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The mere presence of task-irrelevant auditory stimuli is known to interfere with cognitive functioning. Disruption can be caused by changing auditory distractors (the changing-state effect) or by a sound that deviates from the auditory background (the deviation effect). The unitary account of auditory distraction explains both phenomena in terms of attentional capture whereas the duplex-mechanism account posits that they reflect two fundamentally different forms of distraction in which only the deviation effect is caused by attentional capture. To test these predictions, we exploited a physiological index of attention orienting: the pupillary dilation response (PDR). Participants performed visual serial recall while ignoring sequences of spoken letters. These sequences either comprised repeated or changing letters, and one letter could sometimes be replaced by pink noise (the deviant). Recall was poorer in both changing-state and deviant trials. Interestingly, the PDR was elicited by deviant sounds but not changing-state sounds, while a tonic increase in pupil size was found throughout changing-state trials. This physiological dissociation of the changing-state and the deviation effects suggests they are subtended by distinct mechanisms thereby procuring support for the duplex-mechanism account over the unitary account.

Cell-phone conversation is ubiquitous within public spaces. The current study investigates whether ignored cell-phone conversation impairs eyewitness memory for a perpetrator. Participants viewed a video of a staged crime in the presence of 1 side of a comprehensible cell-phone conversation (meaningful halfalogue), 2 sides of a comprehensible cell-phone conversation (meaningful dialogue), 1 side of an incomprehensible cell-phone conversation (meaningless halfalogue), or quiet. Between 24 and 28 hr later, participants freely described the perpetrator's face, constructed a single composite image of the perpetrator from memory, and attempted to identify the perpetrator from a sequential lineup. Further, participants rated the likeness of the composites to the perpetrator. Face recall and lineup identification were impaired when participants witnessed the staged crime in the presence of a meaningful halfalogue compared to a meaningless halfalogue, meaningful dialogue, or quiet. Moreover, likeness ratings showed that the composites constructed after ignoring the meaningful halfalogue resembled the perpetrator less than did those constructed after experiencing quiet or ignoring a meaningless halfalogue or a meaningful dialogue. The unpredictability of the meaningful content of the halfalogue, rather than its acoustic unexpectedness, produces distraction. The results are novel in that they suggest that an everyday distraction, even when presented in a different modality to target information, can impair the long-term memory of an eyewitness. (PsycINFO Database Record

Classically, attentional selectivity has been conceptualized as a passive by-product of capacity limits on stimulus processing. Here, we examine the role of more active cognitive control processes in attentional selectivity, focusing on how distraction from task-irrelevant sound is modulated by levels of task engagement in a visually presented short-term memory task. Task engagement was varied by manipulating the load involved in the encoding of the (visually presented) to-be-remembered items. Using a list of Navon letters (where a large letter is composed of smaller, different-identity letters), participants were oriented to attend and serially recall the list of large letters (low encoding load) or to attend and serially recall the list of small letters (high encoding load). Attentional capture by a single deviant noise burst within a task-irrelevant tone sequence (the deviation effect) was eliminated under high encoding load (Experiment 1). However, distraction from a continuously changing sequence of tones (the changing-state effect) was immune to the influence of load (Experiment 2). This dissociation in the amenability of the deviation effect and the changing-state effect to cognitive control supports a duplex-mechanism over a unitary-mechanism account of auditory distraction in which the deviation effect is due to attentional capture whereas the changing-state effect reflects direct interference between the processing of the sound and processes involved in the focal task. That the changing-state effect survives high encoding load also goes against an alternative explanation of the attenuation of the deviation effect under high load in terms of the depletion of a limited perceptual resource that would result in diminished auditory processing. publishedVersion

Automatic information processing has been and still is a debated topic. Traditionally, automatic processes are deemed to take place autonomously and independently of top-down cognitive control. For decades, the literature on reading has brought to the fore empirical phenomena such as Stroop and semantic priming effects that provide support for the assumption that semantic information can be accessed automatically. More recently, there has been growing evidence that semantic processing is in fact susceptible to higher-level cognitive influences, suggesting that this form of processing is instead conditionally automatic. The purpose of the present study was to revisit this debate using a novel approach: The automatic access to the meaning of irrelevant auditory stimuli was tested through the assessment of their distractive power. More specifically, we aimed to examine whether a categorical change in the content of to-be-ignored auditory sequences composed of speech items that are personally nonsignificant to participants (e.g., a digit among letters) can disrupt an unrelated visual focal task. In seven experiments, we assessed this categorical deviation effect and its functional properties. We established that distraction by categorical deviation is noncontingent on the activated task set and appears resistant to top-down control manipulations. By suggesting not only that the semantic content of the irrelevant sound can be extracted preattentively, but also that such semantic activation is ineluctable during auditory distraction, these findings shed new light on the automatic nature of semantic processing. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

