A Dual Process Account of Coarticulation in Motor Skill Acquisition

Many tasks, such as typing a password, are decomposed into a sequence of subtasks that can be accomplished in many ways. Behavior that accomplishes subtasks in ways that are influenced by the overall task is often described as “skilled” and exhibits coarticulation. Many accounts of coarticulation use search methods that are informed by representations of objectives that define skilled. While they aid in describing the strategies the nervous system may follow, they are computationally complex and may be difficult to attribute to brain structures. Here, the authors present a biologically- inspired account whereby skilled behavior is developed through 2 simple processes: (a) a corrective process that ensures that each subtask is accomplished, but does not do so skillfully and (b) a reinforcement learning process that finds better movements using trial and error search that is not informed by representations of any objectives. We implement our account as a computational model controlling a simulated two-armed kinematic “robot” that must hit a sequence of goals with its hands. Behavior displays coarticulation in terms of which hand was chosen, how the corresponding arm was used, and how the other arm was used, suggesting that the account can participate in the development of skilled behavior.     

Knowledge About Hand Shaping and Knowledge About Objects

Our two experiments investigated associations between cognitive representations of objects and hand-shape categories. Hand configurations were partitioned according to prehensility and the size of the contacting surface, resulting in the classes: pinch, poke, palm, and clench. Experiment 1 elicited object names in response to configuration-name cues, provided ratings of the relevance of each configuration to a set of objects, and probed for the functions determining such relevance. Cueing with a configuration class elicited an associated object category with substantial intersubject agreement, and vice versa. Both the object categories and the functions associated with the four hand-configuration classes differed substantially, although the same object could be associated to some extent with multiple configurations, given variations in function. Experiment 2 elicited the names of hand-configuration classes in response to unfamiliar forms, which varied systematically in depth and the size of the projecting picture-plane surface. The modal response, response time, and degree of intersubject agreement were directly related to these variables. These structural variables, however, did not adequately predict shaping responses to real objects, as ascertained from Experiment 1. The results have implications for cognitive representation of motor categories and hand shaping in response to objects.     

Developing Roles and Skills in Community-Living Adults With Severe and Persistent Mental Illness

People with severe and persistent mental illness often experience a disruption in the development of social roles, and the skills within these roles. Role Development, a set of guidelines for practice, is an intervention to develop roles and skills. The purpose of this study was to continue to examine the efficacy of this intervention. Ten people attending two community mental health programs participated in evaluation and treatment based on Role Development. Quantitative pretest and posttest measures were used. Qualitative components were incorporated to get a sense of the experience involved in developing roles and skills. Quantitative results indicated statistical significance (p < .05) in the development of roles and skills. Qualitative data revealed multiple trends experienced by the participants. This study contributes to the evidenced-based knowledge regarding development of roles and skills for persons living with severe and persistent mental illness.     

Frequency and predictability effects in eye fixations for skilled and less-skilled deaf readers

The illiteracy rate in the deaf population has been alarmingly high for several decades, despite the fact that deaf children go through the standard stages of schooling. Much research addressing this issue has focused on word-level processes, but in the recent years, little research has focused on sentence-levels processes. Previous research (Fischler, 1985) investigated word integration within context in college-level deaf and hearing readers in a lexical decision task following incomplete sentences with targets that were congruous or incongruous relative to the preceding context; it was found that deaf readers, as a group, were more dependent on contextual information than their hearing counterparts. The present experiment extended Fischler's results and investigated the relationship between frequency, predictability, and reading skill in skilled hearing, skilled deaf, and less-skilled deaf readers. Results suggest that only less-skilled deaf readers, and not all deaf readers, rely more on contextual cues to boost word processing. Additionally, early effects of frequency and predictability were found for all three groups of readers, without any evidence for an interaction between frequency and predictability.     

Modifying driver behaviour with passenger feedback

A feedback programme was employed to help drivers improve their safety behaviour based on the idea that particular types of driver error result from contingency traps as defined by Fuller [Journal of Applied Behaviour Analysis, 24 (1991) 73]. Two drivers and their single respective passengers participated. For each driver, repeated in-car observations were made of four unsafe driving behaviours. Two of these were sequentially targeted in the behavioural intervention that involved the passengers providing informational feedback to their driver. Both drivers showed a marked improvement across the targeted behaviours. The study demonstrated the applicability of behaviour analysis to the traffic domain and the efficacy of individual feedback as a behavioural tool for positive behaviour modification.     

Drivers’ illusions––no more risk

In this invited address to the International Congress of Applied Psychology, it is argued that traffic psychology has not had a major impact on accident prevention. The factors that have determined this are discussed. A review of the theories and models pertinent to drivers’ risk taking and road user behaviour in general is presented. It is argued that both risk-homeostasis theories and task capability model are not sufficiently precise to be used as a basis for preventive measures. Attitude–behaviour models derived from social psychology have proved to be powerful in identifying motivational factors influencing road user behaviour, but the majority of empirical evidence is based on self-reported rather than observed behaviour. It is argued that individual differences can provide a basis for accident prevention, in particular driver training.     

