Studying the grammatical aspects of word recognition: lexical priming,parsing, and syntactic ambiguity resolution

Two experiments are reported examining the relationship between lexical and syntactic processing during language comprehension, combining techniques common to the on-line study of syntactic ambiguity resolution with priming techniques common to the study of lexical processing. By manipulating grammatical properties of lexical primes, we explore how lexically based knowledge is activated and guides combinatory sentence processing. Particularly, we find that nouns (like verbs, see Trueswell & Kim, 1998) can activate detailed lexically specific syntactic information and that these representations guide the resolution of relevant syntactic ambiguities pertaining to verb argument structure. These findings suggest that certain principles of knowledge representation common to theories of lexical knowledge—such as overlapping and distributed representations—also characterize grammatical knowledge. Additionally, observations from an auditory comprehension study suggest similar conclusions about the lexical nature of parsing in spoken language comprehension. They also suggest that thematic role and syntactic preferences are activated during word recognition and that both influence combinatory processing.     

Cognition and affective style: Individual differences in brain electrical activity during spatial and verbal tasks

Relations between brain electrical activity and performance on two cognitive tasks were examined in a normal population selected to be high on self-reported measures of Positive or Negative Affectivity. Twenty-five right-handed women, from an original pool of 308 college undergraduates, were the participants. EEG was recorded during baseline and during psychometrically matched spatial and verbal tasks. As predicted, participants who were high in Positive Affectivity performed equally well on the verbal and spatial tasks, while participants who were high in Negative Affectivity had spatial scores that were lower than their verbal scores. There were no group differences in baseline EEG. Both groups exhibited left central activation (i.e., alpha suppression) during the verbal and spatial tasks. When EEG data were analyzed separately for the group high in Positive Affectivity, there was evidence of parietal activation for the spatial task relative to the verbal task. The EEG data for the group high in Negative Affectivity had comparable EEG power values during verbal and spatial tasks at parietal scalp locations. These data suggest that, within a selected normal population, differences in affective style may interact with cognitive performance and with the brain electrical activity associated with that performance.     

The role of the executive system in visuo-spatial memory functioning

Participants were presented with a spatial sequence in which between 4 and 10 cells were highlighted. On each trial list length was unknown to the participant who was required to serially recall the last four cells. Processing of longer lists is assumed to call upon the executive system, which is thought to be involved in updating the contents of the short-term visuo-spatial store. Study 1 revealed that loading the executive system with concurrent random letter generation impaired performance on the spatial task especially recall of the early serial positions. However, contrary to expectation the degree of impairment was no greater on the longer lists, where it had been assumed that updating would be occurring. Study 2 confirmed this finding and demonstrated that relative to sequences of known length, under conditions of uncertainty when the list length was unknown, spatial recall was impaired even on short sequences. The present results support the growing consensus, which is suggestive of closer links between visuo-spatial and executive processes. However, it remains unclear whether or not updating is actually occurring on the longer sequences, and if it is, what specific executive processes are involved.     

Spatial categories and the estimation of location

Four experiments are reported in which people organize a space hierarchically when they estimate particular locations in that space. Earlier work showed that people subdivide circles into quadrants bounded at the vertical and horizontal axes, biasing their estimates towards prototypical diagonal locations within those spatial categories (Psychological Review 98 (1991) 352). In this work Huttenlocher, Hedges, and Duncan showed that the use of such spatial categories can increase the accuracy of estimation of inexactly represented locations. The stimulus locations we examined were uniformly distributed across the circle. In the present study we explore whether variation in the distribution of locations affects how the circle is categorized. Other things being equal, categories that capture high density regions in a stimulus space should contribute most to accuracy of estimation. However, precision of boundaries is also important to accuracy; with imprecise boundaries stimuli may be misclassified, leading to large errors in estimation. We found that people use the same spatial categories regardless of the distribution of the locations. We argue that this spatial organization nevertheless can maximize the accuracy of estimates because vertical and horizontal category boundaries are the most exact, minimizing misclassification of stimuli.     

