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1.
Sci Rep ; 11(1): 15117, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34302032

RESUMO

Our acoustic environment contains a plethora of complex sounds that are often in motion. To gauge approaching danger and communicate effectively, listeners need to localize and identify sounds, which includes determining sound motion. This study addresses which acoustic cues impact listeners' ability to determine sound motion. Signal envelope (ENV) cues are implicated in both sound motion tracking and stimulus intelligibility, suggesting that these processes could be competing for sound processing resources. We created auditory chimaera from speech and noise stimuli and varied the number of frequency bands, effectively manipulating speech intelligibility. Normal-hearing adults were presented with stationary or moving chimaeras and reported perceived sound motion and content. Results show that sensitivity to sound motion is not affected by speech intelligibility, but shows a clear difference for original noise and speech stimuli. Further, acoustic chimaera with speech-like ENVs which had intelligible content induced a strong bias in listeners to report sounds as stationary. Increasing stimulus intelligibility systematically increased that bias and removing intelligible content reduced it, suggesting that sound content may be prioritized over sound motion. These findings suggest that sound motion processing in the auditory system can be biased by acoustic parameters related to speech intelligibility.


Assuntos
Percepção Auditiva/fisiologia , Percepção de Movimento/fisiologia , Inteligibilidade da Fala/fisiologia , Estimulação Acústica/métodos , Adulto , Limiar Auditivo/fisiologia , Sinais (Psicologia) , Feminino , Audição/fisiologia , Testes Auditivos/métodos , Humanos , Masculino , Movimento (Física) , Ruído , Mascaramento Perceptivo/fisiologia , Som , Acústica da Fala , Percepção da Fala/fisiologia , Adulto Jovem
2.
Sci Rep ; 11(1): 11646, 2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34079021

RESUMO

The study aimed to examine the neural mechanisms underlying implicit other-race face processing by the use of the masked and unmasked priming manipulation. Two types of prime-target pairs were presented while recording Event-related potentials (ERPs): Same face pairs (prime-target were identical faces), and Different face pairs (prime-target were different faces). Prime-target pairs were half Asian (other-race) and half Caucasian (own-race) faces. The face stimuli on each pair were of the same gender and race. Participants (all Caucasians) had to decide whether the target was a male or a female face (gender task). The prime face could be unmasked or masked. On the behavioral side, our findings showed a race effect, that is slower reaction times (RTs) for other-race than own-race face stimuli, regardless of masking. On the ERPs side, our data showed a race effect across all components analyzed (P100, N100, N200, P300), under both the unmasked and masked manipulations. Besides, we found, in the unmasked condition, a priming effect as a function of race on the N100, N200, and P300 components; but, interestingly, in the masked condition, only on the P300. Overall, our findings provide evidence that race information is available very early in the brain and can strongly activate and influence people's behaviors even without conscious awareness.


Assuntos
Encéfalo/fisiologia , Potenciais Evocados/fisiologia , Reconhecimento Facial/fisiologia , Mascaramento Perceptivo/fisiologia , Tempo de Reação/fisiologia , Adulto , Grupo com Ancestrais do Continente Asiático , Grupo com Ancestrais do Continente Europeu , Face/anatomia & histologia , Feminino , Humanos , Masculino , Estimulação Luminosa
3.
PLoS One ; 16(4): e0249654, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33826663

RESUMO

Differences in fundamental frequency (F0) or pitch between competing voices facilitate our ability to segregate a target voice from interferers, thereby enhancing speech intelligibility. Although lower-numbered harmonics elicit a stronger and more accurate pitch sensation than higher-numbered harmonics, it is unclear whether the stronger pitch leads to an increased benefit of pitch differences when segregating competing talkers. To answer this question, sentence recognition was tested in young normal-hearing listeners in the presence of a single competing talker. The stimuli were presented in a broadband condition or were highpass or lowpass filtered to manipulate the pitch accuracy of the voicing, while maintaining roughly equal speech intelligibility in the highpass and lowpass regions. Performance was measured with average F0 differences (ΔF0) between the target and single-talker masker of 0, 2, and 4 semitones. Pitch discrimination abilities were also measured to confirm that the lowpass-filtered stimuli elicited greater pitch accuracy than the highpass-filtered stimuli. No interaction was found between filter type and ΔF0 in the sentence recognition task, suggesting little or no effect of harmonic rank or pitch accuracy on the ability to use F0 to segregate natural voices, even when the average ΔF0 is relatively small. The results suggest that listeners are able to obtain some benefit of pitch differences between competing voices, even when pitch salience and accuracy is low.


