Sensory and cognitive components of visual information acquisition.

Describes a theory of visual information acquisition and visual memory. The theory has 2 major components. First, the visual system's initial sensory response to a short-duration, low-contrast stimulus is generated by a linear, low-pass temporal filter that operates on the stimulus's temporal waveform. Second, information is acquired from a stimulus through an independent-sampling process whose sampling rate at time t following stimulus onset is jointly proportional to (1) the magnitude by which the sensory response exceeds some threshold and (2) the proportion of still unacquired information. The theory was successfully tested in 5 variants of a digit recall task in which temporal waveform of the stimulus was systematically manipulated. In a final experiment, the theory simultaneously accounted for performance in detection and identification tasks. Implications for visual information processing, low-contrast detection, and binocular combination of information are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kinematic form and scaling: Further investigations on the visual perception of lifted weight.

Observers are able to judge accurately the weight lifted by another person when only the motions of reflective patches attached to the lifter's major limb joints and head can be seen (Runeson & Frykholm, 1981). What properties of these complex kinematic patterns allow judgments of weight to be made? The pattern of variation in velocity of the lifted object over position is explored as a source of information for weight: It is found to provide limited information. How are variations in kinematic patterns scaled to allow judgments of weight, a kinetic quantity? The possibility of a source of information for scaling in the kinematics is investigated. Judgments based only on patch-light displays are accurate to a degree that is improved by an extrinsic scaling basis. Finally, the sensitivity to scaling of alternative metrics used in judging is explored. Intrinsic metrics are discovered to be less sensitive to the absence of an extrinsic basis for scaling. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A function-structure model for NGF-activated TRK

Mechanisms regulating transit of receptor tyrosine kinases (RTKs) from inactive to active states are incompletely described, but require autophosphorylation of tyrosine(s) within a kinase domain 'activation loop'. Here, we employ functional biological assays with mutated TRK receptors to assess a 'switch' model for RTK activation. In this model: (i) ligand binding stimulates activation loop tyrosine phosphorylation; (ii) these phosphotyrosines form specific charge pairs with nearby basic residues; and (iii) the charge pairs stabilize a functionally active conformation in which the activation loop is restrained from blocking access to the kinase catalytic core. Our findings both support this model and identify residues that form specific charge pairs with each of the three TRK activation loop phosphotyrosines.     

"A theory of visual information acquisition and visual memory with special application to intensity-duration trade-offs": Correction.

Reports an error in the original article by G. R. Loftus and E. Ruthruff (Journal of Experimental Psychology: Human Perception and Performance, 1994[Feb], Vol 20[1], 33–49). A corrected Figure 4 is presented. (The following abstract of this article originally appeared in record 1994-24283-001.) Describes a theory of memory for visual material in which the visual system acts as linear filter operating on a stimulus to produce a function, a(t), relating some sensory response to t (the time since stimulus onset). Stimulus information is acquired at a rate proportional to the product of the magnitude by which a(t) exceeds some threshold, and the amount of as-yet-unacquired information. The theory accounts for data from 2 digit-recall experiments in which stimulus temporal waveform was manipulated. The authors comment on the theory's account of the relation between 2 perceptual events: the phenomenological experience of the stimulus, and the memory representation that accrues from stimulus presentation. It is asserted that these 2 events, although influenced by different variables, can be viewed as resulting from 2 characteristics of the same sensory-response function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Primitive defenses and the borderline patient's perceptions of the psychiatric treatment team.

Investigated the construct validity of several self-report measures of splitting and related primitive defense mechanisms and undertook a preliminary quantitative analysis of the relation of these defenses to here-and-now social perceptions in borderline psychopathology. Based on an integrated framework of object-relations theory, psychoanalytic group psychology, and social cognition theory, the study explored associations between the use of primitive defenses by 31 adult borderline inpatients and their perceptions of the various staff roles that constitute their treatment teams. Reliance on image-distorting defenses and the holding of fragmented images of self as omnipotent and as "bad" were significantly associated with borderlines' perceived proximity to specific members and subgroups of their treatment teams. Results further validate selected measures of primitive defenses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Syndiospecific Living Catalysts for Propylene Polymerization: Effect of Fluorination on Activity,Stereoselectivity, and Termination

The polymerization of propylene using a variety of fluorinated bis(phenoxyimine)titanium complexes is reported. The synthesis of ten complexes containing varying fluorinated N-aryl substituents is described. X-ray structural and solution NMR data indicate that these complexes are C₂-symmetric in the solid state, although in some cases C₁-symmetric isomers are observed in solution. When activated with methylalumoxane, all complexes formed syndiotactic polypropylene. Catalysts with ortho-fluorine substituents formed polymers with very narrow molecular weight distributions, indicative of a living polymerization. Catalysts with fluorine in at least the ortho and para positions exhibited the highest syndio-specificities. Catalysts with meta- or para-fluorine-containing substituents were more active for propylene polymerization than the corresponding non-fluorinated catalyst.     

0.18-μm fully-depleted silicon-on-insulator MOSFET's

High-performance 0.18-μm gate-length fully depleted silicon-on-insulator (FD-SOI) MOSFET's were fabricated using 4-nm gate oxide, 35-nm thick channel, and 80-nm or 150-nm buried oxide layer. An elevated source/drain structure was used to provide extra silicon during silicide formation, resulting in low source/drain series resistance. Nominal device drive currents of 560 μA/μm and 340 μA/μm were achieved for n-channel and p-channel devices, respectively, at a supply voltage of 1.8 V. Improved short-channel performance and reduced self-heating were observed for devices with thinner buried oxide layers