Covert Condition Research Articles

Identifying bias in self-reported pro-environmental behavior

Research on pro-environmental behavior (PEB) informs social policies and interventions, so the quality of PEB measurement is critical. Self-reported PEB measures in surveys often contain non-negligible measurement error that can bias estimates and lead to incorrect findings. Given the potential presence of error, we hypothesize that changes to the way self-reported PEB is measured might lead to systematic measurement errors that affect the validity of results. Study 1 (N = 951) showed that priming participants with related scales like environmentalist identity did not substantively change reported behavior (all ds ≤ 0.12). To investigate the possibility of overreporting without priming, Study 2 (N = 385) measured littering prevention behavior using the Unmatched Count Technique. A standard questionnaire format led to much higher reported behavior compared to the more anonymous covert condition, d = 0.53, and this effect appeared driven by participants who reported a stronger environmentalist identity. These results may help to explain some of the observed error in PEB measures. We suggest that researchers could reduce measurement bias with indirect questioning techniques.

A comparison and classification of oscillatory characteristics in speech perception and covert speech

Covert speech, the mental imagery of speaking, has been studied increasingly to understand and decode thoughts in the context of brain-computer interfaces. In studies of speech comprehension, neural oscillations are thought to play a key role in the temporal encoding of speech. However, little is known about the role of oscillations in covert speech. In this study, we investigated the oscillatory involvements in covert speech and speech perception. Data were collected from 10 participants with 64 channel EEG. Participants heard the words, ‘blue’ and ‘orange’, and subsequently mentally rehearsed them. First, continuous wavelet transform was performed on epoched signals and subsequently two-tailed t-tests between two classes (tasks) were conducted to determine statistical differences in frequency and time (t-CWT). In the current experiment, a task comprised speech perception or covert rehearsal of a word while a condition was the discrimination between tasks. Features were extracted using t-CWT and subsequently classified using a support vector machine. θ and γ phase amplitude coupling (PAC) was also assessed within tasks and across conditions between perception and covert activities (i.e. cross-task). All binary classifications accuracies (80–90%) significantly exceeded chance level, supporting the use of t-CWT in determining relative oscillatory involvements. While the perception condition dynamically invoked all frequencies with more prominent θ and α activity, the covert condition favoured higher frequencies with significantly higher γ activity than perception. Moreover, the perception condition produced significant θ-γ PAC, possibly corroborating a reported linkage between syllabic and phonemic sampling. Although this coupling was found to be suppressed in the covert condition, we found significant cross-task coupling between perception θ and covert speech γ. Covert speech processing appears to be largely associated with higher frequencies of EEG. Importantly, the significant cross-task coupling between speech perception and covert speech, in the absence of within-task covert speech PAC, seems to support the notion that the γ- and θ-bands reflect, respectively, shared and unique encoding processes across tasks.

The Emergency Assessment and Management of Non-Suicidal Self-Injury in Adolescents

Background and Goals: Non-suicidal self-injury (NSSI) is a common presenting issue mental health providers experience in all levels of care from outpatient clinics to inpatient units. It is common among adolescents seen in emergency settings, either as a presenting problem or as a covert condition that may not be detected unless specifically assessed for. The presence of NSSI increases the risk of suicide. This article aims to help the clinician develop a better understanding of NSSI – what it may entail, the prevalence, and the motivations for why young people engage in it. Methods: We review the reasons adolescents injure themselves, the link between NSSI and psychiatric diagnoses and suicide, the assessment of NSSI, and treatment planning, with emphasis on ways to screen for NSSI and interventions that can be implemented in the Emergency Department. We illustrate the complexity of NSSI with the case of a young patient with a complex psychiatric history and an extensive history of self-injury. Results and Discussion: Despite the seeming intractability of NSSI, a number of evidencebased treatments exist. Treatment primarily involves specialized forms of psychotherapy, but interventions can be implemented in the ED that will reduce the immediate risk of NSSI while more definitive intervention is awaited. Conclusion: Mental health consultations in the ED should always include screening for NSSI. Mental health professionals in the ED can play an important role in the detection and treatment of this condition.

