Neural processing of acoustic duration and phonological German vowel length: Time courses of evoked fields in response to speech and nonspeech signals

Recent experiments showed that the perception of vowel length by German listeners exhibits the characteristics of categorical perception. The present study sought to find the neural activity reflecting categorical vowel length and the short-long boundary by examining the processing of non-contrastive durations and categorical length using MEG. Using disyllabic words with varying /a/-durations and temporally-matched nonspeech stimuli, we found that each syllable elicited an M50/M100-complex. The M50-amplitude to the second syllable varied along the durational continuum, possibly reflecting the mapping of duration onto a rhythm representation. Categorical length was reflected by an additional response elicited when vowel duration exceeded the short-long boundary. This was interpreted to reflect the integration of an additional timing unit for long in contrast to short vowels. Unlike to speech, responses to short nonspeech durations lacked a M100 to the first and M50 to the second syllable, indicating different integration windows for speech and nonspeech signals.     

The Draw-A-Person Test and Process-Reactive Schizophrenia

The Draw-A-Pcrson test was administered to three matched groups of 32 male Ss each: reactive schizophrenics, process schizophrenics, and normal control subjects. Patients were rated for prognosis using the Premorbid Subscale of the Phillips Scale. Drawings were rated by two judges on 80 diagnostic signs culled from the literature. No signs were found to significantly differentiate reactive and process schizophrenics, and only three signs significantly differentiated normals from schizophrenics. It was concluded that a sign approach to the DAP is insensitive to the reaction-process dimension of schizophrenia, and of only limited value in differentiating between normals and schizophrenics in general.     

Auditory habituation in the fetus and neonate: an fMEG study

Habituation – the most basic form of learning – is used to evaluate central nervous system (CNS) maturation and to detect abnormalities in fetal brain development. In the current study, habituation, stimulus specificity and dishabituation of auditory evoked responses were measured in fetuses and newborns using fetal magnetoencephalography (fMEG). An auditory habituation paradigm consisting of 100 trains of five 500 Hz tones, one 750 Hz tone (dishabituator) and two more 500 Hz tones, respectively, were presented to 41 fetuses (gestational age 30–39 weeks) and 22 newborns or babies (age 6–89 days). A response decrement between the first and fifth tones (habituation), an increment between the fifth tone and the dishabituator (stimulus specificity) and an increment between the fifth (last tone before the dishabituator) and seventh tones (first tone after the dishabituator) (dishabituation) were expected. Fetuses showed weak responses to the first tone. However, a significant response decrement between the second and fifth tones (habituation) and a significant increment between the fifth tone and the dishabituator (stimulus specificity) were found. No significant difference was found for dishabituation nor was a developmental trend found at the group level. From the neonatal data, significant values for stimulus specificity were found. Sensory fatigue or adaptation was ruled out as a reason for the response decrement due to the strong reactions to the dishabituator. Taken together, the current study used fMEG to directly show fetal habituation and provides evidence of fetal learning in the last trimester of pregnancy.     

Using segmentation to support the learning from animated soccer scenes: An effect of prior knowledge

ObjectivesWe used a cognitive load perspective to investigate the effects of levels of learner expertise and different forms of segmentation in learning from animated soccer scenes.MethodExpert and novice players (N = 48) completed a recall reconstruction-test and rated their invested mental effort after studying a continuous animation, a macro-step and a micro-step segmented animation.ResultsFindings demonstrated an expertise reversal effect for segmentation. It positively affected learning outcomes of novices but not experts (even though they still invested less mental effort and repeated the animation less often in the two segmented conditions). Additionally, novices benefited more from micro-step segmentation than from macro-step segmentation, while experts performed at the same level with both forms of segmentation.ConclusionsStudy results suggested that adapting instructional animation formats to players with different levels of expertise should be a crucial part of successful training.     