We observed how information about the structure of tone sequences modulates cortical responses in the context of a standard short-term memory (STM) task. Participants heard two sequences of one, three, or five tones (203 ms on, 203 ms off) interspersed by a silent interval (2 s) and decided whether the sequences were the same or different. In experiment 1, sequence length was randomized between trials. During the first sequence, the amplitude of the auditory P2 was larger for the second tone in trials with three tones, and for the second and fourth tone in trials with five tones. We hypothesize the increase in P2 reflected a dynamic disambiguation process because these tones were predictive of a sequence longer than one or three tones. This hypothesis was supported by the absence of P2 amplitude modulation during the second sequence (when sequence length was known). In experiment 2, we blocked trials by sequence length to ensure the effects were not caused by some process related to encoding in STM. There was no P2 amplitude modulation in either the first or second sequences. Thus, tones 2 and 4 had a larger amplitude only when they provided new information about the length of the current tone sequence. To some extent, the auditory N1 also showed those modulations. Independent Component Analysis of the ERPs provided evidence the modulations in P2 amplitude could originate in auditory cortex. These results suggest a rapid dynamic adaptation of auditory cortical responses based on the local informativeness of auditory signals.

Telephone conversation is ubiquitous within the office setting. Overhearing a telephone conversation-whereby only one of the two speakers is heard-is subjectively more annoying and objectively more distracting than overhearing a full conversation. The present study sought to determine whether this "halfalogue" effect is attributable to unexpected offsets and onsets within the background speech (acoustic unexpectedness) or to the tendency to predict the unheard part of the conversation (semantic [un]predictability), and whether these effects can be shielded against through top-down cognitive control. In Experiment 1, participants performed an office-related task in quiet or in the presence of halfalogue and dialogue background speech. Irrelevant speech was either meaningful or meaningless speech. The halfalogue effect was only present for the meaningful speech condition. Experiment 2 addressed whether higher task-engagement could shield against the halfalogue effect by manipulating the font of the to-be-read material. Although the halfalogue effect was found with an easy-to-read font (fluent text), the use of a difficult-to-read font (disfluent text) eliminated the effect. The halfalogue effect is thus attributable to the semantic (un)predictability, not the acoustic unexpectedness, of background telephone conversation and can be prevented by simple means such as increasing the level of engagement required by the focal task. (PsycINFO Database Record

Task-irrelevant speech impairs short-term serial recall appreciably. On the interference-by-process account, the processing of physical (i.e., precategorical) changes in speech yields order cues that conflict with the serial-ordering process deployed to perform the serial recall task. In this view, the postcategorical properties (e.g., phonology, meaning) of speech play no role. The present study reassessed the implications of recent demonstrations of auditory postcategorical distraction in serial recall that have been taken as support for an alternative, attentional-diversion, account of the irrelevant speech effect. Focusing on the disruptive effect of emotionally valent compared with neutral words on serial recall, we show that the distracter-valence effect is eliminated under conditions-high task-encoding load-thought to shield against attentional diversion whereas the general effect of speech (neutral words compared with quiet) remains unaffected (Experiment 1). Furthermore, the distracter-valence effect generalizes to a task that does not require the processing of serial order-the missing-item task-whereas the effect of speech per se is attenuated in this task (Experiment 2). We conclude that postcategorical auditory distraction phenomena in serial short-term memory (STM) are incidental: they are observable in such a setting but, unlike the acoustically driven irrelevant speech effect, are not integral to it. As such, the findings support a duplex-mechanism account over a unitary view of auditory distraction. (PsycINFO Database Record

When the frequency of one harmonic, in a sound composed of many harmonics, is briefly mistuned and then returned to the 'in-tune' frequency and phase, observers report hearing this harmonic as a separate tone long after the brief period of mistuning - a phenomenon called harmonic enhancement. Here, we examined the consequence of harmonic enhancement on listeners' ability to detect a brief amplitude notch embedded in one of the harmonics after the period of mistuning. When present, the notch was either on the enhanced harmonic or on a different harmonic. Detection was better on the enhanced harmonic than on a non-enhanced harmonic. This finding suggests that attention was drawn to the enhanced harmonic (which constituted a new sound object) thereby easing the processing of sound features (i.e., a notch) within that object. This is the first evidence of a functional consequence of the after-effect of transient mistuning on auditory perception. Moreover, the findings provide support for an attention-based explanation of the enhancement phenomenon.

