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1.
J Am Coll Health ; : 1-9, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38579128

RESUMEN

The outbreak of the Covid-19 pandemic has been linked with caloric overeating and weight gain. We employed a mediation analysis to determine whether pandemic-associated overeating was a direct effect of Covid-19-related anxiety (affect regulation theory) or mediated by a coping mechanism of escape eating (escape theory). A diverse pool of college students participated in a repeated cross-sectional study during three separate waves: May 2021 (wave 1, n = 349), December 2021 (wave 2, n = 253), and March 2022 (wave 3, n = 132). The results revealed a significant indirect effect of Covid-19-related anxiety on high-caloric overeating mediated by escape eating, but no direct path between Covid-19-related anxiety and caloric overeating. Analysis of racial/ethnic status uncovered significantly greater Covid-weight gain in Hispanic participants compared with White, Black, and Asian participants. Our results suggest that Covid-19 weight gain is a byproduct of a mediated escape mechanism differentially affecting racial/ethnic groups.

2.
J Pers Disord ; 37(5): 542-558, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37903017

RESUMEN

This study distinguishes interpersonal trust learning with a novel trust learning paradigm in participants high (H-BPD) and low (L-BPD) in BPD features. Neutral faces were paired with trust-relevant behaviors in four conditions: trustworthy, untrustworthy, ambiguously trustworthy, and mixed trustworthiness. After training, participants rated faces on untrustworthiness as electroencephalographic measures were recorded. H-BPD rated neutral faces as significantly more untrustworthy than L-BPD at both time periods. Negative and ambiguous trustworthiness pairing conditions led to higher ratings of untrustworthiness, whereas trustworthy and mixed descriptors led to lower ratings of untrustworthiness. Learning enhanced the amplitude of an early sensory event-related potential (ERP) component (i.e., P1) for both groups. The slow-wave ERP, an index of sustained attention, revealed greater focus after learning to trustworthy descriptors in H-BPD and to untrustworthy descriptors in L-BPD. H-BPD utilized greater effort to overcome an inherent mistrust bias and L-BPD to overcome unexpected untrustworthy information.


Asunto(s)
Trastorno de Personalidad Limítrofe , Humanos , Confianza , Aprendizaje , Expresión Facial , Percepción Social
3.
J Neurophysiol ; 129(2): 307-319, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36576265

RESUMEN

Antisaccade and prosaccade (PS) performance were studied in a large cohort of females (age range 42-74 yr). Antisaccade performance was assessed in two variants of the task, a "traditional" antisaccade (TA) task, in which no visual stimuli were present at the saccade goal, and a visually guided antisaccade (VGA) task, in which small visual stimuli were present at the possible saccade goals prior to the imperative visual stimulus. Directional error frequency was similar in the two antisaccade tasks. However, reaction time (RT) was ∼33 ms longer in the VGA task than in the TA task. Across participants, the average saccade amplitudes of prosaccades and TAs were both correlated with those of VGAs but not with each other. TAs had a hypermetria that increased with age. Saccade amplitude variability was much higher for TAs than for PSs and VGAs. Saccade polar angle variability was low for all three tasks. Age diminished performance with modest task dependence, except for an increase in TA hypermetria. These results suggest that the generation of antisaccade directional errors does not depend on visual target presence at the saccade goal, that antisaccade RT can be affected by target presence, that age can increase saccade hypermetria in the absence of visual guidance, and that visually guided antisaccades are governed by distinct voluntary and visually guided saccade mechanisms. Moreover, these results suggest that an understanding of human motor performance benefits from the use of a participant pool with a larger age range than that used in most studies.NEW & NOTEWORTHY This study uses a visually guided antisaccade (VGA) task to determine whether poor performance in a large middle-aged participant pool on an antisaccade task results from problems with executive control or voluntary saccade generation. Spatial and temporal attributes of saccade performance as a function of task and age are analyzed comprehensively. Correlational analysis is used to determine how VGAs are governed jointly by voluntary and visually guided movement mechanisms.


