Phonological and working memory mechanisms involved in written spelling

Recent theories of spelling based on neuropsychological data and on computational modelling (Caramazza & Miceli, 1990; Caramazza, Miceli, Villa, & Romani, 1987; Glasspool & Houghton, 2005; Glasspool, Shallice, & Cipolotti, 2006; Miceli & Capasso, 2006; Rapp & Kong, 2002) assume that a working memory system is used to store identity and order of the graphemes, and propose that an impairment of this system, called Graphemic Buffer (GB), is marked by the presence of a number of typical effects. Recently, this disorder has been simulated by different versions of the Competitive Queuing model (Glasspool & Houghton, 2005; Glasspool et al., 2006). The effect of the disruption of this mechanism in written spelling was investigated by means of a dual task in the present study. Three-syllable and four-syllable words were presented to normal adults for aural presentation (Experiment 1) and spelling by copying (Experiment 2). In order to investigate the effects of dual tasks, and the possible involvement of phonological codes, three conditions were used: simple dictation, concurrent articulation, and foot tapping. The results showed strong effects of concurrent articulation, and were consistent with the hypothesis that this task disrupted the serial operations of readout and sequential planning of the GB. They were also consistent with the simulations of the Competitive Queuing model, suggesting possible loci of the effects.     

Individual Differences in Spatial Memory and Striatal ChAT Activity among Young and Aged Rats

Individual differences in spatial memory among young and aged rats were assessed using memory tasks related to integrity of the hippocampus and the neostriatum. Relationships were then examined between measures of spatial memory and regional choline acetyltransferase (ChAT) activity, a marker for cholinergic integrity. Twenty-four-month-old Long-Evans rats were impaired in comparisons with 6-month-old rats on measures of place learning, working memory, reference memory, and perseveration in water-maze tasks. Aged rats that were impaired on one measure of memory, however, were not necessarily impaired on other measures. ChAT activity in the ventromedial and dorsolateral neostriatum of aged rats was significantly reduced in comparisons with young rats whereas no difference was found in the hippocampus. Aged rats with the most ChAT activity in the anterior ventromedial neostriatum performed best on the place-learning and reference memory tasks but also made the most perseverative errors on the working memory task. In addition, young and aged rats with the most ChAT activity in the anterior dorsolateral neostriatum were those with the least accurate working memory. No relationships were found between ChAT activity in the hippocampus and spatial memory. Thus age-related memory impairment has components that can be segregated by measuring relationships between cholinergic integrity in subregions of the anterior neostriatum and memory tasks with different strategic requirements.     

Do ‘literate’ pigeons (<Emphasis Type="Italic">Columba livia</Emphasis>) show mirror-word generalization?

Many children pass through a mirror stage in reading, where they write individual letters or digits in mirror and find it difficult to correctly utilize letters that are mirror images of one another (e.g., b and d). This phenomenon is thought to reflect the fact that the brain does not naturally discriminate left from right. Indeed, it has been argued that reading acquisition involves the inhibition of this default process. In the current study, we tested the ability of literate pigeons, which had learned to discriminate between 30 and 62 words from 7832 nonwords, to discriminate between words and their mirror counterparts. Subjects were sensitive to the left–right orientation of the individual letters, but not the order of letters within a word. This finding may reflect the fact that, in the absence of human-unique top-down processes, the inhibition of mirror generalization may be limited.     

The discursive construction of community identity

The aim of this article is to illustrate how a discourse‐oriented approach would open new theoretical and methodological perspectives to the study of community identity. Here outlined is the idea that community identity is discursively constructed by members in order to lend meaning to experience. An analysis of how community identity is constructed in subjects' discourse with reference to the local context is presented. Copyright © 2004 John Wiley & Sons, Ltd.     

