Does negative priming reflect inhibitory mechanisms? A review and integration of conflicting views

Negative priming has traditionally been viewed as a reflection of an inhibitory mechanism of attention. However, recent accounts have suggested that negative priming does not reflect inhibitory mechanisms. Rather, slowed reaction times on negative priming trials are either due to retrieval of incompatible response tags or of mismatching perceptual information, or due to extra processes needed to distinguish past from present information. In contrast, it is proposed that there is no firm evidence to discount inhibition models. In fact, although retrieval processes can be implicated in negative priming effects, understanding of these requires consideration of the inhibitory processes involved in selecting information for goal-directed behaviour.     

Visual Search Remains Efficient When Visual Working Memory is Full

Many theories of attention have proposed that visual working memory plays an important role in visual search tasks. The present study examined the involvement of visual working memory in search using a dual-task paradigm in which participants performed a visual search task while maintaining no, two, or four objects in visual working memory. The presence of a working memory load added a constant delay to the visual search reaction times, irrespective of the number of items in the visual search array. That is, there was no change in the slope of the function relating reaction time to the number of items in the search array, indicating that the search process itself was not slowed by the memory load. Moreover, the search task did not substantially impair the maintenance of information in visual working memory. These results suggest that visual search requires minimal visual working memory resources, a conclusion that is inconsistent with theories that propose a close link between attention and working memory.     

African Americans and High Blood Pressure: The Role of Stereotype Threat

We examined the effect of stereotype threat on blood pressure reactivity. Compared with European Americans, and African Americans under little or no stereotype threat, African Americans under stereotype threat exhibited larger increases in mean arterial blood pressure during an academic test, and performed more poorly on difficult test items. We discuss the significance of these findings for understanding the incidence of hypertension among African Americans.     

Individualism,Normativity and the Epistemology of Understanding

Philosophical Studies -     

Neuropsychological Issues in the Assessment of Refugees and Victims of Mass Violence

Brain injury, stressor severity, depression, premorbid vulnerabilities, and PTSD are frequently intertwined in trauma populations. This interaction is further complicated when the neuropsychologist evaluates refugees from other cultures. In addition, the observed psychiatric symptoms reported in refugees and victims of mass violence may in fact not be the primary features of PTSD and depression but psychiatric symptoms secondary to the effects of traumatic brain injury. This paper reviews the occurrence of starvation, torture, beatings, imprisonment, and other head injury experiences in refugee and POW populations to alert treators to the presence of chronic and persistent neuropsychiatric morbidity, with implications for psychosocial adjustment. The concept of fixed neural loss may also interact with environmental and emotional stresses, and a model of neuropsychological abnormalities triggered by traumatic events and influenced by subsequent stress will also be considered. Neuropsychologists working with refugees play an important role in assessing the possibility of traumatic brain injury with tools that are relatively culture-fair.     

Attentional capture by globally defined objects

The abrupt appearance of a new perceptual object in the visual field typically captures visual attention. However, if attention is focused in advance on a different location, onsets can fail to capture attention (Yantis & Jonides, 1990). In the present experiments, we investigated the extent to which the deployment of attention to the local level of a hierarchical scene may be affected by the abrupt appearance of a new object at the global level. Participants searched for a semi-disk target in an array of randomly oriented segmented disks (“pacmen”). On half the trials, a subset of the segmented disks induced a subjective square. On these critical trials, participants were significantly slower to respond to the presence of a local target even though the local features of the display were qualitatively identical across all conditions. This slowing was absent when outline pacmen were used (which do not induce subjective figures) and when the subjective square was perceptually old. When the participants’ task was defined at the global level of the display, a new local element failed to capture attention, suggesting an asymmetry in the ability of objects at different levels of a hierarchical scene to capture attention. In a control experiment, a new local element captured attention, however, when the participants’ task was defined at the local level, indicating that the local item was in principle capable of capturing attention. It is argued that global objects capture attention because they convey important information about the environment that is not available at the local level.     

Stress Induced Oral Behaviors and Facial Pain

Facial pain is frequently associated with environmental stress and emotional distress. One hypothetical mechanism by which stress is translated into pain is through stress induced motor function (e.g., teeth clenching, grinding, nail biting). Existent data partially supports these stress-hyperactivity models although they have also come under theoretical and empirical attack. The purpose of this study was to examine the relationship between oral behaviors and pain in an analog sample of facial pain sufferers and student controls. Subjects engaged in a controlled clenching task and reported on subjective facial pain intensity and unpleasantness at 5 specified times over the subsequent 48 hours. A one-way ANCOVA indicated group differences in self reported oral habits (p < .05) with the facial pain group reporting great frequency of oral habits. Two repeated measures ANCOVAs (i.e., pain intensity and pain unpleasantness), controlling for baseline pain ratings, indicated a between groups effect with facial pain sufferers experiencing significantly greater pain over the 48 hours postexperiment (p < .05). This study supports a hyperactivity model of facial pain and provides clues about relevant factors in facial pain development.     

Reading in Colors: Highlighting for Active Reading in Religious Studies

This note from the classroom suggests that multicolor highlighting is a useful study technique for religious studies students. The note first reviews the literature regarding the effectiveness of traditional highlighting, then discusses advantages of the modified technique. Monochrome highlighting works only if readers select text through a discriminating reading process. Reading in colors fosters this sort of active reading. It prompts readers to ask how and why a given term, phrase or passage is important. This technique can help students grasp the basic categories and concepts of the discipline and it can embody course requirements or learning outcomes. The note concludes with practical suggestions for using the technique in the classroom.