Assuntos
Inteligibilidade da Fala/fisiologia , Percepção da Fala/fisiologia , Adulto , Percepção Auditiva/fisiologia , Implantes Cocleares , Feminino , Humanos , Masculino , Ruído , Mascaramento Perceptivo/fisiologia , Discriminação da Altura Tonal/fisiologia , Reconhecimento Psicológico/fisiologia , Adulto Jovem
4.
J Neurosci ; 41(23): 5045-5055, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-33903222

RESUMO

Many older listeners have difficulty understanding speech in noise, when cues to speech-sound identity are less redundant. The amplitude envelope of speech fluctuates dramatically over time, and features such as the rate of amplitude change at onsets (attack) and offsets (decay), signal critical information about the identity of speech sounds. Aging is also thought to be accompanied by increases in cortical excitability, which may differentially alter sensitivity to envelope dynamics. Here, we recorded electroencephalography in younger and older human adults (of both sexes) to investigate how aging affects neural synchronization to 4 Hz amplitude-modulated noises with different envelope shapes (ramped: slow attack and sharp decay; damped: sharp attack and slow decay). We observed that subcortical responses did not differ between age groups, whereas older compared with younger adults exhibited larger cortical responses to sound onsets, consistent with an increase in auditory cortical excitability. Neural activity in older adults synchronized more strongly to rapid-onset, slow-offset (damped) envelopes, was less sinusoidal, and was more peaked. Younger adults demonstrated the opposite pattern, showing stronger synchronization to slow-onset, rapid-offset (ramped) envelopes, as well as a more sinusoidal neural response shape. The current results suggest that age-related changes in the excitability of auditory cortex alter responses to envelope dynamics. This may be part of the reason why older adults experience difficulty understanding speech in noise.SIGNIFICANCE STATEMENT Many middle-aged and older adults report difficulty understanding speech when there is background noise, which can trigger social withdrawal and negative psychosocial health outcomes. The difficulty may be related to age-related changes in how the brain processes temporal sound features. We tested younger and older people on their sensitivity to different envelope shapes, using EEG. Our results demonstrate that aging is associated with heightened sensitivity to sounds with a sharp attack and gradual decay, and sharper neural responses that deviate from the sinusoidal features of the stimulus, perhaps reflecting increased excitability in the aged auditory cortex. Altered responses to temporal sound features may be part of the reason why older adults often experience difficulty understanding speech in social situations.


Assuntos
Envelhecimento/fisiologia , Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Mascaramento Perceptivo/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ruído , Adulto Jovem
5.
J Vis ; 21(3): 15, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33704373

RESUMO

Divided attention has little effect for simple tasks, such as luminance detection, but it has large effects for complex tasks, such as semantic categorization of masked words. Here, we asked whether the semantic categorization of visual objects shows divided attention effects as large as those observed for words, or as small as those observed for simple feature judgments. Using a dual-task paradigm with nameable object stimuli, performance was compared with the predictions of serial and parallel models. At the extreme, parallel processes with unlimited capacity predict no effect of divided attention; alternatively, an all-or-none serial process makes two predictions: a large divided attention effect (lower accuracy for dual-task trials, compared to single-task trials) and a negative response correlation in dual-task trials (a given response is more likely to be incorrect when the response about the other stimulus is correct). These predictions were tested in two experiments examining object judgments. In both experiments, there was a large divided attention effect and a small negative correlation in responses. The magnitude of these effects was larger than for simple features, but smaller than for words. These effects were consistent with serial models, and rule out some but not all parallel models. More broadly, the results help establish one of the first examples of likely serial processing in perception.