Asunto(s)
Ataxia Cerebelosa , Persona de Mediana Edad , Femenino , Humanos , Adulto , Anciano , Tiempo de Reacción , Función Ejecutiva , Movimientos Sacádicos
4.
Arch Clin Neuropsychol ; 38(1): 12-24, 2023 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-35901461

RESUMEN

OBJECTIVE: Cognitive dysfunction has been observed consistently in a subset of breast cancer survivors. Yet, the precise physiological and processing origins of dysfunction remain unknown. The current study examined the utility of methods and procedures based on cognitive neuroscience to study cognitive change associated with cancer and cancer treatment. METHODS: We used electroencephalogram and behavioral measures in a longitudinal design to investigate pre- versus post-treatment effects on attention performance in breast cancer patients (n = 15) compared with healthy controls (n = 24), as participants completed the revised Attention Network Test, a cognitive measure of alerting, orienting, and inhibitory control of attention. RESULTS: We found no group differences in behavioral performance from pretest to posttest, but significant event-related potential effects of cancer treatment in processing cue validity: After treatment, patients revealed decreased N1 amplitude and increased P3 amplitude, suggesting a suppressed early (N1) response and an exaggerated late (P3) response to invalid cues. CONCLUSIONS: The results suggest that treatment-related attentional disruption begins in early sensory/perceptual processing and extends to compensatory top-down executive processes.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/complicaciones , Neoplasias de la Mama/terapia , Tiempo de Reacción/fisiología , Pruebas Neuropsicológicas , Potenciales Evocados/fisiología , Electroencefalografía , Señales (Psicología)
5.
Clin EEG Neurosci ; 54(5): 472-482, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34657474

RESUMEN

The current study examined frontal alpha asymmetry (FAA) as a marker of approach- and avoidance-related prefrontal activity in participants with and without trauma exposure and posttraumatic stress disorder (PTSD). We investigated FAA in an inhibitory control paradigm (threatening vs nonthreatening cues) under 2 levels of cognitive demand (baseline: images constant within a block of trials; vs filtering: images varied randomly within a block) in 3 groups of participants: individuals with PTSD (n = 16), exposed to trauma but without PTSD (n = 14), and a control group without PTSD or trauma exposure (n = 15). Under low demand (baseline), both PTSD and trauma-exposed participants exhibited significantly greater relative left than right frontal brain activity (approach) to threatening than to nonthreatening images. Under high demand (filtering), no FAA differences were found between threatening and nonthreatening images, but PTSD participants revealed more relative left than right FAA, whereas trauma-exposed participants showed reduced left relative right FAA. In all conditions, healthy controls exhibited reduced left relative to right FAA and no differences between threatening and nonthreatening images. Study findings suggest dysfunctional prefrontal mechanisms of emotion regulation in PTSD, but adaptive prefrontal regulation in trauma-exposed individuals without PTSD.


Asunto(s)
Trastornos por Estrés Postraumático , Humanos , Corteza Cerebral , Electroencefalografía , Imagen por Resonancia Magnética
6.
Clin EEG Neurosci ; 54(2): 189-197, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35118900

RESUMEN

Cognitive impairment has been observed consistently in a subset of breast cancer survivors. Yet, still unknown is whether neural and behavioral effects of cancer exist prior to treatment, which may contribute to later cognitive decline. The current study investigated pre-treatment differences in attention performance and frontal alpha asymmetry (FAA), an established neural index of inhibitory control, in non-metastatic breast cancer patients (n = 42) compared with healthy controls (n = 28). We additionally investigated whether differences between groups appear in specific cuing conditions and across different stages of information processing. Participants underwent EEG while completing the Attention Network Task (ANT), a cognitive measure of alerting, orienting, and inhibitory control of attention. Results revealed no behavioral differences between patients and controls but significantly greater right-hemisphere alpha activity (reduced inhibitory control) in patients, particularly to uninformative (no cue, double cue) versus informative (valid cue) cues and in later stages of information processing (400-800 ms post-stimulus). Results suggest neural differences between groups to uncertain stimulus environments that have yet to manifest behaviorally. FAA may thus serve as a unique neural correlate that could potentially be used to predict later cognitive decline.


