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The effects of a single 3-mg dose of melatonin on the postural control and cognitive performance of community-dwelling older adults were documented. The testing involved stepping down while performing a cognitive task (a Stroop test). Thirty-four older adults were recruited. Immediately before and 1 hr after taking a dose of melatonin, they completed a single-leg standing task after stepping down with and without a simultaneous Stroop test, and a double-leg standing task. The findings indicated a statistically significant increase in sway area under the dual-tasking condition after taking melatonin (p = .04) and the double-leg standing task (p = .018). However, cognitive performance per se was not affected by the melatonin. Melatonin impairs postural control in older adults but not cognitive performance.
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Here we report on MELD-SCH (MEgastudy of Lexical Decision in Simplified CHinese), a dataset that contains the lexical decision data of 1,020 one-character, 10,022 two-character, 949 three-character, and 587 four-character simplified Chinese words obtained from 504 native Chinese users. It also includes a number of word-level and character-level variables. Analyses showed that the reliability of the dataset is satisfactory, as indicated by split-half correlations and comparisons with other datasets. Item-based regression showed that both word-level and character-level variables contributed significantly to the reaction times and error rates of lexical decision. Moreover, we discovered a U-shape relationship between word-length and reaction times, which has not been reported in Chinese before. MELD-SCH can facilitate research in Chinese word recognition by providing high quality normative data and information of different linguistic variables. It also encourages researchers to extend their empirical findings, which are mostly based on one-character and two-character words, to words of different lengths.
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Linguística/métodos , Processos Mentais , Psicolinguística/métodos , Semântica , Vocabulário , Povo Asiático , Pesquisa Comportamental/métodos , Coleta de Dados , Tomada de Decisões , Feminino , Humanos , Masculino , Tempo de Reação , Reconhecimento Psicológico , Reprodutibilidade dos Testes , Tamanho da Amostra , Adulto JovemRESUMO
Teaching assistants (TAs) play an influential role in primary and secondary schools. But there is an absence in literature about the TA's efficacy, and to date no instrument is available for measuring TA's efficacy. The present study aims to develop and validate a scale (Teaching Assistant Efficacy Scale, TAES) for measuring TA's efficacy on identified capabilities. A total of 531 teaching assistants from Hong Kong schools participated in the survey. The multidimensional Rasch model was used to analyse the data. The results revealed that a 5-dimension structure of TA's efficacy was supported. The final 30-item version of TAES assesses TA's efficacy on learning support, teaching support, behaviour management, cooperation, and administrative support. The Rasch reliabilities for all five dimensions were around 0.90. The 6-category response structure worked well for the scale. Further research was recommended to validate and test the robustness of the TAES both in Hong Kong and elsewhere.
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Estudos de Avaliação como Assunto , Docentes/normas , Modelos Estatísticos , Psicometria , Humanos , Conceitos MatemáticosRESUMO
Genotyping is a common and necessary procedure performed on genetically modified animals to distinguish carriers from noncarriers of the variants of interest. Established methods involve collection of tissues such as tips of tails or notches of ears. Noninvasive methods have been described but not widely adopted for reasons including inertia to change, needs to adjust PCR protocols, and the lack of validation; noninvasive genotyping methods are a refinement on animal welfare, but questions remain regarding how they compare with invasive methods in terms of genotyping accuracy rate and reproducibility. To gain answers to these questions, we compared the detection accuracy of the transgene and determination of zygosity in B6;C3-Tg(Prnp-SNCA*A53T)83Vle and B6;C3-Tg(Prnp-SNCA*A53T)83Vle Snca tm1Mjff neonatal mice between tail biopsies and buccal swabs. Moreover, we weighed and observed mice following genotyping to see if any clinical differences can be discerned. Weight data did not support statistically significant differences in mice undergoing different genotyping procedures and control. No statistically significant difference was found between using buccal swabs or tail biopsies for genotyping with PCR or quantitative PCR. None of the pups swabbed was rejected by the dam. Our findings indicate that buccal swabbing is a more humane and feasible alternative to tail biopsies for high-throughput genotyping.