Assuntos
Reconhecimento Visual de Modelos/fisiologia , Mascaramento Perceptivo/fisiologia , Percepção Visual/fisiologia , Adulto , Atenção/fisiologia , Feminino , Humanos , Julgamento , Masculino , Tempo de Reação/fisiologia
6.
J Vis ; 21(2): 1, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33533878

RESUMO

The deleterious effect of nearby flankers on target identification in the periphery is known as visual crowding. Studying visual crowding can advance our understanding of the mechanisms of visual awareness and object recognition. Alleviating visual crowding is one of the major ways to improve peripheral vision. The aim of the current study was to examine whether transcranial direct current stimulation (tDCS) was capable of alleviating visual crowding at different visual eccentricities and with different visual tasks. In the present single-blind sham-controlled study, subjects were instructed to perform an orientation discrimination task or a letter identification task with isolated and crowded targets in the periphery, before and after applying 20 minutes of 2 mA anodal tDCS to visual cortex of the hemisphere contralateral or ipsilateral to visual stimuli. Contralateral tDCS significantly alleviated the orientation crowding effect at two different eccentricities and the letter crowding effect. This alleviation was absent after sham or ipsilateral stimulation and could not be fully explained by the performance improvement with the isolated targets. These findings demonstrated that offline tDCS was effective in alleviating visual crowding across different visual eccentricities and tasks, therefore providing a promising way to improve spatial vision rapidly in crowded scenes.


Assuntos
Aglomeração , Reconhecimento Visual de Modelos/fisiologia , Mascaramento Perceptivo/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Córtex Visual/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Orientação , Método Simples-Cego , Adulto Jovem
7.
J Vis ; 21(2): 3, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33538771

RESUMO

How are visual sensory representations that are acquired peripherally from a saccade target related to sensory representations generated foveally after the saccade? We tested the hypothesis that, when the two representations are perceived to belong to the same object, the post-saccadic value tends to overwrite the pre-saccadic value. Participants executed a saccade to a colored target object, which sometimes changed during the saccade by ±15°, 30°, or 45° in color space. They were post-cued to report either the pre-saccadic or post-saccadic color in a continuous report procedure. Substantial overwriting of the pre-saccadic color by the post-saccadic color was observed. Moreover, the introduction of a brief post-saccadic blank interval (which disrupted the perception of object correspondence) led to a substantial reduction in overwriting. The results provide the first direct evidence for an object-mediated overwriting mechanism across saccades, in which post-saccadic values automatically replace pre-saccadic values.


Assuntos
Movimentos Sacádicos/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Mascaramento Perceptivo/fisiologia , Adulto Jovem
8.
Laryngoscope ; 131(6): E2038-E2043, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33590898

RESUMO

OBJECTIVES: The objectives were to characterize the effects of wearing face coverings on: 1) acoustic speech cues, and 2) speech recognition of patients with hearing loss who listen with a cochlear implant. METHODS: A prospective cohort study was performed in a tertiary referral center between July and September 2020. A female talker recorded sentences in three conditions: no face covering, N95 mask, and N95 mask plus a face shield. Spectral differences were analyzed between speech produced in each condition. The speech recognition in each condition for twenty-three adult patients with at least 6 months of cochlear implant use was assessed. RESULTS: Spectral analysis demonstrated preferential attenuation of high-frequency speech information with the N95 mask plus face shield condition compared to the other conditions. Speech recognition did not differ significantly between the uncovered (median 90% [IQR 89%-94%]) and N95 mask conditions (91% [IQR 86%-94%]; P = .253); however, speech recognition was significantly worse in the N95 mask plus face shield condition (64% [IQR 48%-75%]) compared to the uncovered (P < .001) or N95 mask (P < .001) conditions. CONCLUSIONS: The type and combination of protective face coverings used have differential effects on attenuation of speech information, influencing speech recognition of patients with hearing loss. In the face of the COVID-19 pandemic, there is a need to protect patients and clinicians from spread of disease while maximizing patient speech recognition. The disruptive effect of wearing a face shield in conjunction with a mask may prompt clinicians to consider alternative eye protection, such as goggles, in appropriate clinical situations. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E2038-E2043, 2021.


