Low-noise microvolt level calibrator for measurement of performance of biosignal recording systems

A calibrator, the noise level of which is below the noise level generated in the preamplifier system, was needed for testing and development of a multichannel recording system. A multichannel preamplifier head assembly was used for recording cortical, subcortical, and cerebellar slow potentials and multiunit activity in freely moving cats and restrained rabbits. An inexpensive, battery-powered, lownoise voltage signal generator for calibration of the preamplifiers is described. The circuit provides a square-wave output at a frequency of 10 or 1000 Hz, and the peak-to-peak (p-p) amplitude can be selected at 10, 100, or 1000µV. The measured output noise of the calibrator is below 2µV (p-p, 0.1–6000 Hz). The frequency and amplitude values can be easily adapted for different purposes by changing a few component values. An amplified (gain 1,000×) test output for direct oscilloscope monitoring is included in the calibrator circuit.     

The effect of adaptation on odor detection

The sensitivity of human Ss to a weak odor (hydrogen sulphide) following prior exposure to it varying in both duration (0–5 min) and concentration (4.05 × 10^?7 to 24.40 × 10^?7 mg/liter) was studied with a yes-no detection method and a specially designed olfactometer. The effect of adaptation was demonstrated, because the proportion of hits was lower the higher the concentration of the adaptation stimulus, when the response criterion, as measured by the proportion of false alarms, was fairly constant. By contrast, the proportion of hits was apparently independent of the duration of the exposure to the adaptation concentration. This finding suggests that the sense of smell is more stable than is usually believed. The paper ends with a discussion of the importance of considering adaptation in contemporary detection theory.     

Olfactory adaptation and recovery in man as measured by two psychophysical techniques

Olfactory adaptation and recovery was investigated in man, using two psychophysical procedures: modified category scaling and threshold detection. Both procedures yielded similar qualitative information regarding loss and recovery of olfactory sensitivity as a function of time and concentration of adapting stimuli. However, quantitative differences were observed that could be partially attributed to artifacts inherent in each procedure. Often more than 50% adaptation (and recovery) occurred within the first 2 min with either test procedure. In all experiments the rate of adaptation and recovery was greater at the higher of two adapting concentrations (10 × and 20 × the detection threshold I_t). Recovery occurred more rapidly than adaptation. The usefulness of both techniques is discussed in terms of the overall problem of characterizing the olfactory adaptation and recovery process in man.     

Retention and thermal desorption of helium in pure tungsten

Tungsten (W) is cited as a candidate first-wall material in fusion reactors owing to its outstanding thermal properties and erosion resistance. An important issue is that the energetic isotopes of hydrogen, tritium (T) and deuterium (D) and helium (He) particles damage the surface of W in fusion reactors. He particles cause more notable damage than D or T because the binding energy of defects and He is larger than that of defects and D or T. In this study, well-annealed W specimens were implanted with 5 keV He ions at room temperature and irradiation dosages of 1.0 × 10²⁰ and 2.5 × 10²¹ ions/m². Then, thermal desorption spectroscopy analysis was performed by heating the samples to 1973 K at a ramping rate of 0.5 K/s. Thermal desorption of He in the sample irradiated with a low dosage occurred at 1400 and 1960 K, whereas that in the sample irradiated with a high dosage occurred at 740, 1050 and 1500 K. According to the microstructures observed using transmission electron microscopy, both peaks in the former case were attributed to He de-trapping from irradiation to nduced helium-vacancy clusters of different sizes, whereas the peaks in the latter case were attributed to He de-trapping from surface defects, irradiation-induced dislocation loops and tiny helium-vacancy clusters, respectively.     

