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1.
Nat Commun ; 12(1): 5234, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475391

RESUMO

In spite of the reduced visual acuity, parafoveal information plays an important role in natural reading. However, competing models on reading disagree on whether words are previewed parafoveally at the lexical level. We find neural evidence for lexical parafoveal processing by combining a rapid invisible frequency tagging (RIFT) approach with magnetoencephalography (MEG) and eye-tracking. In a silent reading task, target words are tagged (flickered) subliminally at 60 Hz. The tagging responses measured when fixating on the pre-target word reflect parafoveal processing of the target word. We observe stronger tagging responses during pre-target fixations when followed by low compared with high lexical frequency targets. Moreover, this lexical parafoveal processing is associated with individual reading speed. Our findings suggest that reading unfolds in the fovea and parafovea simultaneously to support fluent reading.


Assuntos
Macula Lutea/fisiologia , Leitura , Movimentos Oculares/fisiologia , Feminino , Fixação Ocular/fisiologia , Fóvea Central/fisiologia , Humanos , Masculino , Modelos Neurológicos , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto Jovem
2.
Sci Rep ; 11(1): 17480, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471183

RESUMO

In natural vision humans and other primates explore environment by active sensing, using saccadic eye movements to relocate the fovea and sample different bits of information multiple times per second. Saccades induce a phase reset of ongoing neuronal oscillations in primary and higher-order visual cortices and in the medial temporal lobe. As a result, neuron ensembles are shifted to a common state at the time visual input propagates through the system (i.e., just after fixation). The extent of the brain's circuitry that is modulated by saccades is not yet known. Here, we evaluate the possibility that saccadic phase reset impacts the anterior nuclei of the thalamus (ANT). Using recordings in the human thalamus of three surgical patients during natural vision, we found that saccades and visual stimulus onset both modulate neural activity, but with distinct field potential morphologies. Specifically, we found that fixation-locked field potentials had a component that preceded saccade onset. It was followed by an early negativity around 50 ms after fixation onset which is significantly faster than any response to visual stimulus presentation. The timing of these events suggests that the ANT is predictively modulated before the saccadic eye movement. We also found oscillatory phase concentration, peaking at 3-4 Hz, coincident with suppression of Broadband High-frequency Activity (BHA; 80-180 Hz), both locked to fixation onset supporting the idea that neural oscillations in these nuclei are reorganized to a low excitability state right after fixation onset. These findings show that during real-world natural visual exploration neural dynamics in the human ANT is influenced by visual and oculomotor events, which supports the idea that ANT, apart from their contribution to episodic memory, also play a role in natural vision.


Assuntos
Núcleos Anteriores do Tálamo/fisiologia , Movimentos Oculares/fisiologia , Fixação Ocular , Vias Neurais , Neurônios/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
3.
Clin Neurophysiol ; 132(11): 2798-2807, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34592558

RESUMO

OBJECTIVE: We combined electroencephalography (EEG) and eye-tracking recordings to examine the underlying factors elicited during the serial Rapid-Automatized Naming (RAN) task that may differentiate between children with dyslexia (DYS) and chronological age controls (CAC). METHODS: Thirty children with DYS and 30 CAC (Mage = 9.79 years; age range 7.6 through 12.1 years) performed a set of serial RAN tasks. We extracted fixation-related potentials (FRPs) under phonologically similar (rime-confound) or visually similar (resembling lowercase letters) and dissimilar (non-confounding and discrete uppercase letters, respectively) control tasks. RESULTS: Results revealed significant differences in FRP amplitudes between DYS and CAC groups under the phonologically similar and phonologically non-confounding conditions. No differences were observed in the case of the visual conditions. Moreover, regression analysis showed that the average amplitude of the extracted components significantly predicted RAN performance. CONCLUSION: FRPs capture neural components during the serial RAN task informative of differences between DYS and CAC and establish a relationship between neurocognitive processes during serial RAN and dyslexia. SIGNIFICANCE: We suggest our approach as a methodological model for the concurrent analysis of neurophysiological and eye-gaze data to decipher the role of RAN in reading.


