Hyperexcitability in Older Adults with Elevated Beta-Amyloid

Background: Growing evidence links beta-amyloid (Aβ) and neuronal hyperexcitability in preclinical mouse models of Alzheimer’s disease (AD). The aim of this study was to compare neuronal excitability between cognitively normal amyloid positive (CNAβ+) and those without elevated amyloid (CNAβ-) older adults. We hypothesized CNAβ+ participants would show hyperexcitability, indexed by greater peak P3 event-related potential peak amplitude, shorter peak latency, and changes in event-related power, compared to CNAβ-.Methods: CNAβ+ participants (n = 17, age: 73 ± 5, 11 women, MOCA scores 26 ± 2) and 17 CNAβ- participants group-matched for age, sex, and MOCA completed the a working memory task (n-back with n = 0, 1, 2) test while wearing a 256-channel EEG net. P3 peak amplitude and latency of the nontarget, target and task difference (nontarget – target), and event-related power, extracted from Fz (main outcome), Cz, and Pz were compared between groups using linear mixed models. Mean Aβ standard uptake value ratios (SUVR) were correlated with P3 amplitude and latency using Pearson r.Results: P3 peak amplitude of the task difference (p = 0.048) and P3 peak latency of non-targets trials (p = 0.006) at Fz differed between groups. Similarly, power was lower in the delta band (p = 0.04) for nontargets at Fz in CNAβ+ participants. CNAβ+ participants also demonstrated higher theta and alpha power in channels at Cz and Pz, but no changes in P3 ERP. Strong correlations were found between mean Aβ SUVR and latency of the 1-back (r = -0.69; p = 0.003) and 2-back (r = -0.69; p = 0.004) of the task difference at channel Fz in the CNAβ+ group.Conclusions: Our pilot data suggests that elevated amyloid in cognitive normal older adults is associated with hyperexcitability in P3 ERP. Further research is warranted to determine the validity of ERP in predicting clinical, neurobiological, and functional manifestations of AD.

Item-specific and relational processing both improve recall accuracy in the DRM paradigm

Using the Deese–Roediger–McDermott (DRM) paradigm, Huff and Bodner found that both item-specific and relational variants of a task improved correct recognition, but only the item-specific variants reduced false recognition, relative to a read-control condition. Here, we examined the outcome pattern when memory was tested using free recall, using the same item-specific versus relational task variants across three experiments as our previous study (processing instructions, pleasantness ratings, anagram generation). The outcome pattern in recall was similar to recognition, except relational processing at study actually reduced the DRM illusion, though not as much as item-specific processing. To reconcile this task difference, we suggest that the memory information laid down during relational encoding enhances the familiarity of the critical items at test. To the extent that familiarity is used less as a basis for responding in free recall than in recognition, relational processing ironically reduces rather than increases the DRM illusion in recall.

Simple dissociations for a higher-powered neuropsychology

Neuropsychological dissociations are often investigated at the level of the single-case, and formal criteria exist for the detection of dissociations, and their sub-classification into ‘classical’ and ‘strong’ types. These criteria require a patient to show a frank deficit on one task (for a classical dissociation) or both tasks (for a strong dissociation), and a significantly extreme difference between tasks. I propose that only the significant between-task difference is logically necessary, and that if this simple criterion is met, the patient should be said to show a dissociation. Using Monte Carlo simulations, I demonstrate that this simplification increases the power to detect dissociations across a range of practically-relevant conditions, whilst retaining excellent control over Type I error. Additional testing for frank deficits on the individual tasks provides further qualifying information, but using these outcomes to sub-classify dissociations as classical or strong may be too uncertain to guide theoretical inferences. I suggest that we should instead characterise the strength of the dissociation using a more continuous index, such as the effect size of the simple between-task difference.

Misoperation Study on Samsung VP－101 Digital Video Camcorder

Digital video camcorder is a kind of mechanical and electrical product that is easy to make misoperation. Chose green hand users as subjects.Then applied experiment method to study their misoperation manner in using Sangsumg VP－101 digital video camcorder. According to industrial design psychology and ergonomics theory , analysed experimental result. Firstly, through F testing of psychology statistics method, found that the major effective reason of misoperation was task difference which was relevant to interface and interacting means design factors, and individual difference of each subject had little effect on misoperation. Secondly, in terms of analysis on the relevance of interacting means design details and misoperation manner, found rational design reasons of misoperation. They were mismatching attribute of perception, mismatching attribute of touching size, lack of visuality. Thirdly, On the basis of statistics on subjects mood research, found that nervous and whiny mood were irrational factors affecting misoperation. The conclusion could be summarized as the three results mentioned above. Specific to this conclusion, discussed methods to deduce misoperation by building user task model, user mental model and green hand user mood model.

False belief understanding in Cantonese-speaking children

The present study investigates the performance of 96 Cantonese-speaking three- to five-year-old preschoolers on three false belief tasks – a deceptive object, a change of location, and an unexpected contents task encompassing a variety of task factors. Most importantly, the research examines the possibility that false belief performance depends on specific linguistic factors such as the type of verb used in the test question – an explicitly false vs. a neutral belief verb. Cantonese was chosen as particularly useful for examining this question because it explicitly codes belief status as either neutral (nam5) or false (ji5wai4), and because it offers additional linguistic and cultural contrasts to research conducted on false belief with children learning English and other Indo-European languages. As expected, a strong age effect was found, as well as a significant advantage for children who received the explicit false belief (ji5wai4) wording and for those who were asked to explain rather than predict the protagonist's actions. Interestingly, there was also a strong task difference with children performing better on the deceptive object task than on the other two false belief tasks. We argue that these results point both to universal trajectories in theory of mind development and to interesting, but localized, effects of language and culture on children's false belief understanding.

Effects of a Circumferentially Vented Mask on Breathing Patterns of Women as Measured by Respiratory Kinematic Techniques

Since pneumotachograph masks are commonly used in studies of speech breathing, the purpose of this study was to measure the differences in respiratory volumetric and frequency measures during speech under two conditions: with and without a circumferentially vented pneumotachograph mask coupled to the face. Thus we sought to identify whether changes in breathing patterns occur with the use of a specific face mask, because these patterns are accepted as representative of normal speech breathing. Subjects were 10 normal-speaking women, each of whom produced a syllable train and a connected speech task, both at comfortable intensity levels. Respiratory measures were made using linearized magnetometers during speech production. The measurements included lung volume, rib cage volume, and abdominal volume at utterance initiation and termination, volume excursions during the utterance, and the number of breath groups during the speech task. There were no significant differences between the mask-on and mask-off conditions in volumetric and frequency measures. A significant task difference for abdominal initiation was found. It was concluded that the use of a circumferentially vented pneumotachograph mask does not alter the reliability of respiratory volume and frequency measures for studies of voice.