Physiologic and self-report comparisons between tension headache sufferers and nonheadache controls

Tension headache sufferers and nonheadache controls were compared with respect to (1) frontal EMG during both baseline and presentation of an imagined stressor, (2) trait anxiety, (3) locus of control expectancies for health related behaviors, and (4) exposure to stressful life events. Tension headache sufferers displayed higher resting muscle tension levels than did nonheadache controls. However, both groups responded similarly to the imagined stress stimulus and displayed significant muscle tension elevations of similar magnitude. While tension headache sufferers reported higher levels of trait anxiety, no differences were found between the two groups for locus of control expectancies and exposure to stressful life events. The diagnostic and treatment implications of these findings are discussed.     

A conjoint measurement approach to color harmony

The aim of this study was to find a rule in color harmony that could reveal the mutual influences of the three basic harmonies, those of hue, lightness, and saturation. One hundred and four color pairs were judged for harmony by five subjects five times. The results were analyzed by the conjoint measurement algorithm of Krantz and Tversky (1971). It was concluded that there is an interaction between saturation harmony and hue and lightness harmony together, and an additivity between hue harmony and lightness harmony. This implies the rule: color harmony = saturation harmony * (hue harmony + lightness harmony).     

Instructional strategy effects on the retention and transfer of procedures of different difficulty level

In the present study, the effects of two instructional strategies on the retention and transfer of procedures of different difficulty level were investigated. Difficulty level was manipulated by providing a different number of cues during training. The instructional strategies differed with respect to the amount of contextual interference. Sixty-four subjects were randomly assigned to either a high interference group or a low interference group. Retention and transfer were measured immediately following training and after a three-week delay. The dependent variables were number of errors and decision time. Results showed no differences between the two training groups over the various difficulty levels. Results further showed that retention performance increased as fewer cues were available during practice. It is suggested that ‘delayed automatization’ can account for the observed increment in performance level. It is further suggested that contextual interference may produce delayed automatization of task performance but is only effective if relationships can be discovered in the learning material.     

Relational Autonomy and Paternalistic Interventions

Relational conceptions of autonomy attempt to take into account the social aspects of autonomous agency. Those views that incorporate not merely causally, but constitutively necessary relational conditions, incorporate a condition that has the form:

(RelAgency) A necessary condition for autonomous agency is that the agent stands in social relations S.

I argue that any account that incorporates such a condition (irrespective of how the relations, S, are spelt out) cannot play one of autonomy’s key normative roles: identifying those agents who ought to be protected from (hard) paternalistic intervention. I argue, against objections from Oshana, that there are good reasons for maintaining the notion of autonomy in this role, and thus that such relational conceptions should not be accepted. This rejection goes beyond that from John Christman, which holds only for those relational conditions which are value-laden.     

Knowing color terms enhances recognition: further evidence from English and Himba

Two experiments attempted to reconcile discrepant recent findings relating to children’s color naming and categorization. In a replication of Franklin and colleagues (Journal of Experimental Child Psychology, 90 (2005) 114-141), Experiment 1 tested English toddlers’ naming and memory for blue-green and blue-purple colors. It also found advantages for between-category presentations that could be interpreted as support for universal color categories. However, a different definition of knowing color terms led to quite different conclusions in line with the Whorfian view of Roberson and colleagues (Journal of Experimental Psychology: General, 133 (2004) 554-571). Categorical perception in recognition memory was now found only for children with a fuller understanding of the relevant terms. It was concluded that color naming can both underestimate and overestimate toddlers’ knowledge of color terms. Experiment 2 replicated the between-category recognition superiority found in Himba children by Franklin and colleagues for the blue-purple range. But Himba children, whose language does not have separate terms for green and blue, did not show a cross-category advantage for that set; rather, they behaved like English children who did not know their color terms.     

Distributed representations of action sequences in anterior cingulate cortex: A recurrent neural network approach

Anterior cingulate cortex (ACC) has been the subject of intense debate over the past 2 decades, but its specific computational function remains controversial. Here we present a simple computational model of ACC that incorporates distributed representations across a network of interconnected processing units. Based on the proposal that ACC is concerned with the execution of extended, goal-directed action sequences, we trained a recurrent neural network to predict each successive step of several sequences associated with multiple tasks. In keeping with neurophysiological observations from nonhuman animals, the network yields distributed patterns of activity across ACC neurons that track the progression of each sequence, and in keeping with human neuroimaging data, the network produces discrepancy signals when any step of the sequence deviates from the predicted step. These simulations illustrate a novel approach for investigating ACC function.     

Electrophysiological measures reveal the role of anterior cingulate cortex in learning from unreliable feedback

Although a growing number of studies have investigated the neural mechanisms of reinforcement learning, it remains unclear how the brain responds to feedback that is unreliable. A recent theory proposes that the reward positivity (RewP) component of the event-related brain potential (ERP) and frontal midline theta (FMT) power reflect separate feedback-related processing functions of anterior cingulate cortex (ACC). In the present study, the electroencephalogram (EEG) was recorded from participants as they engaged in a time estimation task in which feedback reliability was manipulated across conditions. After each response, they received a cue that indicated that the following feedback stimulus was 100%, 75%, or 50% reliable. The results showed that participants’ time estimates adjusted linearly according to the feedback reliability. Moreover, presentation of the cue indicating 100% reliability elicited a larger RewP-like ERP component than the other cues did, and feedback presentation elicited a RewP of approximately equal amplitude for all of the three reliability conditions. By contrast, FMT power elicited by negative feedback decreased linearly from the 100% condition to 75% and 50% condition, and only FMT power predicted behavioral adjustments on the following trials. In addition, an analysis of Beta power and cross-frequency coupling (CFC) of Beta power with FMT phase suggested that Beta-FMT communication modulated motor areas for the purpose of adjusting behavior. We interpreted these findings in terms of the hierarchical reinforcement learning account of ACC, in which the RewP and FMT are proposed to reflect reward processing and control functions of ACC, respectively.