Control of children's observing responses by information feedback during visual discrimination learning

Four experiments examined the control of observing responses by information feedback during visual discrimination learning. Second-grade children participated in Experiment 1; kindergarten, second-, and fifth-grade children were subjects in Experiments 2 and 3, and grade 5 and adult subjects were tested in Experiment 4. In order to view the stimuli, subjects in Experiments 1, 2, and 3 activated lights in viewing boxes; in Experiment 4, stimulus fixations were measured using a corneal reflection technique. Fifth graders and adults observed the discriminative stimuli for longer times on trials following negative feedback than on trials following positive feedback; in contrast, kindergartener's observing was not affected by type of feedback. Second graders showed smaller and less reliable reactions to type of feedback than did older subjects. These results support the view that visual observing is controlled by cognitive processes associated with hypothesis testing.     

The role of articulation in the parsing and retention of letter strings in tachistoscopic free recall

In Mewhort and Campbell's (1981) model of visual word recognition, a scan-parse mechanism transfer information from a character buffer to a short-term store and is largely responsible for the familiarity effects observed in tachistoscopic free recall. Although Mewhort and Campbell do not elaborate on the role of articulation in this task, they do suggest that the scan-parse mechanism acts prior to any involvement of articulatory processes (see Mewhort & Campbell, 1980). However, proponents of working memory (see Baddeley, 1986) are clear that articulation is necessary for the transfer of visual information to a phonological short-term store. In order to clarify the role of articulation in the parsing and retention of letter string, we asked subjects to undertake a tachistoscopic free-recall task, involving first- and fourth-order letter strings, with and without articulatory suppression and/or unattended speech. Unattended speech was observed to interfere with recall, but only when subjects were free to articulate the strings. This implies that subjects were retrieving information from the phonological store and that articulation is necessary for the registration of visual information in this store. The lack of interaction between order-of-approximation and suppression supports the view that the scan-parse mechanism acts independently of articulation. It appears, therefore, that letter strings are parsed at a stage preceding their transfer of the pharmacological store. Finally, the results indicate that subjects are able to draw directly on a representation of the parsed components of a letter string and may do so when phonological storage is difficult.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biases in the perceived timing of perisaccadic perceptual and motor events

Subjects typically experience the temporal interval immediately following a saccade as longer than a comparable control interval. One explanation of this effect is that the brain antedates the perceptual onset of a saccade target to around the time of saccade initiation. This could explain the apparent continuity of visual perception across eye movements. This antedating account was tested in three experiments in which subjects made saccades of differing extents and then judged either the duration or the temporal order of key events. Postsaccadic stimuli underwent subjective temporal lengthening and had early perceived onsets. A temporally advanced awareness of saccade completion was also found, independently of antedating effects. These results provide convergent evidence supporting antedating and differentiating it from other temporal biases.     

Visual processing and the bodily self

The 'body schema' has traditionally been defined as a passively updated, proprioceptive representation of the body. However, recent work has suggested that body representations are more complex and flexible than previously thought. They may integrate current perceptual information from all sensory modalities, and can be extended to incorporate indirect representations of the body and functional portions of tools. In the present study, we investigate the source of a facilitatory effect of viewing the body on speeded visual discrimination reaction times. Participants responded to identical visual stimuli that varied only in their context: being presented on the participant's own body, on the experimenter's body, or in a neutral context. The stimuli were filmed and viewed in real-time on a projector screen. Careful controls for attention, biological saliency, and attribution confirmed that the facilitatory effect depends critically on participants attributing the context to a real body. An intermediate effect was observed when the stimuli were presented on another person's body, suggesting that the effect of viewing one's own body might represent a conjunction of an interpersonal body effect and an egocentric effect.     