When actions speak louder than words: Using changes in operator behavior and system efficiency measures to detect the presence of a cyber attack

Increases in cyber incidents have required substantial investments in cyber defense for national security. However, adversaries have begun moving away from traditional cyber tactics in order to escape detection by network defenders. The aim of some of these new types of attacks is not to steal information, but rather to create subtle inefficiencies that, when aggregated across a whole system, result in decreased system effectiveness. The aim of such attacks is to evade detection for long durations, allowing them to cause as much harm as possible. As a result, such attacks are sometimes referred to as “low and slow” (e.g., Mancuso et al., 2013). It is unknown how effective operators are likely to be at detecting and correctly diagnosing the symptoms of low and slow cyber attacks. Recent research by Hirshfield and colleagues (2015) suggests that the symptoms of the attack may need to be extreme in order to gain operator recognition. This calls into question the utility of relying on operators for detection altogether. Therefore, one goal for this research was to provide an initial exploration of attack deception and magnitude on operator behavior, performance, and potential detection of the attack. Operators in these systems are not passive observers, however, but active agents attempting to further their task goals. As a result, operators may alter their behavior in response to degraded system capabilities. This suggests that changes in the pattern and frequency of operator behavior following the inception of a cyber attack could potentially be used to detect its onset, even without the operator being fully aware of those changes (Mancuso et al., 2014). Similarly, since low and slow attacks are designed to degrade overall system effectiveness, performance measures of system efficiency, such as frequency and duration of tasks completed, may provide additional means to detect an ongoing cyber attack. As such, a second goal for the present research was to determine whether changes in operator behavior and system efficiency metrics could act as indicators of an active low and slow cyber attack. Participants in this experiment performed a multiunmanned aerial vehicle (UAV) supervisory control task. During the task, participant control over their UAVs was disrupted by a simulated cyber attack that caused affected UAVs to stop flying toward participant- selected destinations and enter an idle state. Aside from halting along their designated flight path, idled UAVs displayed no other indication of the cyber attack. The frequency of cyber attacks increased with time-on-task, such that attacks were relatively infrequent at the beginning of the task, occurring once in every five destination assignments made, and were ubiquitous by the end of the task, occurring after each destination assignment. Attack deception was manipulated with regard to participants’ approximate screen gaze location at the time of a cyber attack. In the overt condition, UAVs entered the idle state near the participant’s current focal area (indexed by the location of operator mouse interactions with the simulation), thereby providing some opportunity for operators to directly observe the effects of the cyber attack. In the covert condition, the attack occurred outside the operator’s current focal area, forcing them to rely on memory to detect the cyber attack. In the control condition, no cyber attacks occurred during the experiment. Following the UAV supervisory control task, participants were asked a series of debriefing questions to determine if they had noticed the UAV manipulation during the task. Most participants (approximately 64%) reported noticing the manipulation, but only after a series of questions prompting them to think of any problems they encountered during the task. The remaining participants reported noticing no errors during the task. Results regarding measures of performance and system efficiency indicated that performance decreased as the magnitude of the cyber attack increased. Measures of efficiency were calculated using fan-out (Olsen & Goodrich, 2003) which provided information regarding how many UAVs operators were able to control and how long UAVs were in an idle state during the trial. Operators controlled fewer vehicles, and vehicles sat idle for longer durations, as the magnitude of the cyber attack increased. However, these differences in efficiency were not statistically significantly different until relatively late in the trial. Overall, operators seemed insensitive to the presence of the cyber attack, only disclosing the problem after being prompted several times through guided questions by the experimenter. However, significant changes in operator behavior and system efficiency were observed as the magnitude of the cyber attack increased. These results demonstrate that subtle cyber attacks designed to slowly degrade human performance were measurable, but these changes were not apparent until late in the experiment when the attack was at its midpoint in magnitude. This experiment suggests that even though measurable changes in operator behavior may not occur until late in an attack, these metrics are more effective than reliance on operator detection.

