Comparative psychology 25 years after.

Examined articles published in the Journal of Comparative and Physiological Psychology (JCPP) and Animal Behavior (AB) in the 25 yrs since F. A. Beach first surveyed the literature in 1950. In the JCPP, the number of species studied remained relatively low in view of the greatly increased number of articles published, while the reverse was true of AB, whose articles were also more diversified in terms of number of species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recency effects as a window to generalization: Separating decisional and perceptual sequential effects in category learning.

Accounts of learning and generalization typically focus on factors related to lasting changes in representation (i.e., long-term memory). The authors present evidence that shorter term effects also play a critical role in determining performance and that these recency effects can be subdivided into perceptual and decisional components. Experimental results based on a probabilistic category structure show that the previous stimulus exerts a contrastive effect on the current percept (perceptual recency) and that responses are biased toward or away from the previous feedback, depending on the similarity between successive stimuli (decisional recency). A method for assessing these recency effects is presented that clarifies open questions regarding stimulus generalization and perceptual contrast effects in categorization and in other domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working memory capacity and the top-down control of visual search: Exploring the boundaries of "executive attention".

The executive attention theory of working memory capacity (WMC) proposes that measures of WMC broadly predict higher order cognitive abilities because they tap important and general attention capabilities (R. W. Engle & M. J. Kane, 2004). Previous research demonstrated WMC-related differences in attention tasks that required restraint of habitual responses or constraint of conscious focus. To further specify the executive attention construct, the present experiments sought boundary conditions of the WMC-attention relation. Three experiments correlated individual differences in WMC, as measured by complex span tasks, and executive control of visual search. In feature-absence search, conjunction search, and spatial configuration search, WMC was unrelated to search slopes, although they were large and reliably measured. Even in a search task designed to require the volitional movement of attention (J. M. Wolfe, G. A. Alvarez, & T. S. Horowitz, 2000), WMC was irrelevant to performance. Thus, WMC is not associated with all demanding or controlled attention processes, which poses problems for some general theories of WMC. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physical Modelling of Transport Phenomena in a Delta‐shaped,Four‐strand Tundish with Flow Modifiers

Experiments were conducted in a full‐scale physical model of a delta‐shaped, four‐strand tundish to study the effect of flow modifiers on tundish performance. Two different types of flow modifiers were studied; an existing flow‐modifier and a turbulence‐inhibitor. Their effects were quantified by measuring residence times of fluid in the tundish and residual ratios of inclusions. Although the Turbulence‐Inhibitor appeared to be more effective in guiding flows than the flow‐modifier, the latter gave the longer average residence times and smaller residence time differences between the inner and outer nozzles, which resulted in a higher residual ratio of inclusions.     

Individual Differences in Susceptibility to False Memory in the Deese-Roediger-McDermott Paradigm.

The authors addressed whether individual differences in the working memory capacity (WMC) of young adults influence susceptibility to false memories for nonpresented critical words in the Deese-Roediger-McDermott associative list paradigm. The results of 2 experiments indicated that individuals with greater WMC recalled fewer critical words than individuals with reduced WMC when participants were forewarned about the tendency of associative lists (e.g., bed, rest, . . .) to elicit illusory memories for critical words (e.g., sleep). In contrast, both high and low WMC participants used repeated study-test trials to reduce recall of critical words. These findings suggest that individual differences in WMC influence cognitive control and the ability to actively maintain task goals in the face of interfering information or habit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Turbulence generated by vibrating wire resonators in superfluid 4He at low temperatures

No Heading We have measured responses of vibrating wire resonators in superfluid ⁴He at millikelvin temperatures. We find evidence for turbulence generation above a critical velocity on the order of a few cm/s. At the critical velocity for the onset of turbulence, the resonator velocity abruptly decreases and shows hysteretic behavior. Surprisingly we find that the resonant frequencies of the resonators increase in the turbulent regime. We also find that the critical velocity may be reduced by the presence of turbulence generated by a neighboring vibrating wire resonator, allowing the detection of existing turbulence in the low temperature regime.PACS numbers: 67.40 Vs, 67.40 Pm     