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Técnicas de Genotipagem , Reação em Cadeia da Polimerase , Cauda , Animais , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Técnicas de Genotipagem/veterinária , Técnicas de Genotipagem/métodos , Camundongos , Camundongos Transgênicos , Biópsia/métodos , Mucosa Bucal , Genótipo , Feminino , Camundongos Endogâmicos C57BL , Reprodutibilidade dos Testes , MasculinoRESUMO
This study investigated whether individuals with high autistic traits rely on psychoacoustic abilities in affective prosody recognition (APR). In 94 college students, Autism Spectrum Quotient (AQ) and psychoacoustic abilities were measured. Results indicated that higher AQ, higher rapid auditory processing (RAP), and maleness were associated with a lower APR accuracy for low-intensity prosodies. There was a strong positive association between RAP and APR for participants with high AQ, whereas low-AQ participants showed no such pattern. The findings suggest a reliance on psychoacoustic abilities as compensatory mechanism for deficits in higher-order processing of emotional signals in social interactions, and imply potential benefits of auditory interventions in improving APR among individuals with high autistic traits.
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Transtorno do Espectro Autista , Transtorno Autístico , Humanos , Adulto , Transtorno Autístico/diagnóstico , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/psicologia , Percepção Auditiva , Emoções , Reconhecimento PsicológicoRESUMO
According to the shared signal hypothesis (SSH) the impact of facial expressions on emotion processing partially depends on whether the gaze is directed toward or away from the observer. In autism spectrum disorder (ASD) several aspects of face processing have been found to be atypical, including attention to eye gaze and the identification of emotional expressions. However, there is little research on how gaze direction affects emotional expression processing in typically developing (TD) individuals and in those with ASD. This question is investigated here in two multimodal experiments. Experiment 1 required processing eye gaze direction while faces differed in emotional expression. Forty-seven children (aged 9-12 years) participated. Their Autism Diagnostic Observation Schedule (ADOS) scores ranged from 0 to 6 in the experiment. Event-related potentials (ERPs) were sensitive to gaze direction and emotion, but emotion processing did not depend on gaze direction. However, for angry faces the gaze direction effect on the N170 amplitude, as typically observed in TD individuals, diminished with increasing ADOS score. For neutral expressions this correlation was not significant. Experiment 2 required explicit emotion classifications in a facial emotion composite task while eye gaze was manipulated incidentally. A group of 22 children with ASD was compared to a propensity score-matched group of TD children (mean age = 13 years). The same comparison was carried out for a subgroup of nine children with ASD who were less trained in social cognition, according to clinician's report. The ASD group performed overall worse in emotion recognition than the TD group, independently of emotion or gaze direction. However, for disgust expressions, eye tracking data revealed that TD children fixated relatively longer on the eyes of the stimulus face with a direct gaze as compared with averted gaze. In children with ASD we observed no such modulation of fixation behavior as a function of gaze direction. Overall, the present findings from ERPs and eye tracking confirm the hypothesis of an impaired sensitivity to gaze direction in children with ASD or elevated autistic traits, at least for specific emotions. Therefore, we conclude that multimodal investigations of the interaction between emotional processing and stimulus gaze direction are promising to understand the characteristics of individuals differing along the autism trait dimension.
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This study explores the theoretical proposal that developmental dyslexia involves a failure to develop perceptual expertise with words despite adequate education. Among a group of Hong Kong Chinese children diagnosed with developmental dyslexia, we investigated the relationship between Chinese word reading and perceptual expertise with Chinese characters. In a perceptual fluency task, the time of visual exposure to Chinese characters was manipulated and limited such that the speed of discrimination of a short sequence of Chinese characters at an accuracy level of 80% was estimated. Pair-wise correlations showed that perceptual fluency for characters predicted speeded and non-speeded word reading performance. Exploratory hierarchical regressions showed that perceptual fluency for characters accounted for 5.3% and 9.6% variance in speeded and non-speeded reading respectively, in addition to age, non-verbal IQ, phonological awareness, morphological awareness, rapid automatized naming (RAN) and perceptual fluency for digits. The findings suggest that perceptual expertise with words plays an important role in Chinese reading performance in developmental dyslexia, and that perceptual training is a potential remediation direction.