Assuntos
Dislexia/fisiopatologia , Eletroencefalografia/métodos , Movimentos Oculares/fisiologia , Tecnologia de Rastreamento Ocular , Tempo de Reação/fisiologia , Leitura , Criança , Dislexia/diagnóstico , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos
4.
Invest Ophthalmol Vis Sci ; 62(10): 35, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34459850

RESUMO

Purpose: Research on infantile nystagmus syndrome (INS) and velocity discrimination is limited, and no research has examined velocity discrimination in subjects with INS at their null position and away from it. This study aims to investigate how individuals with INS perform, compared with controls, when carrying out velocity discrimination tasks. Particularly, the study aims to assess how the null position affects their performance. Methods: INS subjects (N = 21, mean age 24 years; age range, 15-34 years) and controls (N = 16, mean age 26 years; age range, 22-39 years) performed horizontal and vertical velocity discrimination tasks at two gaze positions. Eighteen INS subjects were classified as idiopathic INS and three had associated visual disorders (two had oculocutaneous albinism, and one had congenital cataract). For INS subjects, testing was done at the null position and 15° away from it. If there was no null, testing was done at primary gaze position and 15° away from primary. For controls, testing was done at primary gaze position and 20° away from primary. Horizontal and vertical velocity discrimination thresholds were determined and analyzed. Results: INS subjects showed significantly higher horizontal and vertical velocity discrimination thresholds compared with controls at both gaze positions (P < 0.001). Horizontal thresholds for INS subjects were elevated more than vertical thresholds (P < 0.0001) for INS subjects but not for controls. Within the INS group, 12 INS subjects who had an identified null position showed significantly lower horizontal and vertical thresholds at the null than at 15° away from it (P < 0.05). Conclusions: Velocity discrimination was impaired in INS subjects, with better performance at the null. These findings could assist in understanding how INS affects the daily activities of patients in tasks involving moving objects, and aid in developing new clinical visual function assessments for INS.


Assuntos
Movimentos Oculares/fisiologia , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Nistagmo Congênito/fisiopatologia , Músculos Oculomotores/fisiopatologia , Acuidade Visual , Adolescente , Adulto , Feminino , Humanos , Masculino , Síndrome , Adulto Jovem
5.
Sci Rep ; 11(1): 16288, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381127

RESUMO

Veterinary and human medicine are still seeking a conclusive explanation of the function of sleep, including the change in sleep behaviour over the course of an individual's lifetime. In human medicine, sleep disorders and abnormalities in the electroencephalogram are used for prognostic statements, therapeutic means and diagnoses. To facilitate such use in foal medicine, we monitored 10 foals polysomnographically for 48 h. Via 10 attached cup electrodes, brain waves were recorded by electroencephalography, eye movements by electrooculography and muscle activity by electromyography. Wireless polysomnographs allowed us to measure the foals in their home stables. In addition, each foal was simultaneously monitored with infrared video cameras. By combining the recorded data, we determined the time budgeting of the foals over 48 h, whereby the states of vigilance were divided into wakefulness, light sleep, slow-wave sleep and rapid-eye-movement sleep, and the body positions into standing, suckling, sternal recumbency and lateral recumbency. The results of the qualitative analyses showed that the brain waves of the foals differ in their morphology from those previously reported for adult horses. The quantitative data analyses revealed that foals suckle throughout all periods of the day, including night-time. The results of our combined measurements allow optimizing the daily schedule of the foals according to their sleep and activity times. We recommend that stall rest should begin no later than 9.00 p.m. and daily stable work should be done in the late afternoon.


