An investigation of persuasion and sentencing severity with mock juries

The extent to which the personal characteristics of individual mock jurors affect participation and influence with other jurors within the deliberation process was the focus of this investigation. A predeliberation locus of control measure, along with two conditions of jury composition (heterogenous vs homogenous with respect to the locus of control measure) were used to investigate interactions among sentencing severity, persuasiveness in deliberation, and demographic characteristics among 96 jurors. Results indicated that group sentences were significantly more severe than predeliberation sentences and that postdeliberation shifts were significantly more pronounced for the heterogenous juries than for the homogeneous juries.     

Diagnosticity,confidence, and the need for information

Recent research has suggested that people prefer to use the most diagnostic available information as the basis for their choices and decisions, and are most confident in those decisions when information is highly diagnostic. However, the effect of information diagnosticity on the need for additional information has yet to be investigated; that is, in an optional stopping task, will the amount of information requested depend upon information diagnosticity? Three models of the role of diagnosticity in information use were examined; expected value, a confidence criterion, and information cost. Subjects attempted to categorize stimuli with the aid of information of varying costs and diagnosticity levels. They requested more information when it was obtained at a low cost. More importantly, across cost conditions, subjects consistently requested greater amounts of information when that information was of a low diagnosticity. These data seem most consistent with use of a confidence criterion that is adjusted for information costs.     

Saccades in Neal’s “Square o f Three”

A contact-lens optical lever was used to measure saccades during maintained fixation of an “op art” painting that produces striking perceptual effects. Saccade frequency was not affected, but saccade vector magnitude was slightly, but reliably, larger with the painting than with a control stimulus. The perceptual effects, however, do not depend on saccades because saccades could be suppressed and the perceptual effects remained.     

STRUCTURE IN SIMILARITY MATRICES

Waern, Y. Structure in similarity matrices. A graphic approach. Scand. J. Psychol ., 1972, 13 , 5–16.—The present paper proposes a simple method for representing the structure inherent in the similarity matrix, i.e. a graphic representation. The traditional multidimensional scaling methods are compared with each other and with the graphic representation with regard to representation, interpretation and assumptions concerning the subject's performance. The graph gives a topological representation and the derivation of the graph from the similarity matrix may be made so as to reduce the demands on the subjects somewhat. As to interpretation, the graph is able to reveal dimensions, clusters, and hierarchies. Compared with some multidimensional scaling it gives very similar interpretations.     

The extraretinal signal for the visual perception of direction

The dependence of the perception of direction on two kinds of extraretinal signals was measured by asking Ss to indicate the position of a fixation target relative to the subjective straight ahead. Outflow was studied by making such localizations while the fixating eye was loaded by means of weights attached to a suction contact lens. Inflow was studied by making such localizations with brief test flashes to a passively rotated eye while the other eye fixated. Shifts in the perceived direction, of the fixation target were in line with predictions from outflow theory and not influenced by conflicting inflow signals.     

Loss of negative priming following sleep deprivation

It has been argued that one night of sleep loss in young healthy adults produces changes similar to that associated with normal, healthy ageing—in particular, that young sleep-deprived adults perform similarly to 60-year-old sleep-satiated adults on some tasks of frontal lobe function. This proposition was examined using a protocol viewed by many to be a direct probe of nonvolitional attention mechanisms associated with frontal lobe function. A negative priming (NP) procedure was used to compare performance between non-sleep-deprived (NSD) and sleep-deprived (SD, 34 hr) young, healthy adults. This protocol allowed for exploration of two theories of the NP effect based on inhibitory or memorial processes. Under conditions believed to facilitate inhibitory processes a normal NP effect was found for NSD(16 ms) and SD (9 ms) participants. Under conditions believed to rely on memorial processes there was no NPeffect following SD, compared with a normal NP effect for NSD participants (11 ms). Distractor interference was also greater following SD. These findings do not suggest a similar pattern of change following sleep loss in healthy young adults to that of normal, healthy, non-sleep-deprived aged groups.