Investigations of hemispheric specialization of self-voice recognition

Three experiments investigated functional asymmetries related to self-recognition in the domain of voices. In Experiment 1, participants were asked to identify one of three presented voices (self, familiar or unknown) by responding with either the right or the left-hand. In Experiment 2, participants were presented with auditory morphs between the self-voice and a familiar voice and were asked to perform a forced-choice decision on speaker identity with either the left or the right-hand. In Experiment 3, participants were presented with continua of auditory morphs between self- or a familiar voice and a famous voice, and were asked to stop the presentation either when the voice became "more famous" or "more familiar/self". While these experiments did not reveal an overall hand difference for self-recognition, the last study, with improved design and controls, suggested a right-hemisphere advantage for self-compared to other-voice recognition, similar to that observed in the visual domain for self-faces.     

Clock drawing performance and brain morphology in mild cognitive impairment and Alzheimer's disease

The Clock Drawing Test (CDT) is a widely used instrument in the neuropsychological assessment of Alzheimer's disease (AD). As CDT performance necessitates several cognitive functions (e.g., visuospatial and constructional abilities, executive functioning), an interaction of multiple brain regions is likely. Fifty-one subjects with mild cognitive impairment, 23 with AD and 15 healthy controls underwent high-resolution magnetic resonance imaging. Optimized voxel-based morphometry (VBM) was performed to investigate the putative association between CDT performance and gray matter (GM) density throughout the entire brain. In the first step of analysis (p<.001, uncorrected), VBM revealed a reduced GM density in numerous cortical (temporal lobe, frontal lobe, parietal lobe, cerebellum) and subcortical (thalamus, basal ganglia) brain regions to be associated with poorer CDT performance. When corrected for multiple comparisons (p<.01), the associations remained significant predominantly in the left temporal and--less pronounced--the right temporal lobe. VBM demonstrated CDT performance to depend on the integrity of widely distributed cortical and subcortical areas in both brain hemispheres with accentuation in the left-sided temporal lobe region.     

The role of animacy in the real time comprehension of Mandarin Chinese: Evidence from auditory event-related brain potentials

Two auditory ERP studies examined the role of animacy in sentence comprehension in Mandarin Chinese by comparing active and passive sentences in simple verb-final (Experiment 1) and relative clause constructions (Experiment 2). In addition to the voice manipulation (which modulated the assignment of actor and undergoer roles to the arguments), both arguments were either animate or inanimate. This allowed us to examine the interplay of animacy with thematic interpretation. In Experiment 1, we observed no effect of animacy at NP1, but N400 effects for inanimate actor arguments in second position. This result mirrors previous findings in German, thus suggesting that an initial undergoer universally leads to the prediction of an ideal (animate) actor. We also observed an N400 effect for passive sentences with an inanimate initial (undergoer) argument. We attribute this effect to a language-specific property of the passive construction in Chinese, namely that the first argument is negatively affected by the event described (i.e. bears an experiencer role). Experiment 2 showed that both of these effects can also be observed in sentence constructions of another type, in which the critical information sources become available in a different order. These findings provide the first demonstration that the N400 is not only sensitive to general (universal) aspects of thematic processing (i.e. "who is acting on whom") but also to the interaction between thematic interpretation and language-specific pragmatic principles.     

Investigating speech motor practice and learning in people who stutter

In this exploratory study, we investigated whether or not people who stutter (PWS) show motor practice and learning changes similar to those of people who do not stutter (PNS). To this end, five PWS and five PNS repeated a set of non-words at two different rates (normal and fast) across three test sessions (T1, T2 on the same day and T3 on a separate day, at least 1 week apart). The results indicated that PWS and PNS may resemble each other on a number of performance variables (such as movement amplitude and duration), but they differ in terms of practice and learning on variables that relate to movement stability and strength of coordination patterns. These findings are interpreted in support of recent claims about speech motor skill limitations in PWS.

Educational objectives: The reader will be able to: (1) define oral articulatory changes associated with motor practice and learning and their measurement; (2) summarize findings from previous studies examining motor practice and learning in PWS; and (3) discuss hypotheses that could account for the present findings that suggest PWS and PNS differ in their speech motor learning abilities.     

Multisource Assessments of Behavioral Competencies and Selection Interview Performance

This study sought to determine whether and how ratings of leadership in a developmental multisource feedback program compare against those obtained by leadership selection decision makers. Seventy‐seven senior managers received feedback on eight competencies that also formed the basis of a subsequent promotional interview for senior executive positions. Each rating source displayed a unique perspective on the participants, but only the supervisor and peer ratings predicted performance on the interview. As well, peer, subordinate, and self‐ratings failed to improve upon the supervisors' predictions. The results also suggested a general performance factor underlying both the multisource assessments and the interview ratings.     

