A kombinatív képesség rövid távú fejleszthetősége 3. évfolyamon természettudományos kontextusban

Musical aptitude is commonly measured using tasks that involve discrimination of different types of musical auditory stimuli. Performance on such different discrimination tasks correlates positively with each other and with intelligence. However, no study to date has explored these associations using a genetically informative sample to estimate underlying genetic and environmental influences. In the present study, a large sample of Swedish twins (N=10,500) was used to investigate the genetic architecture of the associations between intelligence and performance on three musical auditory discrimination tasks (rhythm, melody and pitch). Phenotypic correlations between the tasks ranged between 0.23 and 0.42 (Pearson r values). Genetic modelling showed that the covariation between the variables could be explained by shared genetic influences. Neither shared, nor non-shared environment had a significant effect on the associations. Good fit was obtained with a two-factor model where one underlying shared genetic factor explained all the covariation between the musical discrimination tasks and IQ, and a second genetic factor explained variance exclusively shared among the discrimination tasks. The results suggest that positive correlations among musical aptitudes result from both genes with broad effects on cognition, and genes with potentially more specific influences on auditory functions

Individual differences in the proneness to have flow experiences are linked to dopamine D2-receptor availability in the dorsal striatum

Flow is a subjective experience of high but effortless attention, enjoyment, and low self-awareness that can occur during the active performance of challenging tasks. The dispositional proneness to experience flow is associated with personality traits that are known to be influenced by dopaminergic neural systems. Here, for the first time, we investigated relations between flow proneness and dopaminergic function. Specifically, we tested the hypothesis that the availability of dopamine D2-receptors in the striatum is positively associated with flow proneness. Striatal D2-receptor availability was measured in a sample of 25 healthy adults using positron emission tomography and [ 11 C]raclopride. Flow proneness was measured using the Swedish Flow Proneness Questionnaire. As hypothesized, there was a significant correlation (r = .41) between striatal D2-receptor availability and flow proneness. An exploratory analysis of striatal subregions showed that the relation was mainly driven by the dorsal striatum, with a significantly higher correlation in the putamen than in the ventral striatum. The findings constitute the first demonstration of an association between flow proneness and dopaminergic function. We suggest that the proneness to experience flow is related to personality dimensions that are under dopaminergic control and characterized by low impulsiveness, stable emotion, and positive affect

Thinking Outside a Less Intact Box: Thalamic Dopamine D2 Receptor Densities Are Negatively Related to Psychometric Creativity in Healthy Individuals

Several lines of evidence support that dopaminergic neurotransmission plays a role in creative thought and behavior. Here, we investigated the relationship between creative ability and dopamine D2 receptor expression in healthy individuals, with a focus on regions where aberrations in dopaminergic function have previously been associated with psychotic symptoms and a genetic liability to schizophrenia. Scores on divergent thinking tests (Inventiveness battery, Berliner Intelligenz Struktur Test) were correlated with regional D2 receptor densities, as measured by Positron Emission Tomography, and the radioligands [11C]raclopride and [11C]FLB 457. The results show a negative correlation between divergent thinking scores and D2 density in the thalamus, also when controlling for age and general cognitive ability. Hence, the results demonstrate that the D2 receptor system, and specifically thalamic function, is important for creative performance, and may be one crucial link between creativity and psychopathology. We suggest that decreased D2 receptor densities in the thalamus lower thalamic gating thresholds, thus increasing thalamocortical information flow. In healthy individuals, who do not suffer from the detrimental effects of psychiatric disease, this may increase performance on divergent thinking tests. In combination with the cognitive functions of higher order cortical networks, this could constitute a basis for the generative and selective processes that underlie real life creativity

Neural mechanisms for the visual control of spatial orientation and locomotion : Electrophysiological and behavioural studies of the supraspinal control of posture and steering in the lamprey central nervous system, with reference to visuo-motor mechanisms

Neural mechanisms for the supraspinal control of posture and steering, in particular visuo- motor control and visuo-vestibular interaction in postural control, were investigated, using the lamprey as a model system. Behavioural experiments on intact and chronically lesioned animals, intra- and extracellular recordings in vitro and retrograde staining of neurons with horseradish peroxidase were utilized. Lampreys actively stabilize their orientation in the vertical planes. The roll control system normally stabilizes a dorsal-side-up orientation of the animal, whereas the pitch control system can stabilize different angles of upward/downward swimming. Turns upwards and downwards are performed by a dorsiflexion or ventroflexion of the body, respectively. Lateral movements of the ventroflexed tail region is presumably an important mechanism for corrective roll turns. Vestibular input plays a crucial role for the stabilization of orientation: unilaterally labyrinthectomized animals roll continuously towards the lesioned side, whereas bilaterally labyrinthectomized animals turn continuously in all directions. Illumination of one eye evoked a horizontal turning movement away from light (negative phototaxis) and a dorsal light response, that is a roll tilt of the whole animal towards the light. The responses were seen both in quiescent animals, attached with their sucker mouths, and during locomotion. The visuo-motor pathways mediating the responses were investigated by chronic lesions. The contralateral pretectal region was found to play a major role for both dorsal light response and negative phototaxis, whereas bilateral ablation of tectum enhanced the responses. The crossed pretecto-reticular projection is crucial for dorsal light response, whereas the non-crossed projection is most important for negative phototaxis. At a rostral spinal level, fibres for yaw turns and negative phototaxis course mainly in the lateral columns, whereas fibres for roll control and dorsal light response travel mainly more medially. Neural correlates of the dorsal light response were investigated by recording visual and vestibular responses in reticulospinal neurons, which form the major descending motor control system in lamprey. In the absence of visual stimulation, vestibular input induced an approximately equal activation of reticulospinal cells on the left and right side in the dorsal- side-up orientation (the set-point of the system). Any asymmetry in the reticulospinal activity will evoke a correcting roll turn, tending to restore the orientation with symmetrical activity. Vestibular responses were strongly affected by the visual stimulation. Optic nerve stimulation potentiated ipsilateral vestibular responses and depressed contralateral responses, so that the set-point was shifted towards the stimulated side. The potentiation induced by optic nerve stimulation could last up to 2 hours. Intracellular recordings showed that around 50% of the studied reticulospinal neurons were potentiated. A likely mechanism for the long-lasting potentiation is increased excitability in visuo-vestibular interneurons projecting to the reticulospinal cells. Lampreys have lateral line skin photoreceptors in the tail. Tail illumination evoked locomotion without any preferential orientation relative to the source of light. Extracellular recordings in a semi-intact preparation showed that tail illumination activates reticulospinal cells bilaterally, which presumably in turn activates the spinal networks for locomotion. The bilateral activation presumably occurred due to bilateral projections both of the primary lateral line afferents and of secondary sensory neurons in the octavolateral area. Candidate neurons of the latter type were characterized morphologically after retrograde staining with HRP. ISBN 9 1-628-2259-4 TRYCKCENTRUM I STOCKHOLM AB 199

