Psychic tonus, body schema and the parietal lobes: a multiple lesion case analysis

The psychic tonus model (Braun and colleagues, 1999, 2002, 2003, 2006) states that the left hemisphere is a "booster" of internal experience and behavior in general, and that the right hemisphere is a "dampener". Twenty-five patients with a "positive" extreme disturbance of body schema (somatoparaphrenia) and 37 patients with a "negative" disturbance of body schema (autotopagnosia or Gerstmann's syndrome), all following a unilateral parietal lesion, were found in the literature and were analyzed to test predictions from Braun's "psychic tonus" model. As expected, patients with a positive syndrome had a right hemisphere lesion significantly more frequently, and those with a negative syndrome had a left hemisphere lesion significantly more frequently. Thus the psychic tonus model of hemispheric specialization, previously supported with regard to psychomotor baseline, libido, talkativeness, memory, auditory and visual perceptual tonus, now incorporates the tonus of representation of the body (body schema) in the parietal lobes.     

Perceptual adaptation to structure-from-motion depends on the size of adaptor and probe objects,but not on the similarity of their shapes

Perceptual adaptation destabilizes the phenomenal appearance of multistable visual displays. Prolonged dominance of a perceptual state fatigues the associated neural population, lowering the likelihood of renewed perception of the same appearance (Nawrot & Blake in Perception & Psychophysics, 49, 230–44, 1991). Here, we used a selective adaptation paradigm to investigate perceptual adaptation for the illusory rotation of ambiguous structure-from-motion (SFM) displays. Specifically, we generated SFM objects with different three-dimensional shapes and presented them in random order, separating successive objects by brief blank periods, which included a mask. To assess the specificity of perceptual adaptation to the shape of SFM objects, we established the probability that a perceived direction of rotation persisted between successive objects of similar or dissimilar shape. We found that the strength of negative aftereffects depended on the volume, but not the shape, of adaptor and probe objects. More voluminous objects were both more effective as adaptor objects and more sensitive as probe objects. Surprisingly, we found these volume effects to be completely independent, since any relationship between two shapes (such as overlap between volumes, similarity of shape, or similarity of velocity profiles) failed to modulate the negative aftereffect. This pattern of results was the opposite of that observed for sensory memory of SFM objects, which reflects similarity between objects, but not volume of individual objects (Pastukhov et al. in Attention, Perception & Psychophysics, 75, 1215–1229, 2013). The disparate specificities of perceptual adaptation and sensory memory for identical SFM objects suggest that the two aftereffects engage distinct neural representations, consistent with recent brain imaging results (Schwiedrzik et al. in Cerebral Cortex, 2012).     

Strategic sequence planning and prospective memory impairments in frontally lesioned head trauma patients performing activities of daily living

The aim of this research was to study strategic sequence planning and prospective memory in activities of daily living (ADL) in 10 patients with frontal lobe lesions after a mild to moderate closed head injury (CHI). The lesions were documented radiologically. The CHI patients were compared to 12 normal controls with a neuropsychological test battery and a realistic simulation of complex multitask ADL (planning and preparing a meal). Though the CHI patients were significantly slow on one test and subject to interference on an attention test, they manifested no basic executive or memory deficit on the paper-pencil tests. However, the CHI patients manifested marked anomalies in the organization of behavior in the meal preparation task. While small sequences of actions were easily produced, large action sets could not be correctly executed. An outstanding difficulty in strategic planning and prospective memory, particularly time-based more than event-based, appears to be an important underpinning of the impairment of ADL observed in the CHI patients with frontal lobe lesions.     

Development of neuronal responsiveness in the mediorostral neostriatum/hyperstriatum ventrale during auditory filial imprinting in domestic chicks

Chronic electrophysiological recordings of slow field potentials from tone-imprinted chicks show significantly enhanced fast Fourier transform (FFT) power during playback of rhythmic 400-Hz imprinting tone stimuli in the presence of a surrogate mother. The FFT power was already significantly higher during the very first imprinting session, when the chick was exposed to the imprinting tone stimuli in the presence of the surrogate mother compared to spontaneous activity (EEG recordings). During discrimination tests, where individual chicks were exposed to the imprinting tone stimuli in alternation to rhythmic 700-Hz tone stimuli (discrimination tone stimuli), the FFT power was significantly higher during playback of the imprinting tone stimuli than the FFT power during playback of the discrimination tone stimuli. Chicks which were imprinted in the absence of the surrogate mother also show enhanced FFT power in the course of the imprinting sessions; however, in contrast to the first group, they did not show significant differences in the FFT power during playback of either the imprinting or discrimination tone stimuli in the discrimination tests. Our results suggest that the high FFT power of a potential imprinting stimulus or situation, which is expressed in newborn (still naive) chicks, is maintained only when the chicks form an association between the tone stimuli and a positive emotional situation (represented by the surrogate mother).     

Patterns of Social Integration of Western European Migrants

This paper investigates whether there are different social integration patterns of intra-European adult migrants who moved between 1974 and 2003 from Britain, France, Germany, Italy, and Spain to one of the other four countries. These patterns are derived by means of latent class analysis based on information on the ethnic origin of both partners and friends. The data were collected by telephone interviews in the ??European Internal Movers?? Social Survey?? in 2004. Approximately 250 interviews were conducted with migrants from each of the 20 combinations of country of origin and country of residence (N?=?4.902). In addition to two patterns of nationalized integration, where partner and friends come predominantly either from the country of residence or the country of origin, two de-nationalized integration patterns were found which are characterized by mixed friendship networks (co-nationals, nationals of the country of residence, and third countries). As a country of residence, Britain provides the most fertile ground for a de-nationalization of friend and partnerships for incoming migrants; the opposite is true for Italy. German and British migrants tend to nationalize integration patterns, that is, they either socialize with their co-nationals or with nationals of their country of residence.     

Rack-and-pinion effects in molecular rolling friction

Rolling lubrication with spherical molecules working as ‘nanobearings’ has failed experimentally so far, without a full understanding of the physics involved and of the reasons why. Past model simulations and common sense have shown that molecules can only roll when they are not too closely packed to jam. The same type of model simulations now shows in addition that molecular rolling friction can develop deep minima once the molecule's peripheral ‘pitch’ can match the substrate periodicity, much as ordinary cogwheels do in a rack-and-pinion system. When the pinion-rack matching is bad, the driven molecular rolling becomes discontinuous and noisy, whence energy is dissipated and friction is large. This suggests experiments to be conducted by varying the rack-and-pinion matching. That could be pursued not only by changing molecules and substrates, but also by applying different sliding directions within the same system, or by applying pressure, to change the effective matching.     

EDITORIAL COMMENT: GUEST COMMENTARY

A pervasive problem faced by children in both classroom and clinic is the lack of transfer from the apparent learning of “skills” to improved overall reading performance. For varied reasons, “skills” learned by children fail to become integrated to enhance reading fluency. A related problem derives from the lack of automaticity that many children fail to achieve either in specific facilitating “skills” or in the reading task generally.