1,354,647 research outputs found
The case of Air Traffic Control training
No full textAir traffic controllers have to guarantee safe and efficient air traffic by predicting future flight paths based on their perception and interpretation of multiple data on the radar display. The multi-tasking nature of their job makes the cognitive and emotional processes required in Air Traffic Control fundamentally different from those traditionally studied in the lab. Thus, Air Traffic Control represents a unique naturalistic opportunity to investigate how such a demanding job may shape cognition. This chapter reviews work dealing with the cognitive characteristics of air traffic control, as well as the few studies that have investigated how training and experience in this profession change different aspects of cognitive functioning, in particular different facets of cognitive flexibility and planning abilities. Finally, it will also examine the cognitive consequences of the unique challenges represented by man-technology interactions inherent in this job. Despite the promising findings reviewed in this chapter, the research on the cognitive enhancement derived from training and experience on ATC is still limited and not conclusive. Further methodologically well-controlled studies are clearly needed to obtain a more comprehensive picture of the extraordinary potentialities of this profession
Connectivity between ventromedial prefrontal cortex and posterior superior temporal sulcus
No full textThe well-articulated Self Attention Network (SAN) framework accounts for a great portion of the available evidence on neurocognitive interactions between self-bias phenomena and attention. I argue that more work is necessary to refine our understanding about the effective and functional connectivity of the different nodes of the proposed network. In particular, the nature of the control of ventro-medial prefrontal cortex over posterior superior temporal sulcus has to be worked out further. Simple excitatory connections between these two nodes, as proposed by the SAN model, do not satisfactorily account for existing neuropsychological dissociations and are not fully warranted by neuroimaging evidence
Prefrontal involvement in source memory: an electrophysiological investigation of accounts concerning confidence and accuracy
No full textAlthough a prefrontal involvement in the memory domain is well-documented, the specific functions the frontal lobes have in episodic memory are still unclear. This study aimed to disentangle theoretical accounts of prefrontal involvement concerning objective characteristics of the retrieval (i.e., accuracy) and accounts based on subjective features (i.e., confidence). Event-related potentials (ERPs) were recorded during the test phase of a source memory task in two experiments. The task was to retrieve the word and the voice of the speaker at study (experiment 1) or the voice of the speaker together with confidence ratings about the source judgment (experiment 2). ERPs in both experiments were not modulated by the success of the voice retrieval, discarding accounts linked to the retrieval success. A right-more-than-left late prefrontal positivity was found in both experiments. Moreover, in experiment 2, waves were more positive for low- than for high-confidence responses. This pattern ..
Dorsolateral prefrontal cortex and motor preparation: a TMS investigation of the foreperiod effect
No full textWhen Foreperiods (FPs) of different duration alternate on a trial-by-trial basis equiprobably but randomly, the reaction time (RT) decreases as the FP increases (FP effect). Another phenomenon observed in that paradigm consists of the sequential effects: RT is slower as the FP in the preceding trial gets longer. It is not clear if the two effects are due to different underlying mechanisms. Patients with lesions on the right dorsolateral prefrontal cortex do not show the typical FP effect [Stuss et al. (2005). Neuropsychologia, 43, 396-417]. Aim of the present study was to replicate this result in healthy adults, through an off-line TMS paradigm (Theta Burst Stimulation). Another purpose was to investigate whether any change of the sequential effects would follow a possible variation of the FP effect. Results of two experiments (with simple and choice RT task, respectively) indicate a significant reduction of the FP effect, selectively after stimulation of the right dorsolateral prefrontal cortex with respect to a pre-TMS baseline, and to the stimulation of a contralateral site and of another site in the right Angular Girus. The dissociation between the two effects supports a dual-process model [Vallesi & Shallice, subm.], according to which they are due to two distinct but interacting processes. In particular, the FP effect is attributed to a strategic process monitoring the conditional probability of the stimulus occurrence, whereas the sequential effects would originate by an automatic mechanism of arousal regulation by the length of the preceding FP
Monitoring Processes in Visual Search Enhanced by Professional Experience: The Case of Orange Quality-Control Workers
