Graded semantic and phonological similarity effects in priming: evidence for a distributed connectionist approach to morphology

A considerable body of empirical and theoretical research suggests that morphological structure governs the representation of words in memory and that many words are decomposed into morphological components in processing. The authors investigated an alternative approach in which morphology arises from the interaction of semantic and phonological codes. A series of cross-modal lexical decision experiments shows that the magnitude of priming reflects the degree of semantic and phonological overlap between words. Crucially, moderately similar items produce intermediate facilitation (e.g., lately-late). This pattern is observed for word pairs exhibiting different types of morphological relationships, including suffixed-stem (e.g., teacher-teach), suffixed-suffixed (e.g., saintly-sainthood), and prefixed-stem pairs (preheat-heat). The results can be understood in terms of connectionist models that use distributed representations rather than discrete morphemes.     

Exploring Ethnic,Gender, and Sexual Orientation Variables in Supervision: Do They Really Matter?

This study explored discussions of cultural variables in supervision and their influence on supervisory satisfaction and working alliance. Results indicated limited discussions occurred, but when these discussions did occur, supervisees reported enhanced supervisory working alliance and increased satisfaction with supervision. These findings highlight the importance of supervisors initiating discussions of cultural variables. Este estudio exploró discusiones sobre variables culturales y su influencia en la satisfacción y alianza de supervisión. Los resultados indicaron discusiones limitadas, pero cuando estas ocurrieron, los supervisados reportaron un aumento en la alianza de trabajo y satisfacción con la supervisión. Estos resultados hacen notable la importancia de que los supervisores inicien discusiones sobre los variables culturales.     

Vowel perception: A neuroradiological localization of the perception of vowels in the human cortex

Whether the perception of vowels takes place in the right or left cerebral hemisphere, or is dependent on bilateral cortical processes, is of importance in our treatment of patients with language deficiencies. To investigate this problem a phonetic test with a series of vowellike stimuli was administered to 68 right-handed adult patients with cerebral lesions, mainly of vascular origin. The results were compared to the results in a control group of 19 speech therapists. Second, a neuroradiologic method was developed in order to visualize the anatomic site of Wernicke's area in the left hemisphere on CT scans. This method formed the basis for an evaluation of the extent and localization of the patients' lesions in Wernicke's area. Of 46 patients with lesions in the left hemisphere, 19 had no perceptual disturbances and 27 had severe perceptual disturbances with lesions predominantly located in Wernicke's area. Twenty-two patients with lesions in the corresponding area in the right hemisphere showed no perceptual disturbances. The results of this investigation appear to indicate that the perception of vowels in right-handed persons is unilaterally located in Wernicke's area in the left hemisphere.     

Spatial cuing in a stereoscopic display: Evidence for a “depth-aware” attentional focus

Two experiments were conducted to explore whether attentional selection occurs in depth, or whether attentional focus is “depth blind,” as suggested by Ghiradelli and Folk (1996). In Experiment 1, observers viewed stereoscopic displays in which one of four spatial locations was cued. Two of the locations were at a near-depth location and two were at a far-depth location, and a single target was presented along with three distractors. The results indicated a larger cost in reaction time for switching attention inx,y and depth than inx,y alone, supporting a “depth-aware” attentional spotlight. In Experiment 2, no distractors were present, similar to the displays used by Ghiradelli and Folk. In this experiment, no effect for switching attention in depth was found, indicating that the selectivity of attention in depth depends on the perceptual load imposed on observers by the tasks and displays.     

A goodness of fit test for the rasch model

The Rasch model is an item analysis model with logistic item characteristic curves of equal slope,i.e. with constant item discriminating powers. The proposed goodness of fit test is based on a comparison between difficulties estimated from different scoregroups and over-all estimates. Based on the within scoregroup estimates and the over-all estimates of item difficulties a conditional likelihood ratio is formed. It is shown that—2 times the logarithm of this ratio isx ²-distributed when the Rasch model is true. The power of the proposed goodness of fit test is discussed for alternative models with logistic item characteristic curves, but unequal discriminating items from a scholastic aptitude test.     

