Explanatory pluralism in cognitive science

This brief commentary has three goals. The first is to argue that "framework debate" in cognitive science is unresolvable. The idea that one theory or framework can singly account for the vast complexity and variety of cognitive processes seems unlikely if not impossible. The second goal is a consequence of this: We should consider how the various theories on offer work together in diverse contexts of investigation. A final goal is to supply a brief review for readers who are compelled by these points to explore existing literature on the topic. Despite this literature, pluralism has garnered very little attention from broader cognitive science. We end by briefly considering what it might mean for theoretical cognitive science.     

Effects of unilateral distractors: A comparison of eye movement and key press responses

We compared the effects of a unilateral distractor on the latencies of voluntary eye movements and key press responses in order to elucidate some of the differences between these two types of response with respect to processing distractors. On each trial, participants indicated the colour of a central patch by making a left or a right response. The colour of the distractor either matched the target colour or matched the colour associated with the incorrect response. Similarly, the side of the distractor corresponded to the side of either the correct or the incorrect response. The results showed that side congruency exerted a main effect only on eye movement responses, but colour congruency affected eye movement and key press responses similarly. Moreover, when we made the target more distinct from the distractor, only distractors that appeared on the same side as the response elicited a colour congruency effect, for both response modalities. Wepropose that (1) the appearance of the distractor activates oculomotor cells, which facilitate a subsequent eye movement with the same direction vector, (2) the distinctiveness of the target determines whether colour and side congruency interact, and (3) spatial codes mediate the interaction between colour and side congruency that occurs when the target is sufficiently distinct from the distractor.     

The influence of emotional awareness and expressiveness on care-giving burden and health complaints in women and men

This study was designed to investigate the role of emotional awareness and expressiveness as influences on the experience of burden and impaired health for women and men maintaining a spouse or relative at home who had been diagnosed as having dementia. One hundred and thirty-one Caucasian care givers, 41 males and 90 females, participated in the study. Multivariate analysis of variance indicated that women scored higher than men on measures of burden, health complaints, and awareness of others' emotions. Regression analysis indicated that self-awareness of emotions interacted with care-giver gender to decrease health complaints for female care givers but increased health complaints for male care givers. Self-awareness of emotions also increased feelings of burden for male care givers in general and for female care givers experiencing low levels of burden. Awareness of others' emotions tended to reduce feelings of burden. Emotional expressiveness did not influence burden or health complaint scores.This research was funded by grants from the Health Research Funds of Quebec, the Quebec Council for Social Research, and the Montreal Alzheimer Society. The authors would like to express their gratitude to Valerie Takeda, Charlene Stamegna, and Helene Fyfe for their work on the project, and to the families, patients, and staff of the various referral agencies for their cooperation with the study.To whom reprint requests should be addressed at Centre for Research in Human Development, Concordia University, 1455 de Maisonneuve Boulevard West, Montreal, Quebec, Canada, H3G 1M8.     

Motor Performance of Stutterers and Nonstutterers on Timing and Force Control Tasks

Recently it has been suggested that speech and manual timing tasks share a common central process (Franz, Zelaznik, & Smith, 1992): Because stuttering is thought to be related to deficits in motoric processes such as timing, stutterers (n = 15) were compared with a set of age-, education-, and sex-matched nonstutterers on timing and isometric force-production tasks. In the timing tasks, subjects flexed and extended the right index finger at the metacarpophalangeal joint at cycle durations of 600, 500, 400, 300, and 200 ms. In the force-production tasks, subjects generated isometric forces to match target force levels displayed on a cathode-ray tube (CRT) screen. There were five levels of force, ranging from.11 to 7.85 newtons. Overall, there were no differences in timing and force-production performance between stutterers and nonstutterers. These results are similar to those obtained recently by Hulstijn, Summers, van Lieshout, and Peters (1992). We suggest that stuttering is not characterized by a general deficit in rhythmic timing. Instead, the motor deficit associated with stuttering should be viewed as speech specific.     

Spatial Coupling in the Coordination of Complex Actions

The majority of investigations on coordinated action have focused on temporal constraints in movements. Recent studies have demonstrated spatial constraints when the hands produce different trajectory shapes simultaneously. The focus of the current study was to determine whether spatial coupling occurs in individual parameters of the actions, or whether the shapes per se undergo accommodation. Subjects were tested on a bimanual paradigm to investigate the nature of spatial constraints in complex tasks. Shape and size of the required trajectories were varied for the two limbs. When trajectories that require different shapes were assigned to the two hands,disruption in the spatial characteristics of the trajectories was observed. Disruption in the global patterns of the trajectories could be described on the basis of coupling in individual parameters of action, direction, and amplitude, which could be inferred by decomposing the trajectories into orthogonal components. Amplitude accommodation in these orthogonal components of motion increased linearly with the difference in required amplitude for the two limbs. Interpretations of these effects suggest that directional coupling is a result of interference between two different response plans, whereas amplitude coupling may be related to either planning or execution variables. These results strongly suggest the need for further investigation of the spatial domain of complex coordinated action.     

A Computer tool for constructing and integrating inferences into text representations

We present a new computer tool for modeling inference generation processes in text comprehension. With this tool, an explicit inference statement is constructed by marker passing in a joint text and knowledge base and a subsequent compilation process. In addition, the tool can be applied to describe knowledge integration processes, which can produce spatial, causal, and other types of representations. Because the system provides explicit accounts for reproductive and creative inferencing, it exceeds the functionality of previous simulations in text research. Text researchers can employ this system as a common ground for comparing their different positions on inferencing in a more precise manner.