How two word-trained dogs integrate pointing and naming

Two word-trained dogs were presented with acts of reference in which a human pointed, named objects, or simultaneously did both. The question was whether these dogs would assume co-reference of pointing and naming and thus pick the pointed-to object. Results show that the dogs did indeed assume co-reference of pointing and naming in order to determine the reference of a spoken word, but they did so only when pointing was not in conflict with their previous word knowledge. When pointing and a spoken word conflicted, the dogs preferentially fetched the object by name. This is not surprising since they are trained to fetch objects by name. However, interestingly, in these conflict conditions, the dogs fetched the named objects only after they had initially approached the pointed-to object. We suggest that this shows that the word-trained dogs interpret pointing as a spatial directive, which they integrate into the fetching game, presumably assuming that pointing is relevant to finding the requested object

Atomic Force Microscopy-Based Screening of Drug-Excipient Miscibility and Stability of Solid Dispersions

ABSTRACT: Purpose: Development of a method to assess the drug/polymer miscibility and stability of solid dispersions using a melt-based mixing method. Methods: Amorphous fractured films are prepared and characterized with Raman Microscopy in combination with Atomic Force Microscopy to discriminate between homogenously and heterogeneously mixed drug/polymer combinations. The homogenous combinations are analyzed further for physical stability under stress conditions, such as increased humidity or temperature. Results: Combinations that have the potential to form a molecular disperse mixture are identified. Their potential to phase separate is determined through imaging at molecular length scales, which results in short observation time. De-mixing is quantified by phase separation analysis, and the drug/polymer combinations are ranked to identify the most stable combinations. Conclusions: The presented results demonstrate that drug/polymer miscibility and stability of solid dispersions, with many mechanistic details, can be analyzed with Atomic Force Microscopy. The assay allows to identify well-miscible and stable combinations within hours or a few day

Atomic Force Microscopy-Based Screening of Drug-Excipient Miscibility and Stability of Solid Dispersions

PURPOSE: Development of a method to assess the drug/polymer miscibility and stability of solid dispersions using a melt-based mixing method. METHODS: Amorphous fractured films are prepared and characterized with Raman Microscopy in combination with Atomic Force Microscopy to discriminate between homogenously and heterogeneously mixed drug/polymer combinations. The homogenous combinations are analyzed further for physical stability under stress conditions, such as increased humidity or temperature. RESULTS: Combinations that have the potential to form a molecular disperse mixture are identified. Their potential to phase separate is determined through imaging at molecular length scales, which results in short observation time. De-mixing is quantified by phase separation analysis, and the drug/polymer combinations are ranked to identify the most stable combinations. CONCLUSIONS: The presented results demonstrate that drug/polymer miscibility and stability of solid dispersions, with many mechanistic details, can be analyzed with Atomic Force Microscopy. The assay allows to identify well-miscible and stable combinations within hours or a few days

Corrigendum: Reduced Mu Power in Response to Unusual Actions Is Context-Dependent in 1-Year-Olds

During social interactions infants predict and evaluate other people’s actions. Previous behavioral research found that infants’ imitation of others’ actions depends on these evaluations and is context-dependent: 1-year-olds predominantly imitated an unusual action (turning on a lamp with one’s forehead) when the model’s hands were free compared to when the model’s hands were occupied or restrained. In the present study, we adapted this behavioral paradigm to a neurophysiological study measuring infants’ brain activity while observing usual and unusual actions via electroencephalography. In particular, we measured differences in mu power (6 – 8 Hz) associated with motor activation. In a between-subjects design, 12- to 14-month-old infants watched videos of adult models demonstrating that their hands were either free or restrained. Subsequent test frames showed the models turning on a lamp or a soundbox by using their head or their hand. Results in the hands-free condition revealed that 12- to 14-month-olds displayed a reduction of mu power in frontal regions in response to unusual and thus unexpected actions (head touch) compared to usual and expected actions (hand touch). This may be explained by increased motor activation required for updating prior action predictions in response to unusual actions though alternative explanations in terms of general attention or cognitive control processes may also be considered. In the hands-restrained condition, responses in mu frequency band did not differ between action outcomes. This implies that unusual head-touch actions compared to hand-touch actions do not necessarily evoke a reduction of mu power. Thus, we conclude that reduction of mu frequency power is context-dependent during infants’ action perception. Our results are interpreted in terms of motor system activity measured via changes in mu frequency band as being one important neural mechanism involved in action prediction and evaluation from early on

Language learning in dogs

Most pet dogs know a few words, but recently, the astonishing communicative skills of domestic dogs ( Canis familiaris ) have been discovered: Some dogs know a great number of words and differentiate objects by label in apparently humanlike ways. However, one must be careful not to overestimate the skills of man's best friend. At best, canine skills are comparable to the receptive language skills of 12– to 18-month-old infants—with grammatical skills being the most debated and questionable. One also must not underestimate their skills. Perhaps most strikingly, and in sharp contrast to other nonhuman species, from puppyhood, dogs of all breeds understand the pointing gesture