Cerebral Venous Sinus Thrombosis Masquerading as High Altitude Cerebral Edema at Extreme Altitude

Introduction: Extreme altitude travel has gained popularity globally for adventurous, scientific, and military endeavors. Cerebral venous sinus thrombosis (CVST) at extreme altitude is a rare, covert, and emergent condition requiring immediate intervention. Case Presentation: A case of CVST masqueraded as high altitude cerebral edema (HACE) at 6700 m/22000 ft in Karakoram Himalayas. Atypical oligosymptomatic presentation along with terrain, weather, and communication restrictions complicated diagnosis and management, leading to demise. CVST, confirmed on autopsy, was not associated with any pre-existing risk factors. Conclusion: CVST at extreme altitude can occur spontaneously due to prolonged hypobaric hypoxia which can precipitate thrombosis through capillary damage, haemoconcentration, and a hypercoagulable state.

Young People Smokers’ Reactions on Peer Influence Not to Smoke

ABSTRACTBackground: Peers exert influence not to smoke but little is yet known on how this affects young people's behavior and cognitions. Objectives: This experimental study investigates the impact of two types of peer influence not to smoke on the verbalized attitudes and responses of daily-smoking young people. Methods: Two conditions were conducted: 1) a peer confederate stating three times that s/he had quit smoking and was glad to have done so (covert peer influence); 2) a peer confederate making similar statements, but urging to quit smoking (overt peer influence). The participant performed a music task with the peer in order to disguise the true nature of the experiment. Thirty-one daily-smoking young people (16–24 years) participated; 44 responses in the overt and 34 responses in the covert condition were analyzed in a discourse analysis. Results: The participants in the covert condition were more elaborative about smoking, i.e., taking an active role in a dialogue about the experiences of the peer or the participant in quitting smoking while in the overt condition participants showed more passive resistance, i.e., not showing an intention to follow the advice but avoid causing the peer embarrassment or discomfort. Open resistance, i.e., demonstration of being well-informed and indicating the redundancy of the advice, does not significantly differ in these two conditions but occurs, for both, primarily at the third discouragement. Conclusions: Overt and frequent discouragement seems to be less effective in stimulating young people to take an active role in the dialogue with their peers about smoking.

Decoding spectrotemporal features of overt and covert speech from the human cortex.

Auditory perception and auditory imagery have been shown to activate overlapping brain regions. We hypothesized that these phenomena also share a common underlying neural representation. To assess this, we used electrocorticography intracranial recordings from epileptic patients performing an out loud or a silent reading task. In these tasks, short stories scrolled across a video screen in two conditions: subjects read the same stories both aloud (overt) and silently (covert). In a control condition the subject remained in a resting state. We first built a high gamma (70–150 Hz) neural decoding model to reconstruct spectrotemporal auditory features of self-generated overt speech. We then evaluated whether this same model could reconstruct auditory speech features in the covert speech condition. Two speech models were tested: a spectrogram and a modulation-based feature space. For the overt condition, reconstruction accuracy was evaluated as the correlation between original and predicted speech features, and was significant in each subject (p < 10−5; paired two-sample t-test). For the covert speech condition, dynamic time warping was first used to realign the covert speech reconstruction with the corresponding original speech from the overt condition. Reconstruction accuracy was then evaluated as the correlation between original and reconstructed speech features. Covert reconstruction accuracy was compared to the accuracy obtained from reconstructions in the baseline control condition. Reconstruction accuracy for the covert condition was significantly better than for the control condition (p < 0.005; paired two-sample t-test). The superior temporal gyrus, pre- and post-central gyrus provided the highest reconstruction information. The relationship between overt and covert speech reconstruction depended on anatomy. These results provide evidence that auditory representations of covert speech can be reconstructed from models that are built from an overt speech data set, supporting a partially shared neural substrate.

Potential mutations associated with occult hepatitis B virus status.