Driving construals: Personal Construct Theory in a reckless driving context

With research revealing low road safety campaign efficacy and links between reckless driving behaviors and crash frequency, further investigation into the foundations and composition of driver education and training is required. Through two studies, the current research aimed to develop a measure that utilized the principles of Kelly’s (1955) Personal Construct Theory to (a) elicit constructs, or construals, specific to selected elements of reckless driving behaviors, (b) pilot a method in which the elicited constructs could be measured by asking participants to choose those they deemed most important, (c) group participants based on their constructs, and (d) assess between-group differences in self-reported reckless driving behavior. Results suggest that drivers can be categorized based on the constructs they use, and that rates of self-reported past engagement in reckless driving behavior, and willingness to do so in the future, vary systematically between these construal-based driver categories. Continuing research is required to develop and test applications of these findings.     

Structural Stability within the Lateral Cerebellar Nucleus of the Rat Following Complex Motor Learning

Complex motor learning, but not mere motor activity, has been previously shown to induce structural modifications within the cerebellar cortex. The present experiment examined whether similar changes occur within one of the primary output targets of the region of the cerebellar cortex in which these structural changes were described, the lateral cerebellar nucleus (LCN; dentate nucleus). Adult female rats were randomly allocated to one of three training conditions. Acrobatic condition (AC) rats were trained to complete a complex motor learning task consisting of a series of elevated obstacles while motor control (MC) condition animals were forced to traverse a flat obstacle-free runway equal in length to the AC task. Inactive condition (IC) animals received no motor training. Unbiased stereological techniques and electron microscopy were used to obtain estimates of synapse number and postsynaptic density (PSD) length within the LCN. Results showed that neither synapse number nor PSD length was significantly altered as a function of training condition. These results indicate that complex motor skill learning is associated with structural plasticity within the cerebellar cortex and with structural stability within the lateral cerebellar nucleus.     

Investigating the effects of Rectangular Rapid Flash Beacons on pedestrian behavior and driver yielding on 25 mph streets: A quasi-experimental field study on a university campus

Rectangular Rapid-Flash Beacons (RRFBs) are safety measures that have become popular in recent years in the USA. Such equipment has demonstrated effectiveness in reducing vehicle speed and conflicts among road users, and increasing drivers’ yielding to pedestrians. However, RRFB effects on pedestrian behaviors are less well documented, and perhaps could produce contraindicated effects in crossing behavior. Specifically, RRFBs may give pedestrians a feeling of protection and induce them to more risk-taking when crossing the road. The current study was designed to investigate drivers and pedestrians’ reactions to a RRFB system installed at a university campus located in Virginia, USA. We deployed (a) field observation, using a multiple pretest/posttest non-equivalent control group quasi-experiment design and (b) interviews of students throughout the project’s multiple time periods. In total, 2454 pedestrians and 1312 drivers were observed and 265 students were interviewed. RRFB installations did not distinguish driver yielding likelihood between sites with or without RRFBs. However, driver yielding overall increased linearly over the five rounds of the study. Whether this was the result of the general presence of RRFBs on campus from the third round to the end of the fifth round is unknown. There is evidence from person interviews that students perceived increased safety for pedestrians over time. Being a RRFB chosen site or actual activation of the RRFBs did not have a significant relationship with pedestrian looking behavior either. The potential consequences of these results as well as the context of RRFB use on a university campus and generally low-speed roads are discussed.     

The effect of fatigue driving on car following behavior

Existing fatigued driving analysis methods mainly focus on lateral driving performance by using the measurements related to the steering wheel or lane position. There is a lack of research on longitudinal car following behavior. In this study, 40 professional drivers are invited to participate in field expressway driving experiment, lasting at least for 6 h. During the test, their performance is measured in terms of their self-reported fatigued driving level according to the Karolinska Sleepiness Scale (KSS), the PERcentage of eye CLOSures (PERCLOS) and the Time Headway (THW). Then the effects of the fatigued driving level on car following behavior are evaluated. The results indicate that the fatigue level (for both KSS and PERCLOS) has significantly impact on THW parameters, including the mean, standard deviation and minimum THW. An increase in KSS and PERCLOS leads to a lower mean and minimum THW. Meanwhile, the standard deviation of THW increases with the increase of KSS and PERCLOS. In conclusion, this study found that a higher fatigue level leads to the driver keeping a smaller THW when following another vehicle and choosing shorter THW to make lane change. More deviation of car following performance was also found with the increase of fatigue level. Therefore, the findings of this study can be used to explain fatigue as one of the major reasons for rear-end collisions. Also, the research findings demonstrate the impact of fatigue on driving behavior in terms of car following performance, which can be used as a measurement for monitoring fatigued drivers.