Preschoolers doing arithmetic: the concepts are willing but the working memory is weak.

The study of early mathematical development provides important insights into young children's emerging academic competencies and, potentially, a basis for adapting instructional methods. We presented nonverbal forms of two- and three-term arithmetic problems to 4-year-olds to determine (a) the extent to which certain information-processing demands make some problems more difficult than others and (b) whether preschoolers use arithmetic concepts spontaneously when solving novel problems. Children's accuracy on simple arithmetic problems (a + b and a - b) was strongly related (r2 = .88) to representational set size, the maximum number of units that need to be held in working memory to solve a given problem. Some children also showed spontaneous use of procedures based on the arithmetic principle of inversion when solving problems of the form a + b - b. These results highlight the importance of identifying information-processing and conceptual characteristics in the early development of mathematical cognition.     

Visual Prior Entry

It has long been claimed that attended stimuli are perceived prior to unattended stimuli–the doctrine of prior entry. Most, if not all, studies on which such claims have been based, however, are open to a nonattentional interpretation involving response bias, leading some researchers to assert that prior entry may not exist. Given this controversy, we introduce a novel methodology to minimize the effect of response bias by manipulating attention and response demands in orthogonal dimensions. Attention was oriented to the left or right (i.e., spatially), but instead of reporting on the basis of location, observers reported the order (first or second) of vertical versus horizontal line segments. Although second-order response biases were demonstrated, effects of attention in accordance with the law of prior entry were clearly obtained following both exogenous and endogenous attentional cuing.     

The effects of scene inversion on change blindness

In two experiments, participants searched for a difference between two views of a scene. In Experiment 1, the authors extended the change-blindness findings from previous work by R. A. Rensink, J. K. O'Regan, and J. J. Clark (1997), which used an experimenter-induced global transient, to a less artificial situation in which participants searched for a difference in a pair of photographic images presented simultaneously. To examine the idea that meaning-driven endogenous orienting was responsible for the previously observed advantage for changes in center-of-interest items, the authors inverted half of the image pairs. The advantage for center-of-interest items was replicated with upright displays, but it was completely eliminated by inversion, strongly supporting the role of meaning-driven endogenous orienting in this task. With flickering displays (Experiment 2), the center-of-interest effect was completely unaffected by inversion. The authors suggest that when change blindness is induced via flicker, scene modifications are typically found by stimulus-driven rather than by meaning-driven processes.     

Visual and motor effects in inhibition of return

Inhibition of return (IOR) refers to slowed reaction times (RTs) when a target appears in the same rather than a different location as a preceding stimulus. The present study tested the hypothesis that IOR reflects a motor bias rather than a perceptual deficit. Two signals (S1 and S2) were presented on each trial. These signals were peripheral onsets or central arrows. The responses required to S1 and S2 were, respectively, no response-manual, manual-manual, saccadic-manual, no response-saccadic, manual-saccadic, and saccadic-saccadic. Uniting perceptual and motor bias views of IOR, the results demonstrated inhibition for responding to (a) peripheral signals when the eyes remained fixed (slowed visual processing) and (b) both peripheral and central signals when the eyes moved (slowed motor production). However, the results also emphasized that the nature of IOR depends fundamentally on the response modality used to reveal its influence.     

The assessment of analogical thinking modifiability among regular,special education,disadvantaged, and mentally retarded children

The objectives of the current study were (a) to develop a measure of children's analogical thinking modifiability (CATM) based on the Feuerstein, Rand, and Hoffman (1979) theory of dynamic assessment of cognitive modifiability, (b) to compare the performance of groups assumed to be differentially modified by intervention, (c) to compare CATM performance with performance on a conventional test, and (d) to study qualitative changes after a learning process. Subjects were disdvantaged, regular, and special education kindergarten children (N=140), and mentally retarded children (N=20). The CATM was administered together with the Ravens Colored Progressive Matrices (RCPM) in a balanced order. Disadvantaged and regular children achieved higher gain scores than other groups in both none-or-all and partial credit methods (p < 01). The MR and the special education groups showed small gains according to the none-or-all credit method; however, according to the partial credit method, the MR group showed high gains and the special education group a performance decrease. Performance scores on the CATM were higher than on the RCPM, especially in comparison to the B₈-B₁₂ items-differences reach a peak of 61% and 67% for the disadvantaged and regular groups, respectively. Qualitative analysis indicated that form mistakes were most resistant to change, whereas color mistakes were most easy to modify. Results were explained within Feuerstein's theoretical framework of cognitive modifiability. Impaired cognitive functions as well as analytic versus synthetic processes were suggested to explain group differences.This research was supported in part by the Internal Research Fund, Bar-Ilan University. We wish to express our appreciation to the children and their teachers for their participation, to Frida Spanier for teaching and data collection, and to Steve Greenwald for data analysis.     