The rare occurrence of a sound deviating from the auditory background tends to trigger attentional orienting. While some sympathetic physiological responses can be used to index this orienting response, findings surrounding the pupillary dilation response (PDR) as a proxy for the orienting response are conflicting. The current study was tailor-designed to examine whether the PDR satisfies specific criteria of an orienting response index, namely the classic habituation pattern and a sensitivity to the size of the deviation. The PDR decrement to a repeated standard sound, recovery to a deviant sound, and dishabituation to the re-presentation of the standard were assessed for small and large deviations embedded in irrelevant auditory sequences. The PDR not only showed habituation and dishabituation, but also recovered in correspondence with the magnitude of the acoustic deviation. This consistency between variations of the PDR and orienting response's properties indicates that the PDR is a valid index of the auditory orienting response.

We compared the electrophysiological correlates for the maintenance of non-musical tones sequences in auditory short-term memory (ASTM) to those for the short-term maintenance of sequences of coloured disks held in visual short-term memory (VSTM). The visual stimuli yielded a sustained posterior contralateral negativity (SPCN), suggesting that the maintenance of sequences of coloured stimuli engaged structures similar to those involved in the maintenance of simultaneous visual displays. On the other hand, maintenance of acoustic sequences produced a sustained negativity at fronto-central sites. This component is named the Sustained Anterior Negativity (SAN). The amplitude of the SAN increased with increasing load in ASTM and predicted individual differences in the performance. There was no SAN in a control condition with the same auditory stimuli but no memory task, nor one associated with visual memory. These results suggest that the SAN is an index of brain activity related to the maintenance of representations in ASTM that is distinct from the maintenance of representations in VSTM.

The occurrence of an unexpected, infrequent sound in an otherwise homogeneous auditory background tends to disrupt the ongoing cognitive task. This "deviation effect" is typically explained in terms of attentional capture whereby the deviant sound draws attention away from the focal activity, regardless of the nature of this activity. Yet, there is theoretical and empirical evidence suggesting that the attention-capture mechanism underlying this form of distraction could rather be triggered in a task-contingent fashion. The present study aimed at determining whether the auditory deviation effect reflects the action of either a stimulus-driven or a task-contingent orienting mechanism. To do so, we conducted a systematic investigation whereby the impact of verbal deviants-a letter embedded in the repetition of another letter-and spatial deviants-a sound presented contralaterally to the other sounds-on verbal and spatial short-term memory (STM) was assessed. This study established that both verbal and spatial deviants can hinder both verbal and spatial order-reconstruction (Experiment 1) and missing-item tasks (Experiment 2). Such results demonstrate that the deviation effect reflects a general form of auditory distraction as interference took place both within and across domains and regardless of the processes engaged in the focal task. (PsycINFO Database Record

Pupillary reactions independent of light conditions have been linked to cognition for a long time. However, the light conditions can impact the cognitive pupillary reaction. Previous studies underlined the impact of luminance on pupillary reaction, but it is still unclear how luminance modulates the sustained and transient components of pupillary reaction – tonic pupil diameter and phasic pupil response. In the present study, we investigated the impact of the luminance on these two components under sustained cognitive load. Fourteen participants performed a novel working memory task combining mathematical computations with a classic n-back task. We studied both tonic pupil diameter and phasic pupil response under low (1-back) and high (2-back) working memory load and two luminance levels (gray and white). We found that the impact of working memory load on the tonic pupil diameter was modulated by the level of luminance, the increase in tonic pupil diameter with the load being larger under lower luminance. In contrast, the smaller phasic pupil response found under high load remained unaffected by luminance. These results showed that luminance impacts the cognitive pupillary reaction – tonic pupil diameter (phasic pupil response) being modulated under sustained (respectively, transient) cognitive load. These findings also support the relationship between the locus-coeruleus system, presumably functioning in two firing modes – tonic and phasic – and the pupil diameter. We suggest that the tonic pupil diameter tracks the tonic activity of the locus-coeruleus while phasic pupil response reflects its phasic activity. Besides, the designed novel cognitive paradigm allows the simultaneous manipulation of sustained and transient components of the cognitive load and is useful for dissociating the effects on the tonic pupil diameter and phasic pupil response.