Interpreting visual preferences in the visual paired-comparison task

Performance on the visual paired-comparison (VPC) task has typically been interpreted with E. Sokolov's (1963) comparator model of the orienting response; novelty preferences are interpreted as evidence of retention, whereas null preferences are interpreted as evidence of forgetting. Here the authors capitalized on the verbal nature of human adults to clarify the interpretation of visual preferences in VPC performance. In 2 experiments, adults were tested on either the VPC task or a forced-choice recognition task after delays of 3 min to 12 months. In Experiment 1, adults tested on the VPC task exhibited novelty preferences after short delays, null preferences after intermediate delays, and familiarity preferences after long delays. In Experiment 2, adults tested on the forced-choice recognition task exhibited high levels of accuracy irrespective of delay, but the latency with which they recognized the stimuli increased systematically over the retention interval. These data are inconsistent with a simple Sokolovian interpretation of VPC performance and instead suggest that memory may be expressed as a novelty preference, null preference, or familiarity preference depending on the accessibility of the representation.     

Time-courses of Fos expression in rat hippocampus and neocortex following acquisition and recall of a socially transmitted food preference

The present study examined expression of the immediate-early gene, c-Fos, following acquisition, 48-h (recent) recall, and 1-week (remote) recall of a socially transmitted food preference (STFP) in multiple brain regions implicated in learning and memory. In comparisons with controls, trained Long-Evans rats had increased Fos immunoreactivity in the ventral hippocampus following acquisition and recent recall. In the parahippocampal cortices, Fos was increased in the lateral entorhinal cortex after acquisition. In the orbitofrontal cortex, increased Fos immunoreactivity was observed in the lateral orbital cortex following both recent and remote recall and in the ventral orbital cortex following remote recall, indicating a role for the orbitofrontal cortex in the remote recall of STFP memory. In contrast, in the medial prefrontal cortex, increased Fos-ir was found following acquisition in the prelimbic cortex and following recent recall in the prelimbic and infralimbic cortices. No differences in Fos expression were found between trained rats and controls in the dorsal hippocampus, posterior parietal cortex, or amygdala. The present findings support a time-limited role of the hippocampus in the acquisition and recall of STFP memory and implicate neocortical regions involved in STFP acquisition, recent, and remote recall.     

Attention as a cueing function during kindergarten children's dimensional change task performance

The purpose of this experiment is to test whether shift flexibility in kindergarten children is a joint function of rule‐usage and inhibition of attention. Sixty‐six children were given either a distraction or facilitation condition in a computerized version of the dimensional change card sort task. In the distraction condition, the background of the post‐shift matching stimulus was inconsistent with the relevant matching dimension. In the facilitation condition, the background of the post‐shift matching stimulus was consistent with the relevant matching dimension. Results revealed that children made few errors in the standard version of the shift task, thereby supporting Cognitive complexity and control theory's contention that 5‐year‐old children shift easily across dimensions due to their use of higher‐order setting rules to solve contradictions. The proportion of errors increased however in the distraction condition suggesting that attention to the background interfered with children's ability to shift between dimensions. Therefore, these data provide evidence that refocusing attention to dimensions along with rule‐use processes affect shift flexibility and argue for the inclusion of both factors into theoretical accounts of shift performance. Copyright © 2009 John Wiley & Sons, Ltd.     

Serial learning with wild card items by monkeys (Cebus apella): implications for knowledge of ordinal position

We investigated monkeys' knowledge of the ordinal positions of stimuli that formed a 5-item serial list, ABCDE, by means of wild card items (W) that could substitute for items in the original series. In Experiment 1, training with wild cards was given on 3-, 4-, and 5-item series. In the last of these series, the wild card substitutions created five wild card sequences, WBCDE through ABCDW. During the final 10 sessions of training with each of two different wild cards (Items x and Y), the 3 subjects were able to successfully complete almost 60% of the wild card sequences. In Experiment 2, the two wild cards were presented on the same trial in 10 different double wild card sequences (e.g., AXCDY). The 2 monkey subjects correctly completed about 59% of the double wild card sequences during the final two training sessions. The performance levels achieved on single and on double wild card sequences, although well below that observed on the baseline sequence ABCDE (90% or better), support the view that the monkeys possessed some knowledge regarding the ordinal position of each baseline item. Consequently, an associative chain interpretation, which does not provide for knowledge of ordinal position, falls short as a complete account of the monkey's capacity for serial learning.