Assuntos
Cavalos/fisiologia , Sono REM/fisiologia , Animais , Encéfalo/fisiologia , Eletroencefalografia/métodos , Eletromiografia/métodos , Eletroculografia/métodos , Estudos de Avaliação como Assunto , Movimentos Oculares/fisiologia , Polissonografia/métodos , Descanso/fisiologia , Vigília/fisiologia
6.
PLoS One ; 16(8): e0255779, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34379645

RESUMO

Helicopter landing on a ship is a visually regulated "rendezvous" task during which pilots must use fine control to land a powerful rotorcraft on the deck of a moving ship tossed by the sea while minimizing the energy at impact. Although augmented reality assistance can be hypothesized to improve pilots' performance and the safety of landing maneuvers by guiding action toward optimal behavior in complex and stressful situations, the question of the optimal information to be displayed to feed the pilots' natural information-movement coupling remains to be investigated. Novice participants were instructed to land a simplified helicopter on a ship in a virtual reality simulator while minimizing energy at impact and landing duration. The wave amplitude and related ship heave were manipulated. We compared the benefits of two types of visual augmentation whose design was based on either solving cockpit-induced visual occlusion problems or strengthening the online regulation of the deceleration by keeping the current [Formula: see text] variable around an ideal value of -0.5 to conduct smooth and efficient landing. Our results showed that the second augmentation, ecologically grounded, offers benefits at several levels of analysis. It decreases the landing duration, improves the control of the helicopter displacement, and sharpens the sensitivity to changes in [Formula: see text]. This underlines the importance for designers of augmented reality systems to collaborate with psychologists to identify the relevant perceptual-motor strategy that must be encouraged before designing an augmentation that will enhance it.


Assuntos
Aeronaves , Aviação , Pilotos , Navios , Adulto , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Militares , Análise e Desempenho de Tarefas , Adulto Jovem
7.
PLoS One ; 16(8): e0254745, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34339439

RESUMO

Evidence shows that skilled readers extract information about upcoming words in the parafovea. Using the boundary paradigm, we investigated native Arabic readers' processing of orthographic, morphological, and semantic information available parafoveally. Target words were embedded in frame sentences, and prior to readers fixating them, one of the following previews were made available: (a) Identity preview; (b) Preview that shared the pattern morpheme with the target; (c) Preview that shared the root morpheme with the target; (d) Preview that was a synonym with the target word; (e) Preview with two of the root letters were transposed thus creating a new root, while preserving all letter identities of the target; (f) Preview with two of the root letters were transposed thus creating a pronounceable pseudo root, while also preserving all letter identities of the target; and (g) Previews that was unrelated to the target word and shared no information with it. The results showed that identity, root-preserving, and synonymous preview conditions yielded preview benefit. On the other hand, no benefit was obtained from the pattern-preserving previews, and significant disruption to processing was obtained from the previews that contained transposed root letters, particularly when this letter transposition created a new real root. The results thus reflect Arabic readers' dependance on morphological and semantic information, and suggest that these levels of representation are accessed as early as orthographic information. Implications for theory- and model-building, and the need to accommodate early morphological and semantic processing activities in more comprehensive models are further discussed.


Assuntos
Fóvea Central/anatomia & histologia , Idioma , Semântica , Adolescente , Movimentos Oculares/fisiologia , Humanos , Modelos Lineares , Estimulação Luminosa , Adulto Jovem
8.
Psychol Aging ; 36(5): 604-615, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34291964

RESUMO

Naturalistic stimuli (e.g., movies) provide the opportunity to study lifelike experiences in the lab. While young adults respond to these stimuli in a highly synchronized manner [as indexed by intersubject correlations (ISC) in their neural activity], older adults respond more idiosyncratically. Here, we examine whether eye-movement synchrony (eye-ISC) also declines with age during movie-watching and whether it relates to memory for the movie. Our results show no age-related decline in eye-ISC, suggesting that age differences in neural ISC are not caused by differences in viewing patterns. Both age groups recalled the same number of episodic details from the movie, but older adults recalled proportionally fewer episodic details due to their greater output of semantic and false information. In both age groups, higher eye-ISC related to a higher proportion of internal details and a lower proportion of false information being recalled. Finally, both older and younger adults showed better cued recall for cues taken from within the same event than those spanning an event boundary, further confirming that events are stored in long-term memory as discrete units with stronger associations within than across event boundaries. Taken together, these findings suggest that naturalistic stimuli drive perception in a similar way in younger and older adults, but age differences in neural synchrony further up the information processing stream may contribute to subtle differences in event memory. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Envelhecimento/psicologia , Movimentos Oculares/fisiologia , Rememoração Mental , Filmes Cinematográficos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Sinais (Psicologia) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
PLoS One ; 16(7): e0254105, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34197536