Time-frequency analysis of SEMG with special consideration to the interelectrode spacing

The surface electromyogram (SEMG) is a complex, nonstationary signal. The spectrum of the SEMG is dependent on the force of contraction being generated and other factors like muscle fatigue and interelectrode distance (IED). The spectrum of the signal is time variant. This paper reports the experimental research conducted to study the influence of force of muscle contraction and IED on the SEMG signal using time-frequency (T-F) analysis. Two T-F techniques have been used: Wigner-Ville distribution (WVD) and Choi-Williams distribution (CWD). The experiment was conducted with the help of ten healthy volunteers (five males and five females) who performed isometric elbow flexions of the active right arm at 20%, 50%, and 80% of their maximal voluntary contraction. The SEMG signal was recorded using surface electrodes placed at a distance of 18 and 36 mm over biceps brachii muscle. The results indicate that the two distributions were spread out across the frequency range at smaller IED. Further, regardless of the spacing, both distributions displayed increased spectral compression with time at higher contraction level.     

Development of a system for measurement of permeability of aroma compounds through multilayer polymer films by coupling dynamic vapour sorption with purge‐and‐trap/fast gas chromatography

A system for measurement of permeability of aroma compounds through laminated polymer films was constructed by combining dynamic vapour sorption (DVS) with purge‐and‐trap/fast gas chromatography (P&T–fGC). Data validation was achieved by measuring the permeability of limonene across an HDPE film (film C) and comparing the permeation data with the literature values. The general applicability of this system, as well as its potential for simultaneous measurement of permeability of multiple aroma compounds, was demonstrated by measuring the permeability of limonene and ethyl butyrate as single permeants or as co‐permeants under different environmental conditions (at 25°C, 30°C or 35°C and 0% or 75% RH) through three different multilayer polymer films (film A, HDPE/EVOH/HDPE/HDPE; film B, HDPE/nylon/HDPE/HDPE; film C, HDPE/HDPE). The results showed that the aroma barrier performance of plastic films was determined by the polymer composition and was affected by various factors, such as temperature and the presence of other co‐permeants. Simplicity, speed and accuracy were some of the attractive features of this system, which indicates its potential as a useful tool that could be applied in the food industry for screening or selection of appropriate packaging materials for specific applications. Copyright © 2004 John Wiley & Sons, Ltd.     

Positions of Truthfully Answered Controls on Control Question Tests With the Polygraph.

Students (N = 120) guilty of a mock crime, innocent and informed, or innocent and uninformed of crime details were examined by polygraph with an altered form of Control Question Test (CQT). Ambiguous, lie-engendering control questions were altered to form clear direct questions answered truthfully. When these control questions were positioned before crime-relevant questions, most guilty and innocent participants were correctly classified. Most participants were classed as guilty when crime-relevant questions were positioned before control questions. Lying to crime-relevant questions in the second position resulted in skin resistance, F(2,108) = 8.2, and blood volume, F(2, 108) = 6.1, responses larger than Orienting Responses to initial control questions. Accurate detection depends on the position of control questions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Attentional Dynamics of Masked Detection.

A dichoptic masking procedure was used to test whether the mask-dependent cuing effects found in luminance detection by P. L. Smith (2000a) were due to integration masking or interruption masking. Attentional cuing enhanced detection sensitivity (d') when stimuli were backwardly masked with either dichoptic or monoptic masks, whereas no cuing effect was found with unmasked stimuli, implying the mask dependencies were due to interruption of stimulus processing in visual cortex by the mask. The effect is predicted by a gated diffusion process model in which masks interrupt stimulus processing and attention controls the flow of information to a sequential-sampling decision mechanism. The model correctly predicts different patterns of performance for detection and discrimination and cuing effects in simple reaction time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)