Asunto(s)
Neoplasias de la Mama , Electroencefalografía , Humanos , Femenino , Tiempo de Reacción
7.
Clin EEG Neurosci ; 53(5): 418-425, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35125036

RESUMEN

The purpose of the current study was to investigate differences in frontal alpha asymmetry (FAA) between children (5-17 years) with or without histories of trauma exposure. EEG data were obtained from 165 children who participated in the Healthy Brain Network Initiative during rest with eyes open and closed. FAA during resting-state electroencephalography was significantly more negative in the trauma-exposed group, suggesting greater left lateralized FAA and avoidance-oriented motivation. Moreover, alpha suppression (difference in alpha amplitude between eyes open and eyes closed conditions) was marginally greater in the trauma-exposed group. The results suggest that early exposure to trauma may be associated with trait-level avoidance of environmental stimuli, which ultimately may be predictive of psychopathology, including posttraumatic stress disorder (PTSD). Study findings thus provide preliminary evidence of brain-based mechanisms that may confer risk for PTSD in the wake of early trauma exposure.


Asunto(s)
Electroencefalografía , Trastornos por Estrés Postraumático , Ritmo alfa , Encéfalo , Niño , Lóbulo Frontal , Humanos , Descanso , Trastornos por Estrés Postraumático/diagnóstico
8.
Behav Brain Res ; 405: 113213, 2021 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-33657438

RESUMEN

Healthy adults performed an auditory version of the flanker task under low versus high perceptual load while behavioral and electrophysiological measures were recorded. Participants experienced less attentional interference under low load than high load, whether analyses were performed between tasks (Garner interference; found in accuracy and RT), between stimuli (flanker congruity; found in accuracy), or between sequences (Gratton effect; found in accuracy). Analysis of event-related potentials to the distractor (flanker), which was physically identical across load conditions, revealed load modulation of tasks effects in the P1 component (peak amplitude and latency), an early perceptual component peaking approximately 75 ms after distractor onset. As in behavioral performance, ERP analyses showed that auditory attentional disruption in P1 was significantly smaller under low perceptual load. Dipole source analysis suggested activation of prefrontal inhibitory control during low load and default mode network during high load. The results are in keeping with the predictions of tectonic theory (Melara & Algom, 2003), but inconsistent with expectations derived from perceptual load theory (Lavie, 1995).


Asunto(s)
Percepción Auditiva/fisiología , Red en Modo Predeterminado/fisiología , Potenciales Evocados/fisiología , Inhibición Psicológica , Corteza Prefrontal/fisiología , Adulto , Atención , Electroencefalografía , Femenino , Humanos , Masculino , Adulto Joven
9.
Clin EEG Neurosci ; 52(4): 246-253, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33167713

RESUMEN

Survivors of breast and other cancers often report protracted difficulty in performing tasks involving concentration and memory, even years after the completion of treatment. The current study investigated whether cancer and treatment history is associated with deficits in sensory filtering (gating out) and sensory memory (gating in), early processes in stimulus processing that may contribute to difficulties in later remembering. A group of breast cancer survivors and age-matched healthy control participants (mean age 54 years) underwent testing with paired-click and oddball tasks while electroencephalographic (EEG) signals were recorded. The survivors showed relatively poor inhibition of redundant sensory stimulation (P50 suppression). Dipole source analysis localized the survivors' impairment to the hippocampus, with preservation of function in gating mechanisms of the frontal lobe and auditory cortex. Survivors also showed disruption to sensory memory processes needed to register novel information in an otherwise uniform auditory environment (mismatch negativity). The findings suggest that survivors experience deficits in early, automatic mechanisms of sensory gating, which may trigger a cascade of later perceived attentional and memory deficits. If our account is accurate, ideal therapies might aim to restore early inhibitory processes, such as those gauged by P50 suppression.