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Povo Asiático , Dislexia/fisiopatologia , Idioma , Percepção , Leitura , Criança , Feminino , Hong Kong , Humanos , Masculino , Análise de Regressão , Reprodutibilidade dos TestesRESUMO
Effective radiation treatment (RT) for recurrent nasopharyngeal cancers (NPC), featuring an intrinsic hypoxic sub-volume, remains a clinical challenge. Lack of disease-specific in-vitro models of NPC, together with difficulties in establishing patient derived xenograft (PDX) models, have further hindered development of personalized therapeutic options. Herein, we established two NPC organoid lines from recurrent NPC PDX models and further characterized and compared these models with original patient tumors using RNA sequencing analysis. Organoids were cultured in hypoxic conditions to examine the effects of hypoxia and radioresistance. These models were then utilized to determine the radiobiological parameters, such as α/ß ratio and oxygen enhancement ratio (OER), characteristic to radiosensitive normoxic and radioresistant hypoxic NPC, using simple dose-survival data analytic tools. The results were further validated in-vitro and in-vivo, to determine the optimal boost dose and fractionation regimen required to achieve effective NPC tumor regression. Despite the differences in tumor microenvironment due to the lack of human stroma, RNA sequencing analysis revealed good correlation of NPC PDX and organoid models with patient tumors. Additionally, the established models also mimicked inter-tumoral heterogeneity. Hypoxic NPC organoids were highly radioresistant and had high α/ß ratio compared to its normoxic counterparts. In-vitro and in-vivo fractionation studies showed that hypoxic NPC was less sensitive to RT fractionation scheme and required a large bolus dose or 1.4 times of the fractionated dose that was effective against normoxic cells in order to compensate for oxygen deficiency. This study is the first direct experimental evidence to predict optimal RT boost dose required to cause sufficient damage to recurrent hypoxic NPC tumor cells, which can be further used to develop dose-painting algorithms in clinical practice.
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This study used event-related potential (ERP) recording to examine the role of lexical tone and rime in Mandarin Chinese spoken sentence comprehension. A violation paradigm was adopted, such that selected target syllables in the sentences were replaced with tone-violated, rime-violated, or double-violated syllables. Participants judged whether each sentence was congruent. The behavioral results confirmed previous findings: Tone violation was more difficult to detect than rime violation. The ERP results showed that rime and double violations, but not tone violation, elicited a larger N400 than the original condition. Similarly, tone and rime violations elicited a larger P600 than the original condition, and the effect started and ended 50 ms earlier in the tone-violation type. Interestingly, the double-violation type differed significantly from the original type only in the posterior electrodes, suggesting a weaker P600 effect than the tone- and rime-violation types. The differences in ERP effects between rime and tone processing indicate that rime played a more important role in semantic access, while tone played a more important role in error recovery. A model of Chinese speech perception was proposed to accommodate the different roles of lexical tone and rime at different processing stages during sentence comprehension.
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Compreensão , Percepção da Fala , Eletroencefalografia , Potenciais Evocados , Feminino , Humanos , Idioma , Masculino , SemânticaRESUMO
Accurate interpretation of speech requires the integration of verbal and nonverbal signals. This study investigated sex differences in behavior and neural activities associated with the integration of semantic content and emotional speech prosody, while the level of autistic traits was controlled for. Adults listened to Cantonese words spoken with happy and sad prosody, and made judgments on semantic valence while event-related potentials (ERP) were recorded. Behaviorally, men were slower than women in making semantic valence judgments. At the neural level, men had a greater congruity effect in the N400 component, whereas women had a greater congruity effect in the 1150-1300 ms time window for happy prosodies. There was no effect of sex in case of sad prosodies. Our study reveals novel findings on sex differences in the timing of the integration between verbal and non-verbal signals that cannot be explained by differences in autistic traits.
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Transtorno Autístico , Encéfalo , Percepção da Fala , Adulto , Transtorno Autístico/complicações , Transtorno Autístico/fisiopatologia , Encéfalo/diagnóstico por imagem , Eletroencefalografia , Potenciais Evocados , Feminino , Humanos , Masculino , Semântica , Caracteres Sexuais , FalaRESUMO
Erotic imagery is one highly salient emotional signal that exists everywhere in daily life. The impact of sexual stimuli on human decision-making, however, has rarely been investigated. This study examines the impact of sexual stimuli on financial decision-making under risk. In each trial, either a sexual or neutral image was presented in a picture categorization task before a gambling task. Thirty-four men made gambling decisions while their physiological arousal, measured by skin conductance responses (SCRs), was recorded. Behaviorally, the proportion of gambling decisions did not differ between the sexual and neutral image trials. Physiologically, participants had smaller arousal differences, measured in micro-siemen per dollar, between losses and gains in the sexual rather than in the neutral image trials. Moreover, participants' SCRs to losses relative to gains predicted the proportion of gambling decisions in the neutral image trials but not in the sexual image trials. The results were consistent with the hypothesis that the presence of emotionally salient sexual images reduces attentional and arousal-related responses to gambling losses. Our results are consistent with the theory of loss attention involving increased cognitive investment in losses compared to gains. The findings also have potential practical implications for our understanding of the specific roles of sexual images in human financial decision making in everyday life, such as gambling behaviors in the casino.
