Communicative deficits in agenesis of the corpus callosum: nonliteral language and affective prosody

While some individuals with agenesis of the corpus callosum can perform normally on standardized intelligence tests, clinical observations suggest that they nevertheless have deficits in the domains of fluid and social intelligence. Particularly important for social competence is adequate understanding and use of paralinguistic information. This study examined the impact of callosal absence on the processing of pragmatic and paralinguistic information. Young adult males with agenesis of the corpus callosum (ACC) were evaluated in the areas of nonliteral language comprehension, proverb recognition and interpretation, and perception of affective prosody. Ten ACC individuals with normal Wechsler IQ were compared to 14 sex, age, and IQ matched normal controls. The Formulaic and Novel Language Comprehension Test (FANL-C), Gorham Proverbs Test, and LA Prosody Test were administered. ACC subjects exhibited significant impairment on the nonliteral items of the FANL-C, but no significant difference from controls in comprehension of literal items. ACC subjects also exhibited significant deficits in both self-generated interpretation and recognition of proverb meaning, and in recognition of affective prosody. These results demonstrate that normally intelligent individuals with ACC are impaired in the understanding of nonliteral language and emotional-prosodic cues that are important in social communication. In all three tests, the performance of individuals with ACC was similar to patients with right hemisphere brain damage. Thus, persons with ACC appear to lack interhemispheric integration of critical aspects of language processed by the right hemisphere.     

Effects of age, task, and frequency on variability of finger tapping

The goal was to assess whether prior studies might have overestimated performance variability in older adults in dual task conditions by relying on primary motor tasks that are not constant with aging. 30 younger and 31 older adults performed a bimanual tapping task at four different frequencies in isolation or concurrently with a secondary task. Results showed that performance of younger and older adults was not significantly different in performing the tapping task at all frequencies and with either secondary task, as indicated by mean tapping performance and low number of errors in the secondary tasks. Both groups showed increased variability as tapping frequency increased and with the presence of a secondary task. Tapping concurrently while reading words increased tapping variability more than tapping concurrently while naming colours. Although older participants' performances were overall more variable, no interaction effects with age were found and at the highest frequencies of tapping, younger and older participants did not differ in performance.     

The good,the bad and the effective: a meta-analytic examination of selling orientation and customer orientation on sales performance

The concept of customer orientation (CO) is a focal construct in marketing and sales literature. Saxe and Weitz introduced CO to contrast the traditional high-pressure approach to sales (selling orientation). This study synthesizes empirical evidence from 1982 to 2013 to provide insight into the antecedents and consequences of both CO and selling orientation (SO). A conceptual meta-analytic model based on research into interpersonal motive models is proposed and tested using effect sizes from 126,790 salesperson survey responses to advance theory development on our understanding of how SO and CO behaviours affect organizations. Findings show that adaptive selling mediates the impact of both SO and CO which has important practical implications for hiring and training salespeople. Furthermore, this study shows that goal orientations are antecedents of SO and CO and that the impact of SO on job performance varies by customer type.     

Change in action: how infants learn to walk down slopes

A critical aspect of perception–action coupling is the ability to modify ongoing actions in accordance with variations in the environment. Infants’ ability to modify their gait patterns to walk down shallow and steep slopes was examined at three nested time scales. Across sessions, a microgenetic training design showed rapid improvements after the first session in infants receiving concentrated practice walking down slopes and in infants in a control group who were tested only at the beginning and end of the study. Within sessions, analyses across easy and challenging slope angles showed that infants used a ‘braking strategy’ to curb increases in walking speed across increasingly steeper slopes. Within trials, comparisons of infants’ gait modifications before and after stepping over the brink of the slopes showed that the braking strategy was planned prospectively. Findings illustrate how observing change in action provides important insights into the process of skill acquisition.     

