Septal lesions impair the acquisition of a cued place navigation task: attentional or memory deficit?

These experiments were designed to analyze how medial septal lesions reducing the cholinergic innervation in the hippocampus might affect place learning. Rats with quisqualic lesions of the medial septal area (MS) were trained in a water maze and on a homing table where the escape position was located at a spatially fixed position and further indicated by a salient cue suspended above it. The lesioned rats were significantly impaired in reaching the cued escape platform during training. In addition rats, did not show any discrimination of the training sector during a probe trial in which no platform or cue was present. This impairment remained significant during further training in the absence of the cue. When the cued escape platform was located at an unpredictable spatial location, the MS-lesioned rats showed no deficit and spent more time under the cue than control rats during the probe trial. On the homing board, with a salient object in close proximity to the escape hole, the MS rats showed no deficit in escape latencies, although a significant reduction in spatial memory was observed. However, this was overcome by additional training in the absence of the cue. Under these conditions, rats with septal lesions were prone to develop a pure guidance strategy, whereas normal rats combined a guidance strategy with a memory of the escape position relative to more distant landmarks. The presence of a salient cue appeared to decrease attention to environmental landmarks, thus reducing spatial memory. These data confirm the general hypothesis that MS lesions reduce the capacity to rely on a representation of the relation between several landmarks with different salience.

Decision-theoretic reflections on processing a fingermark

A recent publication in this journal [Neumann et al., Forensic Sci. Int. 212 (2011) 32-46] presented the results of a field study that revealed the data provided by the fingermarks not processed in a forensic science laboratory. In their study, the authors were interested in the usefulness of this additional data in order to determine whether such fingermarks would have been worth submitting to the fingermark processing workflow. Taking these ideas as a starting point, this communication here places the fingermark in its context of a case brought before a court, and examines the question of processing or not processing a fingermark from a decision-theoretic point of view. The decision-theoretic framework presented provides an answer to this question in the form of a quantified expression of the expected value of information (EVOI) associated with the processed fingermark, which can then be compared with the cost of processing the mark.

Atomic Ordering and Martensitic Transitions in Cu-Zn-Al Shape Memory Alloys

We present results from both, calorimetric and dilatometric studies of the isothermal ordering process taking place in a Cu-Zn-Al shape memory alloy after quenches from Tq temperatures ranging from 350 K to 1200 K. The dissipated energy and the length variations of the system are obtained during the process. The change of these quantities in the whole process have been compared with the difference [MATH] between Ms, measured after the relaxation and Ms measured just after the quench. We obtain that these three quantities present, as a function of Tq, the same qualitative behaviour. These changes are then associated with changes of the L21 ordering after the quench in the system. The relaxational process does not follow a single exponential decay. Instead, a continuous slowing down is observed. A relaxation time [MATH] has been defined to characterize the relaxation rate. We show that [MATH] depends on both the annealing and the quenching (Tq [MATH] 800 K) temperatures through an Arrhenius law.

Persistence of cognitive impairment and its negative impact on psychosocial functioning in lithium-treated, euthymic bipolar patients: a 6-year follow-up study.

BACKGROUND: Previous cross-sectional studies report that cognitive impairment is associated with poor psychosocial functioning in euthymic bipolar patients. There is a lack of long-term studies to determine the course of cognitive impairment and its impact on functional outcome. Method A total of 54 subjects were assessed at baseline and 6 years later; 28 had DSM-IV TR bipolar I or II disorder (recruited, at baseline, from a Lithium Clinic Program) and 26 were healthy matched controls. They were all assessed with a cognitive battery tapping into the main cognitive domains (executive function, attention, processing speed, verbal memory and visual memory) twice over a 6-year follow-up period. All patients were euthymic (Hamilton Rating Scale for Depression score lower than 8 and Young mania rating scale score lower than 6) for at least 3 months before both evaluations. At the end of follow-up, psychosocial functioning was also evaluated by means of the Functioning Assessment Short Test. RESULTS: Repeated-measures multivariate analysis of covariance showed that there were main effects of group in the executive domain, in the inhibition domain, in the processing speed domain, and in the verbal memory domain (p<0.04). Among the clinical factors, only longer illness duration was significantly related to slow processing (p=0.01), whereas strong relationships were observed between impoverished cognition along time and poorer psychosocial functioning (p<0.05). CONCLUSIONS: Executive functioning, inhibition, processing speed and verbal memory were impaired in euthymic bipolar out-patients. Although cognitive deficits remained stable on average throughout the follow-up, they had enduring negative effects on psychosocial adaptation of patients.

