Synapse specificity of long-term potentiation breaks down with aging

Memory shows age-related decline. According to the current prevailing theoretical model, encoding of memories relies on modifications in the strength of the synapses connecting the different cells within a neuronal network. The selective increases in synaptic weight are thought to be biologically implemented by long-term potentiation (LTP). Here, we report that tetanic stimulation of afferent fibers in slices from 12-mo-old mice triggers an LTP not restricted to the activated synapses. This phenomenon, which can be anticipated to hinder memory encoding, is suppressed by blocking either L-type Ca(++) channels or Ca(++)-induced Ca(++) release, both well known to become disregulated with aging.     

Police officers' views of effective interview tactics with suspects: The effects of weight of case evidence and discomfort with ambiguity

This study examined the effects of case‐specific facts and individual discomfort with ambiguity (DA) on investigators' beliefs concerning effective interviewing tactics for suspects. Violent crime investigators (n = 30) responded to a questionnaire including the Need for Closure Scale (NFCS) and ratings of the importance of 39 interrogation tactics in two hypothetical interrogations with a homicide suspect, where the evidence consisted of either technical evidence or soft information. Twenty tactics were analysed with a multidimensional scaling procedure which confirmed two discrete interviewing themes: humane and dominant. More tactics, both dominant and humane, were rated as important if the evidence was soft compared with technical. In the soft evidence condition, investigators who were high on DA rated both types of tactics as more important than did low‐DA investigators. In the technical evidence condition, no such difference emerged. Copyright © 2008 John Wiley & Sons, Ltd.     

Likelihood ratio decisions in memory: Three implied regularities

We analyze four general signal detection models for recognition memory that differ in their distributional assumptions. Our analyses show that a basic assumption of signal detection theory, the likelihood ratio decision axis, implies three regularities in recognition memory: (1) the mirror effect, (2) the variance effect, and (3) the z-ROC length effect. For each model, we present the equations that produce the three regularities and show, in computed examples, how they do so. We then show that the regularities appear in data from a range of recognition studies. The analyses and data in our study support the following generalization: Individuals make efficient recognition decisions on the basis of likelihood ratios.     

Hypnotic susceptibility and verbal automaticity: automatic and strategic processing differences in the Stroop color-naming task.

The original hypothesis of Dixon, Brunet, and Laurence (1990) that highly hypnotizable (HH) subjects process words more automatically than do low hypnotizable (LH) subjects was retested in a paradigm that separated strategic from automatic processes in the Stroop color-naming task. The words red and blue preceded a color patch that was red or blue. Subjects were told that the word predicted the opposite color 75% of the time. Automatic and strategic processes were assessed by varying the interstimulus interval (ISI) between the word and the color patch. Both HH and LH subjects showed significant strategic effects (faster incongruent-trial, color-naming reaction times than congruent-trial reaction times at ISIs over 400 ms), but only HH subjects showed significant automaticity (significantly faster congruent-trial reaction times than incongruent-trial reaction times at 16.7 ms, the lowest ISI).