CONCEPT LEARNING

Une analyse détaillée des données expérimentales portant sur l'apprentissage des concepts, permet de voir que la démarche réelle des sujets peut prendre plusieurs formes. Les formes les plus éloignées l'une de l'autre sont d'une part, le raisonnement strictement logique dont l'algorithme est donné par quelques règles élémentaires, et d'autre part, le tâtonnement par essais et erreurs complètement fortuits. Entre ces deux extrêmes qui sont plus des abstractions que des procédés réels, on trouve beaucoup de formes qui sont des combinaisons diverses de raisonnement logique et d'essais fortuits. On peut schématiser les trajectoires des divers procédés possibles dont le plus fréquent est celui du choix d'une hypothèse dont la vérification se prolonge jusqu'au point où cette hypothèse est confirmée ou éliminée. La démarche réelle du sujet est ainsi une séquence de décisions. La question centrale qui reste à résoudre est celle des facteurs qui déterminent telle ou telle décision. On peut mettre ces facteurs en évidence à l'aide d'un plan expérimental spécial. Mais le choix des hypothèses et leur vérification n'est qu'une étape de cet apprentissage qui peut facilement devenir un apprentissage au sens le plus étroit du terme, à savoir l'apprentissage de l'algorithme (du raisonnement déductif) de l'apprentissage des concepts.     

2-D contour perception resulting from kinetic occlusion

Kinetic occlusion, the progressive deletion or accretion of texture elements as one surface covers or uncovers another, has been shown to be an important source of information for determining depth order. In the present study, the importance of this information for 2-D contour perception was examined. In Experiment 1, subjects were asked to discriminate four different target shapes defined solely by kinetic occlusion. Discrimination increased with an increase in texture density and velocity, with density as the major factor. In Experiment 2, the targets were defined by static untextured regions as well as by kinetic occlusion. Overall, accuracy was similar to that found in Experiment 1, indicating that the presence of static information had little impact on accuracy. In Experiment 3, subjects were unable to discriminate among the four targets when presented with static versions of the displays used in Experiment 2. The results from these experiments indicate that kinetic occlusion can be used for discrimination of different 2-D shapes and that density has a more important role in determining accuracy than velocity.     

Velocity gradients and relative depth perception

The effectiveness of velocity gradients in providing relative depth information was assessed using random dot patterns translating horizontally. The gradients simulated two planes meeting at a horizontal line at the center, and subjects judged whether the center was the nearest or farthest part of the display. Accuracy increased with maximum dot speed, exceeding 90% in conditions combining the highest speed (10.4^o/sec) and longer of two display durations (10 sec) with unrestricted fixation. Separate experiments examined a rotational component perceived in the motion of the planes and the latency in reporting a rigid organization of the displays. Possible reasons for the chance accuracy found by Farber and McConkie (1979) and alternative explanations of the effect of maximum dot speed on accuracy are discussed. A model is presented that accounts for the effects of dot speed and display duration on the accuracy of relative depth judgments.     

The use of occlusion to resolve ambiguity in parallel projections

Previous research has shown that the three-dimensional structure of an object usually can be perceived when viewing a parallel projection of the object rotating in depth. Accurate judgments of direction of rotation, however, have been found only with polar projections. The present study demonstrated that accurate direction judgments can occur with parallel projections if occlusion is included in the displays. The stimuli were parallel projections of pentagonal texture elements on the surface of a rotating sphere. In one condition, the elements were occluded as they rounded the edge of an opaque sphere. In another condition, elements on the far surface of a transparent sphere were occluded by elements on the near surface. Accuracy of direction judgments was consistently high in the first condition and increased monotonically with element size in the second condition, from chance to over 80% correct. The relationship of these results to the general issue of perceptually combining structure in depth information from one source with relative distance information from another source is discussed.