Foster Care Children’s Kinship Involvement and Behavioral Risks: A Longitudinal Study

Researchers have found that individual strengths (e.g., coping, optimism) are protective against behavioral risk (e.g., delinquency, suicide) among traumatized youth in foster care. However, less is known about kinship involvement (i.e., extended family support) as a social strength that can also attenuate the effects of childhood trauma, thereby reducing behavioral risk. Addressing the lack of research on kinship involvement, the present longitudinal study investigated individual strengths (IS) and kinship involvement (KI) as moderators between trauma experiences (TE) and risk behaviors (RB) among 336 youth, ages 6 to 13, who entered the Illinois child welfare system between 2011 and 2014. Controlling for Time 1 (T1) RB, T1 IS, age, gender, and ethnicity, we utilized a three-level Hierarchical Generalized Linear Model to analyze TE?×?KI and TE?×?IS at T2. The study found that KI was negatively associated with RB (β16?=??.08, Event Rate Ratio [ERR]?=?0.92, p?=?<.01), suggesting that youth with more KI had relatively lower RB trajectories. Further, the TE?×?IS interaction was significant in the model (β21?=??.05, ERR?=?0.95, p?<?.01); TE was positively associated with RB at lower levels of IS but not higher levels of IS. These results highlight the importance of assessing children’s kinship networks and individual strengths early in foster care.     

Cognitive Behavioral Training Using a Mobile Application Reduces Body Image-Related Symptoms in High-Risk Female University Students: A Randomized Controlled Study

Body dissatisfaction is prevalent in young women, and is associated with symptoms of body dysmorphic disorder (BDD) and eating disorders (EDs). The aim of the study was to assess the efficacy of a mobile application, based on cognitive behavioral principles, in reducing body dissatisfaction and BDD/ED symptoms in female university students considered at high-risk of developing body image disorders (BIDs). Fifty university students at high-risk of developing BIDs (using self-report questionnaires assessing BIDs and the Structured Clinical Interview for DSM-5 Clinical Version) were randomized in two groups: immediate-use App group (iApp group; n = 25) and delayed-use App group (dApp group; n = 25). The iApp group started using the app at baseline for 16 days (T0 to T1). The dApp group waited for 16 days before starting to use the app (T1 to T2). Participants completed questionnaires at baseline (T0), 16 days from baseline (T1), and 32 days from baseline (T2). Repeated measure Analyses of Variance (ANOVAs) showed a Group (iApp vs. dApp) × Time (T0 vs. T1) interaction on BDD symptoms indicating medium effect size (partial eta squared) reductions in the iApp group compared to dApp group at T1; post-intervention means for BDD symptoms were under the cut-off for extreme body dissatisfaction/BDD symptoms in both groups. Pertaining to ED symptoms, no significant Group × Time interaction was detected. Training 3 minutes a day for 16 days with a CBT-based mobile application may lead to reductions in some forms of body dissatisfaction, including BDD symptoms in female university students at high-risk of developing BIDs. On the other hand, effects of the intervention on ED symptoms seem more limited.     

Right Hemisphere Positivity Bias in Preconscious Processing: Data From Five Experiments

Using a signal detection paradigm, participants’ sensitivity to emotionally toned stimuli was evaluated in five experiments. A tachistoscope was used to present stimuli to one hemisphere at a time, too rapidly for conscious identification. Pictures, words, and faces were pretested for emotional valence and familiarity. Stimulus selection was based on obtaining the largest possible difference between the positive and negative valence ratings, keeping familiarity equal. Each experiment used a 2×2×2 mixed groups design. The within-subject variables were the hemispheric presentation (right and left) and the emotional tone of the stimuli (positive and negative). Gender of the participant was the between-subjects variable. The results of these studies indicate greater sensitivity in the right than in the left hemisphere, and greater sensitivity to positive than to negative stimuli. Interpretations focus on the automatization of affect and the brain lateralization of emotional processing.     

Depressive rumination and the C957T polymorphism of the DRD2 gene

Depressed individuals who ruminate have difficulties learning from punishment and suppressing task-irrelevant information. The C957T polymorphism of the DRD2 gene, which affects functioning of D2 dopamine receptors (DRD2) that are expressed predominantly in the indirect pathway of the basal ganglia, has been found to influence suppression and punishment learning. Given these associations, we examined in the present study whether depressive rumination is related to the C957T polymorphism in 317 clinically depressed individuals and 317 never-depressed control individuals. A 2 × 2 (diagnostic group ×C957T polymorphism) analysis of variance conducted on depressive rumination scores yielded a significant interaction of group and C957T: Individuals with two 957C alleles reported higher levels of depressive rumination than did individuals with one or two 957T alleles if they were depressed, but not if they were healthy. The present findings suggest that the dopaminergic system and DRD2 are related to the frequency of maladaptive rumination in depressed individuals. Thus, DRD2 may be an important target for the pharmacological treatment of depressive rumination.     