Context:Occult hepatitis B virus (HBV) status (OHBS) is simply defined as the presence of HBV DNA in the liver (with or without detectable HBV DNA in the serum), in the absence of serum HBV surface antigen (HBsAg). Importance of OHBS is mostly clinical, related to its possible role in spreading through blood transfusion and liver transplantation; causing classic forms of HBV. Mechanisms underlying this entity are poorly defined. Several possibilities have been suggested, with major classification into two groups: defective host immune response and viral replication activity through mutations of HBV DNA sequence. Mutations are extensively investigated in all four overlapping open reading frames (ORFs) of HBV genome, to define their possible role in the pathogenesis of OHBS. Some of these mutations like S-escape mutants could not be detected by the routine available assays, making them difficult to diagnosis. Therefore, trying to detect this covert condition could be more helpful for defining better preventive and therapeutic strategies.Evidence Acquisition:In the present study we provided an in-depth review of the most important new data available on different mutations in HBV genome of patients with OHBS, which may play a role in the pathogenesis of OHBS. The data were collected through reviewing the full-text articles, identified by the PubMed search, using the following keywords and their different combinations: occult hepatitis B, HBV genome, "a" determinant, HBV open reading frames, S mutations, X mutations, P mutations and C mutations.Results:Variants within the major hydrophilic region (MHR) of the HBsAg, deletions in the pre-S1region, codon stop in the S open reading frames (ORF), sporadic non common mutations, some mutations affecting the posttranslational production of HBV proteins in the S ORF like deletion mutations, mutations in start codon and nucleotide changes in the X ORF, deletion and point mutations in P ORF and sometimes, nucleotide substitution in the C ORF are among the assumed mutations detected to have a role in OHBS appearance.Conclusions:Studies mostly lacked a control group and the whole-length HBV sequencing was scant with conflicting results, suggesting that OHBS is often a result of multiple mechanisms. Additional studies on full-length HBV genomes from occult and non-occult HBV cases may shed more light on the interplay between different mechanisms involved in the pathogenesis of OHBS.

Presence and Duration of Reactivity to Pedometers in Adults

This study aimed to examine the presence and duration of reactivity to wearing a pedometer and recording daily step counts in free-living adults. On the first visit to the laboratory, 90 participants (69% were females, age = 26.8 ± 13.0 yr, body mass index = 23.4 ± 4.0 kg·m(-2)), blinded to the study aim, were provided with a sealed pedometer (New Lifestyles NL-800) and informed that it was a "body posture monitor" (covert condition). Participants wore the pedometer throughout waking hours for 1 wk. On their return to the laboratory, stored step counts were recorded, and participants were informed that the device was a pedometer. Participants wore the pedometer unsealed (no restriction on viewing the step count display) for 2 wk, during which they recorded their daily step count in a diary (diary condition). Mean daily step counts recorded during the covert condition and during weeks 1 and 2 of the diary condition were compared using a repeated-measures ANOVA. There was a significant overall effect of study condition (P < 0.001), with post hoc analyses revealing that mean daily step counts reported during the first week of the diary condition (9898 ± 3002 steps per day) were significantly higher than those reported during the covert condition (8331 ± 3010 steps per day) and during the second week of the diary condition (8226 ± 3170 steps per day, P < 0.001). Reactivity to wearing unsealed pedometers and step count recording seems to last for 1 wk. In the absence of any intervention material, step counts return to normal levels during the second week of monitoring and therefore represent a more accurate estimate of habitual activity. These findings have important implications to both researchers and practitioners interested in the use of pedometers for physical activity surveillance and promotion.

TEL-AML1 Affects the Regulation of Cytoskeleton and Causes Alteration In Cellular Adhesive and Migratory Properties In An In Vitro Model of Pre-Leukemia.