No full textVisual search tasks have often been used to investigate how cognitive processes change with expertise. Several studies have shown visual experts' advantages in detecting objects related to their expertise. Here, we tried to extend these findings by investigating whether professional search experience could boost top-down monitoring processes involved in visual search, independently of advantages specific to objects of expertise. To this aim, we recruited a group of quality-control workers employed in citrus farms. Given the specific features of this type of job, we expected that the extensive employment of monitoring mechanisms during orange selection could enhance these mechanisms even in search situations in which orange-related expertise is not suitable. To test this hypothesis, we compared performance of our experimental group and of a well-matched control group on a computerized visual search task. In one block the target was an orange (expertise target) while in the other block the target was a Smurfette doll (neutral target). The a priori hypothesis was to find an advantage for quality-controllers in those situations in which monitoring was especially involved, that is, when deciding the presence/absence of the target required a more extensive inspection of the search array. Results were consistent with our hypothesis. Quality-controllers were faster in those conditions that extensively required monitoring processes, specifically, the Smurfette-present and both target-absent conditions. No differences emerged in the orange-present condition, which resulted to mainly rely on bottom-up processes. These results suggest that top-down processes in visual search can be enhanced through immersive real-life experience beyond visual expertise advantages
Evidence for the chimeric origin of a pheromone-coding gene in Euplotes raikovi
No full textCiliates, unique among eukaryotes, evolved two types of nucleus which are distinct in both structure and function. A diploid transcriptionally silent germline micronucleus (MIC) with an orthodox chromosomicstructure coexists in the same cytoplasm with a polyploid transcriptionally active somatic macronucleus (MAC) showing a unique sub-chromosomic structure. This structure is acquired in coincidence with every sexual event, when the ex-conjugant (or ex-autogamic) cell initiates a new life cycle developing a new MAC from a mitotic product of the synkaryon. In spirotrichous ciliates such as Euplotes, the chromosomes of this product undergo impressive phenomena of polytenization, fragmentation in thousands of DNA fragments known as ‘Macronuclear Destined Sequences’ (MDSs), and DNA elimination. Under the guide of noncoding RNA templates synthesized by the old MAC before being destroyed, theseMDSs are assembled into sub-chromosomic (‘gene-size’)DNA molecules which,amplified to thousands of copies, compose the new MAC.The way to a correct MDSassembly may be crossed by errors, with the consequent generation of functional chimeric genes which can stably be integrated and expressed in the MAC genome.One of these chimeric genes came to light by studying the genetic basis of the pheromone-mediated self/not-self recognition mechanism in E. raikovi. The genome of type I cells secreting pheromone Er-1 was found to contain two structurally distinct MAC Er-1 coding genes,both expressed via a mechanism of intron splicing responsible for the synthesis of the Er-1 soluble form and a membrane-bound Er-1 isoform functioning as autocrine pheromone receptor. The sequence of one gene resulted unmistakably homologous throughout its length with the sequences of other members of the E. raikovipheromone gene family. In contrast, the sequence of the second gene resulted unique at level of a 359-bp segment of the 5’ region destined to specify the cytoplasmic domain of the Er-1 membrane-bound isoform. By showing that this segment arises from a wrong assembly of a MDS destined to a 2417-bp gene with no relationship with the signaling pheromone system, we provide additional evidence that the generation of functionally active chimeric genesfrom not-programmed phenomena of somatic MDS recombination is an effective and MIC-independent source of gene variants in the ciliate MAC genome
The often overlooked coming out of ciliates: biological and experimental benefits from accepting genetically identical conspecifics as sexual partners
No full textCiliates usually manifest sex in the form of conjugation, a unique phenomenon in which cells temporarily unite two by two in mating pairs to perform a mutual exchange of gamete-nuclei derived from meiotic products of their germinal micronucleus. The native view of conjugation as a spontaneous manifestation associated with environmental famine conditions was eventually denied by the milestone Sonneborn’s finding (PNAS, 1937) that the most popular ciliate, Paramecium, actually controls conjugation through a genetic mechanism of mating types. Being only two in the Paramecium species studied by Sonneborn, these mating types were functionally equated to ‘male’ and ‘female’ sexes. And, as a consequence of this equation, conjugation was since thought of as a phenomenon committed to involve, as a rule, genetically distinct cells representing two ‘complementary’ mating types. However, this is a wrong tenet adverse the evidence that many ciliates conjugate with no discrimination between sex identity and diversity. And from this no discrimination both the ciliate biology and the students of ciliate biology draw benefit. The ciliate biology, because the homo-sexual pairs (yet ineffective to reshuffle the species gene pool) multiply the opportunity for cells to practice conjugation which, in every case, determines the initiation of a new life cycle and the replacement of the cell ‘old’ transcriptionally active somatic (macronuclear) genome with a completely new one generated from the permanently ‘young’ transcriptionally inert germinal (micronuclear) genome. The students of ciliate biology, because homo-sexual pairs form without requiring physical interactions between sexually/genetically different cells. They form as well in cultures of cells of the same identity previously suspended with filtrates from cultures of conspecific cells of different identity. Which immediately identifies species that interact sexually via water-borne mating signals (pheromones), and greatly facilitates the isolation and function-structure characterization of these signals directly from cell-culture filtrates
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