Implicit and Explicit Learning of Temporal Sequences Studied With the Process Dissociation Procedure

We studied whether temporal sequences can be learned implicitly using a process dissociation procedure (PDP). Participants performed repeated serial recalls of sequential stimuli with a random ordinal structure and fixed temporal structure. Explicit knowledge was evaluated through verbal questions and PDP analysis of two generation tasks (inclusion and exclusion). Participants were divided into two groups: in the Ordinal group, stimulus presentation was visual and the participants were instructed to repeat the ordinal structure; in the Temporal+Ordinal group, stimulus presentation was audio-visual and the participants were instructed to repeat temporal and ordinal structure. We expected predominantly implicit learning in the Ordinal group and explicit learning in the Temporal+Ordinal group. This was supported by two findings. First, a significant difference between inclusion and exclusion performance was seen only in the Temporal+Ordinal group. Second, in both groups, a negative relation was found between the degree of improvement during serial recall and a measure of explicit knowledge in the generation tasks. This relation was independent of the final level of performance during serial recall. These findings suggest that distinct implicit and explicit systems may exist for learning of temporal sequences: implicit learning is gradual and gives rise to knowledge that is inaccessible to conscious control while the explicit system is fast and results in representations that can be used to control performance in inclusion and exclusion tasks

Independent Processing of the Temporal and Ordinal Structure of Movement Sequences37

We investigated if the temporal and ordinal structures of sequences can be represented and learned independently. In Experiment 1, subjects learned three rhythmic sequences of key presses with the right index finger: Combined consisted of nine key presses with a corresponding temporal structure of eight intervals; Temporal had the temporal structure of Combined but was performed on one key; Ordinal had the ordinal structure of Combined but an isochronous rhythm. Subjects were divided into two groups. Group 1 first learned Combined, then Temporal and Ordinal; Group 2 first learned Temporal and Ordinal, then Combined. Strong transfer effects were seen in both groups. In Group 1, having learned combined facilitated the learning of the temporal (Temporal) or ordinal (Ordinal) sequence alone; in Group 2, having learned Temporal and Ordinal facilitated the learning of Combined, where the two are combined. This supports that subjects had formed independent temporal and ordinal representations. In Experiment 2, we investigated if these can be learned independently. Subjects repeatedly reproduced sequences with fixed temporal and random ordinal structure; random temporal and fixed ordinal structure; and random temporal and ordinal structures. Temporal and ordinal learning was seen only in the first and second sequences, respectively. In summary, we provide evidence for the existence of independent systems for learning and representation of ordinal and temporal sequences and for implicit learning of temporal sequences. This may be important for fast learning and flexibility in motor control

Dissociation between melodic and rhythmic processing during piano performance from musical scores

When performing or perceiving music, we experience the melodic (spatial) and rhythmic aspects as a unified whole. Moreover, the motor program theory stipulates that the relative timing and the serial order of the movement are invariant features of a motor program. Still, clinical and psychophysical observations suggest independent processing of these two aspects, in both production and perception. Here, we used functional magnetic resonance imaging to dissociate between brain areas processing the melodic and the rhythmic aspects during piano playing from musical scores. This behavior requires that the pianist decodes two types of information from the score in order to produce the desired piece of music. The spatial location of a note head determines which piano key to strike, and the various features of the note, such as the stem and flags determine the timing of each key stroke. We found that the medial occipital lobe, the superior temporal lobe, the rostral cingulate cortex, the putamen and the cerebellum process the melodic information, whereas the lateral occipital and the inferior temporal cortex, the left supramarginal gyrus, the left inferior and ventral frontal gyri, the caudate nucleus, and the cerebellum process the rhythmic information. Thus, we suggest a dissociate involvement of the dorsal visual stream in the spatial pitch processing and the ventral visual stream in temporal movement preparation. We propose that this dissociate organization may be important for fast learning and flexibility in motor control