Dilution, not load, affects distractor processing

Lavie and Tsal (1994) proposed that spare attentional capacity is allocated involuntarily to the processing of irrelevant stimuli, thereby enabling interference. Under this view, when task demands increase, spare capacity should decrease and distractor interference should decrease. In support, Lavie and Cox (1997) found that increasing perceptual load by increasing search set size decreased interference from an irrelevant distractor. In three experiments, we manipulated the cue set size (number of cued locations) independently of the display set size (number of letters presented). Increasing the display set size reduced distractor interference regardless of whether the additional letters were relevant to the task. In contrast, increasing the cue set size increased distractor interference. Both findings are inconsistent with the load explanation, but are consistent with a proposed two-stage dilution account.     

A voice-operated method for administering the MMPI

Paper/pencil psychological tests such as the Minnesota Multiphasic Personality Inventory (MMPI) are difficult to complete independently by patients with limited hand function. This paper describes a voice recognition system developed to allow patients with no hand function to take the MMPI independently. Profiles generated by this system are not statistically different from those generated by standard MMPI booklet format. Limitations and possible extensions of the system as it currently exists are discussed.     

Progressive and imaginal relaxation training for elderly persons with subjective anxiety.

Elders exposed to either progressive or imaginal relaxation procedures reported significant relaxation effects and showed improvement on measures of personal functioning. The results of the Physical Assessment Scale of the Relaxation Inventory indicated that relaxation responses were acquired within and across sessions. Large, consistent changes in relaxation occurred in all 4 sessions. The Symptom Checklist-90-R, which measures self-reported personal adjustment, showed significant positive changes following relaxation training and at 1-month follow-up. Elders who imagined muscle tension release profited as much as those engaged in actual muscle tension-release activities. This finding is of importance for older adults who may experience physical limitations that contraindicate muscle-tension-release procedures.     

Developmental changes in the recognition and comprehension of facial expression: implications for frontal lobe function.

Children aged 6-15 years old and adults (over 18) were given three tests designed to test perception and comprehension of facial expression. In the first test subjects were given two composite symmetrical faces made from the left or right half of a normal face, the subjects' task being to indicate which composite more closely resembled the original face. In the second test the subjects matched a series of photographs from Life magazine with key photographs of one of six distinct emotions (sad, fear, happy, anger, disgust, surprise). In the third test the subjects chose a key photograph that was appropriate for the face of a faceless character in a cartoon. On the composite faces test the subjects in all groups exhibited a preference for the left visual field composite, implying that all age groups were processing the faces in a similar manner. The results of the other two tests showed that there was an improvement in the perception of facial expression between the ages of 6 and 8 years, little change until about 13 years, and then a second improvement to adult performance at about 14 years. The performance of the 8- to 13-year-old children was similar to that of adult patients with frontal lobe injuries, which could be taken as evidence that the regions of the frontal lobe involved in the performance of these tasks may not be mature until about 14 years of age.     

Predicting Zimbabwean women's ability to tell their partners to use condoms.

The effectiveness of AIDS education may depend on the development of models that predict and explain HIV prevention behavior. In this study, the aim was to test Fishbein and Ajzen's theory of reasoned action model in predicting women's capacity to tell their partner to use condoms. The basic theory pertains to the relationship of 1) attitude toward behavior and 2) the subjective norms to behavior; further refinements reflect factors such as 3) perceived behavioral control or self-efficacy, 4) and perceived barriers. A sample was drawn of 123 female first-year teacher trainees in Harare, Zimbabwe, in late 1990; a self-administered questionnaire was distributed and returned. 72% of the respondents were sexually experienced. The mean age of the entire sample was 24 years. The results of the multiple linear regression indicated that the model was able to predict were F(2,74)=32.81, p.0001. 47% of the variance was explained by this Fishbein model. Attitude toward behavior was significantly associated with the intention to tell one's partner to use condoms (beta = .60, p .05). Subjective norms were not significant (beta = .15, p .05). Perceived behavioral control and perceived barriers were also not significantly associated with the intention to tell one's partner to use condoms. A caveat was that the subjective norm was measured by only one item, and an improved conceptualization and measurement of this construct might have changed the relationship. The suggestion is that health educators should address women's underlying beliefs and attitudes about the benefits of telling their partners to use condoms. Future prospective studies will better delineate the relationship between attitude and behavior.     

