Visual field differences in recognizing letters

Differences due to visual field location were examined for single letters placed at one of 12 clockface positions 3° and 6° from fixation. Results compared closely with established findings using simple light stimuli, showing best recognition on the horizontal meridian, poorest on the vertical and intermediate on oblique meridians. Subjects’ confidence ratings followed the same pattern. There was evidence for a specific right superiority along the horizontal meridian, as found in previous studies, but no evidence for a general right hemifield superiority. The difficulty of arguing from these findings to available dominance or scanning explanations is pointed out. It is proposed that effects due to visual field variability may have a pervasive yet largely unrecognized influence in visual perception research.     

Visual scanning during pattern recognition in children and adults

Eye movement and fixation responses of 3- to 6-year-old children and adults were recorded during a pattern recognition task. During familiarization, fixations were more repetitive and less extensive for older subjects. The fixation patterns of older children who were consistently able to solve the recognition problems were like those of the adults. Unsuccessful 4- to 6-year-olds spent more time fixating the modified area of the nonstandard pattern presented in paired comparison with the standard, even though their final decision was false. Thus, preschool children were able to locate relevant visual information even when they did not use this information to solve tasks. The results suggest that visual fixations do not always reflect active attention, and that direct fixations of visual information are clearly not sufficient and may not be necessary for problem solving.     

Clarifying the convergence between obsessive compulsive personality disorder criteria and obsessive compulsive disorder

In this study we examined the convergence between obsessive-compulsive personality disorder (OCPD) criteria and obsessive-compulsive disorder (OCD). Baseline assessments of 629 participants of the Collaborative Longitudinal Personality Disorders Study were used to examine the associations between OCPD criteria and diagnoses of OCD. Three of the eight OCPD criteria--hoarding, perfectionism, and preoccupation with details--were significantly more frequent in subjects with OCD (n = 89) than in subjects without OCD (n = 540). Logistic regressions were used to predict the probability of each OCPD criterion as a function of Axis I diagnoses (OCD, additional anxiety disorders, and major depressive disorder). Associations between OCD and these three OCPD criteria remained significant in the logistic regressions, showing unique associations with OCD and odds ratios ranging from 2.71 to 2.99. In addition, other anxiety disorders and major depressive disorder showed few associations with specific OCPD criteria. This study suggests variability in the strength of the relationships between specific OCPD criteria and OCD. The findings also support a unique relationship between OCPD symptoms and OCD, compared to other anxiety disorders or major depression. Future efforts to explore the link between Axis I and Axis II disorders may be enriched by conducting analyses at the symptom level.     

Not just right experiences and obsessive-compulsive features: experimental and self-monitoring perspectives

Individuals with obsessive-compulsive disorder (OCD) often report compulsions aimed at reducing feelings of something not being just right or sensations of incompleteness. Research using self-report questionnaires has demonstrated a link between not just right experiences (NJREs) and OCD symptoms (Behav. Res. Therapy 41 (2003) 681; Anxiety, 1 (1995) 208). Extending previous work, this paper presents experimental and self-monitoring data on NJREs in an undergraduate sample. NJREs produced distress and urges to change something, but feared consequences were rare. Stronger responses were found for naturally occurring self-monitored NJREs compared to NJREs elicited in the laboratory. Several significant relationships were found between features of NJREs and OC symptoms and constructs theoretically related to OCD (e.g., responsibility, incompleteness), but no significant relationships were found between features of NJREs and non-OCD-related constructs (worry, depressive symptoms, social anxiety). Further consideration of NJREs will be useful in improving our understanding of the phenomenology, neurobiological substrates, and treatment, of OCD.     

Where did you go wrong? Errors, partial errors, and the nature of human information processing

Human performance is seldom perfect, and even when an overt response is correct it may be accompanied by partial-error activity that does not achieve the level of a complete incorrect response. Partial errors can be detected in measures of the lateralized readiness potential, of the electromyogram, and of response force. Correct responses accompanied by partial errors tend to have slower reaction times than “clean” correct responses (because of response competition), and condition differences in reaction time can, on some occasions, be explained in terms of differences in the incidence of partial errors. In two-choice reaction time tasks, partial errors are more frequent when the imperative stimulus contains information that favors both responses, than when it contains information that favors only one response. The non-random nature of partial errors supports the inference that partial information about the stimulus is used to guide responses. A similar inference is supported by the observation that, in hybrid choice Go/No-go tasks, the kinds of partial errors that follow a No-go stimulus represent activation of the response that would have been correct had the stimulus been a Go stimulus. Finally, we note that the human processing system is capable of monitoring its own behavior and of initiating remedial actions if necessary. The activity of an error-detection system, as revealed by measures of the error-related negativity, is related to the degree to which responses are slowed after errors.     

IF ATTITUDES AFFECT HOW STIMULI ARE PROCESSED, SHOULD THEY NOT AFFECT THE EVENT-RELATED BRAIN POTENTIAL?

Abstract— In Experiment 1, subjects completed an attitude survey to identify items toward which they held positive and negative attitudes. Subsequently, subjects were instructed to count the number of positive (or negative) stimuli in a series. Each series contained six attitude stimuli from a given semantic category (e.g., fruits), and the structure of the series was varied so that positive and negative stimuli, as indexed by subjects' idiosyncratic attitudes, were evaluatively consistent or inconsistent within the series. In Experiment 2, subjects were exposed to personality traits that were positive or negative in series of six. Again, the structure of the series was varied so that positive and negative traits were evaluatively consistent or inconsistent within the series. Results of Experiments 1 and 2 indicated that although the event-related brain potential did not differ as a function of stimulus valence per se, evaluatively inconsistent, in contrast to consistent, stimuli evoked a larger amplitude late P300-like positive component that was maximal over the centroparietal region.     

Your mistake is my mistake . . . or is it? Behavioural adjustments following own and observed actions in cooperative and competitive contexts

A social speeded choice-reaction-time task was used to study adaptive behaviours following own and observed actions (errors and correct responses) in cooperative and competitive contexts. After making an erroneous response, the appropriate remedial action to avoid future errors in speeded reaction tasks is to slow down. Consistent with previous results, people indeed slow down following their own errors. Importantly, people who slow down most following own errors also slow down following observed errors in a cooperative situation. In a competitive context, a different pattern was found. People accelerated after errors from their opponent. The current findings demonstrate that the social context determines the way people respond to the errors of others, indicating that the neural systems that control remedial actions are highly flexible. These systems may underlie social adaptive behaviour, enabling people to respond flexibly to other people's actions in a wide variety of social contexts.     

Social anxiety and difficulty disengaging threat: evidence from eye-tracking

Theoretical models of social phobia propose that biased attention contributes to the maintenance of symptoms; however these theoretical models make opposing predictions. Specifically, whereas Rapee and Heimberg (1997) suggested the biases are characterised by hypervigilance to threat cues and difficulty disengaging attention from threat, Clark and Wells (1995) suggested that threat cues are largely avoided. Previous research has been limited by the almost exclusive reliance on behavioural response times to experimental tasks to provide an index of attentional biases. The current study evaluated the relationship between the time-course of attention and symptoms of social anxiety and depression. Forty-two young adults completed a dot-probe task with emotional faces while eye-movement data were collected. The results revealed that increased social anxiety was associated with attention to emotional (rather than neutral) faces over time as well as difficulty disengaging attention from angry expressions; some evidence was found for a relationship between heightened depressive symptoms and increased attention to fear faces.