RESUMO

The perception of moving objects (real motion) is a critical function for interacting with a dynamic environment. Motion perception can be also induced by particular structural features of static images (illusory motion) or by photographic images of subjects in motion (implied motion, IM). Many cortical areas are involved in motion processing, particularly the medial temporal cortical area (MT), dedicated to the processing of real, illusory, and implied motion. Recently, there has been a growing interest in the influence of high-level visual processes on pupillary responses. However, just a few studies have measured the effect of motion processing on the pupil, and not always with consistent results. Here we systematically investigate the effects of real, illusory, and implied motion on the pupil diameter for the first time, by showing different types of stimuli (movies, illusions, and photos) with the same average luminance to the same observers. We find different pupillary responses depending on the nature of motion. Real motion elicits a larger pupillary dilation than IM, which in turn induces more dilation than control photos representing static subjects (No-IM). The pupil response is sensitive even to the strength of IM, as photos with enhanced IM (blur, motion streaks, speed lines) induce larger dilation than simple freezed IM (subjects captured in the instant they are moving). Also, the subject represented in the stimulus matters: human figures are interpreted as more dynamic and induce larger dilation than objects/animals. Interestingly, illusory motion induces much less dilation than all the other motion categories, despite being seen as moving. Overall, pupil responses depend on the individual perception of dynamicity, confirming that the pupil is modulated by the subjective interpretation of complex stimuli. We argue that the different pupillary responses to real, illusory, and implied motion reflect the top-down modulations of different cortical areas involved in their processing.


Assuntos
Cognição/fisiologia , Movimentos Oculares/fisiologia , Percepção de Movimento/fisiologia , Pupila/fisiologia , Adulto , Atenção/fisiologia , Feminino , Humanos , Ilusões/fisiologia , Masculino , Fenômenos Fisiológicos Oculares , Estimulação Luminosa , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiologia , Visão Ocular/fisiologia , Adulto Jovem
10.
J Neurosci ; 41(37): 7876-7893, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34326145

RESUMO

Visual object recognition relies on elaborate sensory processes that transform retinal inputs to object representations, but it also requires decision-making processes that read out object representations and function over prolonged time scales. The computational properties of these decision-making processes remain underexplored for object recognition. Here, we study these computations by developing a stochastic multifeature face categorization task. Using quantitative models and tight control of spatiotemporal visual information, we demonstrate that human subjects (five males, eight females) categorize faces through an integration process that first linearly adds the evidence conferred by task-relevant features over space to create aggregated momentary evidence and then linearly integrates it over time with minimum information loss. Discrimination of stimuli along different category boundaries (e.g., identity or expression of a face) is implemented by adjusting feature weights of spatial integration. This linear but flexible integration process over space and time bridges past studies on simple perceptual decisions to complex object recognition behavior.SIGNIFICANCE STATEMENT Although simple perceptual decision-making such as discrimination of random dot motion has been successfully explained as accumulation of sensory evidence, we lack rigorous experimental paradigms to study the mechanisms underlying complex perceptual decision-making such as discrimination of naturalistic faces. We develop a stochastic multifeature face categorization task as a systematic approach to quantify the properties and potential limitations of the decision-making processes during object recognition. We show that human face categorization could be modeled as a linear integration of sensory evidence over space and time. Our framework to study object recognition as a spatiotemporal integration process is broadly applicable to other object categories and bridges past studies of object recognition and perceptual decision-making.