Individuals with schizophrenia typically show increased levels of distractibility. This has been attributed to impaired working memory capacity (WMC), since lower WMC is typically associated with higher distractibility, and schizophrenia is typically associated with impoverished WMC. Here, participants performed verbal and spatial serial recall tasks that were accompanied by to-be-ignored speech tokens. For the few trials wherein one speech token was replaced with a different token, impairment was produced to task scores (a deviation effect). Participants subsequently completed a schizotypy questionnaire and a WMC measure. Higher schizotypy scores were associated with lower WMC (as measured with operation span, OSPAN), but WMC and schizotypy scores explained unique variance in relation to the mean magnitude of the deviation effect. These results suggest that schizotypy is associated with heightened domain-general distractibility, but that this is independent of its relationship with WMC.

The review of literature in sociology and distributed artificial intelligence reveals that the occurrence of conflict is a remarkable precursor to the disruption of multi-agent systems. The study of this concept could be applied to human factors concerns, as man-system conflict appears to provoke perseveration behavior and to degrade attentional abilities with a trend to excessive focus. Once entangled in such conflicts, the human operator will do anything to succeed in his current goal even if it jeopardizes the mission. In order to confirm these findings, an experimental setup, composed of a real unmanned ground vehicle, a ground station is developed. A scenario involving an authority conflict between the partici- pants and the robot is proposed. Analysis of the effects of the conflict on the participants’ cognition and arousal is assessed through heart-rate measurement (reflecting stress level) and eye-tracking techniques (index of attentional focus). Our results clearly show that the occurrence of the conflict leads to perseveration behavior and can induce higher heart rate as well as excessive attentional focus. These results are discussed in terms of task commitment issues and increased arousal. Moreover, our results suggest that individual differences may predict susceptibility to perseveration behavior.

Objective: We employed a computer-controlled command-and-control (C2) simulation and recorded eye movements to examine the extent and nature of the inability to detect critical changes in dynamic displays when change detection is implicit (i.e., requires no explicit report) to the operator’s task. Background: Change blindness—the failure to notice significant changes to a visual scene—may have dire consequences on performance in C2 and surveillance operations. Method: Participants performed a radar-based risk-assessment task involving multiple subtasks. Although participants were not required to explicitly report critical changes to the operational display, change detection was critical in informing decision making. Participants’ eye movements were used as an index of visual attention across the display. Results: Nonfixated (i.e., unattended) changes were more likely to be missed than were fixated (i.e., attended) changes, supporting the idea that focused attention is necessary for conscious change detection. The finding of significant pupil dilation for changes undetected but fixated suggests that attended changes can nonetheless be missed because of a failure of attentional processes. Conclusion: Change blindness in complex dynamic displays takes the form of failures in establishing task-appropriate patterns of attentional allocation. Application: These findings have implications in the design of change-detection support tools for dynamic displays and work procedure in C2 and surveillance.

There is growing evidence that processes formerly believed to be automatic are, in fact, strongly modulated by top–down influences. The purpose of the present work was to investigate how cognitive control can affect the purported automaticity of word processing by examining the impact of task switching on semantic processing using the ERP technique. In the context of the psychological refractory period dual-task paradigm, two experiments contrasted the context-sensitive N400 ERP elicited by the second of two target words under conditions that involved either a task switch or no-task switch. Although the N400 was not affected by SOA in the absence of switching, it was strongly attenuated at short SOAs when the psychological refractory period procedure involved a switch from a perceptual to a semantic task (Experiment 1) or a switch between two different semantic tasks (Experiment 2). These findings suggest that semantic processing cannot be performed in parallel with task switching and illustrate limitations in the ability of the cognitive system to adapt flexibly to the dynamically changing challenges of the environment according to task demands and behavioral goals.

