The time-course of generating discourse-level representations in Tunisian Arabic: Effects of task demands on detecting character-attribute anomalies

Neurons in cortical area MT have localized receptive fields (RF) representing the contralateral hemifield and play an important role in processing visual motion. We recorded the activity of these neurons during a behavioral task in which two monkeys were required to discriminate and remember visual motion presented in the ipsilateral hemifield. During the task, the monkeys viewed two stimuli, sample and test, separated by a brief delay and reported whether they contained motion in the same or in opposite directions. Fifty to 70% of MT neurons were activated by the motion stimuli presented in the ipsilateral hemifield at locations far removed from their classical receptive fields. These responses were in the form of excitation or suppression and were delayed relative to conventional MT responses. Both excitatory and suppressive responses were direction selective, but the nature and the time course of their directionality differed from the conventional excitatory responses recorded with stimuli in the RF. Direction selectivity of the excitatory remote response was transient and early, whereas the suppressive response developed later and persisted after stimulus offset. The presence or absence of these unusual responses on error trials, as well as their magnitude, was affected by the behavioral significance of stimuli used in the task. We hypothesize that these responses represent top-down signals from brain region(s) accessing information about stimuli in the entire visual field and about the behavioral state of the animal. The recruitment of neurons in the opposite hemisphere during processing of behaviorally relevant visual signals reveals a mechanism by which sensory processing can be affected by cognitive task demands.

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Impact of task demands and fixation to features on the time course of facial emotion processing

Journal of Vision ◽

10.1167/14.10.1397 ◽

2014 ◽

Vol 14 (10) ◽

pp. 1397-1397 ◽

Cited By ~ 1

Author(s):

K. Neath ◽

R. Itier

Keyword(s):

Time Course ◽

Emotion Processing ◽

Task Demands ◽

Facial Emotion ◽

Facial Emotion Processing

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The Electrophysiology and Time Course of Processing Vocal Emotion Expressions

The Oxford Handbook of Voice Perception ◽

10.1093/oxfordhb/9780198743187.013.20 ◽

2018 ◽

pp. 458-472

Author(s):

Silke Paulmann ◽

Sonja A. Kotz

Keyword(s):

Time Course ◽

Emotion Processing ◽

Task Demands ◽

Emotional Communication ◽

Social Psychological ◽

Eeg Recordings ◽

The Voice ◽

Expression Processing ◽

Processing Steps ◽

Vocal Emotion

Emotional communication is a key component of human social interactions. Listeners need to rapidly decode emotionally relevant signals and adapt their behaviour accordingly. This chapter summarizes recent findings on the time course underlying vocal emotion processing, with a particular focus on suprasegmental information as expressed by the voice and intonation in speech. Evidence from both behavioural investigations and electrophysiological (EEG) recordings confirms that vocal emotion processing includes early rapid—most likely involuntary—appraisal, as well as enhanced cognitive emotional meaning evaluation. Reviewed findings also suggest that influences such as task demands, individual differences, as well as social-psychological factors can alter the identified processing steps. In short, findings suggest that emotional vocal expression processing is a multi-layered process which follows a distinct time course.

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Isn't It Ironic? An Electrophysiological Exploration of Figurative Language Processing

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2010.21411 ◽

2011 ◽

Vol 23 (2) ◽

pp. 277-293 ◽

Cited By ~ 84

Author(s):

Stefanie Regel ◽

Thomas C. Gunter ◽

Angela D. Friederici

Keyword(s):

