Aging and the perception of 3-D shape from dynamic patterns of binocular disparity

In two experiments, we investigated the ability of younger and older observers to perceive and discriminate 3-D shape from static and dynamic patterns of binocular disparity. In both experiments, the younger observers' discrimination accuracies were 20% higher than those of the older observers. Despite this quantitative difference, in all other respects the older observers performed similarly to the younger observers. Both age groups were similarly affected by changes in the magnitude of binocular disparity, by reductions in binocular correspondence, and by increases in the speed of stereoscopic motion. In addition, observers in both age groups exhibited an advantage in performance for dynamic stereograms when the patterns of binocular disparity contained significant amounts of correspondence "noise." The process of aging does affect stereopsis, but the effects are quantitative rather than qualitative.     

Phenomenological reports diagnose accuracy of eyewitness identification decisions

This study investigated whether measuring the phenomenology of eyewitness identification decisions aids evaluation of their accuracy. Witnesses (N = 502) viewed a simulated crime and attempted to identify two targets from lineups. A divided attention manipulation during encoding reduced the rate of remember (R) correct identifications, but not the rates of R foil identifications or know (K) judgments in the absence of recollection (i.e., K/[1 − R]). Both RK judgments and recollection ratings (a novel measure of graded recollection) distinguished correct from incorrect positive identifications. However, only recollection ratings improved accuracy evaluation after identification confidence was taken into account. These results provide evidence that RK judgments for identification decisions function in a similar way as for recognition decisions; are consistent with the notion of graded recollection; and indicate that measures of phenomenology can enhance the evaluation of identification accuracy.     

Orienting Under Load: Intrinsic Dynamics and Postural Affordances for Visual Perception

Orientation toward one's surroundings is necessary for prospective control of action, and constraints on orienting activity have consequences for animal survival. Physically coupled load is a constraint for humans wearing protective equipment (firefighters, soldiers, etc.). The consequences of load on postural affordances while transitioning to upright stance was used to quantify the impact of different soldier configurations. Eight participants established upright posture in 4 relevant load configurations (5.0 to 79.2 lb). Load affected the accessibility of optical information at a distance as evidenced by increasing downward head angles and reductions in postural coordination. Reductions in the variability of time to establish upright stance with load suggests a loss of functional adaptability. Load asymmetries played a significant role as the most asymmetric configuration (not the heaviest) had the most detrimental effect on postural affordances. Center of Pressure (CoP) dynamics reflected the consequences of asymmetric loading on postural regulation as greater power and fluctuations across frequencies were observed. Physically coupled load induces significant constraints on orienting activity, and load asymmetry contributes significantly to the detrimental effects of protective equipment on action-perception coupling during whole-body movements.     

Perceptions of Children Who Lie: Influence of Lie Motive and Benefit

KILMARTIN (1994) suggested that masculine traits may result from externalizing defense style and that when unconscious and unwanted feminine traits about the self occur, they are dealt with in an external way, radier man being directiy resolved by the individual. However, this dieory has received little empirical support. Lobel and Winch (1986) measured defense style among male college students; they found mat men who scored higher in masculinity tended to score higher on acting out (finding an object to attack) and splitting (separating affect from content). Lobel and Winch concluded mat use of diese defense styles reflects avoidance of emotional expression. In turn, diese findings have been supported by research that has suggested mat men use avoidance coping strategies more man women do (McCall &; Struthers, 1994).     

Alterations in Rorschach's Experience Balance under Conditions of Food and Sleep Deprivation: A Construct Validation Study

Clinard, Marshall B. (Ed.), Anomie and Deviant Behavior: A Discussion and Critique. New York, Toronto, London: Collier-Macmillan, Ltd., 1964, Free Press of Glencoe, xii, pp. 324. Reviewed by Leon J. Whitsell     

Book Review

Heath, Douglas H. Exploration of Maturity. New York: Appleton-Century-Crofts, 1965. pp xiv, 423. $7.50. Reviewed by A. Barclay; Audrey M. Thaman     

Children's Mechanistic Reasoning

Reasoning about mechanisms is one of the hallmarks of disciplined inquiry in science and engineering, but comparatively little is known about its precursors and development. Children at grades 2 and 5 predicted and explained the motion of simple mechanical systems composed entirely of visible linkages (levers). Students' explanations of device behavior suggested four forms of knowledge: simple recognition of device components, noting of structural relations among components, construction of cause-effect rules derived by observation of regularities in device behavior, and identification of essential system components and interactions among components that accounted for cause–effect rules. Only a few children coordinated multiple essential components to constitute a mechanistic causal scheme. Mechanistic causal schemes, in turn, were associated with successful prediction of the output motion of a system. Device tracing via gesture and talk appeared to support this form of knowledge development, and hence may inform future instructional design.     

Capes on the W-Defense

According to the principle of alternative possibilities (PAP), a person is morally responsible for what he has done only if he could have done otherwise. Widerker (Philosophical Perspectives 14: 181-201, 2000) offers an intriguing argument for PAP as it applies to moral blameworthiness. His argument is known as the “What-should-he-have-done defense” of PAP or the “W-defense” for short. In a recent article, Capes (Philosophical Studies 150: 61-77, 2010) attacks Widerker’s argument by rejecting the central premise on which it rests, namely, the premise that a person is blameworthy for his action only if in the circumstances it would be morally reasonable to expect him not to have acted as he did. In this paper, I show that Capes’ criticism does not undermine this premise and, to this extent, Widerker’s argument is safe from Capes’ attack.     

Prior experience with negative spectral correlations promotes information integration during auditory category learning

Complex sounds vary along a number of acoustic dimensions. These dimensions may exhibit correlations that are familiar to listeners due to their frequent occurrence in natural sounds—namely, speech. However, the precise mechanisms that enable the integration of these dimensions are not well understood. In this study, we examined the categorization of novel auditory stimuli that differed in the correlations of their acoustic dimensions, using decision bound theory. Decision bound theory assumes that stimuli are categorized on the basis of either a single dimension (rule based) or the combination of more than one dimension (information integration) and provides tools for assessing successful integration across multiple acoustic dimensions. In two experiments, we manipulated the stimulus distributions such that in Experiment 1, optimal categorization could be accomplished by either a rule-based or an information integration strategy, while in Experiment 2, optimal categorization was possible only by using an information integration strategy. In both experiments, the pattern of results demonstrated that unidimensional strategies were strongly preferred. Listeners focused on the acoustic dimension most closely related to pitch, suggesting that pitch-based categorization was given preference over timbre-based categorization. Importantly, in Experiment 2, listeners also relied on a two-dimensional information integration strategy, if there was immediate feedback. Furthermore, this strategy was used more often for distributions defined by a negative spectral correlation between stimulus dimensions, as compared with distributions with a positive correlation. These results suggest that prior experience with such correlations might shape short-term auditory category learning.