Changes in the isoflavone profile and in the chemical composition of tempeh during processing and refrigeration

The objective of this work was to analyze changes in the isoflavone profile, determined by high performance liquid chromatography, at different processing stages and after refrigeration of tempeh. For tempeh production, clean soybean grains from cultivars BR 36 (low isoflavone content) and IAS 5 (high) were dehulled, and the separated cotyledons were hydrated and then cooked in boiling water for 30 min. Spores of the fungus Rhizopus microsporus var. oligosporus were inoculated in the cooked and cooled cotyledons, and incubated at 32ºC for 6, 12, 18, and 24 hours in perforated polypropylene bags, for fermentation. The resulting tempeh was stored at 4ºC for 6, 12, 18, and 24 hours. After 24-hour fermentation, isoflavone glucosides were 50% reduced, and the aglycone forms in the tempeh from both cultivars was increased. The malonyl forms reduced 83% after cooking. Less than 24 hours of refrigeration did not affect the isoflavone profile of tempeh from either cultivar, which is a good indicator of its quality. The tempeh maintains the high and low isoflavone content of the cultivars, which indicates that cultivar differences in this trait should be considered when processing tempeh.

Metabolic activation pattern of distinct hippocampal subregions during spatial learning and memory retrieval.

Activation dynamics of hippocampal subregions during spatial learning and their interplay with neocortical regions is an important dimension in the understanding of hippocampal function. Using the (14C)-2-deoxyglucose autoradiographic method, we have characterized the metabolic changes occurring in hippocampal subregions in mice while learning an eight-arm radial maze task. Autoradiogram densitometry revealed a heterogeneous and evolving pattern of enhanced metabolic activity throughout the hippocampus during the training period and on recall. In the early stages of training, activity was enhanced in the CA1 area from the intermediate portion to the posterior end as well as in the CA3 area within the intermediate portion of the hippocampus. At later stages, CA1 and CA3 activations spread over the entire longitudinal axis, while dentate gyrus (DG) activation occurred from the anterior to the intermediate zone. Activation of the retrosplenial cortex but not the amygdala was also observed during the learning process. On recall, only DG activation was observed in the same anterior part of the hippocampus. These results suggest the existence of a functional segmentation of the hippocampus, each subregion being dynamically but also differentially recruited along the acquisition, consolidation, and retrieval process in parallel with some neocortical sites.

Functional connectivity of reward processing in the brain

Controversial results have been reported concerning the neural mechanisms involved in the processing of rewards and punishments. On the one hand, there is evidence suggesting that monetary gains and losses activate a similar fronto-subcortical network. On the other hand, results of recent studies imply that reward and punishment may engage distinct neural mechanisms. Using functional magnetic resonance imaging (fMRI) we investigated both regional and interregional functional connectivity patterns while participants performed a gambling task featuring unexpectedly high monetary gains and losses. Classical univariate statistical analysis showed that monetary gains and losses activated a similar fronto-striatallimbic network, in which main activation peaks were observed bilaterally in the ventral striatum. Functional connectivity analysis showed similar responses for gain and loss conditions in the insular cortex, the amygdala, and the hippocampus that correlated with the activity observed in the seed region ventral striatum, with the connectivity to the amygdala appearing more pronounced after losses. Larger functional connectivity was found to the medial orbitofrontal cortex for negative outcomes. The fact that different functional patterns were obtained with both analyses suggests that the brain activations observed in the classical univariate approach identifi es the involvement of different functional networks in the current task. These results stress the importance of studying functional connectivity in addition to standard fMRI analysis in reward-related studies.

The validity of clinical diagnoses of dementia in a group of consecutively autopsied memory clinic patients.

BACKGROUND: Epidemiological studies show that up to 10% of individuals aged 65 years and older suffer from dementia, most commonly from dementia of the Alzheimer Type (DAT) (1). Clinicopathological studies are critical to our understanding of this disease and improving the accuracy of clinical diagnoses. OBJECTIVES: Our objectives were to examine the validity of clinical diagnoses of DAT, to determine the prevalence of different forms of dementia in this sample, and to investigate the relationship between age at death and polymorbidity. SUBJECTS AND METHOD: Clinical data were available from 221 patients who had been examined at the Basel Memory Clinic between 1986 and 1996. From this population, 34% (75 patients) were autopsied in the Department of Pathology, University Hospital Basel, and neuropathological examinations were additionally performed on 62 (83%) of these patients. Clinical and neuropathological data were retrospectively compared. RESULTS: 67.8% of the neuropathologically examined patients received a definitive diagnosis of AD (Alzheimer's disease), vascular dementia (VaD) or mixed dementia (AD and VaD). AD alone or with other histopathological hallmarks of dementia was the most prevalent neuropathological diagnosis (63%). VaD was deemed the only cause of dementia in only 4.8% of patients. The sensitivity for DAT was 75.9%, the specificity 60.6%. Increasing age was associated with an increasing number of clinical and neuropathological diagnoses. CONCLUSION: The sensitivity and specificity of the clinical diagnoses of DAT found in our study are similar to previous reports (2-5). Older patients had more etiologies of their dementia than younger patients. This study reaffirms the need for internationally accepted criteria for clinical and neuropathological diagnoses, as well as further clinical-neuropathological investigations to further refine the clinical diagnostic process.

