Theoretical accounts of spatial learning: A neurobiological view (commentary on Pearce, 2009)

Theories of learning have historically taken, as their starting point, the assumption that learning processes have universal applicability. This position has been argued on grounds of parsimony, but has received two significant challenges: first, from the observation that some kinds of learning, such as spatial learning, seem to obey different rules from others, and second, that some kinds of learning take place in processing modules that are separate from each other. These challenges arose in the behavioural literature but have since received considerable support from neurobiological studies, particularly single neuron studies of spatial learning, confirming that there are indeed separable (albeit highly intercommunicating) processing modules in the brain, which may not always interact (within or between themselves) according to classic associative principles. On the basis of these neurobiological data, reviewed here, it is argued that rather than assuming universality of associative rules, it is more parsimonious to assume sets of locally operating rules, each specialized for a particular domain. By this view, although almost all learning is associative in one way or another, the behavioural-level characterization of the rules governing learning may vary depending on which neural modules are involved in a given behaviour. Neurobiological studies, in tandem with behavioural studies, can help reveal the nature of these modules and the local rules by which they interact.     

Influence of the movement parameter to be controlled on manual RT asymmetries in right-handers

In this experiment we test whether the effects of manual asymmetries on movement preparation depend on the parameter (amplitude or direction) to be programmed. In two experiments, only the amplitude, or the direction, of aiming movements was constrained. Reaction and movement times were measured. Results show that RTs are always shorter for left-hand than for right-hand movements. There is an effect of target extent in the amplitude condition, but not in the direction one. RTs for ipsilateral movements are shorter than RTs for contralateral movements. These results are discussed in the light of the processes involved in setting the amplitude or direction of the movement and with regard to the competency of the two hemispheres regarding these processes.     

The relation of learning disabilities to the long-term outcomes of concussion

ObjectiveThis study sought to cross-sectionally evaluate the relation between learning disorders (LD) and long-term concussion outcomes.MethodSeventy-three asymptomatic male university athletes (23 history of concussion with LD; 24 history of concussion no LD; 26 controls) completed the Beck Depression Inventory-2 (BDI-II), the Profile of Mood States (POMS), the Cogstate battery, and an Oddball task during which event-related brain potentials were recorded.ResultsConcussed athletes with LD exhibited greater depressive symptoms (BDI-II), greater total mood disturbance (POMS), decreased accuracy on the One-Card Learning and the N-back task (Cogstate), decreased accuracy on the Oddball task, and reduced ERN amplitude relative to both the concussed athletes without a LD and controls. Concussed athletes with LD also exhibited prolonged P3 latency relative to controls. Irrespective of LD, concussed athletes exhibited increased anger-hostility and decreased Pe amplitudes relative to controls. No differences were observed in P3a amplitude or latency.ConclusionHaving LD may be a significant factor moderating the neurophysiological, cognitive and psycho-affective outcomes of concussion, and may explain a significant portion of the persistent deficits observed by researchers and clinicians.     

Human Cloning and Embryo Research: The 2003 John J. Conley Lecture on Medical Ethics

The author, a member of the U.S.President's Council on Bioethics, discussesethical issues raised by human cloning, whetherfor purposes of bringing babies to birth or forresearch purposes. He first argues that everycloned human embryo is a new, distinct, andenduring organism, belonging to the speciesHomo sapiens, and directing its owndevelopment toward maturity. He then distinguishesbetween two types of capacities belonging toindividual organisms belonging to this species,an immediately exerciseable capacity and abasic natural capacity that develops over time. He argues that it is the second type ofcapacity that is the ground for full moralrespect, and that this capacity (and itsconcomitant degree of respect) belongs tocloned human embryos no less than to adulthuman beings. He then considers and rejectscounter-arguments to his position, includingthe suggestion that the capacity of embryos isequivalent to the capacity of somatic cells,that full human rights are afforded only tohuman organisms with functioning brains, thatthe possibility of twinning diminishes themoral status of embryos, that the fact thatpeople do not typically mourn the loss of earlyembryos implies that they have a diminishedmoral status, that the fact that earlyspontaneous abortions occur frequentlydiminishes the moral status of embryos, andthat his arguments depend upon a concept ofensoulment. He concludes that if the moralstatus of cloned human embryos is equivalent tothat of adults, then public policy should bebased upon this assumption.     

想象空间中物体搜索的方位效应和注意效应

该工作提出,在故事阅读产生的想象场景中,位于其中的观察者对身体四周物体的搜索应分为两个阶段：第一阶段是目标方位的判断,认知加工时间的模式是前后〈后〈左＝右;第二阶段是注意指出目标方位,从而辩别目标物体,认知加工时间的模式是注意点〈注意对面〈注意点左侧＝注意点右侧。     

Head Start Children at Third Grade: Preliminary Special Education Identification and Placement of Children with Emotional, Learning, and Related Disabilities

Although children in Head Start are at risk for emotional or behavioral problems, little is known about their later need for special education. There is evidence that children at risk for emotional disturbance are underidentified or misidentified in other special education categories. We examined special education identification rates for Head Start children at risk for emotional disturbance, learning disabilities, speech or language impairments, and mental retardation as they complete third grade. Two cohorts of 4136 children across 30 sites were followed as part of a larger study on transition. Diagnosis of each child as being at risk for emotional disturbance or related disabilities was made using clinical cut-offs on teacher ratings and individual testing completed in the spring of third grade. Special education eligibility of these children was determined from school records. Only 31.8% of children considered to be at risk, based on research diagnostic criteria, were actually identified by the schools, and fewer than 6% of children at risk for ED were identified in the school category of ED. Comparisons were made between school-identified and nonidentified children in gender, ethnicity, and school variables; and findings were discussed in relation to underidentification or misidentification of children with emotional disturbance.     