AbstractAbstract 3624 Introduction:The t(12;21) chromosome translocation generating TEL-AML1 chimeric fusion gene is a frequent initiating event in childhood leukaemia. Its impact is to generate a clone of covert, clinically silent pre-leukemic B cell progenitors. The leukemia arises only following second, post-natal hit/genetic events occurring years later. Moreover, relapse of leukemia is frequently arising from the pre-leukemic clone. Aimof our study is to investigate how TEL-AML1 expression can sustain this covert condition for many years. In a recent paper we described that the fusion gene rendered the B precursors resistant to the inhibitory activity of TGFbeta. Here we want to inquire into other factors that can explain the positive selection of the pre-leukemic clones over the normal counterpart. In particular, given the importance of the interaction with the microenvironment for survival signals for normal and leukemic stem cells, we question if the fusion gene causes changes in cellular adhesive and migratory properties. Methods:the study was performed by using two different models: i) a TEL-AML1 inducible expression system on the murine pro-B Ba/F3 cell line and ii) murine primary B lymphocytes (pre-BI cells) isolated from fetal liver, stably transduced with the pMIGR1-TEL-AML1-IRES-GFP construct. Gene expression assays were performed by using TaqMan (Applied Biosystems) and PCR Array technologies (SABioscences). Results:The expression of TEL-AML1 in Ba/F3 cell line causes over-expression of genes regulators of the cytoskeleton, specifically involved in cellular movement and in the regulation of actin dynamics. This gene expression alteration results in changes in the cellular morphology and phenotype: the cells acquire long extensions and several molecules involved in cell adhesion and migration are disregulated. Moreover, the TEL-AML1 positive cells present an increased ability to adhere to the ICAM1 substrate, but they also show a significant defect in the chemotactic response to CXCL12 in transwell migration assays in vitro, although the expression and the recycling of CXCR4 receptor are unaffected. This inability is not due to defects to migrate in general, as spontaneous motility is enhanced, but it is associated with a defect in CXCR4 signaling. In particular, CXCL12 calcium flux and ERK phosphorylation were inhibited. Those results have been confirmed in murine PreBI primary cells. Conclusions:in our murine models, TEL-AML1 affects the cytoscheleton regulation and causes alteration in cellular adhesive and migratory properties. We are now investigating how these alterations can give advantages to the pre-leukemic cells in the pathogenesis of TEL-AML1–expressing leukemia. Disclosures:No relevant conflicts of interest to declare.

'A hidden disorder until the pieces fall into place'--a qualitative study of vaginal prolapse.

BackgroundVaginal prolapse affects quality of life negatively and is associated with urinary, bowel, and sexual symptoms. Few qualitative studies have explored women's experiences of vaginal prolapse. The objective of the study was to elucidate the experiences of living with prolapse and its impact on daily life, prior to surgical intervention.MethodsIn-depth interviews were conducted with 14 women with vaginal prolapse, prior to surgical treatment. Recruitment of the informants was according to 'purposive sampling'. An interview guide was developed, including open-ended questions addressing different themes, which was processed and revised during the data collection and constituted part of a study-emergent design. Data were collected until 'saturation' was achieved, that is, when no significant new information was obtained by conducting further interviews. Interviews were audiotaped, transcribed verbatim, and analyzed according to manifest and latent content analysis.ResultsThe theme defining the process of living with prolapse and women's experiences was labelled 'process of comprehension and action'. The findings constitute two categories: obstacles and facilitators to seeking health care. The category obstacles comprises six subcategories that define the factors restraining women from seeking health care: absence of information, blaming oneself, feeling ignored by the doctor, having a covert condition, adapting to successive impairment, and trivializing the symptoms and de-prioritizing own health. The category facilitators include five subcategories that define the factors promoting the seeking of health care: confirmation and support by others, difficulty in accepting an ageing body, feeling sexually unattractive, having an unnatural body, and reaching the point of action.ConclusionThe main theme identified was the 'process of comprehension and action'. This process consisted of factors functioning as either obstacles or facilitators to seeking health care. The main obstacles described by the participants were lack of information and confirmation. The main facilitators constituted feeling sexually unattractive and impaired physical ability due to prolapse. Information on prolapse should be easily accessible, to improve the possibility for women to gain knowledge about the condition and overcome obstacles to seeking health care. Health care professionals have a significant role in facilitating the process by confirming and informing women about available treatment.