Is Posner's "beam" the same as Treisman's "glue"?: On the relation between visual orienting and feature integration theory

In the present study we investigated whether the visually allocated "beam" studied by Posner and others is the same visual attentional resource that performs the role of feature integration in Treisman's model. Subjects were cued to attend to a certain spatial location by a visual cue, and performance at expected and unexpected stimulus locations was compared. Subjects searched for a target letter (R) with distractor letters that either could give rise to illusory conjunctions (PQ) or could not (PB). Results from three separate experiments showed that orienting attention in response to central cues (endogenous orienting) showed similar effects for both conjunction and feature search. However, when attention was oriented with peripheral visual cues (exogenous orienting), conjunction search showed larger effects of attention than did feature search. It is suggested that the attentional systems that are oriented in response to central and peripheral cues may not be the same and that only the latter performs a role in feature integration. Possibilities for future research are discussed.     

The Elusiveness of Gustatory Potentiation of an Environmental Aversion

Two experiments investigated conditions that influence whether or not the presence of a flavor cue potentiates acquisition of an environmental aversion. Experiments 1 and 2 exposed rats to either a salient sucrose flavor or nonsalient water with black box-illness pairings. Half of the rats in the sucrose and water treatment groups became ill after exposure to the black chamber in their home cage. The other half of the rats in the two treatment conditions became ill in the black box. The results of each study indicated that a strong environmental aversion was established when illness was associated with exposure to the black box. The aversiveness of the black chamber was indicated by both less time spent in the black side and reduced intake in the black chamber. The presence of sucrose during conditioning did produce a stronger black box aversion than did water. Reliable potentiation of the environmental aversion, however, was seen only when the illness experience occurred in the black chamber but not when illness occurred in the home cage. A weaker aversion to the black chamber was also found in the water groups when illness occurred shortly after experience with the black box than when illness immediately followed exposure to the black chamber.

     

Elaboration, organization, and the self-reference effect in memory

Relating information to the self (self-referent encoding) has been shown to produce better recall than purely semantic encoding. This finding has been interpreted as demonstrating that self-reference produces a more elaborate memory trace than semantic encoding, and it has been cited frequently as evidence that the self is one of the most highly elaborated structures in memory. The experiments reported in this article challenge this interpretation of the self-reference effect by demonstrating that self-referent and semantic encodings produce virtually identical free recall levels if they are first equated for the amount of organization they encourage. On the basis of our findings we conclude the following: Organization, not elaboration, is responsible for the superior recall performance obtained when information is encoded self-referentially, and organization is not a necessary component of self-referent encoding and can be orthogonally varied within self-referent and semantic encoding tasks. Finally, we discuss how a single-factor theory based on organization can account for many of the self-referent recall findings reported in the literature.     

Distance distortions in children's cognitive maps: an examination of the information storage model

Second graders (mean age = 7-8), fourth graders (mean age = 9-8), and sixth graders (mean age = 11-11) walked two paths located in and around their school. Children in the Unsegmented condition estimated the distance and time taken to walk a path that was relatively undifferentiated in terms of the number of qualitatively different areas of the school through which it passed. Children in the Segmented condition made the same estimates for a path that went through different areas (segments) of the school (i.e., cafeteria, hall, vestibule, and outside the building). Children at all three grade levels estimated that the distance traversed in the Segmented condition was longer than the distance in the Unsegmented condition. This difference was not significant on the time measure. It was concluded that (1) paths with a large number of segments are perceived as being longer than paths of the same length with fewer segments, (2) distances along paths with few segments are underestimated, (3) distances along paths with many segments may be overestimated as a function of developmental level, and (4) only younger children may have used time to estimate distance.