Assuntos
Tomada de Decisões/fisiologia , Reconhecimento Facial/fisiologia , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa , Tempo de Reação/fisiologia
11.
J Neurosci ; 41(33): 7120-7135, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34244360

RESUMO

Our visual environment is complicated, and our cognitive capacity is limited. As a result, we must strategically ignore some stimuli to prioritize others. Common sense suggests that foreknowledge of distractor characteristics, like location or color, might help us ignore these objects. But empirical studies have provided mixed evidence, often showing that knowing about a distractor before it appears counterintuitively leads to its attentional selection. What has looked like strategic distractor suppression in the past is now commonly explained as a product of prior experience and implicit statistical learning, and the long-standing notion the distractor suppression is reflected in α band oscillatory brain activity has been challenged by results appearing to link α to target resolution. Can we strategically, proactively suppress distractors? And, if so, does this involve α? Here, we use the concurrent recording of human EEG and eye movements in optimized experimental designs to identify behavior and brain activity associated with proactive distractor suppression. Results from three experiments show that knowing about distractors before they appear causes a reduction in electrophysiological indices of covert attentional selection of these objects and a reduction in the overt deployment of the eyes to the location of the objects. This control is established before the distractor appears and is predicted by the power of cue-elicited α activity over the visual cortex. Foreknowledge of distractor characteristics therefore leads to improved selective control, and α oscillations in visual cortex reflect the implementation of this strategic, proactive mechanism.SIGNIFICANCE STATEMENT To behave adaptively and achieve goals we often need to ignore visual distraction. Is it easier to ignore distracting objects when we know more about them? We recorded eye movements and electrical brain activity to determine whether foreknowledge of distractor characteristics can be used to limit processing of these objects. Results show that knowing the location or color of a distractor stops us from attentionally selecting it. A neural signature of this inhibition emerges in oscillatory alpha band brain activity, and when this signal is strong, selective processing of the distractor decreases. Knowing about the characteristics of task-irrelevant distractors therefore increases our ability to focus on task-relevant information, in this way gating information processing in the brain.


Assuntos
Atenção/fisiologia , Encéfalo/fisiologia , Visão Ocular/fisiologia , Adulto , Ritmo alfa/fisiologia , Sinais (Psicologia) , Eletroencefalografia , Eletrorretinografia , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Oscilometria , Adulto Jovem
12.
Psychol Aging ; 36(4): 531-542, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34124924

RESUMO

Increased predictability effects in older compared to younger adults have been mostly observed in late eye-movement measures during reading. However, it is unclear whether and how these effects may be related to verbal ability, which typically improves with age. Past studies have shown that verbal abilities modulate the predictability effect. Here, we aimed to replicate predictability effects in younger and older adults in a sentence reading paradigm and to investigate how verbal ability modulates the predictability effect. We monitored 26 younger and 27 older adults' eye movements as they read sentences with target words varying in predictability and examined the impact of age and verbal ability, as reflected in vocabulary and print exposure measures. Replicating previous studies, we found that older adults relied more heavily on contextual information in their anticipation of upcoming input in one late measure. In one early measure (first-fixation duration), participants with higher scores in verbal ability showed greater predictability effects, whereas the predictability effect was virtually absent in those with low scores. In one late measure (regression-path duration), age interacted with predictability. However, verbal ability, when included as a covariate in this model, could not account for the age-related increases in predictability effects. Collectively, our findings indicate that verbal ability influences predictability effects in early processing stages, suggesting facilitation of initial word processing and that some aspect of aging other than verbal ability influences predictability effects in late measures. The latter finding most likely reflects a shift toward integrative controlled processes with age. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Envelhecimento/fisiologia , Atenção/fisiologia , Movimentos Oculares/fisiologia , Adulto , Idoso , Feminino , Humanos , Idioma , Masculino , Pessoa de Meia-Idade , Leitura , Vocabulário , Adulto Jovem
13.
Nat Commun ; 12(1): 4029, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34188047