Seeking a Balance Between the Statistical and Scientific Elements in Psychometrics

In this paper, I will review some aspects of psychometric projects that I have been involved in, emphasizing the nature of the work of the psychometricians involved, especially the balance between the statistical and scientific elements of that work. The intent is to seek to understand where psychometrics, as a discipline, has been and where it might be headed, in part at least, by considering one particular journey (my own). In contemplating this, I also look to psychometrics journals to see how psychometricians represent themselves to themselves, and in a complementary way, look to substantive journals to see how psychometrics is represented there (or perhaps, not represented, as the case may be). I present a series of questions in order to consider the issue of what are the appropriate foci of the psychometric discipline. As an example, I present one recent project at the end, where the roles of the psychometricians and the substantive researchers have had to become intertwined in order to make satisfactory progress. In the conclusion I discuss the consequences of such a view for the future of psychometrics.     

Age-related changes in motor imagery from early childhood to adulthood: Probing the internal representation of speed-accuracy trade-offs

The purpose of this study was to chart the development of motor imagery ability between 5 and 29 years of age and its relationship to fine-motor skill. 237 participants performed a computerized Virtual Radial Fitts Task (VRFT) as a measure of Motor Imagery (MI) ability. Participants aimed at five targets, positioned along radial axes from a central target circle. The targets differed in width over trials (2.5, 5, 10, 20 or 40 mm). Performance was indexed by the relationship between the movement time (MT) in executed and imagined movements. A subset of participants (11–19 years old, n = 22) also performed the task with their non-preferred hand. We also examined if manual skill (measured by peg board task and posting coins) was related to the executed and imagined MT on the VRFT. Our results showed that the accuracy of the imagined movement improved steadily over childhood, reaching an asymptote during adolescence and into early adulthood. The correlation between the real and virtual MT using the preferred hand did not differ appreciably from that using the non-preferred hand. If the children could perform the tasks with their non-preferred hand (11 years and older), they also scaled performance in relatively precise terms using the less dextrous non-preferred hand. The correlation between real MT on the VRFT and fine-motor performance ranged between .53 and .42, while that for virtual movement was between .37 and .34. MI ability predicts manual skill to a moderate degree.     

An 18-month follow-up investigation of motor coordination and working memory in primary school children

The aim of the current study was to examine the relationship between motor coordination and visual working memory in children aged 5–11 years. Participants were 18 children with movement difficulty and 41 control children, assessed at baseline and following an 18-month time period. The McCarron Assessment of Neuromuscular Development provided a measure of motor skills and the CogState One-Back task was used to assess visual working memory. Multi-level mixed effects linear regressions were used to assess the relationship between fine motor skills, gross motor skills, and visual working memory. The results revealed that for children with movement difficulty, better fine motor skills at baseline significantly predicted greater One-Back accuracy and greater (i.e., faster) speed at 18-month follow-up. Conversely, fine motor skills at baseline did not predict One-Back accuracy and speed for control children. However, for both groups, greater One-Back accuracy at baseline predicted better fine and gross motor skills at follow-up. These findings have important implications for the assessment and treatment of children referred for motor difficulties and/or working memory difficulties.     

Relational knowledge: the foundation of higher cognition

Accumulating evidence on the nature, function and acquisition of relational knowledge indicates a crucial role of such knowledge in higher cognitive processes. In this review, we specify the essential properties of relational knowledge, together with the role it plays in reasoning, categorisation, planning, quantification and language. Furthermore, we discuss the processes involved in its acquisition and how these processes have been implemented in contemporary neural network models. We present evidence demonstrating that relational knowledge integrates heuristic and analytic cognition, is important for symbolic processes and the creation of novelty, activates specific regions of the prefrontal cortex, and is the most recently evolved and slowest-developing cognitive process. Arguably, relational knowledge represents the core of higher cognition.     

SORTO: Factor Analyzing Q Sorts of Kelly's Personal Construct Productions

A procedure for evaluating personality is described. Conventional and transposed factor analyses are made from Q sort data describing the important people in the subject's life in terms of his own constructs (á la Kelly) as variables. The scoring procedure produces construct-factors and people-factors. Sorts from a subject illustrate the method. Cross-cultural applications are possible since the translation of personal constructs is not essential. Simulation of relationships to others, SORTO, combines Kelly's (1955) personal constructs with Stephenson's (1953) Q sort procedure. A large amount of personal data is factor analyzed by the computer to reveal the main idiosyncratic features of a subject's perceptions of his relationships to others. Maximum output from the analysis occurs when the nature of personal constructs employed is supplied as input to the analysis.