Brain areas sensitive to coherent visual motion

Detection of coherent motion versus noise is widely used as a measure of global visual-motion processing. To localise the human brain mechanisms involved in this performance, functional magnetic resonance imaging (fMRI) was used to compare brain activation during viewing of coherently moving random dots with that during viewing spatially and temporally comparable dynamic noise. Rates of reversal of coherent motion and coherent-motion velocities (5 versus 20 deg s-1) were also compared. Differences in local activation between conditions were analysed by statistical parametric mapping. Greater activation by coherent motion compared to noise was found in V5 and putative V3A, but not in V1. In addition there were foci of activation on the occipital ventral surface, the intraparietal sulcus, and superior temporal sulcus. Thus, coherent-motion information has distinctive effects in a number of extrastriate visual brain areas. The rate of motion reversal showed only weak effects in motion-sensitive areas. V1 was better activated by noise than by coherent motion, possibly reflecting activation of neurons with a wider range of motion selectivities. This activation was at a more anterior location in the comparison of noise with the faster velocity, suggesting that 20 deg s-1 is beyond the velocity range of the V1 representation of central visual field. These results support the use of motion-coherence tests for extrastriate as opposed to V1 function. However, sensitivity to motion coherence is not confined to V5, and may extend beyond the classically defined dorsal stream.     

Examining the effectiveness of a community-based self-help program to increase women's readiness for smoking cessation

This study investigated the effectiveness of two components of a smoking cessation intervention: a reading manual and a series of televised programs. Female smokers in the Chicago metropolitan area with a high school education or less were interviewed at 4 different times: baseline, immediate postintervention, and 6 and 12 months. We examined the effects of several baseline measures (race, age, number of cigarettes smoked, and stage of readiness to change) and exposure to the intervention components on subsequent stage of change. Race, baseline smoking rate, baseline stage, and exposure to both intervention components had direct effects on stage at immediate postintervention, with both intervention components increasing readiness to quit. Furthermore, exposure to the manual interacted with baseline stage, such that the manual benefited women at earlier stages more than women at later stages. Effects of both components were sustained at 6 months, and the effects of the manual were sustained at 12 months.     

Age-of-acquisition and cumulative frequency have independent effects

Lewis (1999) argued that effects of age of acquisition (AoA) are entirely attributable to cumulative frequency. He reported an instance-based model in which the number of instances of the stimulus stored in memory predicts reaction time. We note four aspects of the literature on AoA that cannot be explained by this instance-based approach. Firstly, an effect of AoA has been observed in the absence of an effect of frequency. Secondly, an effect of AoA has been observed when cumulative frequency has been controlled. Thirdly, the effect of AoA is dependent on task. Fourthly, the effect of word frequency is dependent on stimulus modality. Lewis reported an experiment in which participants make a decision based on identity-specific semantic information to celebrity faces to demonstrate an effect of the number of instances in memory, which he interpreted as an effect of AoA. We note that effects of AoA have been found in lexical and perceptual tasks, but to date all attempts to demonstrate an advantage for early-acquired items in semantic classification tasks have failed. We conclude that the effects of AoA cannot be attributed solely to the effects of cumulative frequency.     

Influences of age, performance, and item relatedness on verbatim and gist recall of verb-noun pairs

Age differences in adults' memory for performed actions (e.g., wave hand) are sometimes smaller than age differences in memory for nonperformed phrases. In this study, we examined the conditions under which performance reduces age differences in recall. Younger and older adults performed or read verb-noun phrases that were either related (e.g., actions performed in a kitchen) or unrelated. Performance did not reduce age differences in recall of the exact verbs and nouns used to describe an action, but performance did reduce age differences in memory for the gist of related actions. Older adults especially had difficulty recalling the exact verb used to describe the action. These results suggest that older adults may have better memory for actions than is revealed by tests of verbatim recall. They may remember performing the action but not remember the exact words used to describe the action.     

Pathways of Economic Influence on Adolescent Adjustment

An important part of a science aimed at the prevention of human dysfunction involves the development of empirically based models that identify processes of risk for or protection from emotional distress or behavioral problems over time. The present study developed and evaluated such a model that proposed two pathways through which family economic pressure was expected to influence change in adolescent internalizing symptoms (depression and anxiety) during the period from the eighth to the tenth grades. A total of 377 rural families in a midwestern state provided data for the analyses. The results were generally consistent with the conceptual model in that family economic pressure increased adolescent perceptions of family economic hardship, which, in turn, reduced the adolescent's sense of control or mastery over time. Lowered mastery was associated with increases in emotional distress. Also consistent with the model, prior levels of mastery appeared to reduce the magnitude of economic stress experienced by the adolescent, whereas prior emotional distress intensified the economic stress process. Although gender differences were found in these processes, the overall pattern of results suggests that girls and boys are both at risk for internalizing problems when families experience economic pressure. Implicatios of the findings for the dvelopment of effective preventive interventions with financially stressed families in rural areas are discussed.     

Does contextual strength modulate the subordinate bias effect? A reply to Kellas and Vu

In their reply to Binder and Rayner (1998), Kellas and Vu (1999) raised questions about the criteria we used to exclude items from the Kellas, Martin, Yehling, Herman, and Vu (1995) stimulus set. In this reply, we further document these criteria and also address the issue of local versus published norms. We continue to believe that the stimulus set used by Kellas et al. (1995) was problematic. We also address the issue of strength of context, a concept used in earlier research that dealt with the subordinate bias effect. We argue that the contexts used by Kellas et al. (1995) were no stronger than the contexts previously used that established this effect. Therefore, we continue to think that our finding that context does not eliminate the subordinate bias effect is valid.     

Rhetorical Unity and Social Division: A Longitudinal Study of Change in Australian Self-Stereotypes

This paper examines the impact of social division associated with the emergent "race debate" in Australia (and the so-called "Hanson phenomenon") on the consensus of Australian students' stereotypes of their national ingroup. It compares the stereotypes held by a sample of students in 1997 ( N = 20) with those revealed in studies conducted from 1992 onwards ( N = 102). Results provide strong evidence that stereotype consensus was reduced in the current phase of research and post-testing also indicates that participants themselves interpreted this as being the product of political change in Australian society. The findings are consistent with the argument that stereotypes are sensitive to changes in intergroup and intragroup relations, and that they respond to the reality of social division rather than to the rhetoric of unity.     

Translating the ICAP Theory of Cognitive Engagement Into Practice

ICAP is a theory of active learning that differentiates students’ engagement based on their behaviors. ICAP postulates that I nteractive engagement, demonstrated by co‐generative collaborative behaviors, is superior for learning to C onstructive engagement, indicated by generative behaviors. Both kinds of engagement exceed the benefits of A ctive or P assive engagement, marked by manipulative and attentive behaviors, respectively. This paper discusses a 5‐year project that attempted to translate ICAP into a theory of instruction using five successive measures: (a) teachers’ understanding of ICAP after completing an online module, (b) their success at designing lesson plans using different ICAP modes, (c) fidelity of teachers’ classroom implementation, (d) modes of students’ enacted behaviors, and (e) students’ learning outcomes. Although teachers had minimal success in designing Constructive and Interactive activities, students nevertheless learned significantly more in the context of Constructive than Active activities. We discuss reasons for teachers’ overall difficulty in designing and eliciting Interactive engagement.