Assuntos
Implantes Cocleares , Respiradores N95 , Mascaramento Perceptivo , Percepção da Fala , Adulto , Estudos de Coortes , Sinais (Psicologia) , Feminino , Perda Auditiva/fisiopatologia , Humanos , Masculino , Mascaramento Perceptivo/fisiologia , Estudos Prospectivos , Espectrografia do Som , Acústica da Fala , Testes de Discriminação da Fala , Percepção da Fala/fisiologia
9.
Neuroimage ; 228: 117699, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33387631

RESUMO

Understanding speech in noise (SiN) is a complex task that recruits multiple cortical subsystems. There is a variance in individuals' ability to understand SiN that cannot be explained by simple hearing profiles, which suggests that central factors may underlie the variance in SiN ability. Here, we elucidated a few cortical functions involved during a SiN task and their contributions to individual variance using both within- and across-subject approaches. Through our within-subject analysis of source-localized electroencephalography, we investigated how acoustic signal-to-noise ratio (SNR) alters cortical evoked responses to a target word across the speech recognition areas, finding stronger responses in left supramarginal gyrus (SMG, BA40 the dorsal lexicon area) with quieter noise. Through an individual differences approach, we found that listeners show different neural sensitivity to the background noise and target speech, reflected in the amplitude ratio of earlier auditory-cortical responses to speech and noise, named as an internal SNR. Listeners with better internal SNR showed better SiN performance. Further, we found that the post-speech time SMG activity explains a further amount of variance in SiN performance that is not accounted for by internal SNR. This result demonstrates that at least two cortical processes contribute to SiN performance independently: pre-target time processing to attenuate neural representation of background noise and post-target time processing to extract information from speech sounds.


Assuntos
Atenção/fisiologia , Mascaramento Perceptivo/fisiologia , Percepção da Fala/fisiologia , Adulto , Córtex Auditivo , Limiar Auditivo/fisiologia , Eletroencefalografia , Potenciais Evocados Auditivos/fisiologia , Feminino , Humanos , Masculino , Ruído , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído , Adulto Jovem
10.
Optom Vis Sci ; 98(1): 41-50, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33394930

RESUMO

SIGNIFICANCE: Performance on clinical tests of visual acuity can be influenced by the presence of nearby targets. This study compared the influence of neighboring flanking bars and letters on foveal and peripheral letter identification. PURPOSE: Contour interaction and crowding refer to an impairment of visual resolution or discrimination produced by different types of flanking stimuli. This study compared the impairment of percent correct letter identification that is produced in normal observers when a target letter is surrounded by an array of four flanking bars (contour interaction) or four flanking letters (crowding). METHODS: Performance was measured at the fovea and at eccentricities of 1.25, 2.5, and 5° for photopic (200 cd/m2) and mesopic stimuli (0.5 cd/m2) and a range of target-to-flanker separations. RESULTS: Consistent with previous reports, foveal contour interaction and crowding were more pronounced for photopic than mesopic targets. However, no statistically significant difference existed between foveal contour-interaction and crowding functions at either luminance level. On the other hand, flanking bars produced much less impairment of letter identification than letter flankers at all three peripheral locations, indicating that crowding is more severe than contour interaction in peripheral vision. In contrast to the fovea, peripheral crowding and contour-interaction functions did not differ systematically for targets of photopic and mesopic luminance. CONCLUSION: The similarity between foveal contour interaction and crowding and the dissimilarity between peripheral contour interaction and crowding suggest the involvement of different mechanisms at different retinal locations.