The attentional blink (AB) refers to the impairment in accurate report of a second target (T2) when presented shortly after a first target (T1) in a rapid serial visual presentation of distractors. The goal of the present study was to determine whether the AB is caused by a failure in early selection processes, which leads to the selection and consolidation of the wrong item in working memory, by measuring the frequency-related P3 to T2 and to T2 + 1. During the AB, an attenuation of the P3 to T2 was observed, as well as an increase in the amplitude of the P3 to T2 + 1. Whereas the P3 to T2 was observed only when T2 was correctly reported, the P3 to T2 + 1 was observed only in trials where T2 was incorrectly reported, and its amplitude was correlated to individual differences in misselection rate. These results support the claim that failure of temporal selection underlies the AB.

A fatal case of dengue (DEN) infection associated with a spleen rupture and with hepatitis is reported here. Microscopic studies showed numerous areas of spleen rupture with hematomas and revealed necrotic foci in liver samples obtained at autopsy. Although hepatitis was reported in several cases of DEN fever, the mechanism of liver injury remains poorly understood. In this case, immunohistochemistry showed that DEN viral antigens were mostly detected in hepatocytes surrounding the necrotic foci. By in situ detection of DNA fragmentation, apoptotic hepatocytes were found to be colocated with DEN virus-infected hepatocytes. These findings suggest that hepatocytes are the major sites of DEN virus replication in the liver and that DEN virus induces apoptosis of hepatocytes in vivo.

Objective: The aim of this study was to test whether inattentional deafness to critical alarms would be observed in a simulated cockpit. Background: The inability of pilots to detect unexpected changes in their auditory environment (e.g., alarms) is a major safety problem in aeronautics. In aviation, the lack of response to alarms is usually not attributed to attentional limitations, but rather to pilots choosing to ignore such warnings due to decision biases, hearing issues, or conscious risk taking. Method: Twenty-eight general aviation pilots performed two landings in a flight simulator. In one scenario an auditory alert was triggered alone, whereas in the other the auditory alert occurred while the pilots dealt with a critical windshear. Results: In the windshear scenario, 11 pilots (39.3%) did not report or react appropriately to the alarm whereas all the pilots perceived the auditory warning in the no-windshear scenario. Also, of those pilots who were first exposed to the no-windshear scenario and detected the alarm, only three suffered from inattentional deafness in the subsequent windshear scenario. Conclusion: These findings establish inattentional deafness as a cognitive phenomenon that is critical for air safety. Pre-exposure to a critical event triggering an auditory alarm can enhance alarm detection when a similar event is encountered subsequently. Application: Case-based learning is a solution to mitigate auditory alarm misperception.

The purpose of this study was to investigate the possibility to integrate a free head motion eye-tracking system as input device in air traffic control (ATC) activity. Sixteen participants used an eye tracker to select targets displayed on a screen as quickly and accurately as possible. We assessed the impact of the presence of visual feedback about gaze position and the method of target selection on selection performance under different difficulty levels induced by variations in target size and target-to-target separation. We tend to consider that the combined use of gaze dwell-time selection and continuous eye-gaze feedback was the best condition as it suits naturally with gaze displacement over the ATC display and free the hands of the controller, despite a small cost in terms of selection speed. In addition, target size had a greater impact on accuracy and selection time than target distance. These findings provide guidelines on possible further implementation of eye tracking in ATC everyday activity.We investigated the possibility to integrate a free head motion eye-tracking system as input device in air traffic control (ATC). We found that the combined use of gaze dwell-time selection and continuous eye-gaze feedback allowed the best performance and that target size had a greater impact on performance than target distance.

We used magnetoencephalography (MEG) to examine brain activity related to the maintenance of non-verbal pitch information in auditory short-term memory (ASTM). We focused on brain activity that increased with the number of items effectively held in memory by the participants during the retention interval of an auditory memory task. We used very simple acoustic materials (i.e., pure tones that varied in pitch) that minimized activation from non-ASTM related systems. MEG revealed neural activity in frontal, temporal, and parietal cortices that increased with a greater number of items effectively held in memory by the participants during the maintenance of pitch representations in ASTM. The present results reinforce the functional role of frontal and temporal cortices in the retention of pitch information in ASTM. This is the first MEG study to provide both fine spatial localization and temporal resolution on the neural mechanisms of non-verbal ASTM for pitch in relation to individual differences in the capacity of ASTM. This research contributes to a comprehensive understanding of the mechanisms mediating the representation and maintenance of basic non-verbal auditory features in the human brain.