Right Hemisphere Positivity Bias in Preconscious Processing: Data From Five Experiments

Using a signal detection paradigm, participants’ sensitivity to emotionally toned stimuli was evaluated in five experiments. A tachistoscope was used to present stimuli to one hemisphere at a time, too rapidly for conscious identification. Pictures, words, and faces were pretested for emotional valence and familiarity. Stimulus selection was based on obtaining the largest possible difference between the positive and negative valence ratings, keeping familiarity equal. Each experiment used a 2×2×2 mixed groups design. The within-subject variables were the hemispheric presentation (right and left) and the emotional tone of the stimuli (positive and negative). Gender of the participant was the between-subjects variable. The results of these studies indicate greater sensitivity in the right than in the left hemisphere, and greater sensitivity to positive than to negative stimuli. Interpretations focus on the automatization of affect and the brain lateralization of emotional processing.     

Interaction of attention and temporal object priming

Within a 3 × 3 matrix of 90° corner junctions, detection of a Kanizsa-type square is facilitated when the target display is preceded by a 40-Hz flickering premask of 3 × 3 crosses, with four crosses synchronously oscillating at the subsequent target location. To examine whether this ‘synchrony-priming’ effect is influenced by, or dependent on, visuo-spatial attention, a spatial-cueing manipulation was introduced. Observers were presented with a visual or acoustic cue which indicated the likely target quadrant. The main finding was that synchrony priming was larger for invalidly, compared with validly, cued locations, and that the priming effect was figural, rather than spatial, in nature (i.e., confined to points associated with the completed boundary, rather than extending to the inner region, defined by the synchronous premask elements). This pattern of effects argues that target processing is expedited not by attracting spatial attention to the primed location, but by the prime expediting (figure-specific) target encoding, as a result of which the target position gains a processing and selection advantage relative to non-primed locations.     

Perceived probability and evaluation of balance,agreement, and attraction: Toward a solution of conflicting results

Fifty-four subjects rated sixteen hypothetical situations on four evaluative and four probability scales. The situations were of the P-O-X type, consisting of two persons and an issue. A2×2×2×2 factorial design was used to test the relative importance of attitude (P to × relation), issue (marijuana or premarital sex), agreement (P to × and O to × relations), attraction (P to O relation), and balance (agreement × attraction interaction) on the evaluation and probability variables. As predicted from a critical review of past research on balance theory, balance was the main determinant of perceived probability. Attraction was the main determinant of evalution. In light of a review of past balance research and of the present data, we propose to restrict the balance hypothesis to cognitive variables, i.e., expectancy and perceived probability. In addition, support was obtained for the hypothesis that the more dogmatic a person is, the more frequently he will perceive balanced relationships as occurring and the more positively he will evaluate balanced situations.     

Judgment Processes Relevant to Drunk Driving1

The present study uses psychological theories of judgment and decision making in analyzing cognitions relevant to drunk driving decisions. Four groups of individuals were examined: (a) those having multiple convictions for drunk driving, (b) those having one conviction for drunk driving, (c) those never having been convicted of drunk driving but, who admit to having driven while intoxicated, and (d) those who drive, but claim to not have driven while intoxicated. Cognitions examined included perceived drunkenness relative to legally allowable blood alcohol levels for driving, perceived probabilities for being stopped and arrested and being involved in an automobile accident if driving drunk, and drunk driving tendencies. Perceived probabilities of being stopped and arrested and being involved in an accident were evaluated as a function of manipulations of 4 cues in a 2 × 2 × 4 × 3 factorial design (Distance to Destination × Weather and Road Conditions × Number of Drinks × Time to Consume). Perceived drunkenness was evaluated as a function of the manipulations of two cues in a 4 × 3 factorial design (Number of Drinks Consumed × Time to Consume). Results indicated the presence of several misperceptions and inappropriate response tendencies that potentially can be modified with educational efforts. These results are discussed in terms of the differential impact of previous arrest for DWI on different DWI-related judgments.     