Assuntos
Aglomeração , Fóvea Central/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Mascaramento Perceptivo/fisiologia , Acuidade Visual/fisiologia , Humanos
11.
Neuroimage ; 230: 117789, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33497774

RESUMO

Our senses are continuously bombarded with more information than our brain can process up to the level of awareness. The present study aimed to enhance understanding on how attentional selection shapes conscious access under conditions of rapidly changing input. Using an attention task, EEG, and multivariate decoding of individual target- and distractor-defining features, we specifically examined dynamic changes in the representation of targets and distractors as a function of conscious access and the task-relevance (target or distractor) of the preceding item in the RSVP stream. At the behavioral level, replicating previous work and suggestive of a flexible gating mechanism, we found a significant impairment in conscious access to targets (T2) that were preceded by a target (T1) followed by one or two distractors (i.e., the attentional blink), but striking facilitation of conscious access to targets shown directly after another target (i.e., lag-1 sparing and blink reversal). At the neural level, conscious access to T2 was associated with enhanced early- and late-stage T1 representations and enhanced late-stage D1 representations, and interestingly, could be predicted based on the pattern of EEG activation well before T1 was presented. Yet, across task conditions, we did not find convincing evidence for the notion that conscious access is affected by rapid top-down selection-related modulations of the strength of early sensory representations induced by the preceding visual event. These results cannot easily be explained by existing accounts of how attentional selection shapes conscious access under rapidly changing input conditions, and have important implications for theories of the attentional blink and consciousness more generally.


Assuntos
Intermitência na Atenção Visual/fisiologia , Encéfalo/fisiologia , Estado de Consciência/fisiologia , Eletroencefalografia/métodos , Estimulação Luminosa/métodos , Adolescente , Feminino , Humanos , Masculino , Mascaramento Perceptivo/fisiologia , Distribuição Aleatória , Adulto Jovem
12.
Neuroimage ; 228: 117711, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33385562

RESUMO

The deployment of neural alpha (8-12 Hz) lateralization in service of spatial attention is well-established: Alpha power increases in the cortical hemisphere ipsilateral to the attended hemifield, and decreases in the contralateral hemisphere, respectively. Much less is known about humans' ability to deploy such alpha lateralization in time, and to thus exploit alpha power as a spatio-temporal filter. Here we show that spatially lateralized alpha power does signify - beyond the direction of spatial attention - the distribution of attention in time and thereby qualifies as a spatio-temporal attentional filter. Participants (N = 20) selectively listened to spoken numbers presented on one side (left vs right), while competing numbers were presented on the other side. Key to our hypothesis, temporal foreknowledge was manipulated via a visual cue, which was either instructive and indicated the to-be-probed number position (70% valid) or neutral. Temporal foreknowledge did guide participants' attention, as they recognized numbers from the to-be-attended side more accurately following valid cues. In the magnetoencephalogram (MEG), spatial attention to the left versus right side induced lateralization of alpha power in all temporal cueing conditions. Modulation of alpha lateralization at the 0.8 Hz presentation rate of spoken numbers was stronger following instructive compared to neutral temporal cues. Critically, we found stronger modulation of lateralized alpha power specifically at the onsets of temporally cued numbers. These results suggest that the precisely timed hemispheric lateralization of alpha power qualifies as a spatio-temporal attentional filter mechanism susceptible to top-down behavioural goals.


Assuntos
Atenção/fisiologia , Percepção Auditiva/fisiologia , Lateralidade Funcional/fisiologia , Orientação Espacial/fisiologia , Mascaramento Perceptivo/fisiologia , Adulto , Sinais (Psicologia) , Feminino , Humanos , Magnetoencefalografia/métodos , Masculino , Motivação/fisiologia , Processamento de Sinais Assistido por Computador , Adulto Jovem
13.
Q J Exp Psychol (Hove) ; 74(2): 254-276, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32988313