Occult hepatitis B virus infection: a covert operation

Detection of occult hepatitis B requires assays of the highest sensitivity and specificity with a lower limit of detection of less than 10 IU/mL for hepatitis B virus (HBV) DNA and <0.1 ng/mL for hepatitis B surface antigen (HBsAg). This covert condition is relatively common in patients with chronic hepatitis C virus (HCV) that seems to exert some influence on the replicative capacity and latency of HBV. Detection of virus-specific nucleic acid does not always translate into infectivity, and the occurrence of primer-generated HBV DNA that is of partial genomic length in immunocompetent individuals who have significant levels of hepatitis B surface antibody (anti-HBs) may not be biologically relevant. Acute flares of alanine aminotransferase (ALT) that occur during the early phase of therapy for HCV or ALT levels that remain elevated at the end of therapy in biochemical nonresponders should prompt an assessment for occult hepatitis B. Similarly, the plasma from patients with chronic hepatitis C that is hepatitis B core antibody (anti-HBc) positive (+/-anti-HBs at levels of <100 mIU/mL) should be examined for HBV DNA with the most sensitive assay available. If a liver biopsy is available, immunostaining for hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) should be contemplated and a portion of the sample tested for HBV DNA. This is another reason for optimal collection of a specimen (e.g. two passes with a 16-guage needle under ultrasound guidance). Transmission of HBV to immunosuppressed orthotopic liver transplant recipients by donors with occult hepatitis B (OHB) will continue to occupy the interests of the transplant hepatologist. As patients with OHB may have detectable HBV DNA in serum, peripheral blood mononuclear cells (PBMC) and/or liver that can be reactivated following immunosuppression or intensive cytotoxic chemotherapy, the patient needs to be either monitored or treated depending on the pretreatment serological results such as an isolated anti-HBc reaction or a detectable HBV DNA.

A comparison of brain activation patterns during covert and overt paced auditory serial addition test tasks

The Paced Auditory Serial Addition test (PASAT) is a sensitive task for evaluating cognitive impairment in patients with diffuse brain disorders, such as multiple sclerosis patients. Brain areas involved in this task have been investigated in diverse fMRI studies using different methodologies to control the subjects' responses during scanning. Here, we examined the possible differences between overt and covert responses during the PASAT task in 13 volunteers. Results showed similar activations in parietal and frontal brain areas during both versions of the task. The contrast between the two conditions (overt and covert) indicated that differences in these two methodologies were minimal. Unlike the covert condition, the overt version of the task obtained significant activations in the left superior and inferior frontal gyrus, bilateral occipital cortex, caudate nucleus and cerebellum. As expected, no significant overactivations were observed in the covert when compared with the overt condition. Discussion focuses on the lower cost of using verbal responses to monitor performance during the PASAT task, which might be generalisable to other frontal lobe tasks requiring discrete responses.

Differential neural responses to overt and covert presentations of facial expressions of fear and disgust

There is debate in cognitive neuroscience whether conscious versus unconscious processing represents a categorical or a quantitative distinction. The purpose of the study was to explore this matter using functional magnetic resonance imaging (fMRI). We first established objective thresholds of the critical temporal parameters for overt and covert presentations of fear and disgust. Next we applied these stimulus parameters in an fMRI experiment to determine whether non-consciously perceived (covert) facial expressions of fear and disgust show the same double dissociation (amygdala response to fear, insula to disgust) observed with consciously perceived (overt) stimuli. A backward masking paradigm was used. In the psychophysics experiment, the following parameters were established: 30-ms target duration for the covert condition, and 170-ms target duration for the overt condition. Results of the block-design fMRI study indicated substantial differences underlying the perception of fearful and disgusted facial expressions, with significant effects of both emotion and target duration. Findings for the overt condition (170 ms) confirm previous evidence of amygdala activation to fearful faces, and insula activation to disgusted faces, and a double dissociation between these two emotions. In the covert condition (30 ms), the amygdala was not activated to fear, nor was the insula activated to disgust. Overall, findings demonstrate significant differences between the neural responses to fear and to disgust, and between the covert presentations of these two emotions. These results therefore suggest distinct neural correlates of conscious and unconscious emotion perception.

Self-Report Bias and Underreporting of Depression on the BDI-II

One problem in identifying and treating depression is underreporting of symptoms by individuals. Previous research suggests that there may be systematic sex differences in self-report bias, with men tending to minimize their depressive symptoms more than women. This study used an experimental design with a sample of 238 community members to test whether disguising the purpose of the Beck Depression Inventory-II would significantly reduce self-report bias, especially in men. We found a main effect of condition such that both men and women reported significantly more core depressive symptoms in the covert condition, suggesting that surveys of community samples may underestimate the prevalence of depression.