The role of attention in the facilitation effect and another "inhibition of return"

The present study investigated how anticipation of a target's appearance affects human attention to gaze cues provided by a schematic face. Subjects in a 'catch' group received a high number of 'catch' trials, in which no target stimulus appeared. Subjects in the control group did not receive any catch trials. As in previous studies, both groups showed a facilitation effect to the cued location during shorter stimulus onset asynchrony (SOA). In both groups, an analysis of eye movements confirmed that subjects' eyes remained on the fixation point, ruling out the possibility that the facilitation effect was due to shifting eye movements (saccades) as opposed to a shift in covert attention. But while the control group's response time (RT) decreased as SOA increased, the catch group's RT had a U-shaped pattern and the facilitation effect to the cued location was reversed at the longest SOA (1005 ms). These results suggest that subjects in the catch group disengaged their attention during long SOAs because they expected the trial to be a catch trial. This disengagement of attention during long SOAs results in a delay before attention could be re-focused to the previous location regardless of the cue validity ["IOR (inhibition of return)"-like-phenomenon]. Unlike the conventional IOR, we suggest that this "IOR"-like phenomenon caused by an unpredictive central gaze cue is likely to be mediated by an endogenous mechanism.     

Conflict of interest from a Romanian geneticist’s perspective

This paper examines Romanian bioethics regulations for biomedical sciences, looking in particular at the genetics area as a source for conflict of interest. The analysis is focused on the organizational level, national regulations, the sources for generating conflicts of interest, and management of conflicts. Modern biotechnology and gene technology are among the key technologies of the twenty-first century. The application of gene technology for medical and pharmaceutical purposes is widely accepted by society, but the same cannot be said of the development and application of gene technology in agriculture and food processing. Because the use of a technology in the production and processing of food is regarded more sceptically than in the production of biomedical products, there can be areas of conflict in many cases when communication is undertaken about gene technology in the agro-food sector. Ethical concerns play an important factor in this, but a society’s attitude to a developing technology is an amalgam of many effects which are beyond ethics as such. This paper contains a study carried out by the author for the Romanian Association for Consumer Protection about the attitudes of consumers towards genetically modified (GM) foods. This study revealed that in Romania more than 98% of consumers did not know anything about GM foods and frequently were confused about the definitions of these terms. In conclusion, it is necessary to say that there is a low level of knowledge regarding biotechnology in Romania and this is an important reason why there is neither public acceptance of gene technology products nor is there a rejection. An earlier version of this paper was presented at an International Conference on “Conflict of Interest and its Significance in Science and Medicine” held in Warsaw, Poland on 5–6 April, 2002. Ioana Ispas, MD in Molecular Biology, is a scientific researcher and Member of the Romanian Association for Consumer Protection, NCP for FP5-Quality of life and management of living resources.     

Gaze direction and maternal pitch in surprise-eliciting situations

The purpose of this study was to test the hypothesis that not only do babies use emotional signals from adults in order to relate emotions to specific situations (e.g., Campos & Stenberg, 1981) but also that mothers seek out emotional information from their infants ( Emde, 1992). Three groups of mothers and their infants, 3, 5 and 9 months old were video- and audio-taped, while playing in their homes with a soft toy and a remote-control Jack-in-the-box. During surprise-eliciting play with the Jack-in-the-box, maternal and infant gaze direction and their emotional expressions of surprise, pleasure, fear and neutral expressions were coded in three regions of the face. In addition, the mean fundamental frequency of maternal surprise-vocalisations was analysed. Maternal exclamations of surprise were compared with similar utterances of these mothers while playing with a soft toy as a baseline. During the surprise event, maternal and infant gaze directions as well as infant age were analysed in relation to maternal pitch. Results are discussed in terms of maternal use of the pitch of her voice to mark surprising situations, depending on the gaze-direction of the infant.     

Teacher implementation of precorrection and praise statements in Head Start classrooms as a component of a program-wide system of positive behavior support

Although research has clearly supported the use of school-wide positive behavior support (PBS) in elementary school settings, data-based research has not been conducted to support program-wide PBS in early childhood settings. The purpose of this study was to specifically support teachers’ use of universal features of program-wide PBS and to determine whether increases in the use of positive teacher behaviors, including precorrection and praise, were functionally related to decreases in students’ problem behavior. Using a multiple baseline design, three teachers were introduced to an intervention to increase their use of precorrections and specific behavioral praise statements. A relationship was established between the three teachers’ use of key features of program-wide PBS and the reduction of students’ problem behavior in a small group setting. However, findings should be viewed as tentative and future research should explore the relative influence of each of the intervention components on preschool students’ behavior.