RESUMO

There is a growing understanding that the parafoveal preview effect during reading may represent a combination of preview benefits and preview costs due to interference from parafoveal masks. It has been suggested that visually degrading the parafoveal masks may reduce their costs, but adult readers were later shown to be highly sensitive to degraded display changes. Four experiments examined how preview benefits and preview costs are influenced by the perception of distinct parafoveal degradation at the target word location. Participants read sentences with four preview types (identity, orthographic, phonological, and letter-mask preview) and two levels of visual degradation (0% vs. 20%). The distinctiveness of the target word degradation was either eliminated by degrading all words in the sentence (Experiments 1a-2a) or remained present, as in previous research (Experiments 1b-2b). Degrading the letter masks resulted in a reduction in preview costs, but only when all words in the sentence were degraded. When degradation at the target word location was perceptually distinct, it induced costs of its own, even for orthographically and phonologically related previews. These results confirm previous reports that traditional parafoveal masks introduce preview costs that overestimate the size of the true benefit. However, they also show that parafoveal degradation has the unintended consequence of introducing additional costs when participants are aware of distinct degradation on the target word. Parafoveal degradation appears to be easily perceived and may temporarily orient attention away from the reading task, thus delaying word processing.


Assuntos
Movimentos Oculares/fisiologia , Fóvea Central/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Mascaramento Perceptivo/fisiologia , Leitura , Adulto , Atenção , Fixação Ocular , Humanos
14.
Psychol Res ; 85(2): 660-678, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32020364

RESUMO

The possibility that interference between motor responses contributes to dual-task costs has long been neglected, yet is supported by several recent studies. There are two competing hypotheses regarding this response-related interference. The motor-bottleneck hypothesis asserts that the motor stage of Task 1 triggers a refractory period that delays the motor stage of Task 2. The response-monitoring hypothesis asserts that monitoring of the Task-1 motor response delays the response-selection stage of Task 2. Both hypotheses predict lengthening of Task-2 response time (RT2) when Task 1 requires motor processing relative to when it does not. However, they assume different loci for the response-related bottleneck, and therefore make different predictions regarding (a) the interaction between Task-1 motor requirement and the Task-2 difficulty effect as measured by RT2 and (b) the premotoric durations and motoric durations of Task 2 as measured by lateralized readiness potentials (LRPs). To test these predictions, we conducted two experiments manipulating the Task-1 motor requirement (Go vs. NoGo) and Task-2 response-selection difficulty, as well as the stimulus-onset asynchrony (SOA). Task-1 motor processing significantly lengthened RT2, suggesting response-related interference. Importantly, the Task-1 motor response reduced the Task-2 difficulty effect at the short SOA, indicating postponement of the Task-2 motor stage, consistent with the motor-bottleneck hypothesis. Further consistent with the motor-bottleneck hypothesis, the Task-2 LRP indicated a consistent premotoric duration of Task 2 regardless of Task-1 motor requirement. These results are difficult to reconcile with the response-monitoring hypotheses, which places the response-related bottleneck before the response-selection stage of Task 2. The results also have important implications regarding use of locus-of-slack logic in PRP studies.


Assuntos
Atenção/fisiologia , Comportamento de Escolha/fisiologia , Mascaramento Perceptivo/fisiologia , Período Refratário Psicológico/fisiologia , Adulto , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia , Adulto Jovem
15.
Psychol Res ; 85(2): 605-617, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31974636

RESUMO

The present study investigated participants' ability to introspect about the effect of between-task crosstalk in dual tasks. In two experiments, participants performed a compatibility-based backward crosstalk dual task, and additionally provided estimates of their RTs (introspective reaction times, IRTs) after each trial (Experiment 1) or after each pair of prime and test trials (Experiment 2). In both experiments, the objective performance showed the typical backward crosstalk effect and its sequential modulation depending on compatibility in the previous trial. Very similar patterns were observed in IRTs, despite the typical unawareness of the PRP effect. In sum, these results demonstrate the reliability of between-task crosstalk in dual tasks and that people's introspection about the temporal processing demands in this complex dual-task situation is intriguingly accurate and severely limited at the same time.