RESUMO

The representation of space in mouse visual cortex was thought to be relatively uniform. Here we reveal, using population receptive-field (pRF) mapping techniques, that mouse visual cortex contains a region in which pRFs are considerably smaller. This region, the "focea," represents a location in space in front of, and slightly above, the mouse. Using two-photon imaging we show that the smaller pRFs are due to lower scatter of receptive-fields at the focea and an over-representation of binocular regions of space. We show that receptive-fields of single-neurons in areas LM and AL are smaller at the focea and that mice have improved visual resolution in this region of space. Furthermore, freely moving mice make compensatory eye-movements to hold this region in front of them. Our results indicate that mice have spatial biases in their visual processing, a finding that has important implications for the use of the mouse model of vision.


Assuntos
Movimentos Oculares/fisiologia , Córtex Visual/fisiologia , Campos Visuais/fisiologia , Percepção Visual/fisiologia , Animais , Feminino , Movimentos da Cabeça/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estimulação Luminosa
14.
Muscle Nerve ; 64(3): 328-335, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34131928

RESUMO

INTRODUCTION/AIMS: Videonystagmography (VNG) which directly records eye movements using infrared video goggles with mini-cameras, is used to measure nystagmus. Our aim is to explore whether VNG can be used to detect a decrement in the extraocular muscle (EOM) activity of patients with myasthenia gravis (MG). METHODS: Thirty-four patients with MG, including 13 with ocular-predominant and 21 with generalized MG, and 23 healthy controls participated. Using VNG we recorded the velocity of the eye movements of the patients as they followed a moving target. We then calculated the gain by dividing the eye movement velocity (degrees/second) by the target velocity (degrees/second). RESULTS: In MG subjects, the mean initial gain (maximum gain) was 1.23 ± 0.31 (range: 0.63-2.15) for the right eye and 1.22 ± 0.37 (range; 0.60-2.28) for the left eye. The mean minimum gain was 0.11 ± 0.12 (0.01-0.58) for the right and 0.14 ± 0.5 (0.02-0.55) for the left. Due to fatigue, the movement gain was reduced by 91.7% in the right eye and 88.2% in the left eye. After reaching minimum velocity, gain remained at a minimum for a mean of 1.08 ± 0.52 (0.3-2.4) s for the right and 1.49 ± 0.85 (0.4-3.6) s for the left, before the velocity increased again. There was no fatigue-induced decrement in healthy subjects. DISCUSSION: Our study documents a decrement in EOM activity recorded by VNG in patients with MG which begins to improve within 1-2 s after reaching minimum velocity, analogous to traditional low-frequency repetitive nerve stimulation testing and its U-shaped pattern. Thus, VNG may be a promising diagnostic test for MG.


Assuntos
Medições dos Movimentos Oculares , Movimentos Oculares/fisiologia , Miastenia Gravis/diagnóstico , Músculos Oculomotores/fisiopatologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/fisiopatologia , Adulto Jovem
15.
J Alzheimers Dis ; 82(3): 1033-1044, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34151787

RESUMO

BACKGROUND: Biological information drawn from eye-tracking metrics is providing evidence regarding drivers of cognitive decline in Alzheimer's disease. In particular, pupil size has proved useful to investigate cognitive performance during online activities. OBJECTIVE: To investigate the oculomotor correlates of impaired performance of patients with mild Alzheimer's Clinical Syndrome (ACS) on a recently developed memory paradigm, namely the Short-Term Memory Binding Test (STMBT). METHODS: We assessed a sample of eighteen healthy controls (HC) and eighteen patients with a diagnosis of mild ACS with the STMBT while we recorded their oculomotor behaviors using pupillometry and eye-tracking. RESULTS: As expected, a group (healthy controls versus ACS) by condition (Unbound Colours versus Bound Colours) interaction was found whereby behavioral group differences were paramount in the Bound Colours condition. Healthy controls' pupils dilated significantly more in the Bound Colours than in the Unbound Colours condition, a discrepancy not observed in ACS patients. Furthermore, ROC analysis revealed the abnormal pupil behaviors distinguished ACS patients from healthy controls with values of sensitivity and specify of 100%, thus outperforming both recognition scores and gaze duration. CONCLUSION: The biological correlates of Short-Term Memory Binding impairments appear to involve a network much wider than we have thought to date, which expands across cortical and subcortical structures. We discuss these findings focusing on their implications for our understanding of neurocognitive phenotypes in the preclinical stages of Alzheimer's disease and potential development of cognitive biomarkers that can support ongoing initiatives to prevent dementia.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/fisiopatologia , Movimentos Oculares/fisiologia , Tecnologia de Rastreamento Ocular , Memória de Curto Prazo/fisiologia , Pupila/fisiologia , Idoso , Doença de Alzheimer/psicologia , Percepção de Cores/fisiologia , Feminino , Percepção de Forma/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Músculos Oculomotores/fisiologia , Estimulação Luminosa/métodos , Reconhecimento Psicológico/fisiologia , Síndrome
17.
Neuroimage ; 239: 118313, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34175425

