An examination of the effects of axis foreshortening, monocular depth cues, and visual field on object identification

Four experiments are reported on the identification of line drawings of common objects. In each experiment, performance on “unconventional” views of the objects, in which the major axis of the object was foreshortened, was compared to performance on more “conventional” views without appreciable foreshortening. In each experiment, except Experiment 2, where performance on the two views was experimentally equated, the foreshortened views were more difficult to identify than were the conventional views. Experiments 1 and 2 showed that if the foreshortened views were presented on a background with strong monocular depth cues, object identification was improved. This result suggests that part of the difficulty in identifying objects depicted from such a view stems from an improper depth interpretation of the object depictions. Experiments 3 and 4 examined visual field differences in the identification of the two types of object view. Results reported in the neuropsychological literature have shown that people with right-hemisphere damage have particular difficulty with the identification of unconventional views of objects that foreshorten major axes. Accordingly, it was expected that there would be a left visual field advantage for the foreshortened views. Neither experiment yielded any visual field effects consistent with this expectation. Possible reasons for the lack of a field effect are discussed.     

The use of control groups in artificial grammar learning

Experimenters assume that participants of an experimental group have learned an artificial grammar if they classify test items with significantly higher accuracy than does a control group without training. The validity of such a comparison, however, depends on an additivity assumption: Learning is superimposed on the action of non-specific variables—for example, repetitions of letters, which modulate the performance of the experimental group and the control group to the same extent. In two experiments we were able to show that this additivity assumption does not hold. Grammaticality classifications in control groups without training (Experiments 1 and 2) depended on non-specific features. There were no such biases in the experimental groups. Control groups with training on randomized strings (Experiment 2) showed fewer biases than did control groups without training. Furthermore, we reanalysed published research and demonstrated that earlier experiments using control groups without training had produced similar biases in control group performances, bolstering the finding that using control groups without training is methodologically unsound.     

Algorithmic solution of arithmetic problems and operands-answer associations in long-term memory

Many developmental models of arithmetic problem solving assume that any algorithmic solution of a given problem results in an association of the two operands and the answer in memory (Logan & Klapp, 1991; Siegler, 1996). In this experiment, adults had to perform either an operation or a comparison on the same pairs of two-digit numbers and then a recognition task. It is shown that unlike comparisons, the algorithmic solution of operations impairs the recognition of operands in adults. Thus, the postulate of a necessary and automatic storage of operands-answer associations in memory when young children solve additions by algorithmic strategies needs to be qualified.     

The development of emotion recognition from facial expressions and non‐linguistic vocalizations during childhood

Sensitivity to facial and vocal emotion is fundamental to children's social competence. Previous research has focused on children's facial emotion recognition, and few studies have investigated non‐linguistic vocal emotion processing in childhood. We compared facial and vocal emotion recognition and processing biases in 4‐ to 11‐year‐olds and adults. Eighty‐eight 4‐ to 11‐year‐olds and 21 adults participated. Participants viewed/listened to faces and voices (angry, happy, and sad) at three intensity levels (50%, 75%, and 100%). Non‐linguistic tones were used. For each modality, participants completed an emotion identification task. Accuracy and bias for each emotion and modality were compared across 4‐ to 5‐, 6‐ to 9‐ and 10‐ to 11‐year‐olds and adults. The results showed that children's emotion recognition improved with age; preschoolers were less accurate than other groups. Facial emotion recognition reached adult levels by 11 years, whereas vocal emotion recognition continued to develop in late childhood. Response bias decreased with age. For both modalities, sadness recognition was delayed across development relative to anger and happiness. The results demonstrate that developmental trajectories of emotion processing differ as a function of emotion type and stimulus modality. In addition, vocal emotion processing showed a more protracted developmental trajectory, compared to facial emotion processing. The results have important implications for programmes aiming to improve children's socio‐emotional competence.     

CONCEPTIONS ET STRATEGIES D'ADAPTATION DES ADOLESCENTS FACE A LA DEPRESSION*

The purpose of the study is to investigate how adolescents perceive and face depression. Two questionnaires, the Beliefs about Behaviour (BAB; Rippere 1977a) and the Coping Strategies Scales (COSTS; Beckham and Adams 1984), were given to 221 boys and 65 girls, with an age ranging from 11 to 18 years and from two different schools (Collège St-Alexandre and High School Erablière, both in Gatineau, Québec). Adolescents have a well-defined picture of depression. They face depression with strategies as given in COSTS and the strategies are more and more homogeneous as a function of increasing age.