Assuntos
Desempenho Psicomotor/fisiologia , Período Refratário Psicológico/fisiologia , Análise e Desempenho de Tarefas , Percepção do Tempo/fisiologia , Adulto , Função Executiva/fisiologia , Feminino , Objetivos , Humanos , Masculino , Mascaramento Perceptivo/fisiologia , Tempo de Reação/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
16.
Eur J Sport Sci ; 21(4): 521-530, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32321368

RESUMO

When executing a sport-specific movement, athletes cannot use all perceptual resources to control their actions. The complexity of a basketball match, demands that individuals command their attention towards the context to make decisions. The dependency on the perceptual sources to control a movement should be kept to a minimum. During a match due to situational constraints, players often see themselves with impaired perceptual sources (e.g. auditory and peripheral vision occlusions). Assuming that professional basketball players are more skilled than amateurs, we analysed how both groups were affected by perceptual impairment, within and in-between groups in a dribbling task. A variability analysis (correlation dimension, approximate entropy and Lyapunov exponent) was used to evaluate how an increased variability or stability, in a specific joint movement, contributes to a better adaptive behaviour when facing perceptual impairment. Professionals showed a significantly lower variability of the wrist movements, but had a significantly higher value of variability in the shoulder horizontal movements (anterior-posterior and lateral), and also in the lateral elbow movements when their downwards peripheral vision was impaired. The increase in variability in such joint movements reflects adaptive behaviour and might be a performance factor.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Movimento/fisiologia , Percepção/fisiologia , Adolescente , Adulto , Atenção/fisiologia , Percepção Auditiva/fisiologia , Tomada de Decisões/fisiologia , Articulação do Cotovelo/fisiologia , Feminino , Humanos , Masculino , Mascaramento Perceptivo/fisiologia , Articulação do Ombro/fisiologia , Análise e Desempenho de Tarefas , Percepção Visual/fisiologia , Articulação do Punho/fisiologia , Adulto Jovem
17.
Neuroimage ; 228: 117681, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33359346

RESUMO

Sequences of repeating tones can be masked by other tones of different frequency. When these tone sequences are perceived, nevertheless, a prominent neural response in the auditory cortex is evoked by each tone of the sequence. When the targets are detected based on their isochrony, participants know that they are listening to the target once they detected it. To explore if the neural activity is more closely related to this detection task or to perceptual awareness, this magnetoencephalography (MEG) study used targets that could only be identified with cues provided after or before the masked target. In experiment 1, multiple mono-tone streams with jittered inter-stimulus interval were used, and the tone frequency of the target was indicated by a cue. Results showed no differential auditory cortex activity between hit and miss trials with post-stimulus cues. A late negative response for hit trials was only observed for pre-stimulus cues, suggesting a task-related component. Since experiment 1 provided no evidence for a link of a difference response with tone awareness, experiment 2 was planned to probe if detection of tone streams was linked to a difference response in auditory cortex. Random-tone sequences were presented in the presence of a multi-tone masker, and the sequence was repeated without masker thereafter. Results showed a prominent difference wave for hit compared to miss trials in experiment 2 evoked by targets in the presence of the masker. These results suggest that perceptual awareness of tone streams is linked to neural activity in auditory cortex.


Assuntos
Atenção/fisiologia , Córtex Auditivo/fisiologia , Conscientização/fisiologia , Mascaramento Perceptivo/fisiologia , Percepção do Timbre/fisiologia , Adulto , Potenciais Evocados Auditivos/fisiologia , Feminino , Humanos , Magnetoencefalografia/métodos , Masculino , Adulto Jovem
18.
Proc Natl Acad Sci U S A ; 117(47): 29363-29370, 2020 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-33229552