RESUMO

Growing evidence shows that theta-band (4-7 Hz) activity in the auditory cortex phase-locks to rhythms of overt speech. Does theta activity also encode the rhythmic dynamics of inner speech? Previous research established that silent reading of direct speech quotes (e.g., Mary said: "This dress is lovely!") elicits more vivid inner speech than indirect speech quotes (e.g., Mary said that the dress was lovely). As we cannot directly track the phase alignment between theta activity and inner speech over time, we used EEG to measure the brain's phase-locked responses to the onset of speech quote reading. We found that direct (vs. indirect) quote reading was associated with increased theta phase synchrony over trials at 250-500 ms post-reading onset, with sources of the evoked activity estimated in the speech processing network. An eye-tracking control experiment confirmed that increased theta phase synchrony in direct quote reading was not driven by eye movement patterns, and more likely reflects synchronous phase resetting at the onset of inner speech. These findings suggest a functional role of theta phase modulation in reading-induced inner speech.


Assuntos
Córtex Auditivo/fisiologia , Eletroencefalografia , Eletroculografia , Movimentos Oculares/fisiologia , Processos Mentais/fisiologia , Leitura , Fala/fisiologia , Ritmo Teta/fisiologia , Adulto , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
18.
PLoS One ; 16(6): e0250763, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34143788

RESUMO

This study examined involuntary capture of attention, overt attention, and stimulus valence and arousal ratings, all factors that can contribute to potential attentional biases to face and train objects in children with and without autism spectrum disorder (ASD). In the visual domain, faces are particularly captivating, and are thought to have a 'special status' in the attentional system. Research suggests that similar attentional biases may exist for other objects of expertise (e.g. birds for bird experts), providing support for the role of exposure in attention prioritization. Autistic individuals often have circumscribed interests around certain classes of objects, such as trains, that are related to vehicles and mechanical systems. This research aimed to determine whether this propensity in autistic individuals leads to stronger attention capture by trains, and perhaps weaker attention capture by faces, than what would be expected in non-autistic children. In Experiment 1, autistic children (6-14 years old) and age- and IQ-matched non-autistic children performed a visual search task where they manually indicated whether a target butterfly appeared amongst an array of face, train, and neutral distractors while their eye-movements were tracked. Autistic children were no less susceptible to attention capture by faces than non-autistic children. Overall, for both groups, trains captured attention more strongly than face stimuli and, trains had a larger effect on overt attention to the target stimuli, relative to face distractors. In Experiment 2, a new group of children (autistic and non-autistic) rated train stimuli as more interesting and exciting than the face stimuli, with no differences between groups. These results suggest that: (1) other objects (trains) can capture attention in a similar manner as faces, in both autistic and non-autistic children (2) attention capture is driven partly by voluntary attentional processes related to personal interest or affective responses to the stimuli.