The role of memory in behavioral distraction by auditory attentional capture was investigated: We examined whether capture is a product of the novelty of the capturing event (i.e., the absence of a recent memory for the event) or its violation of learned expectancies on the basis of a memory for an event structure. Attentional capture-indicated by disruption of a focal visually presented serial recall task-was found when the voice conveying a concurrent irrelevant auditory sequence changed every 5 recall trials (from male to female or vice versa). There was no evidence of attentional capture when the irrelevant sequence was first encountered and hence novel; capture occurred only when an expectation for a particular voice had been learned and then violated. Furthermore, with the increasing predictability of (and hence expectancy for) the voice changes across the experimental session, the capture response diminished only to be reinstated when that session-wide expectation was itself violated by a break in the change-every-5-trials pattern. The results highlight the critical role of learned expectations, as opposed to novelty detection, in behavioral auditory attentional capture. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

We studied the neuronal mechanisms that implement acoustic short-term memory (ASTM) for pitch using event-related potentials (ERP). Experiment 1 isolated an ERP component, the sustained anterior negativity (SAN), that increased in amplitude with increasing memory load in ASTM using stimuli with equal duration at all memory loads. The SAN load effect found in Experiment 1, when pitch had to be remembered to perform the task, was absent in Experiment 2 using the same sounds when memory was not required. In Experiment 3, the memory task was performed without or with concurrent articulatory suppression during the retention interval to prevent rehearsal via an articulatory loop. Load-related effects observed in Experiment 1 were found again, whether participants engaged in concurrent suppression or not. The results suggest that the SAN reflects activity required to maintain pitch objects in an ASTM system that is distinct from articulatory rehearsal.

Since the introduction of the concept of auditory scene analysis, there has been a paucity of work focusing on the theoretical explanation of how attention is allocated within a complex auditory scene. Here we examined signal detection in situations that promote either the fusion of tonal elements into a single sound object or the segregation of a mistuned element (i.e., harmonic) that "popped out" as a separate individuated auditory object and yielded the perception of concurrent sound objects. On each trial, participants indicated whether the incoming complex sound contained a brief gap or not. The gap (i.e., signal) was always inserted in the middle of one of the tonal elements. Our findings were consistent with an object-based account in which perception of two simultaneous auditory objects interfered with signal detection. This effect was observed for a wide range of gap durations and was greater when the mistuned harmonic was perceived as a separate object. These results suggest that attention may be initially shared among concurrent sound objects thereby reducing listeners' ability to process acoustic details belonging to a particular sound object. These findings provide new theoretical insight for our understanding of auditory attention and auditory scene analysis.

To describe the presentation and clinical course of septic shock due to Toxoplasma gondii in patients infected with the human immunodeficiency virus (HIV).From April 1988 to February 1992, nine HIV-infected patients were admitted because of predominant septic shock (7 patients) or developed septic shock in the ICU (2 patients). The recent CD4+ cell count ranged from 2 to 84 x 10(6)/L.The main clinical features were (1) a history of fever for longer than 15 days, with a recent increase to more than 39.5 degrees C; (2) a recent history of dyspnea (15 days, 8 cases;7 days, 3 cases); and (3) recent onset of thrombocytopenia (6 of 9 cases). All patients were in shock (hyperkinetic profile in 6 of 7; hypokinetic in 1 of 7), and 8 of 9 were in respiratory distress (ratio of PaO2 over fractional concentration of oxygen in the inspired gas of 117 +/- 23; range, 88 to 155). Chest roentgenograms revealed diffuse alveolar infiltrates in six of nine cases. The serum lactate dehydrogenase (LDH) activity was 6,510 +/- 5,080 IU/L (range, 1,010 to 15,450 IU/L). Serologic tests for T gondii were negative in two cases. Toxoplasma gondii was isolated from lung (9/9), bone marrow (5/7), or blood (2/2). One, 3, and 2 patients had brain, ocular, and myocardial involvement, respectively. No other microbial pathogens were isolated. Seven patients died, 5 less than 3 days after admission.Disseminated toxoplasmosis can cause septic shock in HIV-infected patients. In two cases, the disease was probably a primary infection. The association of high fever, acute dyspnea, recent onset of thrombocytopenia, and a very high level of LDH activity is suggestive of disseminated toxoplasmosis.

