The effects of local and global processing demands on perception and action

The line-bisection task, adapted to utilise a wooden rod as the bisection stimulus, has revealed that patients with visuo-spatial neglect may be more accurate at bisection when asked to pick up the rod, compared to pointing to its centre. We recently reported that neurologically intact participants show a similar dissociation on this task-demonstrating a rightward bias when pointing to the centre, which was not present when grasping the rod by the centre. The current paper examined how pointing and grasping responses were affected by adapted rod-bisection tasks that emphasised local or global processing. In Experiment 1, 26 participants completed four rod-bisection tasks. The rods were compound stimuli and the participants directed to focus on either the local or global level. The results demonstrated that when participants focused on the global level, the previous dissociations found for pointing and grasping conditions were evident. However, the perception of centre did change when participants focused on the local level: both the pointing and grasping responses were rightward biased. In Experiment 2, 42 participants completed three bisection tasks which again emphasised either the local or global level, but in different sets of stimuli. The results of this task further support the findings in Experiment 1: the rightward bias in the local-bisection task was again evident and in addition, the global-bisection task resulted in no bias and no difference between the pointing and grasping bisections. These results demonstrate how task demands can similarly affect the pointing and grasping responses, and indicate that local and global processing may be involved in perception/action dissociations on rod bisection.     

The least likely of times: how remembering the past biases forecasts of the future

Atypical events are both memorable and unrepresentative of their class. We tested the hypotheses that (a) people tend to recall atypical instances of events, and (b) when they are unaware of this, they rely on these atypical instances in forecasting their affective reactions to future events. In three studies, participants who were asked to recall an instance of an event and participants who were asked to recall an atypical instance of an event recalled equally atypical instances. However, only the former participants made extreme forecasts about their reactions to future events. The results suggest that the impact bias (the tendency to overestimate the affective impact of future events) may be due in part to people's reliance on highly available but unrepresentative memories of the past.     

A psychometric approach to intuitive physics

The literature on intuitive physics shows that many people exhibit systematic errors when predicting the behavior of simple physical events. Most previous research has attributed these errors to factors specific to a certain class of tasks. In the present study, we investigated the possibility that intuitive physics performance may be related to general measures of cognitive ability. Two hundred four adults (ages, 20-91 years) were presented with five pairs of intuitive physics questions. It was found that performance on the intuitive physics items was moderately intercorrelated, suggesting that they were tapping into a unitary construct. Despite the correlation with factors that decline with advancing age, intuitive physics performance was not correlated with age (r= .00). The findings are discussed in the context of research on intuitive physics, as well as research on cognitive aging.     

Effects of processing bias on the recognition of composite face halves

Research has shown that face recognition accuracy can be improved by prior global processing and impaired by prior local processing (Macrae & Lewis, 2002). The aim of this study was to test the processing bias account of face recognition, using the composite face task (Young, Hellawell, & Hay, 1987), a test of featural recognition. Undergraduate volunteers (N=75) participated in a between-subjects design that tested their ability to recognize face halves within a composite, following either global or local Navon processing or a control task. Results showed that, as compared with the control task, local processing speeded ability to recognize face halves. These results provide support for the processing bias account of face recognition.     

Schizophrenia and the experience of intersubjectivity as threat

Many with schizophrenia find social interactions a profound and terrifying threat to their sense of self. To better understand this we draw upon dialogical models of the self that suggest that those with schizophrenia have difficulty sustaining dialogues among diverse aspects of self. Because interpersonal exchanges solicit and evoke movement among diverse aspects of self, many with schizophrenia may consequently find those exchanges overwhelming, resulting in despair, the sensation of fusion with another, and/or self-dissolution. In short, compromised dialogical capacities may be a contributing factor to social dysfunction in schizophrenia.     

More on least squares estimation of the transition matrix in a stationary first-order markov process from sample proportions data

Miller suggested ordinary least squares estimation of a constant transition matrix; Madansky proposed a relatively more efficient weighted least squares estimator which corrects for heteroscedasticity. In this paper an efficient generalized least squares estimator is derived which utilizes the entire covariance matrix of the distrubances. This estimator satisfies the condition that each row of the transition matrix must sum to unity. Madansky noted that estimates of the variances could be negative; a method for obtaining consistent non-negative estimates of the variances is suggested in this paper. The technique is applied to the hypothetical sample data used by Miller and Madansky.I am indebted to a referee for his thoughtful suggestions on content and style.     

What is the optimal position of low-frequency words across line boundaries? An eye movement investigation

When displaying text on a page or a screen, only a finite number of characters can be presented on a single line. If the text exceeds that finite value, then text wrapping occurs. Often this process results in longer, more difficult to process words being positioned at the start of a line. We conducted an eye movement study to examine how this artefact of text wrapping affects passage reading. This allowed us to answer the question: should word difficulty be used when determining line breaks? Thirty-nine participants read 20 passages where low-frequency target words were either line-initial or line-final. There was no statistically reliable effect of our manipulation on passage reading time or comprehension despite several effects at a local level. Regarding our primary research question, the evidence suggests that word difficulty may not need to be accounted for when determining line breaks and assigning words to new lines.     

Vocal indicators of facilitative interpersonal skills

The facilitative interpersonal skills (FIS) method uses simulations of difficult client moments as a test of helpers' ability to remain therapeutic in therapeutically stressful situations. A total of 135 participants completed the FIS task as part of a training in helping skills and provided verbal responses that were assessed by trained raters for interpersonal skills. Audio recordings of these verbal responses were then analysed acoustically for fundamental frequency (F0), spectral slope and F0 range. Mean F0 and F0 range were more highly associated with trained raters' ratings of FIS for female participants than for male participants, although F0 range was associated with FIS of both males and females. The results suggest that F0 is associated with FIS for females, especially the FIS items that are indicative of emotional expression and verbal fluency. Findings are discussed as possibly indicating that some expression of higher F0 in response to distressed client situations may be part of interpersonal skills, such that more skilled therapists respond to stressful client situations with a higher F0.     

FIXED-TIME SCHEDULES ATTENUATE EXTINCTION-INDUCED PHENOMENA IN THE TREATMENT OF SEVERE ABERRANT BEHAVIOR

We compared the effects of extinction (EXT) and fixed-time (FT) schedules as treatment for severe problem behavior displayed by 3 individuals with developmental disabilities. First, functional analyses identified the reinforcers maintaining aberrant behavior for all 3 individuals. Next, EXT and FT schedules were compared using a multielement design. During EXT, the reinforcer maintaining problem behavior was withheld. During FT, the reinforcers were presented response independently at preset intervals. Results showed that FT schedules were generally more effective than EXT schedules in reducing aberrant behavior. FT schedules may be used in situations when extinction-induced phenomena are problematic.     

Near-Death Experiences, Shamanism, and the Scientific Method

The first 20 years of near-death studies have thoroughly documented the existence of this phenomenon. The field of near-death studies appears to be evolving from a purely academic one to include an applied, clinical component. I discuss the overlap between shamanism and near-death experiences (NDEs) and suggest that the study of shamanism would be helpful in more fully understanding this phenomena and beginning the development of an applied methodology. Although it may be difficult to verify subjective accounts of NDEs and shamanic journeys, from a clinical stand-point it may not be necessary to do so in order to develop a technique that passes the test of scientific scrutiny.