RESUMO

A fundamental natural visual task is the identification of specific target objects in the environments that surround us. It has long been known that some properties of the background have strong effects on target visibility. The most well-known properties are the luminance, contrast, and similarity of the background to the target. In previous studies, we found that these properties have highly lawful effects on detection in natural backgrounds. However, there is another important factor affecting detection in natural backgrounds that has received little or no attention in the masking literature, which has been concerned with detection in simpler backgrounds. Namely, in natural backgrounds the properties of the background often vary under the target, and hence some parts of the target are masked more than others. We began studying this factor, which we call the "partial masking factor," by measuring detection thresholds in backgrounds of contrast-modulated white noise that was constructed so that the standard template-matching (TM) observer performs equally well whether or not the noise contrast modulates in the target region. If noise contrast is uniform in the target region, then this TM observer is the Bayesian optimal observer. However, when the noise contrast modulates then the Bayesian optimal observer weights the template at each pixel location by the estimated reliability at that location. We find that human performance for modulated noise backgrounds is predicted by this reliability-weighted TM (RTM) observer. More surprisingly, we find that human performance for natural backgrounds is also predicted by the RTM observer.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Modelos Neurológicos , Reconhecimento Visual de Modelos/fisiologia , Mascaramento Perceptivo/fisiologia , Artefatos , Teorema de Bayes , Humanos , Distribuição Normal , Estimulação Luminosa/métodos
19.
J Vis ; 20(10): 19, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33064123

RESUMO

Macular degeneration (MD), a retinal disease affecting central vision, represents the leading cause of visual impairment in the Western world, and MD patients face severe limitations in daily activities like reading and face recognition. A common compensation strategy adopted by these patients involves the use of a region in the spared peripheral retina as a new fixation spot and oculomotor reference (preferred retinal locus, or PRL). Still, peripheral vision is characterized by poorer visual acuity, fixation stability, and larger crowding zones that further hinder processes like object recognition, visual search, and reading. Perceptual learning (PL) has been successfully used to improve visual acuity in mild visual conditions (e.g., presbyopia, amblyopia and myopia), but results in MD are less clear, often showing limited generalization of learning, unlike what is observed in a healthy population. A possible reason is the suboptimal fixation in the PRL that might prevent patients from processing the briefly presented training stimuli. Following this hypothesis, we trained five MD patients and four age- and eccentricity-matched controls with a protocol that combined contrast detection and a task previously used to train fixation stability. Results showed transfer of learning to crowding reduction, reading speed, and visual acuity in both MD patients and controls. These results suggest that in the case of central vision loss, PL training might benefit from the integration of oculomotor components to optimize the effect of training and promote transfer of learning to other visual functions.


Assuntos
Fixação Ocular/fisiologia , Aprendizagem/fisiologia , Degeneração Macular/fisiopatologia , Mascaramento Perceptivo/fisiologia , Percepção Visual/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escotoma/fisiopatologia , Baixa Visão/fisiopatologia , Acuidade Visual/fisiologia
20.
Perception ; 49(9): 926-939, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33002393

RESUMO

According to the sequential surface integration process hypothesis, the fine near-ground-surface representation and the homogeneous ground surface play a vital role in the representation of the ground surface. When an occluding box or opaque wall is placed between observers and targets, observers underestimate egocentric distance. However, in our daily life, many obstacles are perforated and cover the ground surface and targets simultaneously (e.g., fences). Humans see and observe through fences. The images of these fences and targets, projected onto observers' retinas, overlap each other. This study aims to explore the effects of perforated obstacles (i.e., fences) on space perception. The results showed that observers underestimated the egocentric distances when there was a fence on the ground surface relative to the no-fence condition, and the effect of widely spaced thick wood fences was larger than that of narrowly spaced thin iron fences. We further demonstrated that this effect was quite robust when the target size had a visual angle of 1°, 2°, or 4° in three virtual reality experiments. This study may add support for the notion that the sequential surface integration process hypothesis is applicable even if the obstacle is perforated and covers the target.


Assuntos
Mascaramento Perceptivo/fisiologia , Percepção Espacial/fisiologia , Percepção Visual/fisiologia , Adulto , Percepção de Distância/fisiologia , Feminino , Humanos , Masculino , Realidade Virtual , Adulto Jovem
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