Age-Related Changes in Temporal Allocation of Visual Attention: Evidence From the Rapid Serial Visual Presentation (RSVP) Paradigm

The present study explored the temporal allocation of attention in groups of 8-year-old children, 10-year-old children, and adults performing a rapid serial visual presentation task. In a dual-condition task, participants had to detect a briefly presented target (T2) after identifying an initial target (T1) embedded in a random series of distractors. A single-condition control task required participants to detect T2 without first identifying T1. The attentional blink (AB) reflects impairments in T2 detection due to the previous identification of T1. Although the amplitude of the AB (difference in T2 detection performance between the single task and the dual task) was found to be similar across age groups, its temporal expression (as a function of the T1–T2 lag) differed across age groups. Our results revealed age-related changes a) in the duration of the first lag(s) sparing effect (longer in the younger age groups), b) in the peak position of the AB (temporal displacement toward later lags in the younger age groups), and c) in the width of the AB (T2 impairments occurring for T1–T2 intervals of 400 ms and 500 ms in 8-year-old children, 300 ms in 10-year-old children, and 200 ms and 300 ms in adults). We discuss these differences in terms of changes in the efficiency of perceptual selection and inhibitory processes (attentional gating mechanisms) during development.     

Using high frame rate CMOS sensors for three-dimensional eye tracking

A novel three-dimensional eye tracker is described and its performance evaluated. In contrast to previous devices based on conventional video standards, the present eye tracker is based on programmable CMOS image sensors, interfaced directly to digital processing circuitry to permit real-time image acquisition and processing. This architecture provides a number of important advantages, including image sampling rates of up to 400/sec measurement, direct pixel addressing for preprocessing and acquisition, and hard-disk storage of relevant image data. The reconfigurable digital processing circuitry also facilitatesin-line optimization of the front-end, time-critical processes. The primary acquisition algorithm for tracking the pupil and other eye features is designed around the generalized Hough transform. The tracker permits comprehensive measurement of eye movement (three degrees of freedom) and head movement (six degrees of freedom), and thus provides the basis for many types of vestibulo-oculomotor and visual research. The device has been qualified by the German Space Agency (DLR) and NASA for deployment on the International Space Station. It is foreseen that the device will be used together with appropriate stimulus generators as a general purpose facility for visual and vestibular experiments. Initial verification studies with an artificial eye demonstrate a measurement resolution of better than 0.1° in all three components (i.e., system noise for each of the components measured as 0.006° H, 0.005° V, and 0.016° T. Over a range of ±20° eye rotation, linearity was found to be <0.5% (H), <0.5% (V), and <2.0% (T). A comparison with the scierai search coil technique yieldednear equivalent values for the systemnoise and the thickness of Listing’s plane.     

Responses to visual,tactile and visual–tactile forward collision warnings while gaze on and off the road

The objective of the current driving simulator study (N = 20) was to assess brake reaction time (BRT) and subjective experiences of visual (V), tactile (T), and visual–tactile (VT) collision warnings when the drivers’ visual orientation was manipulated between four locations (i.e., road and three different mirror locations). V warning was a blinking light in a windscreen, T warning was implemented by a vibrating accelerator pedal, and VT warning was their synchronous combination. The results showed that all the warning stimuli were detected in 100% accuracy in all visual orientations, but T and VT warnings produced significantly faster BRTs when compared to V warning. It was found that BRT to V warning was the slowest while observing the furthermost side mirror. However, BRTs following T and VT warnings remained unaffected by the visual orientations. Both the objective BRT measurements and subjective evaluations indicated a superiority of T and VT warnings against a sole V warning, not only in general terms, but also separately for different visual orientations.     

Ethnicity,Idiocentrism–Allocentrism,and Intergroup Attitudes1

The study examined the relationships among ethnicity, idiocentrism–allocentrism and intergroup attitudes in Singapore. Thirty Malay and 30 Chinese students completed questionnaires which measured in-group and out-group attitudes and attitudes toward ethnic-based community development groups. Intergroup attitudes were analyzed by a 2 × 2 × 2 (Subject Ethnicity × Target Group Ethnicity × Idiocentrism–Allocentrism) analysis of variance. A 2 × 2 interaction revealed that both Malay and Chinese subjects expressed ethnocentric biases; however, planned comparisons indicated that this was due to the responses of allocentrics. A separate 2 × 2 (Subject Ethnicity × Idiocentrism-Allocentrism) ANOVA further revealed that allocentrics had more favorable attitudes toward ethnic-based community development groups than did idiocentrics.     

