Differential fan effect and attentional focus

As people study more facts about a concept, it takes longer to retrieve a particular fact about that concept. This fan effect (Anderson, 1974) has been attributed to competition among associations to a concept. Alternatively, the mental-model theory (Radvansky & Zacks, 1991) suggests that the fan effect disappears when the related concepts are organized into a single mental model. In the present study, attentional focus was manipulated to affect the mental model to be constructed. One group of participants focused on the person dimension of personlocation pairs, whereas the other group focused on the location dimension. The result showed that the fan effect with the focused dimension was greater than the fan effect with the nonfocused dimension, which is contrary to the mental-model theory. The number of associations with a concept is indeed crucial during retrieval, and the importance of the information seems to be accentuated with attentional focus.     

Informed consent and the use of placebo in poland: Ethical and legal aspects

The concept of informed consent was one of the most fruitful ideas that deeply changed the relationships between physicians and their patients from paternalism to respect for the personal autonomy of subjects needing professional medical care. The great progress in medicine, also involving the pharmaceutical industry, has created an increasing need to perform different clinical and experimental trials. The evolution of clinical research in the last decades has influenced strongly the design of these studies. One of the most important changes in this field has been the use of placebo groups in double-blind controlled studies. The controversies have involved not only the use of placebo when standard or proven treatment was available, but also some specific problems concerning the procedure of obtaining informed consent in such trials. This paper briefly presents the evolution of informed consent in Poland as well as different ethical and legal problems concerning informed consent and the use of placebo controls in clinical trials. An earlier version of this paper was presented at an international conference, “Placebo: Its Action and Place in Health Research Today,” held in Warsaw, Poland on 12–13 April, 2003.     

Functional connectivity during working memory maintenance

Neurophysiological experiments with monkeys have demonstrated that working memory (WM) is associated with persistent neural activity in multiple brain regions, such as the prefrontal cortex (PFC), the parietal cortex, and posterior unimodal association areas. WM maintenance is believed to require the coordination of these brain regions, which do not function in isolation but, rather, interact to maintain visual percepts that are no longer present in the environment. However, single-unit physiology studies and traditional univariate analyses of functional brain imaging data cannot evaluate interactions between distant brain regions, and so evidence of regional integration during WM maintenance is largely indirect. In this study, we utilized a recently developed multivariate analysis method that allows us to explore functional connectivity between brain regions during the distinct stages of a delayed face recognition task. To characterize the neural network mediating the on-line maintenance of faces, the fusiform face area (FFA) was defined as a seed and was then used to generate whole-brain correlation maps. A random effects analysis of the correlation data revealed a network of brain regions exhibiting significant correlations with the FFA seed during the WM delay period. This maintenance network included the dorsolateral and ventrolateral PFC, the premotor cortex, the intraparietal sulcus, the caudate nucleus, the thalamus, the hippocampus, and occipitotemporal regions. These findings support the notion that the coordinated functional interaction between nodes of a widely distributed network underlies the active maintenance of a perceptual representation.     

The use of a distractor-assigned response slows later responding in a location negative priming task

Responding to a target's location takes longer when that location has recently contained a distractor event (ignored-repetition [IR] trial) relative to when it has been unoccupied (control trial). This is known as the location negative priming (NP) effect. We aimed to determine whether the elevated reaction time observed for IR trials was due to the reuse of a distractor location (location locus) and/or to the need to execute a (just inhibited) distractor response (response locus). We isolated these loci latency effects by using many-to-one and one-to-many location-response assignments. Our results showed that reusing a distractor location hastened target processing at that position (facilitative location locus), whereas the production of a distractor response was associated with a time cost (interfering response locus). Accordingly, part of the latency elevation seen with IR trials results from the need on these occasions to execute ajust inhibited (distractor) response, and, hence, the location NP effect has a response locus.     