The cognitive system is able to reconfigure mental resources flexibly to adapt to new a task. While task-set switching is known to be detrimental to behavioral performance, less is known about the precise loci of these effects on stimulus processing. We measured event-related potentials to explore the neural consequences of task-set switching on semantic processing. We examined the context-sensitive N400 component evoked by the second of two target words embedded in a rapid serial visual presentation under conditions that involved either a task-set switch or no switching. Whereas the N400 was unaffected by the lag separating the targets in the absence of switching, it was delayed and attenuated in the switch condition when the targets were adjacent in the sequence. These findings indicate that task-set reconfiguration temporarily prevents semantic activation and provide evidence for the nonautomaticity of semantic processing of words.

Serum concentrations of carcinoembryonic antigen (CEA) were measured in 43 consecutive patients with HIV-related Pneumocystis carinii pneumonia (PCP). The subjects were divided into 2 groups according to the severity of the PCP:PaO2 in ambient air (AA) less than or equal to 50 mmHg on admission (n = 22, group 1) and PaO2 greater than 50 mmHg (n = 21, group 2). In addition, 57 HIV patients with either non-PCP pulmonary diseases (n = 34, group 3) or extrapulmonary disease (n = 23, group 4) were studied. Mean CEA levels (ng/ml) were 13 +/- 10 in group 1 and 4.9 +/- 5.5 in group 2 (p less than 0.001). The corresponding values in groups 3 and 4 were much lower (2.7 +/- 1.8 and 2.4 +/- 1.8, respectively). In group 1, mean initial CEA levels were higher (p less than 0.001) in the patients who died (n = 6; 23.5 +/- 11) than in the survivors (n = 16; 8.9 +/- 7), although the initial mean PaO2 were identical (39 +/- 7 and 39 +/- 8 mmHg, respectively) and the initial mean LDH levels were not significantly different (1544 +/- 530 and 1200 +/- 457 IU/l). CEA levels fell during specific anti-PCP therapy associated with corticosteroids but returned to normal only in the survivors. We conclude that CEA levels are increased in patients with PCP and acute respiratory distress. Among the patients with PaO2 levels of less than or equal to 50 mmHg before treatment, only high levels of CEA (greater than 20 ng/ml) were associated with a fatal outcome, regardless of anti-PCP therapy associated with corticosteroids.(ABSTRACT TRUNCATED AT 250 WORDS)

In North America Europe and many parts of Asia the ignition of regional epidemics and rapid HIV transmission has been associated principally with the sharing of contaminated injecting equipment and with anal intercourse. Though heterosexual intercourse has been virtually the sole explanation offered for the AIDS epidemic in sub-Saharan Africa to our knowledge in no other part of the world has penile-vaginal exposure (as opposed to “heterosexual sex”) been demonstrated to initiate or sustain rapid HIV propagation. HIV is not transmitted by “sex” but only by specific risky practices. It is not transmitted by “injections” but only by contaminated implements which need to be clearly differentiated as to type and frequency of injection and by the conditions of the exposure setting. In virtually all societies affected by HIV to date both routes seem to play important roles. If we are to understand and intervene in each of these epidemics well-designed studies at both the population and individual levels are urgently needed. It is vital that these be properly controlled for parenteral exposure specific sexual practices and other co-factors and the complex and specific social patterns and networks that accompany them. (excerpt)

We report the first 2 cases of fatal invasive aspergillosis complicating severe malaria. In 2 nonimmune European adults without underlying disease, death was directly ascribable to invasive aspergillosis. We believe that transient malaria-induced immunosuppression allowed massive growth and overwhelming dissemination of preexisting Aspergillus colonization.

Blackwater fever (BWF) is a severe clinical syndrome, characterized by intravascular hemolysis, hemoglobinuria, and acute renal failure that is classically seen in European expatriates chronically exposed to Plasmodium falciparum and irregularly taking quinine. BWF virtually disappeared after 1950, when chloroquine superseded quinine. We report 21 cases of BWF seen in France from 1990 through 1999 in European expatriates who lived in sub-Saharan Africa. All patients had macroscopic hemoglobinuria, jaundice, and anemia. Acute renal failure occurred in 15 patients (71%), 7 of whom required dialysis. The presumed triggers of BWF were halofantrine (38%), quinine (24%), mefloquine (24%), and halofantrine or quinine (14%). Glucose-6-phosphate dehydrogenase (G6PD) activity was normal in the 14 patients who underwent this test. Low-level P. falciparum parasitemia was found in 8 patients. All 21 patients survived. Our data and 13 cases reported in the literature suggest a resurgence of classic BWF among Europeans living in Africa and a need to discuss attendant therapeutic implications.