Neurocognitive deficits and personality traits among euthymic patients with mood disorders in late life.

BACKGROUND: Previous studies revealed that acute depressive episodes are associated with both cognitive deficits and modified personality patterns in late life. Whether or not these psychological changes are present after remission remains a matter of debate. To date, no study provided concomitant assessment of cognition and psychological functions in this particular clinical setting. METHOD: Using a cross-sectional design, 58 remitted outpatients (36 with unipolar early-onset depression (EOD) and 22 with bipolar disorder (BD)) were compared to 62 healthy controls. Assessment included detailed neurocognitive measures and evaluation of the five factor personality dimensions (NEO-Personality Inventory). RESULTS: Group comparisons revealed significant slower processing speed, working and episodic memory performances in BD patients. EOD patients showed cognitive abilities comparable to those of elderly controls. In NEO PI assessment, both BD and EOD patients displayed higher Depressiveness facet scores. In addition, the EOD but not BD group had lower Extraversion factor, and Warmth and Positive Emotion facet scores than controls. CONCLUSIONS: After remission from acute affective symptoms, older BD patients show significant impairment in several cognitive functions while neuropsychological performances remained intact in elderly patients with EOD. Supporting a long-lasting psychological vulnerability, EOD patients are more prone to develop emotion-related personality trait changes than BD patients.