An Event-Related fMRI Study of Overt and Covert Word Stem Completion

In fMRI studies of language processing, it would be extremely useful to obtain high-quality images during tasks requiring spoken output. Recent studies have suggested that this may be possible, particularly if event-related fMRI methods are used. This study assesses the feasibility of acquiring interpretable images during speech by applying event-related methods to visual word stem completion, a task that has been studied extensively. On each trial, a different three-letter word stem (e.g., COU) was presented visually and subjects were required to generate a word beginning with that stem (e.g., COUSIN). In covert runs, subjects were instructed to say the word once to themselves, without moving their lips. In overt runs, subjects were instructed to say the word once aloud. Ten subjects were scanned during six overt runs and six covert runs at three presentation rates. Data were analyzed using an implementation of the general linear model making no assumptions about response shape. Images were relatively free of artifacts, and regions demonstrating task-related activation were similar to those reported in previous imaging studies. Regions active during overt task performance were similar to those active during covert task performance, with the addition of several regions commonly associated with motor aspects of speech production. Consistent with other studies, magnitude of activation was greater in the overt condition than in the covert condition, and there was a modest decrease in magnitude at the fastest presentation rate. Together, these results help to validate the use of event-related fMRI during tasks that require spoken output.

Overt vs covert problem solving, transfer effects, and programming sequence: I: Inverted triangles.

129 college students were individually requested to successively turn 2 of 3 upright triangles upside-down. Triangle consists of 3 rows of coins: 1 on top, 2 in the middle, and 3 at the bottom. Only 2 coins may be relocated. Triangle B has 4 rows with 4 coins at the bottom. Only 3 coins may be moved. Triangle C is arranged in 5 rows with 5 coins at the bottom. Only 5 coins are allowed to change places. Analysis shows (a) Problem A is the easiest, B in between, and C the hardest. (b) Overt manipulation is more efficient than a covert method. (c) Transfer in all cases is positive, the amount increasing with difficulty of the preceding problem. (d) From easy to difficult problems is more economical than the opposite sequence as measured by the total time required to solve both problems. The advantage is a little greater under the overt than the covert condition.

A Comparison of Covert and Overt Assessment Procedures in Stuttering Therapy Outcome Evaluation

This study aimed to compare covert and overt assessments in outcome evaluation of an adult stuttering therapy program. Three situations (talking with strangers, with familiars, and on the telephone) in which nine subjects attained fluency within the therapy program were used to evaluate speech behavior three months and six months after treatment. In each situation, an overt and covert recording was made of each subject’s speech behavior. Percentage of stuttered syllables spoken and rate of speech of the group showed changes that were associated with the difference in assessment conditions. At three months after treatment, there was a small but significant increase in stuttering and reduction in speech rate during the covert condition. At six months this trend remained although differences in percentage syllables stuttered under both conditions were not significant. The findings suggested that, for some subjects, fluency attained under overtly recorded conditions may be illusory and, by implication, could give a false impression of the efficacy of therapy.

Cardiac activity preparatory to overt and covert behavior.

The heart rates of 17 women subjects were recorded as they prepared to make both overt (key press) and covert (silently thinking the word "stop") responses. A very reliable preparatory cardiac response was obtained regardless of whether the overt or covert response mode was employed. The temporal development of this cardiac response faithfully reflected the speed with which the subjects were asked to respond, suggesting that in the covert condition heart rate could be used to detect the time at which a mental event was being generated.

The developmental control of operant motor responding by verbal operants

The developmental control of operant motor responding (tapping response) by the verbal operants “faster” and “slower” was examined with 54 kindergarten and 30 first grade children. The effects of the verbal operants on motor behavior were assessed under three conditions: E verbalized the verbal operants; S said the verbal operants to themselves aloud; S whispered the verbal operants using only lip movements (approximating a covert condition). The major finding was an interaction between age and mode of delivery in controlling motor behavior. Kindergarten children's motor performance approximated first grade children when self-verbalizations were overt, but covert self-instructions had minimal functional control over motor behavior. First-grade children's self-verbalizations had more functional control over motor behavior when covert than overt. The results suggested a developmental sequence of the functional interaction between speech-for-self and nonverbal operants.