Memory for actions: Item and relational information in categorized lists

Enacting action phrases in subject-performed tasks (SPTs) leads to better free recall than hearing or reading the same materials in verbal tasks (VTs). This enactment effect is usually explained by better item-specific information in SPTs than in VTs. The role of relational information is controversial. In the present paper, we will take the multiple recall approach to study the role of item and relational information in memory for actions by computing the number of item gains and the number of item losses over trials. This approach has previously been applied to lists of unrelated action phrases. We applied it to categorically related lists, also allowing a measure of relational information by clustering scores. It was found that SPTs produced more item gains than VTs. This finding confirmed the assumption that SPTs provide better item-specific information than VTs. The number of item losses did not differ between VTs and SPTs. This finding suggests that relational information is equally provided by VTs and SPTs. However, the organizational scores showed a more differentiated picture. Clustering was greater in SPTs than in VTs with randomly presented lists, but not with blocked lists. We suggested that these results, as well as other findings from the literature, could be explained by distinguishing automatic and strategic processes and the types of item associations that are addressed by these processes.     

Which processes are involved in cognitive procedural learning?

Procedural memory is characterised by a relative resistance to pathology, making its assessment of the utmost importance. However, few studies have looked at the cognitive processes involved in cognitive procedural learning. In an initial experiment, we studied the role of different cognitive functions in massed cognitive procedural learning. Our results confirmed the existence of three separate learning phases and, for the first time, demonstrated the involvement of episodic memory and executive functions in the first learning phase. In a second experiment, we studied the effect of distributed learning conditions on the dynamics of procedural learning. This second study confirmed our results but showed that these conditions slow down the process of cognitive procedural learning. Our overall findings call into question the status of functionally autonomous memory system that is currently allotted to procedural memory, and suggest that the role of nonprocedural cognitive components should be taken into account in patient rehabilitation.     

Chronic corticosterone-induced deterioration in rat behaviour is not paralleled by changes in hippocampal NF-kappaB-activation

We investigated whether long-lasting stress induced by chronic glucocorticoid (GC) exposure affects activation of brain NF-kappaB and whether these changes are related to functional deterioration and structural changes in the rat hippocampus. Psychometric investigations were conducted using a holeboard test system in 28 one-year-old male Wistar rats. Thereafter, rats were divided into three groups for daily administration of 10 mg corticosterone (treatment) or sesame oil (placebo = sham control for effects of the vehicle) for 60 days. Additional control rats did not receive any treatment or handling until the end of the experiment. Behavioural and cognitive changes were tested again in the holeboard system. Rat body weights and corticosterone concentrations in plasma, hippocampus and urine were determined and adrenal glands were investigated histopathologically. Hippocampal concentrations of corticosterone, NF-kappaB and I-kappaBalpha were determined using RIA, EMSA and Western blotting techniques, respectively. Structural changes in rat hippocampus were measured using magnetic resonance imaging techniques. High peripheral corticosterone concentrations after chronic treatment led to significant reductions in rat body weight. Significant atrophy of both adrenal glands with marked histological deterioration was detected. Furthermore, an increase in hippocampal corticosterone concentrations was observed after chronic administration. Chronic corticosterone treatment also significantly altered behaviour and working and reference memory capacity without changing hippocampal structure. Daily injections of sesame oil in the placebo group, however, were also sufficient to reduce the pellet-finding time. However, neither in the corticosterone group nor in the placebo group were behavioural changes paralleled by significant changes in brain NF-kappaB activation and I-kappaBalpha expression. Thus, cognitive alterations in rats seen after chronic corticosterone exposure are not paralleled by hippocampal NF-kappaB modulation.     

How "implicit" are implicit color effects in memory?

Processing colored pictures of objects results in a preference to choose the former color for a specific object in a subsequent color choice test (Wippich & Mecklenbr?uker, 1998). We tested whether this implicit memory effect is independent of performances in episodic color recollection (recognition). In the study phase of Experiment 1, the color of line drawings was either named or its appropriateness was judged. We found only weak implicit memory effects for categorical color information. In Experiment 2, silhouettes were colored by subjects during the study phase. Performances in both the implicit and the explicit test were good. Selections of "old" colors in the implicit test, though, were almost completely confined to items for which the color was also remembered explicitly. In Experiment 3, we applied the opposition technique in order to check whether we could find any implicit effects regarding items for which no explicit color recollection was possible. This was not the case. We therefore draw the conclusion that implicit color preference effects are not independent of explicit recollection, and that they are probably based on the same episodic memory traces that are used in explicit tests.