Asunto(s)
Neoplasias de la Mama , Supervivientes de Cáncer , Estimulación Acústica , Electroencefalografía , Potenciales Evocados Auditivos , Humanos , Persona de Mediana Edad , Filtrado Sensorial , Sobrevivientes
10.
Neurosci Lett ; 735: 135241, 2020 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-32659312

RESUMEN

Black cigarette smokers experience higher craving, lower cessation rates, and increased health complications from tobacco use than Whites. We examined psychophysiological and behavioral differences in attentional bias to smoking cues between Black and White smokers. Thirty-one participants (Blacks, n = 20; MAge = 45 and Whites, n = 11, MAge = 47.64) discriminated line orientations while ignoring temporally flanking lines and smoking-related, positive-, negative-, and neutral-images as behavioral responses and event-related potentials (ERPs) were recorded. Results revealed a three-way interaction in reaction time among Group (White, Black), Congruity (congruent vs. incongruent flankers) and Cue (smoking-related, positive, negative) factors, F(2,58) = 3.63, p = .03, MSe = .001, η2 = .002. Smoking-related cues yielded the largest congruity effects in Whites, but the smallest congruity effects in Blacks. Random presentation of smoking-related cues (re: baseline) weakened P1 ERP amplitude (125 ms after stimulus onset) in Whites, but not Blacks (Cue x Group x Task, F(3,87) = 3.44, p < .05, MSe = 65.96, η2 = .01), suggesting an early sensory effect of smoking cues in Whites. The difference between Whites and Blacks in P2 amplitude (226 ms; amplitude weaker in Whites) was greatest to the smoking-related cues (Cue x Group, F(3,87) = 2.81, p < .05, MSe = 60.68, η2 = .01), indicating a stronger draw in attention from smoking cues in Whites. Findings suggest White and Black smokers respond differently to smoking-related cues during early sensory processing. Findings need to be replicated.


Asunto(s)
Sesgo Atencional/fisiología , Población Negra/psicología , Fumar Cigarrillos/psicología , Señales (Psicología) , Potenciales Evocados/fisiología , Población Blanca/psicología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa/métodos , Proyectos Piloto , Tiempo de Reacción/fisiología , Fumadores/psicología
11.
Brain Sci ; 9(9)2019 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-31470590

RESUMEN

To better understand the biopsychosocial mechanisms associated with development and maintenance of cannabis use disorder (CUD), we examined frontal alpha asymmetry (FAA) as a measure of approach bias and inhibitory control in cannabis users versus healthy nonusers. We investigated: (1) whether FAA could distinguish cannabis users from healthy controls; (2) whether there are cue-specific FAA effects in cannabis users versus controls; and (3) the time course of cue-specific approach motivation and inhibitory control processes. EEG data were analyzed from forty participants (CUD (n = 20) and controls (n = 20)) who completed a modified visual attention task. Results showed controls exhibited greater relative right hemisphere activation (indicating avoidance/withdrawal motivation) when exposed to cannabis cues during the filtering task. By contrast, cannabis users exhibited greater relative left activation (approach) to all cues (cannabis, positive, negative, and neutral), reflecting a generalized approach motivational tendency, particularly during later stages of inhibitory control processes. The difference between cannabis users and controls in FAA was largest during mid- to late processing stages of all cues, indicating greater approach motivation during later stages of information processing among cannabis users. Findings suggest FAA may distinguish cannabis users from healthy controls and shows promise as a measure of inhibitory control processes in cannabis users.