Effects of the periodic administration of odor or vibration on a 3-hr. vigilance task

The present study examined performance during 3 hr. of simulated sentry duty with and without the intermittent administration of low-level sensory stimuli (odor or vibration). For odor and control conditions, target-detection latency increased steadily over the course of the 3-hr. session. Administration of a tactile stimulus reduced the increase in detection latency compared to that found in odor and control conditions. For all conditions, there were no significant differences in target-detection frequency, shot accuracy, or friend-foe discrimination. Across all conditions, restlessness (motor activity) increased significantly the first hour and remained elevated for the rest of the session. Subjective measures of workload (NASA-TLX) indicated that the 3-hr. task rated high on physical demand, mental demand, frustration, and overall workload. These findings suggest that the intermittent delivery of a clearly detectable tactile stimulus can reduce reaction-time decrements that occur as time on task increases.     

The planning and execution of sequential eye movements: saccades do not show the one target advantage

The present experiment examined the one-target advantage (OTA) with regard to saccadic eye movements. The OTA, previously found with manual pointing responses, refers to the finding that movements are executed faster when the limb is allowed to stop on the target compared to the situation where it has to proceed and hit a second target. Using an adapted limb movement OTA task, saccades of 5 degrees and 15 degrees were made to (a) a single target (one-target), (b) one target and immediately to another target without a change in direction (two-target-extension), and (c) one target and immediately back to the start location (two-target-reversal). Unlike manual movements, the movement times for the initial saccade in the two-target-extension condition were not prolonged compared to either of the other two conditions. Moreover, this pattern of results was found for both the shorter and longer amplitude saccades. The results indicate that the OTA does not occur in the oculomotor system and therefore is not a general motor control phenomenon.     

Responsivity to two odorants, androstenone and amyl acetate, and the affective impact of odors on interpersonal relationships

Substantial variation exists in the importance of olfaction in influencing individuals' preferences, yet the sources of this variation remain elusive. The authors explored responsivity to 2 odorants as 1 potential source. Participants (N = 258) completed the Affective Impact of Odor Scale and were assessed for responsivity to the putative human pheromone androstenone and amyl acetate. Results showed a significant relationship between odorant responsivity and self-reports of the influence of odors. People able to smell androstenone more commonly reported odors as having a negative effect on interpersonal relationships than did people anosmic to androstenone, whereas responsivity to amyl acetate was associated with positive effects of odors on relationships. Responsivity to certain odorants may be an important factor affecting human social interactions.     

Infants' comprehension of toy replicas as symbols for real objects

Infants' understanding of toy model-real exemplar relations was assessed through preferential looking and habituation tasks. Results from the preferential looking task suggest that 18-month toddlers are just beginning to demonstrate comprehension of symbolic relations between iconic models and their real object counterparts. Performance of 10- and 14-month-old infants in the preferential looking task did not improve when across-domain pairs of videos were used in place of within-domain pairs. Habituation task results indicated that 10-month-olds do not comprehend symbolic relations between miniature toy replicas and their "real" counterparts, but that such understanding begins to emerge by age 14 months. Interactions between symbolic processing and early lexical development are considered, as are methodological implications for the study of infant categorization.     

Gender, grade, and relationship differences in emotional closeness within adolescent friendships

Previous research has examined gender and grade differences in the emotional closeness of adolescents' same- and cross-sex friendships. However, findings from these studies have been inconsistent because they have failed to (1) differentiate between cross-sex friendships and romantic relationships and (2) compare same- and cross-sex friendships. In an attempt to clarify previous findings, gender and grade differences in adolescent reports of emotional closeness within same- and cross-sex friendships were examined in the current study. Responses from two hundred seventy adolescents indicated gender differences in reports of time spent with their friends daily and levels of relationship closeness, cohesion, and commitment. Further, grade moderated relationship differences in reports of relationship cohesion and closeness. Differences in predictors of intimacy support previous studies that have found grade and gender differences in levels of intimacy in adolescents' same- and cross-sex friendships. Results also elaborate on previous research by indicating grade differences in adolescents' perceptions of cohesion and closeness in their same- and cross-sex friendships. Findings are discussed in terms of understanding differences in adolescent reports of intimacy within same- and cross-sex friendships.