Contrast adaptation implies two spatiotemporal channels but three adapting processes

The contrast gain control model of adaptation predicts that the effects of contrast adaptation correlate with contrast sensitivity. This article reports that the effects of high contrast spatiotemporal adaptors are maximum when adapting around 19 Hz, which is a factor of two or more greater than the peak in contrast sensitivity. To explain the discrepancy, the predictions made by parallel versus cascaded models of spatiotemporal processing are compared. It is demonstrated that a parallel two-temporal channel model, in which the adaptive attenuation of a channel is proportional to its response, cannot explain the effects of adaptation on threshold contrast but that a cascaded model can. The cascaded model suggests that the visual system temporally encodes spatiotemporal signals via an adaptive transient encoding process that lies in cascade with an adaptable two-temporal channel system of sustained versus transient processes.     

Extending the e-z reader model of eye movement control to chinese readers

Chinese readers' eye movements were simulated in the context of the E-Z Reader model, which was developed to account for the eye movements of readers of English. Despite obvious differences between English and Chinese, the model did a fairly good job of simulating the eye movements of Chinese readers. The successful simulation suggests that the control of eye movements in reading Chinese is similar to that in an alphabetic language such as English.     

A treatment trial of an information package to help patients accept new dentures

Intolerance of dentures can be very distressing and difficult to treat. Therefore, 44 patients, having had partial or total dental clearance, completed the Brief Symptom (Psychiatric) Inventory, the Hospital Anxiety and Depression Scale and the Satisfaction with Life Scale. Allocated alternately, each patient had treatment as usual or watched a video containing information, recapitulated in a leaflet, based on the Self Regulatory Model of health beliefs explaining the experiences of wearing dentures and how to tolerate them. They were then fitted with dentures. Two and six weeks later, although both groups expressed favourable expectations of their dentures, the control group deteriorated continually on all measures, correlated with a decline in self-reported dental functioning. The video group improved on all measures except Satisfaction with Life. Therefore, our study is unique in showing that appropriate management of patients can arrest (1) clinically significant distress which can be occasioned by the replacement of teeth by dentures and (2) the development of complaints which may be seen as spurious. Experimental procedures are suggested to determine the influences which have brought this about in our study.     

Real Donors, Real Consent: Testing the Theory of Reasoned Action on Organ Donor Consent

In an attempt to apply the theory of reasoned action (TRA) to the process underlying organ donor consent, participants completed questionnaires concerning their affective responses to organ donation, as well as their intentions to donate. Participants were given the opportunity to sign an organ donor card. Those who chose to sign the card had more positive attitudes about donation, perceived donation as something that their reference group would encourage, and had stronger intentions to consent to signing a card. The current investigation extends the organ donor literature by using a true behavioral outcome measure indicating consent. Moreover, the pattern of results between attitudes, norms, intention, and behavior illustrates the usefulness of applying the TRA to yet another health-related behavior.     

Social outcomes in childhood brain disorder: a heuristic integration of social neuroscience and developmental psychology

The authors propose a heuristic model of the social outcomes of childhood brain disorder that draws on models and methods from both the emerging field of social cognitive neuroscience and the study of social competence in developmental psychology/psychopathology. The heuristic model characterizes the relationships between social adjustment, peer interactions and relationships, social problem solving and communication, social-affective and cognitive-executive processes, and their neural substrates. The model is illustrated by research on a specific form of childhood brain disorder, traumatic brain injury. The heuristic model may promote research regarding the neural and cognitive-affective substrates of children's social development. It also may engender more precise methods of measuring impairments and disabilities in children with brain disorder and suggest ways to promote their social adaptation.     

Variability in response criteria affects estimates of conscious identification and unconscious semantic priming

Three experiments examined the role of response criteria in a masked semantic priming paradigm using an exclusion task. Experiment 1 used on-line prime-report (“report the prime if you saw it”) and exclusion instructions in which participants were told to avoid completing a word stem (e.g. mo—) with a word related to a prime (e.g. cash) flashed for 0, 38 or 212 ms. Semantic priming (i.e. exclusion failure) was significant in the items analysis, but was moderated by peoples’ ability to report the prime in the participant analysis. Prime-report thresholds in Experiment 2 were made more liberal by instructing participants to guess on every trial. Prime-report increased from Experiment 1 as exclusion failures were eliminated. Experiment 3 clarified the relationship between awareness and prime identification using an on-line measure of confidence and different liberal prime report instructions. The current findings suggest that the ability to act upon (via exclusion performance) and report information in a masked prime is determined by a variable response criterion, which can be manipulated as an independent variable.     

Can Executive Functions Explain the Relationship Between Attention Deficit Hyperactivity Disorder and Social Adjustment?

This study examined the ability of executive functions (EF) to account for the relationship between Attention Deficit Hyperactivity Disorder (ADHD) status and social adjustment as indexed by parent and teacher report and by performance on a standardized observational “chat room” task. Children with the Combined subtype (ADHD-C; n = 23), the Primarily Inattentive Subtype (ADHD-I; n = 33), and non-ADHD controls (n = 36) participated. EF did not mediate the relationship between ADHD status and parent or teacher report of social adjustment. EF accounted for about 40–50% of the variance between ADHD status and the ability of children to detect subtle verbal cues as well as memory for the conversation in the chat room task, but did not mediate the relationship between ADHD and the number of prosocial, hostile, or on-topic statements that were made. Results are consistent with other recent reports, and suggest that the role of EF deficits in the production of social skill deficits in ADHD may not be as prominent as is typically assumed. The implications for the development of intervention programs designed to target core cognitive etiologic factors are discussed.     

Eye Movements and Visual Encoding During Scene Perception

ABSTRACT— The amount of time viewers could process a scene during eye fixations was varied by a mask that appeared at a certain point in each eye fixation. The scene did not reappear until the viewer made an eye movement. The main finding in the studies was that in order to normally process a scene, viewers needed to see the scene for at least 150 ms during each eye fixation. This result is surprising because viewers can extract the gist of a scene from a brief 40- to 100-ms exposure. It also stands in marked contrast to reading, as readers need only to view the words in the text for 50 to 60 ms to read normally. Thus, although the same neural mechanisms control eye movements in scene perception and reading, the cognitive processes associated with each task drive processing in different ways.