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Nível de Alerta/fisiologia , Literatura Erótica , Jogo de Azar/psicologia , Comportamento Sexual , Adolescente , Adulto , Tomada de Decisões , Resposta Galvânica da Pele/fisiologia , Humanos , Masculino , Adulto JovemRESUMO
This study aimed to examine individual differences in the integration of emotional prosody when processing semantic meaning in speech among men with high and low levels of autistic traits, as measured by the Autism Spectrum Quotient (AQ). The behavioral and neural responses of high- and low-AQ men during semantic valence judgment were compared. The stimuli were positive or negative words spoken with either happy or sad prosody; in other words, the prosody was either congruous or incongruous to the valence of meaning. Participants were required to judge the (positive vs. negative) valence of word meaning as accurately and as quickly as possible while ignoring emotional prosody. Behavioral results showed that high-AQ men responded significantly more slowly than low-AQ men in all stimulus conditions, indicating lower automaticity in processing emotional speech. Neural data revealed that low-AQ men (but not high-AQ men) had significantly increased N200 and N400 amplitudes for incongruous (compared to congruous) stimuli spoken with happy prosody. Our findings supported our hypotheses that high levels of autistic traits are associated with reduced behavioral automaticity and less differential neural resources allocated to processing emotional speech stimuli with different cognitive demands.
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Transtorno Autístico/fisiopatologia , Transtorno Autístico/psicologia , Encéfalo/fisiopatologia , Emoções/fisiologia , Semântica , Percepção da Fala/fisiologia , Adolescente , Adulto , Eletroencefalografia , Potenciais Evocados , Humanos , Julgamento/fisiologia , Masculino , Tempo de Reação , Adulto JovemRESUMO
Criminal investigation often involves finding out what a suspect knows about people, such as victims and confederates, who are involved in the crime. This study explored the possibility of determining a person's recognition of other individuals by analyzing the steady-state visually evoked potentials (SSVEP) triggered by visual oscillations of familiar and unfamiliar faces. In our study, 23 adult (10 men) participants gave subjective familiarity ratings (in a 7-point Likert scale) of >300 celebrities' and strangers' faces. For each participant, ten familiar and ten unfamiliar faces were selected based on his/her ratings. The selected faces were presented at 6â¯Hz while the participants performed a color change detection task orthogonal to the attributes of faces. The task was designed to maintain participants' visual attention towards the faces throughout the stimulus oscillations. Any difference between conditions would indicate modulation of visual attention by face familiarity. Results showed that the 12-Hz event-related spectral perturbations (ERSPs in decibel) at parietal-occipital electrodes were significantly lower when viewing familiar faces compared to unfamiliar faces. In individual level analysis, 18 out of 23 (78%) participants had significantly lower 12-Hz ERSPs at left parietal-occipital ROI in familiar face than unfamiliar face trials. This is the first study to demonstrate that SSVEPs triggered by stimulus oscillations can reveal people's recognition of faces with only 20 trials per condition and 10-s for each trial.
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Atenção/fisiologia , Eletroencefalografia/métodos , Potenciais Evocados Visuais/fisiologia , Reconhecimento Facial/fisiologia , Lobo Occipital/fisiologia , Lobo Parietal/fisiologia , Reconhecimento Psicológico/fisiologia , Adulto , Percepção de Cores/fisiologia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
In order to recognize banter or sarcasm in social interactions, listeners must integrate verbal and vocal emotional expressions. Here, we investigated event-related potential correlates of this integration in Asian listeners. We presented emotional words spoken with congruous or incongruous emotional prosody. When listeners classified word meaning as positive or negative and ignored prosody, incongruous trials elicited a larger late positivity than congruous trials in women but not in men. Sex differences were absent when listeners evaluated the congruence between word meaning and emotional prosody. The similarity of these results to those obtained in Western listeners suggests that sex differences in emotional speech processing depend on attentional focus and may reflect culturally independent mechanisms.