Early auditory processing

ABSTRACT (English)An accurate processing of the order between sensory events at the millisecond time scale is crucial for both sensori-motor and cognitive functions. Temporal order judgment (TOJ) tasks, is the ability of discriminating the order of presentation of several stimuli presented in a rapid succession. The aim of the present thesis is to further investigate the spatio-temporal brain mechanisms supporting TOJ. In three studies we focus on the dependency of TOJ accuracy on the brain states preceding the presentation of TOJ stimuli, the neural correlates of accurate vs. inaccurate TOJ and whether and how TOJ performance can be improved with training.In "Pre-stimulus beta oscillations within left posterior sylvian regions impact auditory temporal order judgment accuracy" (Bernasconi et al., 2011), we investigated if the brain activity immediately preceding the presentation of the stimuli modulates TOJ performance. By contrasting the electrophysiological activity before the stimulus presentation as a function of TOJ accuracy we observed a stronger pre-stimulus beta (20Hz) oscillatory activity within the left posterior sylvian region (PSR) before accurate than inaccurate TOJ trials.In "Interhemispheric coupling between the posterior sylvian regions impacts successful auditory temporal order judgment" (Bernasconi et al., 2010a), and "Plastic brain mechanisms for attaining auditory temporal order judgment proficiency" (Bernasconi et al., 2010b), we investigated the spatio-temporal brain dynamics underlying auditory TOJ. In both studies we observed a topographic modulation as a function of TOJ performance at ~40ms after the onset of the first sound, indicating the engagement of distinct configurations of intracranial generators. Source estimations in the first study revealed a bilateral PSR activity for both accurate and inaccurate TOJ trials. Moreover, activity within left, but not right, PSR correlated with TOJ performance. Source estimations in the second study revealed a training-induced left lateralization of the initial bilateral (i.e. PSR) brain response. Moreover, the activity within the left PSR region correlated with TOJ performance.Based on these results, we suggest that a "temporal stamp" is established within left PSR on the first sound within the pair at early stages (i.e. ~40ms) of cortical processes, but is critically modulated by inputs from right PSR (Bernasconi et al., 2010a; b). The "temporal stamp" on the first sound may be established via a sensory gating or prior entry mechanism.Behavioral and brain responses to identical stimuli can vary due to attention modulation, vary with experimental and task parameters or "internal noise". In a fourth experiment (Bernasconi et al., 2011b) we investigated where and when "neural noise" manifest during the stimulus processing. Contrasting the AEPs of identical sound perceived as High vs. Low pitch, a topographic modulation occurred at ca. 100ms after the onset of the sound. Source estimation revealed activity within regions compatible with pitch discrimination. Thus, we provided neurophysiological evidence for the variation in perception induced by "neural noise".ABSTRACT (French)Un traitement précis de l'ordre des événements sensoriels sur une échelle de temps de milliseconde est crucial pour les fonctions sensori-motrices et cognitives. Les tâches de jugement d'ordre temporel (JOT), consistant à présenter plusieurs stimuli en succession rapide, sont traditionnellement employées pour étudier les mécanismes neuronaux soutenant le traitement d'informations sensorielles qui varient rapidement. Le but de cette thèse est d'étudier le mécanisme cérébral soutenant JOT. Dans les trois études présentées nous nous sommes concentrés sur les états du cerveau précédant la présentation des stimuli de JOT, les bases neurales pour un JOT correct vs. incorrect et sur la possibilité et les moyens d'améliorer l'exécution du JOT grâce à un entraînement.Dans "Pre-stimulus beta oscillations within left posterior sylvian regions impact auditory temporal order judgment accuracy" (Bernasconi et al., 2011),, nous nous sommes intéressé à savoir si l'activité oscillatoire du cerveau au pré-stimulus modulait la performance du JOT. Nous avons contrasté l'activité électrophysiologique en fonction de la performance TOJ, mesurant une activité oscillatoire beta au pré-stimulus plus fort dans la région sylvian postérieure gauche (PSR) liée à un JOT correct.Dans "Interhemispheric coupling between the posterior sylvian regions impacts successful auditory temporal order judgment" (Bernasconi et al., 2010a), et "Plastic brain mechanisms for attaining auditory temporal order judgment proficiency" (Bernasconi et al., 2010b), nous avons étudié la dynamique spatio-temporelle dans le cerveau impliqué dans le traitement du JOT auditif. Dans ses deux études, nous avons observé une modulation topographique à ~40ms après le début du premier son, en fonction de la performance JOT, indiquant l'engagement des configurations de générateurs intra- crâniens distincts. La localisation de source dans la première étude indique une activité bilatérale de PSR pour des JOT corrects vs. incorrects. Par ailleurs, l'activité dans PSR gauche, mais pas dans le droit, est corrélée avec la performance du JOT. La localisation de source dans la deuxième étude indiquait une latéralisation gauche induite par l'entraînement d'une réponse initialement bilatérale du cerveau. D'ailleurs, l'activité dans la région PSR gauche corrèlait avec la performance de TOJ.Basé sur ces résultats, nous proposons qu'un « timbre-temporel » soit établi très tôt (c.-à-d. à ~40ms) sur le premier son par le PSR gauche, mais module par l'activité du PSR droite (Bernasconi et al., 2010a ; b). « Le timbre- temporel » sur le premier son peut être établi par le mécanisme neuronal de type « sensory gating » ou « prior entry ».Les réponses comportementales et du cerveau aux stimuli identiques peut varier du à des modulations d'attention ou à des variations dans les paramètres des tâches ou au bruit interne du cerveau. Dans une quatrième expérience (Bernasconi et al. 2011B), nous avons étudié où et quand le »bruit neuronal« se manifeste pendant le traitement des stimuli. En contrastant les AEPs de sons identiques perçus comme aigus vs. grave, nous avons mesuré une modulation topographique à env. 100ms après l'apparition du son. L'estimation de source a révélé une activité dans les régions compatibles avec la discrimination de fréquences. Ainsi, nous avons fourni des preuves neurophysiologiques de la variation de la perception induite par le «bruit neuronal».

Threading libraries performance when applied to image acquisition and processing in a forensic application

Peer-reviewed

Taking on new challenges in multi-word unit processing for Machine Translation

This paper discusses the qualitativecomparative evaluation performed on theresults of two machine translation systemswith different approaches to the processing ofmulti-word units. It proposes a solution forovercoming the difficulties multi-word unitspresent to machine translation by adopting amethodology that combines the lexicongrammar approach with OpenLogos ontologyand semantico-syntactic rules. The paper alsodiscusses the importance of a qualitativeevaluation metrics to correctly evaluate theperformance of machine translation engineswith regards to multi-word units.

Normative Topographic ERP Analyses of Speed of Speech Processing and Grammar Before and After Grammatical Treatment.

Typically developing (TD) preschoolers and age-matched preschoolers with specific language impairment (SLI) received event-related potentials (ERPs) to four monosyllabic speech sounds prior to treatment and, in the SLI group, after 6 months of grammatical treatment. Before treatment, the TD group processed speech sounds faster than the SLI group. The SLI group increased the speed of their speech processing after treatment. Posttreatment speed of speech processing predicted later impairment in comprehending phrase elaboration in the SLI group. During the treatment phase, change in speed of speech processing predicted growth rate of grammar in the SLI group.