Discriminant validity of the ZKPQ in a sample meeting BPD diagnosis vs. normal-range controls

Widiger and Simonsen (2005) state that given the limitations of the categorical model of Personality Disorders classification proposals are to be expected for dimensional classifications. The purpose of this paper is to test the alternative five factorial model (AFFM) of personality in a sample with PDs. Subjects were administered the ZKPQ to test the discriminant capacity of the AFFM in classifying subjects diagnosed with BPD (n = 74) vs normal-range controls (n = 148) paired by age and sex, and identifying sensitive and/or specific dimensions that can be of help in diagnosing BPD. The results showed that high scores on N-Anx and Imp-SS, and low scores on Act are prognostic factors for being diagnosed with BPD. Likewise, this model correctly classified 88% of subjects with a kappa index of 0.73. The AFFM of personality appears to have a substantial power for predicting SCID-II interview-based BPD diagnosis.     

No protective effects of education during normal cognitive aging: results from the 6-year follow-up of the Maastricht Aging Study

Recent large-scale longitudinal aging studies question earlier claims that higher education protects against cognitive decline in older age. In the present study, the authors addressed this issue by determining whether educational level had an attenuating effect on the rate of cognitive change assessed with a broad range of neuropsychological tests in a community sample of 872 healthy individuals aged 49 to 81 years at baseline. The participants were followed for 6 years and were tested 3 times (at baseline and at 3 and 6 years after baseline). Results of linear mixed-model analyses showed that education had no significant effect on cognitive change over time. These results are discussed in terms of the age range of the sample, definition and range of education, cognitive measures used, length of the study and number of consecutive assessments, and confounding effect of health. The findings question the extent of the presumed protective effects of higher education on cognitive decline during normal aging.     

Personal values and relational models

In this study, the comprehensive value research by Schwartz (e.g. 1992) was linked to Fiske's relational models theory (RMT, e.g. Fiske, 1991). A sample of 297 people answered the personal values questionnaire (PVQ), the modes of relationship questionnaire (MORQ) and the relationship profile scale (RPS) in a web‐based online survey. As hypothesized, the set of 10 values correlated in a systematic manner—according to the circular structure of personal value systems—with both trait‐like construal of and motivational investment in the relational models communal sharing (CS), authority ranking (AR) and market pricing (MP). Further research concerning a person–environment value congruency approach to predict well‐being is suggested combining the two research traditions. Copyright © 2008 John Wiley & Sons, Ltd.     

Overconfidence in an objective anticipatory motor task

Overconfidence can place humans in hazardous situations, and yet it has been observed in a variety of cognitive tasks in which participants have to rate their own performance. We demonstrate here that overconfidence can be revealed in a natural and objective visuo-motor task. Participants were asked to press a key in synchrony with a predictable visual event and were rewarded if they succeeded and sometimes penalized if they were too quick or too slow. If they had used their own motor uncertainty in anticipating the timing of the visual stimulus, they would have maximized their gain. However, they instead displayed an overconfidence in the sense that they underestimated the magnitude of their uncertainty and the cost of their error. Therefore, overconfidence is not limited to subjective ratings in cognitive tasks, but rather appears to be a general characteristic of human decision making.     

Preservation of long-term memory and synaptic plasticity despite short-term impairments in the Tc1 mouse model of Down syndrome

Down syndrome (DS) is a genetic disorder arising from the presence of a third copy of the human chromosome 21 (Hsa21). Recently, O’Doherty and colleagues in an earlier study generated a new genetic mouse model of DS (Tc1) that carries an almost complete Hsa21. Since DS is the most common genetic cause of mental retardation, we have undertaken a detailed analysis of cognitive function and synaptic plasticity in Tc1 mice. Here we show that Tc1 mice have impaired spatial working memory (WM) but spared long-term spatial reference memory (RM) in the Morris watermaze. Similarly, Tc1 mice are selectively impaired in short-term memory (STM) but have intact long-term memory (LTM) in the novel object recognition task. The pattern of impaired STM and normal LTM is paralleled by a corresponding phenotype in long-term potentiation (LTP). Freely-moving Tc1 mice exhibit reduced LTP 1 h after induction but normal maintenance over days in the dentate gyrus of the hippocampal formation. Biochemical analysis revealed a reduction in membrane surface expression of the AMPAR (α-amino-3-hydroxy-5-methyl-4-propionic acid receptor) subunit GluR1 in the hippocampus of Tc1 mice, suggesting a potential mechanism for the impairment in early LTP. Our observations also provide further evidence that STM and LTM for hippocampus-dependent tasks are subserved by parallel processing streams.