12.
J Natl Med Assoc ; 111(6): 606-615, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31375277

RESUMEN

BACKGROUND: African American smokers suffer disproportionately from tobacco-related disease caused, in part, by lower rates of smoking cessation. We examined whether smoke-free home policies and delay discounting were differentially associated with cigarettes smoked per day (CPD) and nicotine dependence (ND) among African Americans and Whites. METHODS: Secondary data analysis was conducted using data from 65 African American (n = 40) and White (n = 25) smokers who completed measures of CPD, ND, tobacco craving, stress, depression, home smoking policy, and delay discounting. RESULTS: A significant interaction was found between race and home smoking policy on CPD (B = -11.21, p = 0.002) and ND (B = -3.42, p = 0.004). Smoke-free policies in the home were associated with fewer CPD and lower ND levels among Whites, but not among African Americans. Whites who allowed smoking in their homes had significantly greater mean CPD and higher mean ND than their counterparts who did not allow smoking in the home. Among African American smokers, there were no differences in CPD and ND among those who allowed smoking in their home versus those who did not. CONCLUSIONS: The findings extend the scientific literature by suggesting that a malleable environmental factor (home smoking policy) commonly associated with cessation among Whites does not have the same influence on cessation among African American.


Asunto(s)
Negro o Afroamericano , Conductas Relacionadas con la Salud/etnología , Prevención del Hábito de Fumar , Fumar/etnología , Tabaquismo/etnología , Población Blanca , Adulto , Estudios Transversales , Descuento por Demora , Composición Familiar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ciudad de Nueva York , Controles Informales de la Sociedad
13.
Psychol Addict Behav ; 33(1): 69-80, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30589308

RESUMEN

The current pilot study probed the time course of attentional bias to cannabis-related cues among individuals with cannabis use disorders (CUDs) compared with healthy controls. Forty participants (individuals with CUDs, n = 20, Mage = 26.2 and healthy controls, n = 20, Mage = 28) completed a modified visual attention task in which they made decisions about the orientation of a target line while ignoring temporally flanking lines and cannabis-related, positive-, negative-, and neutral-images as behavioral responses and event-related potentials (ERPs) were recorded. To examine the time course of attentional bias, we analyzed ERP responses separately to targets and distractors from 125 ms to 620 ms after stimulus onset. Results showed that, compared with healthy controls, cannabis users demonstrated greater selective attention failure (i.e., had more difficulties ignoring distractor stimuli) when making decisions in the presence of cannabis cues. Likewise, cannabis smokers demonstrated relatively larger differences in accuracy (i.e., committed more errors in target decisions) between trials involving cannabis cues versus neutral cues. ERP data revealed that the N1 component (125-200 ms after stimulus onset) to flankers preceding cannabis cues peaked relatively earlier and was of larger amplitude in cannabis users, suggesting an early perceptual bias toward the cannabis cues. Findings suggest that individuals with CUDs have poorer selective attention, impaired inhibitory control, and early attentional biases toward cannabis uses compared with healthy nonusers. The augmented early perceptual response suggests an involuntary orienting of attention toward cannabis cues. Implications for future research and intervention development for individuals with CUD are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Asunto(s)
Sesgo Atencional/fisiología , Encéfalo/fisiopatología , Señales (Psicología) , Potenciales Evocados/fisiología , Abuso de Marihuana/psicología , Adolescente , Adulto , Atención/fisiología , Estudios de Casos y Controles , Electroencefalografía , Potenciales Relacionados con Evento P300/fisiología , Femenino , Humanos , Masculino , Abuso de Marihuana/fisiopatología , Orientación/fisiología , Proyectos Piloto , Adulto Joven
14.
Front Hum Neurosci ; 12: 191, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29875644

