Odor enrichment increases interneurons responsiveness in spatially defined regions of the olfactory bulb correlated with perception

Odor enrichment enhances rats’ ability to discriminate between chemically similar odorants. We show here that this modulation of olfactory perception is accompanied by increases in the density of local inhibitory interneuron expressing Zif268 in response to olfactory stimuli. These changes depend on the overlap of the olfactory bulb activation patterns induced by the enrichment odorants with those induced by the testing odorants, in a manner similar to changes in perception. Moreover, we show that enrichment leads to an alteration of the pattern of Zif268 expression, dependent on the odors used for the enrichment indicating a restructuring of odor representation in the olfactory bulb.     

Relative contributions of kind- and domain-level concepts to expectations concerning unfamiliar exemplars: Developmental change and domain differences

Two inferential routes allow children to produce expectations about new instances of ontological categories like “animal” and “artefact.” One is to generalise information from a “look-up table” of familiar kind-concepts. The other one is to use independent expectations at the level of ontological domains. Our experiment pits these two sources of information against each other, using a sentence-judgement task associating properties with images of familiar and unfamiliar artefacts and animals. “Strange” properties are compatible with the ontological concept, but not encountered in any familiar kind. A look-up strategy would lead children to reject them and an independent expectation strategy to accept them. In both domains, we find a difference in reaction to strange properties associated with familiar vs. unfamiliar items, which shows that even young children do use independent domain-level information. We also found a U-shaped curve in propensity to use such abstract information. In addition, animal categories are the object of much more definite domain-level expectations, which supports the notion that the animal domain is more causally integrated than the artefact domain.     

Memory for words location in writing

In two experiments, we investigated memory for words location after writing a text. Experiment 1 demonstrated the existence of a memory for words location in writing by showing that participants who first composed a text and were then asked to locate words extracted from their text performed above a chance level established using a computer simulation, and better than participants who did not compose a text but were told the subject of the text. Experiment 2 showed that memory for words location in writing is mainly supported by a visuospatial representation of the text, as indicated by the lower recall of words location by participants who performed a visuospatial concurrent task at the time of the composition, compared with participants who performed a verbal concurrent task. The findings highlight the role of a spatial representation of the physical layout of the text and the role of such a memory in the writing process.

---

Comparing detailed and less detailed pre-lineup instructions

It is generally agreed that proper pre-lineup instructions can reduce the rate of mistaken identifications of innocent suspects. However, the exact nature of these instructions has not been empirically established. We compared the effects of the detailed pre-lineup instructions recommended by the US Department of Justice to a simple instruction that the perpetrator may or may not be present. Both forms of unbiased instructions significantly reduced mistaken identifications when compared with biased instructions. Comparison of performance using the utility-based analysis deviation from perfect performance demonstrated that unbiased instructions are to be preferred under assumptions of low base rates or high costs of mistaken identifications and do as well as biased instructions under assumptions of high base rates or low cost of misidentification.     

Deficit in phonological processes: a characteristic of the neuropsychological profile of children with NF1

Learning disabilities are one of the most frequent complications of neurofibromatosis type 1 (NF1) in children. Studies of the effects of the neurocognitive deficit on academic performance are relatively rare, owing to the small size of the populations concerned. However, research is needed to develop effective rehabilitation programs. In the present study, we explored the impact of a possible phonological deficit on the reading abilities of children with NF1. A multicenter, cross-sectional study was conducted in France on two groups of 75 children with or without NF1 aged 8–12 years, matched for age, sex, handedness, and reading level. All participants underwent a neuropsychological evaluation to assess their general cognitive level, reading skills, phonological processes, visuoperceptual abilities, and attentional capacity. Phonological skills were assessed by means of two phonological awareness tasks and one short-term memory task. In the group of children with NF1, 41% had reading difficulties. Phonological processes were impaired in this group, compared with the children without NF1. Similar differences were found for a phoneme deletion task after adjustment for reading difficulties, IQ level, and visuoperceptual abilities. Phonological awareness, but not phonological short-term memory, was impaired in children with NF1, and not just those whose reading was impaired. Results suggest that children with NF1 have a phonological awareness deficit, whatever their reading level. Identification of reduced phonological skills may warrant the implementation of a specific rehabilitation program before early reading difficulties emerge.