodness-of-fit are suggested, taking advantage of this relation between the models.     

Dual effects of response blocking following avoidance learning

It was shown that either enhanced or decreased avoidance responding by rats could be produced by the same response blocking procedure occurring after avoidance training. The particular result produced depended on (1) the duration of the blocking trial and (2) when during the retention interval the blocking trial occurred. Results were interpreted in terms of a memory reactivation explanation and implications for the therapeutic uses of extinction were discussed.     

Decreased locomotor and investigatory exploration after denervation of catecholamine terminal fields in the forebrain of rats.

Exploratory behaviors were examined after bilateral microinjections of 6-hydroxydopamine into two hypothalamic sites that produced different patterns of denervation of forebrain catecholamine terminal fields. After anterolateral injections rats locomoted and reared less in a novel open field, responded abnormally to changes in the degree of novelty of the open field, and investigated a novel object less. These are deficits in exploratory behavior because they were not secondary to the inhibition of open-field behavior by hyperemotionality, by general motor disability, or by the failure to detect novel spaces or objects. Such anterolateral injections produced loss of catecholamine fibers, determined histochemically, in neocortical, hippocampal, anterolateral hypothalamic, mesolimbic, mesocortical, and anteromedioventral striatal terminal fields and loss of dopaminergic perikarya in the A10 and anteromedial A9 cell groups. No deficits in exploratory behaviors occurred, however, after bilateral anteromedial 6-hydroxydopamine injections that denervated neocortical, hippocampal, and anteromedial hypothalamic catecholamine terminal fields. A critical forebrain catecholaminergic innervation for exploratory responses to novel stimuli may be within areas that were denervated by anterolateral but not by anteromedial hypothalamic 6-nydroxydopamine injections. These areas are mesolimbic, mesocortical, anteromedioventral, and anterolateral hypothalamic terminal fields.     

Affective and cognitive mediators of reactions to spatial invasions

At a crosswalk on a busy street, a confederate, sketching a drawing or not, stood close or far from a pedestrian for 10 sec before the street light indicated “Walk.” In the first study, pedestrians were given the opportunity to subsequently help this confederate or another accomplice by calling attention to a dropped pen. In the second study, crossing speeds were timed and pedestrians were asked to record their mood and reactions to “another pedestrian,” who happened to be the confederate. These studies tested and found evidence for both cognitive and arousal explanations of reactions to spatial invasions. Cognitive and attributional theories imply that characteristics of the invader are important mediators of reactions to the invasion. The close nonartist was judged to be more inappropriate, produced faster escape speeds, and was helped less than the close artist or the far confederates. Arousal explanations imply that any invasion produces a generalized reaction which would be unrelated to characteristics of the invader. The other accomplice was helped less when the subject had been invaded and this reduction in helping was unaffected by the artist manipulation. These findings suggest a general arousal response to any invasion with a subsequent reliance on cognitive interpretations.     

Semantic categorization in a linear order problem

The present investigation was conducted to determine whether subjects could use categorical codes based on semantic memory information (gender of names) to make rapid decisions about the order of names in a linear series. Subjects were taught linear order problems in which 12 names (six male and six female) were either randomly ordered or blocked by sex. The results support a dual-process model which proposes that subjects use both categorical information (discrete linguistic codes) and serial position information when asked to make mental comparisons of arbitrarily ordered items. Furthermore, the data indicate that both the ordinal distance between the terms in the test pair (step size) and the serial position of the test terms in the linear order affect the reaction time to a particular test comparison.