Clinical and biological pitfalls that lead to incorrect or delayed diagnoses of airport malaria are described based on 7 cases reported from the Paris region in the summer of 1994. We also report the outcome and the epidemiological features of these patients.

To evaluate right ventricle (RV) anatomy and performance and its relationships with pulmonary circulation in AIDS patients.We conducted a prospective blinded study by using cine-MRI, a well-accepted method to assess RV and pulmonary circulation.A university hospital.Ten healthy volunteers and 13 asymptomatic AIDS patients.RV end-diastolic and end-systolic volumes, RV ejection fraction (RVEF), pulmonary artery (PA) diameter, main pulmonary artery distensibility (MPAD), RV free wall diastolic thickness (RVWT), and RV mass were measured. The RVWT/left ventricular wall thickness index was calculated.AIDS patients had significantly increased RV end-diastolic and end-systolic volumes and decreased RVEF (50 +/- 10 vs 59 +/- 6; p0.03). Four AIDS patients had RV wall motion abnormalities; 5 (38%) had an RVEF under 45%. RVWT, the RVWT/left ventricular wall thickness index, and PA diameter were significantly increased in AIDS patients. RV mass was increased in 54% of AIDS patients. MPAD was significantly lower in AIDS patients (18.8 +/- 15 vs 26 +/- 4; p0.01). A significant relationship was found between RV mass and MPAD (r = 0.76; p = 0.02).RV function is frequently impaired in AIDS patients. Anatomic and functional abnormalities found in RV and PA parameters suggest a systolic overload on RV. Pulmonary circulation abnormalities may influence RV structure and function in AIDS patients.

International audience; OBJECTIVE: To determine more precisely the clinical and biological characteristics of AIDS-related cholangitis, and to investigate prognostic variables of this disease. DESIGN: Retrospective clinical and prognostic study. SETTING: Biliary unit, Bicêtre Hospital, France. PATIENTS: HIV-positive patients (n = 52) referred to the unit between December 1986 and June 1993 for biliary symptoms leading to the suspicion of AIDS-related cholangitis, (42 men; 10 women; mean age, 37 +/- 8 years). INTERVENTION: Endoscopic retrograde cholangiopancreatography (ERCP) was performed in order to determine the cause of the biliary symptoms. MAIN OUTCOME MEASURE: Clinical features and evolution of the cholangitis. RESULTS: Among the 52 patients, 45 met the ERCP criteria of AIDS-related cholangitis (36 men; nine women). The diagnosis of cholangitis was strongly suggested by abdominal ultrasonography in 47% of the cases. ERCP showed papillary stenosis, diffuse cholangitis, extrahepatic cholangitis alone, and intrahepatic cholangitis alone in 60, 67, 7 and 27%, respectively. Endoscopic sphincterotomy was performed in 28 patients. Pain was relieved by sphincterotomy in nine patients, but the other clinical or biological features were not influenced. One-year and 2-year survival rates were 41 +/- 7% and 8 +/- 4%, respectively. Multidimensional analysis using a Cox model showed that a lymphocyte count > 500 x 10(6)/l was the only independent predictive factor of better survival. CONCLUSION: AIDS-related cholangitis is a disease which leads preferentially to papillary stenosis or diffuse abnormalities of the biliary tract. Prognostic factors depend on the stage of the HIV infection. Another diagnosis of cholestasis was found in approximately 15% of the patients who showed biliary symptoms.

Disseminated infection by Fusarium is being increasingly reported in immunocompromised patients. We report the first case of Fusarium oxysporum disseminated infection with well-documented fungal myocarditis. Despite antifungal therapy and hematologic recovery, the patient died in cardiogenic shock, myocardial involvement clearly contributing to the fatal outcome.

During a 10-yr period, 40 cases of severe Listeria monocytogenes meningitis were observed. All patients showed consciousness disturbances and 27 of them (68%) focal neurologic signs. Cranial nerve palsies were common (57%). Early general seizures (13 patients) and presence of underlying disease (12 patients) were associated with a high mortality rate. Although the management of antibiotic therapy is open for discussion, chloramphenicol (used in 7 patients) seems to be more effective than other drugs.