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Povo Asiático/psicologia , Córtex Cerebral/fisiologia , Formação de Conceito/fisiologia , Comparação Transcultural , Emoções/fisiologia , Relações Interpessoais , Semântica , Acústica da Fala , Percepção da Fala/fisiologia , Adulto , Conscientização/fisiologia , Dissonância Cognitiva , Dominância Cerebral/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Hong Kong , Humanos , Julgamento , Idioma , Masculino , Tempo de Reação/fisiologia , Fatores SexuaisRESUMO
PURPOSE: The current study examined whether children with autism spectrum disorder (ASD), in comparison with typically developing children, perceive and produce gestures to identify nonpresent objects (i.e., referent-identifying gestures), which is crucial for communicating ideas in a discourse. METHOD: An experimenter described the uses of daily-life objects to 6- to 12-year-old children both orally and with gestures. The children were then asked to describe how they performed daily activities using those objects. RESULTS: All children gestured. A gesture identified a nonpresent referent if it was produced in the same location that had previously been established by the experimenter. Children with ASD gestured at the specific locations less often than typically developing children. Verbal and spatial memory were positively correlated with the ability to produce referent-identifying gestures for all children. However, the positive correlation between Raven's Children Progressive Matrices score and the production of referent-identifying gestures was found only in children with ASD. CONCLUSIONS: Children with ASD might be less able to perceive and produce referent-identifying gestures and may rely more heavily on visual-spatial skills in producing referent-identifying gestures. The results have clinical implications for designing an intervention program to enhance the ability of children with ASD to communicate about nonpresent objects with gestures.
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Transtorno do Espectro Autista/psicologia , Gestos , Comunicação não Verbal/psicologia , Semântica , Estudos de Casos e Controles , Criança , Feminino , Mãos , Humanos , Masculino , Língua de SinaisRESUMO
Previous work leaves open the question of whether children with autism spectrum disorders aged 6-12 years have delay in producing gestures compared to their typically developing peers. This study examined gestural production among school-aged children in a naturalistic context and how their gestures are semantically related to the accompanying speech. Delay in gestural production was found in children with autism spectrum disorders through their middle to late childhood. Compared to their typically developing counterparts, children with autism spectrum disorders gestured less often and used fewer types of gestures, in particular markers, which carry culture-specific meaning. Typically developing children's gestural production was related to language and cognitive skills, but among children with autism spectrum disorders, gestural production was more strongly related to the severity of socio-communicative impairment. Gesture impairment also included the failure to integrate speech with gesture: in particular, supplementary gestures are absent in children with autism spectrum disorders. The findings extend our understanding of gestural production in school-aged children with autism spectrum disorders during spontaneous interaction. The results can help guide new therapies for gestural production for children with autism spectrum disorders in middle and late childhood.
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Transtorno do Espectro Autista/psicologia , Gestos , Desenvolvimento da Linguagem , Aprendizagem Verbal , Estudos de Casos e Controles , Criança , Feminino , Humanos , Testes de Linguagem , Masculino , Testes Neuropsicológicos , Semântica , FalaRESUMO
Emotions change our perception of time. In the past, this has been attributed primarily to emotions speeding up an "internal clock" thereby increasing subjective time estimates. Here we probed this account using an S1/S2 temporal discrimination paradigm. Participants were presented with a stimulus (S1) followed by a brief delay and then a second stimulus (S2) and indicated whether S2 was shorter or longer in duration than S1. We manipulated participants' emotions by presenting a task-irrelevant picture following S1 and preceding S2. Participants were more likely to judge S2 as shorter than S1 when the intervening picture was emotional as compared to neutral. This effect held independent of S1 and S2 modality (Visual: Exps. 1, 2, & 3; Auditory: Exp. 4) and intervening picture valence (Negative: Exps. 1, 2 & 4; Positive: Exp. 3). Moreover, it was replicated in a temporal reproduction paradigm (Exp. 5) where a timing stimulus was preceded by an emotional or neutral picture and participants were asked to reproduce the duration of the timing stimulus. Taken together, these findings indicate that emotional experiences may decrease temporal estimates and thus raise questions about the suitability of internal clock speed explanations of emotion effects on timing. Moreover, they highlight attentional mechanisms as a viable alternative.
