Differential involvement of M1-type and M4-type muscarinic cholinergic receptors in the dorsomedial striatum in task switching

Previous experiments have demonstrated that the rat dorsomedial striatum is one brain area that plays a crucial role in learning when conditions require a shift in strategies. Further evidence indicates that muscarinic cholinergic receptors in this brain area support adaptations in behavioral responses. Unknown is whether specific muscarinic receptor subtypes in the dorsomedial striatum contribute to a flexible shift in response patterns. The present experiments investigated whether blockade of M1-type and/or M4-type cholinergic receptors in the dorsomedial striatum underlie place reversal learning. Experiment 1 investigated the effects of the M1-type muscarinic cholinergic antagonist, muscarinic-toxin 7 (MT-7) infused into the dorsomedial striatum in place acquisition and reversal learning. Experiment 2 investigated the effects of the M4-type muscarinic cholinergic antagonist, muscarinic-toxin 3 (MT-3) injected into the dorsomedial striatum in place acquisition and reversal learning. All testing occurred in a modified cross-maze across two consecutive sessions. Bilateral injections of MT-7 into the dorsomedial striatum at 1 or 2 microg, but not 0.05 microg impaired place reversal learning. Analysis of the errors revealed that MT-7 at 1 and 2 microg significantly increased regressive errors, but not perseverative errors. An injection of MT-7 2 microg into the dorsomedial striatum prior to place acquisition did not affect learning. Experiment 2 revealed that dorsomedial striatal injections of MT-3 (0.05, 1 or 2 microg) did not affect place acquisition or reversal learning. The findings suggest that activation of M1-type muscarinic cholinergic receptors in the dorsomedial striatum, but not M4-type muscarinic cholinergic receptors facilitate the flexible shifting of response patterns by maintaining or learning a new choice pattern once selected.     

Preservation of mouth region processing in two cases of prosopagnosia

Although most adults are considered experts in face recognition, brain trauma can produce a selective loss in this ability, a condition referred to as prosopagnosia. This study examined the processing strategies of prosopagnosic patients LR and HH using the Face Dimensions Test. In this test, featural and configural information in the upper and lower halves of the face was parametrically varied and sensitivity to these changes measured. We found that relative to age‐matched control participants, LR and HH exhibited an impaired ability to discriminate differences in the eye region, but a preserved ability to detect featural and configural differences in the mouth region. This pattern of impairment and sparing was demonstrated in tests of direct perception and immediate memory. The obtained findings demonstrate that prosopagnosia does not necessarily cause a global impairment to face perception, but a selective impairment to the perception of information in the upper half of the face.     

Where's the Religion? Distinguishing Faith‐Based from Secular Social Service Agencies

The charitable choice provision and President Bush's proposed Faith-Based and Community Initiative have spurred debates regarding government support of faith-based social service programs and their effectiveness. To address the issue of relative effectiveness, the logically prior question of what constitutes a faith-based agency and how they differ from secular providers must be answered. Utilizing data from a mailed survey, this study compares the organizational characteristics of faith-based and secular agencies that provide services to the homeless in Houston, Texas. Results indicate that the two agency types vary significantly across several dimensions including funding sources and preferences, decision-making tools, organizational culture, practices, leadership, and staffing characteristics. In addition, survey data and content analysis of mission statements reveal that 80 percent of faith-based agencies use religious imagery in some form of their "public face" to communicate their religiousness.     

Reasons for Reason-giving in a Public-Opinion Survey

This paper explores why respondents to a telephone public-opinion survey often give reasons for answering as they do, even though reason-giving is neither required nor encouraged and it is difficult to see the reasons as attempts to deal with disagreement. We find that respondents give reasons for the policy claims they make in their answers three times as frequently as they give reasons for value or factual claims, that their reasons tend to involve appeals to personal experience, and that they often talk about their thought processes, especially when the evidentiary stakes are high. We then explore several ways of explaining these findings. We suggest that one useful approach is to see the reason-giving in the survey interviews as deliberative, reflexive argumentation of the sort described as `critical thinking. We further suggest that the reason such argumentation is often conducted out loud in the interviews, rather than internally, is that it functions in the service of rhetorical ethos, in particular the need to display the fact that one is human, with human autonomy and agency. Doing this may be particularly important in contexts such as anonymous survey interviews in which people are at risk of being treated like machines.     

Methodists and Muslims in the Gambia

The Gambia (West Africa) is a predominantly Muslim country, with a small Christian community. Christian–Muslim encounters in the Gambia can be traced back as far as the fifteenth century. This article explores part of this long interreligious history of the Gambia. It researches – on the basis of archival materials – the attitudes and perceptions of the Gambian Methodist Church towards Muslims in the nineteenth and twentieth centuries. The article argues that, although the attitude of the Methodists towards Muslims changed in the middle of the twentieth century from aggressive evangelization towards more irenic relations, Methodism in the Gambia still perceives Christian witness to Muslims to be one of its core callings.     

The visual perception of motion by observers with autism spectrum disorders: A review and synthesis

Traditionally, psychological research on autism spectrum disorder (ASD) has focused on social and cognitive abilities. Vision provides an important input channel to both of these processes, and, increasingly, researchers are investigating whether observers with ASD differ from typical observers in their visual percepts. Recently, significant controversies have arisen over whether observers with ASD differ from typical observers in their visual analyses of movement. Initial studies suggested that observers with ASD experience significant deficits in their visual sensitivity to coherent motion in random dot displays but not to point-light displays of human motion. More recent evidence suggests exactly the opposite: that observers with ASD do not differ from typical observers in their visual sensitivity to coherent motion in random dot displays, but do differ from typical observers in their visual sensitivity to human motion. This review examines these apparently conflicting results, notes gaps in previous findings, suggests a potentially unifying hypothesis, and identifies areas ripe for future research.     

Larger brain and white matter volumes in children with developmental language disorder

Developmental language disorder (DLD) is predominantly a language disorder, but children with DLD also manifest non-language impairments, and neuroanatomical abnormalities have been found in multiple areas of the brain, not all language-associated. We therefore performed a whole brain general segmentation analysis of all major brain regions on MRI scans of 24 DLD subjects (16M, 8F) and 30 controls (15M, 15F), ages 5.7 to 11.3 years. Children with DLD showed increased total brain volume, driven predominantly by a substantial increase in the volume of cerebral white matter. Cerebral cortex and caudate were relatively but not absolutely smaller in DLD. These findings are discussed in relation to issues of specificity vs. generality as they arise in debates about (1) modular vs. general processing deficits and connectionist modeling in DLD, (2) language-specific vs. pervasive, non-specific deficits in DLD and (3) specificity of the disorder vs. overlap with other disorders, notably autism.