Cross‐Situational Learning of Phonologically Overlapping Words Across Degrees of Ambiguity

Cross‐situational word learning (XSWL) tasks present multiple words and candidate referents within a learning trial such that word–referent pairings can be inferred only across trials. Adults encode fine phonological detail when two words and candidate referents are presented in each learning trial (2 × 2 scenario; Escudero, Mulak, & Vlach, 2016a ). To test the relationship between XSWL task difficulty and phonological encoding, we examined XSWL of words differing by one vowel or consonant across degrees of within‐learning trial ambiguity (1 × 1 to 4 × 4). Word identification was assessed alongside three distractors. Adults finely encoded words via XSWL: Learning occurred in all conditions, though accuracy decreased across the 1 × 1 to 3 × 3 conditions. Accuracy was highest for the 1 × 1 condition, suggesting fast‐mapping is a stronger learning strategy here. Accuracy was higher for consonant than vowel set targets, and having more distractors from the same set mitigated identification of vowel set targets only, suggesting possible stronger encoding of consonants than vowels.     

Guilty knowledge versus innocent associations: Effects of trait anxiety and stimulus context on skin conductance

A simulated lie detection procedure was used to investigate skin conductance responsivity among self-reported skin responders. Subjects were grouped according to reported trait anxiety as measured by Lykken's Activity Preference Questionnaire and then engaged in either a mock crime or a neutral activity. The “crime” gave subjects “guilty knowledge,” and the neutral task provided “innocent associations” to relevant stimuli imbedded in each scenario. Subjects were then interrogated using Lykken's Guilty Knowledge technique. Anxiety classification, guilty vs. innocent treatment, and type of stimulus were manipulated in a 2 × 2 × (2) factorial design. Results for differential responsivity scores showed significant main and interaction effects. Low-anxiety subjects showed almost no effects, but highly anxious subjects responded strongly in the “guilty” rather than the “innocent” treatment. Contrary to previous findings, results showed a substantial—but qualified—relationship between self-reported anxiety and electrodermal responsivity. Also, the Guilty Knowledge technique with rank scoring yielded 97.5% correct classification.     

Perceptual automaticity in expert chess players: Parallel encoding of chess relations

A check detection task in a 5 × 5 section of the chessboard, containing a King and one or two potential checking pieces was employed. The checking status (i.e., the presence or absence of a check) and the number of attackers (one or two) were manipulated. It was found that the reaction time cost for adding a distractor was differentially greater inno trials thanyes trials for novice, but not for expert, chess players. In addition, we contrasted standard check detection trials with trials in which one of two attackers was cued (colored red) and the task was to determine the checking status of the cued attacker while ignoring the other attacker. We documented a Stroop-like interference effect on trials in which a cued nonchecking attacker appeared together with an attacker that was checking (i.e., incongruent). These findings suggest automatic and parallel encoding procedures for chess relations in experts.     

The Correspondence Between Attachment Dimensions and Prayer in College Students

Attachment theory applied to religious behavior suggests that at a given point in time, "avoidant" individuals (who experience discomfort with closeness) engage in less prayer overall, and less prayer during times of stress than nonavoidant individuals. Additionally, "anxious" individuals (who worry about abandonment) would be expected to engage in more help-seeking prayer than nonanxious individuals. To test these hypotheses in a college sample, the frequency of three types of prayer were individually regressed on avoidance, anxiety, anxiety × avoidance, stress, stress × avoidance, stress × anxiety, in addition to the control variables of age, church attendance during childhood and adolescence, gender, gender × avoidance, and gender × anxiety. The hypotheses were supported in so far as: (a) avoidance was significantly and negatively related to colloquial (conversational) and meditative (contemplative) prayer, (b) stress × avoidance showed the predicted relation to colloquial and meditative prayer, and (c) anxiety was a significant predictor of petitionary (materialistic help-seeking) prayer, only.