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Atenção/fisiologia , Relógios Biológicos/fisiologia , Emoções/fisiologia , Percepção do Tempo/fisiologia , Análise de Variância , Feminino , Humanos , Probabilidade , Adulto JovemRESUMO
We studied a lie detection protocol immune to countermeasures. The 4 stimulus conditions were (1 and 2) supraliminal acquaintance name primed by subliminal acquaintance name (A-A) versus subliminal nonacquaintance name (N-A) and (3 and 4) supraliminal nonacquaintance name primed by subliminal acquaintance name (A-N) versus subliminal nonacquaintance name (N-N). In Experiment 1 and replication, principal components analysis-derived event-related potential components revealed significant differences between dishonestly answered supraliminal acquaintance conditions with differing primes (A-A vs. N-A). In Experiment 2 subjects were required to lie in A-N and N-N conditions, in contrast to Experiment 1, in which subjects lied in A-A and N-A conditions. No significant effects were found. In Experiment 3, the lying task was removed and no significant differences were found. We conclude that subliminal primes modulate ERPs in conditions with supraliminal acquaintance name when the task involves lying.
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Detecção de Mentiras/psicologia , Estimulação Subliminar , Terrorismo/psicologia , Adolescente , Sinais (Psicologia) , Interpretação Estatística de Dados , Reações Falso-Positivas , Feminino , Humanos , Masculino , Análise de Componente Principal , Adulto JovemRESUMO
Previous tests of P300 in deception detection have focused mainly on amplitude analysis. Since countermeasures for such tests have been reported, we looked here at other possible variables as deception indices: P300 scalp distribution and amplitude variance, both across 30 sites. We were also concerned, for the first time, in testing for recognition of more than one guilty item in a mock crime scenario. There were three groups: (1) two-probe group, two of six items were guilty knowledge (GK) items; (2) three-probe group, three of six items were GK items; (3) control group, zero of six items were GK items. In group analyses, in the two-probe group, P300s for lies were significantly greater than P300s for truthful responses. There were significant interactions of condition (Lie vs Truth) by site, suggesting different scalp profiles for deceptive versus truthful responding. Amplitude variance across sites was also greater in Lie than in Truth blocks. These results did not obtain in the three-probe and control groups. In terms of amplitude variances in probe conditions across groups, two-probe group was larger than three-probe and control groups. Regarding individual diagnostics, the variance method yielded a greater-than-chance detection rate of 71% versus 28% false positives. Regarding amplitude at multiple nonfrontal sites, 71% of guilty subjects were detected versus 14% false positives. Grier's (1971) A' indices of various test discrimination efficiencies varied from .76 to .87. Results of the present study suggested further investigation of the variance method as a diagnostic tool for lie detection.
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Enganação , Potenciais Evocados P300/fisiologia , Detecção de Mentiras/psicologia , Algoritmos , Crime/psicologia , Eletroencefalografia , Reações Falso-Positivas , Feminino , Culpa , Humanos , Individualidade , Masculino , Estimulação Luminosa , Adulto JovemRESUMO
Neural correlates of explicit and implicit memory tend to co-occur and are therefore difficult to measure independently, posing problems for understanding the unique nature of different types of memory processing. To circumvent this problem, we developed an experimental design wherein subjects acquired information from words presented in a subliminal manner, such that conscious remembering was minimized. Cross-modal word repetition was used so that perceptual implicit memory would also be limited. Healthy human subjects viewed subliminal words six times each and about 2 min later heard the same words interspersed with new words in a category-verification test. Electrophysiological correlates of word repetition included negative brain potentials over left-frontal locations beginning approximately 500 ms after word onset. Behavioral responses were slower for repeated words than for new words. Differential processing of word meaning in the absence of explicit memory was most likely responsible for differential electrical and behavioral responses to old versus new words. Moreover, these effects were distinct from neural correlates of explicit memory observed in prior experiments, and were observed here in two separate experiments, thus providing a foundation for further investigations of relationships and interactions between different types of memory engaged when words repeat.