Treatment outcome in personality disorder: The effect of social,psychological and behavioural variables

The study followed-up 245 patients referred to the Henderson Hospital (194 admitted for treatment and 51 not admitted) and for whom information had been collected on their social background and certain psychological variables allowing a classification and typology of personality disorder to be worked out. The study indicates that the therapeutic community treatment is effective with selected individuals showing the antisocial behaviour associated with such disorder. In particular this treatment is of benefit to the offenders with only one conviction and who are able to persevere with treatment for a period of 6 months for treatment to be maximally effective. The variation of psychological types within the broad category of personality disorder was demonstrated and this has a bearing on the outcome of treatment, the extrapunitive neurotic being of poorest prognosis with or without treatment. Yet even in this group, therapeutic community treatment can be effective.     

Facilitated processing of visual stimuli associated with the body

Recent work on tactile perception has revealed enhanced tactile acuity and speeded spatial-choice reaction times (RTs) when viewing the stimulated body site as opposed to viewing a neutral object. Here we examine whether this body-view enhancement effect extends to visual targets. Participants performed a speeded spatial discrimination between two lights attached either to their own left index finger or to a wooden finger-shaped object, making a simple distal--proximal decision. We filmed either the finger-mounted or the object-mounted lights in separate experimental blocks and the live scene was projected onto a screen in front of the participants. Thus, participants responded to identical visual targets varying only in their context: on the body or not. Results revealed a large performance advantage for the finger-mounted stimuli: reaction times were substantially reduced, while discrimination accuracy was unaffected. With this finding we address concerns associated with previous work on the processing of stimuli attributed to the self and extend the finding of a performance advantage for such stimuli to vision.     

Telephone versus print delivery of an individualized motivationally tailored physical activity intervention: Project STRIDE.

OBJECTIVE: Given that only 25% of Americans meet physical activity recommendations, there is a need to develop and disseminate effective, evidence-based interventions to promote physical activity. The authors tested 2 delivery channels, telephone and print, to determine whether one was more effective in promoting physical activity. DESIGN: The authors randomly assigned 239 healthy, sedentary adults to (a) telephone-based individualized feedback, (b) print-based individualized feedback, or (c) contact control. Both intervention arms were guided by a motivationally tailored, theoretically driven computer expert system. MAIN OUTCOME MEASURES: Physical activity as measured by the 7-day Physical Activity Recall interview. RESULTS: At 6 months, both telephone and print arms significantly increased in minutes of moderate intensity physical activity compared with control, with no differences between the intervention arms. At 12 months, print participants reported a significantly greater number of moderate intensity minutes than both telephone and control participants, who did not differ. CONCLUSION: Results suggest that both telephone and print enhance the adoption of physical activity among sedentary adults; however, print interventions may be particularly effective in maintaining physical activity in the longer term.     

Mediators of physical activity behavior change: a multivariate approach

OBJECTIVE: Using a multivariate extension of the Baron and Kenny (1986) mediation framework, we examined the simultaneous effect of variables hypothesized to mediate the relationship between a motivationally tailored physical activity intervention, and 6-month physical activity behavior in 239 healthy, underactive adults (M age = 47.5; 82% women). DESIGN: Participants were randomly assigned to (a) print-based feedback; (b) telephone-based feedback; or (c) contact control. MAIN OUTCOME MEASURES: Psychosocial variables, including self-efficacy, decisional balance, and processes of change. RESULTS: All mediation criteria were satisfied for both intervention arms. A moderate indirect effect of print (0.39, 95% CI = 0.21, 0.57) was found due to increases in behavioral processes (0.54, 95% CI = 0.29, 0.80) being attenuated by decreases due to cognitive processes (-0.17, 95%CI = 0.31,-.03). A moderate indirect effect was observed for telephone (0.47, 95% CI = 0.28, 0.66), with increases due to behavioral processes (0.61, 95% CI = 0.34, 0.87) attenuated by decreases due to cognitive processes (0.15, 95% CI = -0.27, -0.02); self-efficacy and decisional balance mediational paths did not attain statistical significance. CONCLUSIONS: These findings highlight the importance of studies that deconstruct the theoretical components of interventions to determine which combination produces the greatest behavior changes at the lowest cost.