Assuntos
Atenção/fisiologia , Transtorno do Espectro Autista/fisiopatologia , Movimentos Oculares/fisiologia , Reconhecimento Facial/fisiologia , Percepção Visual/fisiologia , Adolescente , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Tempo de Reação
19.
PLoS One ; 16(6): e0252622, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34125863

RESUMO

In recent decades reported findings regarding gender differences in reading achievement, cognitive abilities and maturation process in boys and girls are conflicting. As reading is one of the most important processes in the maturation of an individual, the aim of the study was to better understand gender differences between primary school students. The study evaluates differences in Heart Rate Variability (HRV), Electroencephalography (EEG), Electrodermal Activities (EDA) and eye movement of participants during the reading task. Taking into account that colour may affect reading skills, in that it affects the emotional and physiological state of the body, the research attempts to provide a better understanding of gender differences in reading through examining the effect of colour, as applied to reading content. The physiological responses of 50 children (25 boys and 25 girls) to 12 different background and overlay colours of reading content were measured and summarised during the reading process. Our findings show that boys have shorter reading duration scores and a longer Saccade Count, Saccade Duration Total, and Saccade Duration Average when reading on a coloured background, especially purple, which could be caused by their motivation and by the type of reading task. Also, the boys had higher values for the Delta band and the Whole Range of EEG measurements in comparison to the girls when reading on coloured backgrounds, which could reflect the faster maturation of the girls. Regarding EDA measurements we did not find systematic differences between groups either on white or on coloured/overlay background. We found the most significant differences arose in the HRV parameters, namely (SDNN (ms), STD HR (beats/min), RMSSD (ms), NN50 (beats), pNN50 (%), CVRR) when children read the text on coloured/overlay backgrounds, where the girls showed systematically higher values on HRV measurements in comparison to the boys, mostly with yellow, red, and orange overlay colours.


Assuntos
Percepção de Cores/fisiologia , Cor , Leitura , Estudantes/estatística & dados numéricos , Criança , Eletrocardiografia/instrumentação , Eletrocardiografia/métodos , Eletrocardiografia/estatística & dados numéricos , Eletroencefalografia/instrumentação , Eletroencefalografia/métodos , Eletroencefalografia/estatística & dados numéricos , Movimentos Oculares/fisiologia , Feminino , Resposta Galvânica da Pele/fisiologia , Humanos , Masculino , Psicofisiologia/instrumentação , Psicofisiologia/métodos , Psicofisiologia/estatística & dados numéricos , Movimentos Sacádicos/fisiologia , Fatores Sexuais , Fatores de Tempo
20.
J Alzheimers Dis ; 82(1): 421-433, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34024820

RESUMO

BACKGROUND: Alzheimer's disease (AD) is characterized by progressive deterioration of cognitive functions and may be preceded by mild cognitive impairment (MCI). Evidence shows changes in pupil and vergence responses related to cognitive processing of visual information. OBJECTIVE: Here we test the hypothesis that MCI and AD are associated with specific patterns in vergence and pupil responses. METHODS: We employed a visual oddball task. In the distractor condition (80%of the trials), a blue stimulus was presented whereas in the target condition (20%of trials) it was red. Participants (23 Controls, 33 MCI patients, and 18 AD patients) were instructed to press a button when a target appeared. RESULTS: Participants briefly converged their eyes 200 ms after stimulus presentation. In controls, this transient peak response was followed by a delay response to targets but not to distractor stimuli. In the patient groups, delay responses to distractors were noticed. Consequently, the differential vergence response was strong in the control group, weak in the MCI group, and absent in the AD group. Pupils started to dilate 500-600 ms after the appearance of a target but slightly contracted after the presentation of a distractor. This differential pupil response was strongest in the AD group. CONCLUSION: Our findings support the idea of a role of vergence and pupil responses in attention and reveal altered responses in MCI and AD patients. Further studies should assess the value of vergence and pupil measurements as an objective support tool for early diagnosis of AD.


Assuntos
Doença de Alzheimer/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Movimentos Oculares/fisiologia , Pupila/fisiologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Medições dos Movimentos Oculares , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Percepção Visual
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