RESUMEN

Two groups of healthy young adults were exposed to 3 weeks of cognitive training in a modified version of the visual flanker task, one group trained to discriminate the target (discrimination training) and the other group to ignore the flankers (inhibition training). Inhibition training, but not discrimination training, led to significant reductions in both Garner interference, indicating improved selective attention, and in Stroop interference, indicating more efficient resolution of stimulus conflict. The behavioral gains from training were greatest in participants who showed the poorest selective attention at pretest. Electrophysiological recordings revealed that inhibition training increased the magnitude of Rejection Positivity (RP) to incongruent distractors, an event-related potential (ERP) component associated with inhibitory control. Source modeling of RP uncovered a dipole in the medial frontal gyrus for those participants receiving inhibition training, but in the cingulate gyrus for those participants receiving discrimination training. Results suggest that inhibitory control is plastic; inhibition training improves conflict resolution, particularly in individuals with poor attention skills.

15.
Biol Psychol ; 133: 89-98, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29409740

RESUMEN

The current study investigated links between trauma exposure, Post-traumatic Stress Disorder (PTSD) symptoms, and inhibitory control assessed using a modified version of the visual flanker task. The study had three aims: (1) specifically confirm general non-affective deficits in sustained attention in PTSD; (2) probe the influence of threatening and trauma-related stimuli on inhibitory control; and (3) explore neural correlates connecting PTSD, facets of dissociation, and inhibitory control. Participants with PTSD (n = 16), trauma-exposed individuals without PTSD (TE; n = 14), and healthy controls (n = 15) discriminated line orientations while ignoring temporally flanking lines and images depicting threatening or non-threatening scenes or faces. Electrophysiological recordings were made during task performance. Relative to TE participants, PTSD participants had poor sustained non-affective attention, but nevertheless exhibited greater inhibition of distractors (i.e., high event-related potential [ERP] Rejection Positivity [RP]) to threatening (versus non-threatening) stimuli. RP was associated with greater self-reported depersonalization in PTSD participants, but with less depersonalization in TE participants. Dipole source analysis localized RP to the posterior cingulate cortex in both PTSD and TE (and healthy controls), but with an additional source in the ventromedial prefrontal cortex in TE, components of the default mode network. Results suggest a paradox in the executive control of distraction in PTSD: Whereas individuals with PTSD experience a general impairment in non-affective inhibitory control, their enhanced control of threat is associated with more severe symptoms of dissociation.


Asunto(s)
Trastornos Disociativos/psicología , Inhibición Psicológica , Trastornos por Estrés Postraumático/psicología , Heridas y Lesiones/psicología , Adulto , Atención/fisiología , Estudios de Casos y Controles , Potenciales Evocados/fisiología , Femenino , Giro del Cíngulo/fisiopatología , Humanos , Masculino , Corteza Prefrontal/fisiopatología , Análisis y Desempeño de Tareas , Adulto Joven
16.
Brain Sci ; 7(2)2017 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-28165364

RESUMEN

This study is the first to explore spontaneous eye blink rate (sEBR) in individuals with post-traumatic stress disorder (PTSD). We investigated the connection between the magnitude of flanker interference in PTSD participants and sEBR during performance on a modified version of the Eriksen flanker task. As a peripheral measure of cognitive control and dopaminergic function, sEBR may illuminate the relationship between PTSD and executive function. Findings revealed a positive relationship between sEBR and flanker interference in participants diagnosed with PTSD, to both threat-related and neutral stimuli, whereas this relationship was negative in participants exposed to trauma but without PTSD and in healthy controls. Although our results are suggestive of sEBR as a potential physiological index of emotional management in PTSD, most of the correlations were not significant, indicating that further research with a larger sample is needed.

