Exposure and Occluded Duration Effects in a Ball-Catching Skill

Male Ss (N=48) from a university population attempted single-handed catches of lawn tennis balls delivered by a mechanical projection machine. The within-and between-S variables in a split-plot factorial design were the period for which the ball was illuminated (VP) and the subsequent period of occlusion (OP). Both variables and their interaction were significant sources of variation. Generally the effect of VP diminished as OP was extended. This was discussed in terms of (1) information processing time and (2) motion prediction. With respect to the first issue, the most important variable was not VP, but a composite term VP + OP. On the second issue, support was provided for an hypothesis to account for prediction error raised in a previous study.     

Residual Effects of Slavery: A Delphi Study

Slavery and its aftermath have created multiple challenges that are unique to the African American community. Although literature exists within other disciplines, no published empirical study within the marriage and family therapy literature has examined the residual effects of slavery. We used a modified Delphi methodology to explore the residual effects of slavery on African Americans and to determine resultant clinical implications. To obtain information from panelists who have expertise in this area, we conducted three rounds of data collection: an open-ended questionnaire, a Likert-scale questionnaire, and a round of in-depth interviews. Based on our analysis of the data collected, this empirical study describes the influence of the residual effects of slavery, implications for clinicians and directions for future research.

     

The effect of the availability of a dynamic model on the acquisition of a complex cyclical action

This study examines the effect of the availability of a dynamic model on the acquisition of a complex cyclical action: slalom-type ski movements on a ski-simulator. A two-condition design was used, with N = 20 subjects per condition. In the experimental condition subjects had, during training trials, the benefit of the availability of a dynamic (video) model of an expert performer, while subjects in the control condition were left entirely to “discovery learning”. The dependent variables were the amplitude, frequency and fluency of the movement of the ski-simulator platform on which subjects were required to stand in operating the simulator. Movement characteristics of the platform were recorded by means of a microcomputer (Apple II+) coupled to a Selcom 403 camera (SELSPOT system). Subjects having the benefit of a dynamic model during training were shown, at the end of the five-day training period, to produce more fluent movements (of the platform) and to show greater consistency of fluency and of tempo than subjects left entirely to discovery learning. The results are discussed in the context of theories of perception and of motor learning.     

Top-down processing modulates older adults’ susceptibility to noise

The present study examined older and younger adults’ ability to use top-down processes to mitigate the effects of display noise during simple feature, visual search. As display noise levels increased, older adults (age 60–74 years, n = 32) exhibited greater top-down search reaction time (RT) benefits (bottom-up minus top-down search RT), compared to younger adults (age 18–27, n = 32). Older adults’ ability to mitigate the effects of noise was further assessed with RT variability, as measured by intra-individual standard deviations across trials. Older adults again exhibited larger top-down benefits (i.e., less RT variability) compared to younger adults, and more so when display noise was present vs. absent. These results suggest a sparing of top-down processes with age (Madden, Whiting, Spaniol, & Bucur, 2005; Psychology and Aging, 20, 317), and that top-down processes in older adults enhance search efficiency by optimizing signal-to-noise ratios.     

What is the Normativity of Meaning?

There has been much debate over whether to accept the claim that meaning is normative. One obstacle to making progress in that debate is that it is not always clear what the claim amounts to. In this paper, I try to resolve a dispute between those who advance the claim concerning how it should be understood. More specifically, I critically examine two competing conceptions of the normativity of meaning, rejecting one and defending the other. Though the paper aims to settle a dispute among proponents of the claim that meaning is normative, it should be of interest to those who challenge it. After all, before one takes aim, one’s target needs to be in clear view.