Lexical orthographic knowledge develops from the beginning of literacy acquisition

This study reports two experiments assessing the spelling performance of French first graders after 3 months and after 9 months of literacy instruction. The participants were asked to spell high and low frequency irregular words (Experiment 1) and pseudowords, some of which had lexical neighbours (Experiment 2). The lexical database which children had been exposed to was strictly controlled. Both a frequency effect in word spelling accuracy and an analogy effect in pseudoword spelling were obtained after only 3 months of reading instruction. The results suggest that children establish specific orthographic knowledge from the very beginning of literacy acquisition.     

Commanding the direction of passive whole-body rotations facilitates egocentric spatial updating

In conditions of slow passive transport without vision, even tenuous inertial signals from semi-circular canals and the haptic-kinaesthetic system should provide information about changes relative to the environment provided that it is possible to command the direction of the body's movements voluntarily. Without such control, spatial updating should be impaired because incoming signals cannot be compared to the expected sensory consequences provided by voluntary command. Participants were seated in a rotative robot (Robuter) and learnt the positions of five objects in their surroundings. They were then blindfolded and assigned either to the active group (n=7) or to the passive group (n=7). Members of the active group used a joystick to control the direction of rotation of the robot. The acceleration (25 degrees /s2) and plateau velocity (9 degrees /s) were kept constant. The participants of the passive group experienced the same stimuli passively. After the rotations, the participants had to point to the objects whilst blindfolded. Participants in the active group significantly outperformed the participants in the passive group. Thus, even tenuous inertial cues are useful for spatial updating in the absence of vision, provided that such signals are integrated as feedback associated with intended motor command.     

Imaginal perspective switches in remembered environments: transformation versus interference accounts

Imaginal perspective switches are often considered to be difficult, because they call for additional cognitive transformations of object coordinates (transformation hypothesis). Recent research suggests that problems can also result from conflicts between incompatible sensorimotor and cognitive object location codes during response specification and selection (interference hypothesis). Three experiments tested contrasting predictions of both accounts. Volunteers had to point to unseen object locations after imagined self-rotations and self-translations. Results revealed larger pointing latencies and errors for rotations as compared to translations, and monotic latency and error increases for both tasks as a function of the disparity of object directions between real and imagined perspective. Provision of advance information about the to-be-imagined perspective left both effects unchanged. These results, together with those from a systematic error analysis, deliver clear support for an interference account of imaginal perspective switches in remembered surroundings.     

More evidence on size modification in spatial axes systems of varying complexity

Pictorial space can be conceptualized as aggregate space (where figures compete for limited available space) or as axial space (where space is infinite and exists independently of figures). That these two kinds of space concepts follow a developmental sequence was tested by investigating size regulation mechanisms in 7- to 12-year-old children's figure drawings. An earlier longitudinal study had shown that the more figures were drawn and the more complex the spatial axes system, the smaller the figures. Two studies confirmed that object-driven size reduction was the size regulation mechanism in younger children, whereas axes-driven size reduction was the only factor regulating figure size in 12-year-old children. Size reduction occurred in a gradual fashion in younger children, whereas size reduction was more pronounced in crossed axes systems in older children. In addition, 7-year-old children showed a dynamic and fluid interaction between internal and external task demands for size regulation.     

Normative and Descriptive Analyses of Simpson's Paradox in Decision Making

Suppose that you are evaluating two delivery companies. Your investigation shows that Company B has a better on-time rate for small packages and also for large packages. Despite Company B's performance, however, Company A has a better overall on-time rate. This situation exemplifies Simpson's Paradox, in which the judged relationship between two variables (e.g., company and performance) differs depending on whether that relationship is viewed within subcategories of a third variable (e.g., package size) or in the aggregate. A normative analysis is presented arguing that the reasonableness of using the third variable depends upon the sample size as well as the separation between and variability within categories. To test subjects' abilities to behave appropriately in Simpson's Paradox situations, we examined responses to variations in these factors in five studies. Results showed that subjects had little or no sensitivity to differing stimulus set sizes. Also, subjects were sensitive to relationship strength and the variability within and between groups, and in nonnormative ways. Subjects' judgment behavior is related to a broader perspective concerning selection among multiple available levels of analysis based on a consideration of argument strength.