17.
J Speech Lang Hear Res ; 59(3): 415-29, 2016 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-27168125

RESUMEN

PURPOSE: The present study examined whether engaging working memory in a secondary task benefits speech fluency. Effects of dual-task conditions on speech fluency, rate, and errors were examined with respect to predictions derived from three related theoretical accounts of disfluencies. METHOD: Nineteen adults who stutter and twenty adults who do not stutter participated in the study. All participants completed 2 baseline tasks: a continuous-speaking task and a working-memory (WM) task involving manipulations of domain, load, and interstimulus interval. In the dual-task portion of the experiment, participants simultaneously performed the speaking task with each unique combination of WM conditions. RESULTS: All speakers showed similar fluency benefits and decrements in WM accuracy as a result of dual-task conditions. Fluency effects were specific to atypical forms of disfluency and were comparable across WM-task manipulations. Changes in fluency were accompanied by reductions in speaking rate but not by corresponding changes in overt errors. CONCLUSIONS: Findings suggest that WM contributes to disfluencies regardless of stuttering status and that engaging WM resources while speaking enhances fluency. Further research is needed to verify the cognitive mechanism involved in this effect and to determine how these findings can best inform clinical intervention.


Asunto(s)
Memoria a Corto Plazo , Habla , Tartamudeo/psicología , Adolescente , Adulto , Femenino , Humanos , Pruebas de Inteligencia , Pruebas del Lenguaje , Masculino , Pruebas Neuropsicológicas , Índice de Severidad de la Enfermedad , Percepción Visual , Adulto Joven
18.
Front Hum Neurosci ; 10: 118, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27047362

RESUMEN

In two experiments, we evaluated whether a perceiver's prior expectations could alone obliterate his or her awareness of a salient visual stimulus. To establish expectancy, observers first made a demanding visual discrimination on each of three baseline trials. Then, on a fourth, critical trial, a single, salient and highly visible object appeared in full view at the center of the visual field and in the absence of any competing visual input. Surprisingly, fully half of the participants were unaware of the solitary object in front of their eyes. Dramatically, observers were blind even when the only stimulus on display was the face of U.S. President Barack Obama. We term this novel, counterintuitive phenomenon, Barack Obama Blindness (BOB). Employing a method that rules out putative memory effects by probing awareness immediately after presentation of the critical stimulus, we demonstrate that the BOB effect is a true failure of conscious vision.

19.
Front Hum Neurosci ; 8: 585, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25191244

RESUMEN

A series of computer simulations using variants of a formal model of attention (Melara and Algom, 2003) probed the role of rejection positivity (RP), a slow-wave electroencephalographic (EEG) component, in the inhibitory control of distraction. Behavioral and EEG data were recorded as participants performed auditory selective attention tasks. Simulations that modulated processes of distractor inhibition accounted well for reaction-time (RT) performance, whereas those that modulated target excitation did not. A model that incorporated RP from actual EEG recordings in estimating distractor inhibition was superior in predicting changes in RT as a function of distractor salience across conditions. A model that additionally incorporated momentary fluctuations in EEG as the source of trial-to-trial variation in performance precisely predicted individual RTs within each condition. The results lend support to the linking proposition that RP controls the speed of responding to targets through the inhibitory control of distractors.

20.
Atten Percept Psychophys ; 76(8): 2229-39, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24935808

RESUMEN

In two experiments, we investigated the impact of feature-based attention on observers' awareness of object appearance. Participants were shown a sequence of two displays, each containing eight objects (rectangles), and were asked to detect changes in the orientation of a cued rectangle. A set of baseline trials preceded probe trials in which half of the rectangles in each display were unexpectedly distorted by 70 %. Participants in both Experiment 1 (100-ms display duration) and Experiment 2 (100- and 400-ms display durations) were unaware of these modifications in the task-irrelevant feature (texture), even when they were asked to select the viewed object in a forced choice procedure. A control experiment showed that participants could identify the physical distortion when they were made aware of its presence. The results demonstrate that feature-based attention moderates the appearance of objects, even when those objects are fully expected and fully attended, implying a distinct form of unawareness that we term feature-based inattentional blindness.


Asunto(s)
Atención/fisiología , Concienciación/fisiología , Desempeño Psicomotor/fisiología , Percepción Visual/fisiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Adulto Joven
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