Comprehension of human pointing gestures in young human-reared wolves (<Emphasis Type="Italic">Canis lupus</Emphasis>) and dogs (<Emphasis Type="Italic">Canis familiaris</Emphasis>)

Dogs have a remarkable skill to use human-given cues in object-choice tasks, but little is known to what extent their closest wild-living relative, the wolf can achieve this performance. In Study 1, we compared wolf and dog pups hand-reared individually and pet dogs of the same age in their readiness to form eye-contact with a human experimenter in an object-choice task and to follow her pointing gesture. The results showed that dogs already at 4 months of age use momentary distal pointing to find hidden food even without intensive early socialization. Wolf pups, on the contrary, do not attend to this subtle pointing. Accordingly in Studies 2 and 3, these wolves were tested longitudinally with this and four other (easier) human-given cues. This revealed that wolves socialized at a comparable level to dogs are able to use simple human-given cues spontaneously if the human’s hand is close to the baited container (e.g. touching, proximal pointing). Study 4 showed that wolves can follow also momentary distal pointing similarly to dogs if they have received extensive formal training. Comparing the wolves to naïve pet dogs of the same age revealed that during several months of formal training wolves can reach the level of dogs in their success of following momentary distal pointing in parallel with improving their readiness to form eye-contact with a human experimenter. We assume that the high variability in the wolves’ communicative behaviour might have provided a basis for selection during the course of domestication of the dog.     

Posture and the emergence of manual skills

In this paper, we examine how infants’ natural manual and postural activities — what they prefer and do week by week — are related to developmental transitions in reaching skill and its neuromuscular control. Using a dense, longitudinal design, we tracked the manual and postural activities of four infants in a natural, free‐play setting across the first year of life, and related these activities to two transitions in reaching as measured in a structured laboratory setting: the transition to reaching and the transition to stable reaching. Our data indicated that specific advances in the free‐play setting preceded both transitions. Head and upper torso control, the ability to extend the arm and hand to a distant target, and the ability to touch and grasp objects placed nearby were all precursors to the onset of reaching, whereas sitting independently was associated with the transition to stable reaching. We also found important individual variability in when these ‘components’ were in place, indicating that it is the ensemble of components that is essential, not the order in which they develop or the timing of their contribution. These findings suggest that subsequent experimental manipulations should be planned with respect to infants’ individual constellations of skills, rather than looking at only a single precursor to change.     

Free(z)ing Degrees of Freedom in Skill Acquisition

This study reports an empirical investigation into Bernstein's (1967) ideas that in the early stages of the acquisition of a movement skill the coordination problem is reduced by an initial freezing out of degrees of freedom, followed later in the learning process by the release of these degrees of freedom and their incorporation into a dynamic, controllable system. “Freezing” degrees of freedom was made operational both as a rigid fixation of individual degrees of freedom and as the formation of rigid couplings between multiple degrees of freedom. Five subjects practiced slalom-like ski movements on a ski apparatus for 7 consecutive days. Results showed that at the early phases of learning, the joint angles of the lower limbs and torso displayed little movement, as expressed by their standard deviations and ranges of angular motion, whereas joint couplings were high, as shown by the relatively high cross correlations between joint angles. Over practice, angular movement significantly increased in all joint angles of the lower limbs and torso, although the cross correlations decreased. Support for the processes of freezing and releasing degrees of freedom was thus given at both levels of operationalization. In addition, a consistent change from laterally symmetric to laterally asymmetric cross-correlation patterns were observed as a function of practice. Overall, the findings provide empirical support for Bernstein's ideas regarding the mastery of redundant degrees of freedom in the acquisition of coordination.     

Response to Comment: Starting to Solve the Method Puzzle in Salesperson Self-Report Evaluations

This response addresses the comments of Sharma, Rich, and Levy (2004) about the generalizability of the performance effect. The comments are addressed by bringing additional theoretical and empirical support with a new study that replicates and extends the results of our 2003 paper. Results confirm our 2003 findings that bottom performers overestimate and that top performers underestimate their job performance. Further, results confirm our 2003 findings that bottom performers are significantly more inaccurate than top salespeople in their performance estimation. Finally, this study extends previous research by providing evidence that the inaccuracy in self-evaluations is reduced when factualbased questions are used.     

A Meta-Analytic Comparison of Managerial Ratings and Self-Evaluations

The purpose of this study was to examine the equivalence of self-reports and managerial ratings of salesperson job performance. A meta-analysis showed that the two measures exhibited low convergent validity (mean corrected correlation = 0.19), which indicated that they are not interchangeable. The predictive validity of self-reports and managerial ratings was compared. Managerial ratings had a corrected mean correlation of 0.44 with objective performance, whereas the corrected mean correlation between self-reports and objective measures was 0.34. Further meta-analytic investigations showed that the divergence between self-reports and managerial ratings was attributable to the performance effect. A discussion of the findings and avenues for further research are also provided.