Language Processing ◽

Cognitive Processes ◽

Time Course ◽

Figurative Language ◽

Semantic Integration ◽

Task Demands ◽

Brain Potentials ◽

Late Positivity ◽

Figurative Language Processing ◽

N400 Component

Although the neurocognitive processes underlying the comprehension of figurative language, especially metaphors and idioms, have been studied extensively, less is known about the processing of irony. In two experiments using event-related brain potentials (ERPs), we examined the types of cognitive processes involved in the comprehension of ironic and literal sentences and their relative time course. The experiments varied in modality (auditory, visual), task demands (comprehension task vs. passive reading), and probability of stimulus occurrence. ERPs consistently revealed a large late positivity (i.e., P600 component) in the absence of an N400 component for irony compared to equivalent literal sentences independent of modality. This P600 was shown to be unaffected by the factors task demands and probability of occurrence. Taken together, the findings suggest that the observed P600 is related to irony processing, and might be a reflection of pragmatic interpretation processes. During the comprehension of irony, no semantic integration difficulty arises (absence of N400), but late inferential processes appear to be necessary for understanding ironic meanings (presence of P600). This finding calls for a revision of current models of figurative language processing.

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Individual Variations in Effort: Assessing Pupillometry for the Hearing Impaired

Trends in Hearing ◽

10.1177/2331216519845596 ◽

2019 ◽

Vol 23 ◽

pp. 233121651984559 ◽

Cited By ~ 4

Author(s):

Anita E. Wagner ◽

Leanne Nagels ◽

Paolo Toffanin ◽

Jane M. Opie ◽

Deniz Başkent

Keyword(s):

Time Course ◽

Experimental Manipulation ◽

Individual Variability ◽

Pupil Dilation ◽

Task Demands ◽

Hearing Impaired ◽

Speech Comprehension ◽

Growth Curve Analysis ◽

Pupillary Responses ◽

Individual Variations

Assessing effort in speech comprehension for hearing-impaired (HI) listeners is important, as effortful processing of speech can limit their hearing rehabilitation. We examined the measure of pupil dilation in its capacity to accommodate the heterogeneity that is present within clinical populations by studying lexical access in users with sensorineural hearing loss, who perceive speech via cochlear implants (CIs). We compared the pupillary responses of 15 experienced CI users and 14 age-matched normal-hearing (NH) controls during auditory lexical decision. A growth curve analysis was applied to compare the responses between the groups. NH listeners showed a coherent pattern of pupil dilation that reflects the task demands of the experimental manipulation and a homogenous time course of dilation. CI listeners showed more variability in the morphology of pupil dilation curves, potentially reflecting variable sources of effort across individuals. In follow-up analyses, we examined how speech perception, a task that relies on multiple stages of perceptual analyses, poses multiple sources of increased effort for HI listeners, wherefore we might not be measuring the same source of effort for HI as for NH listeners. We argue that interindividual variability among HI listeners can be clinically meaningful in attesting not only the magnitude but also the locus of increased effort. The understanding of individual variations in effort requires experimental paradigms that (a) differentiate the task demands during speech comprehension, (b) capture pupil dilation in its time course per individual listeners, and (c) investigate the range of individual variability present within clinical and NH populations.

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Oculomotor Target Selection is Mediated by Complex Objects

Journal of Neurophysiology ◽

10.1152/jn.00580.2020 ◽

2021 ◽

Author(s):

Devin Heinze Kehoe ◽

Jennifer Lewis ◽

Mazyar Fallah

Keyword(s):

Time Course ◽

Target Selection ◽

Dorsal Stream ◽

Oculomotor System ◽

Task Demands ◽

Frequency Error ◽

Complex Objects ◽

Vector Modulation ◽

Featural Processing ◽

Vector Representations

Oculomotor target selection often requires discriminating visual features, but it remains unclear how oculomotor substrates encoding saccade vectors functionally contribute to this process. One possibility is that oculomotor vector representations (observed directly as physiological activation or inferred from behavioral interference) of potential targets are continuously re-weighted by task-relevance computed elsewhere in specialized visual modules, while an alternative possibility is that oculomotor modules utilize local featural analyses to actively discriminate potential targets. Strengthening the former account, oculomotor vector representations have longer onset latencies for ventral- (i.e., color) than dorsal-stream features (i.e., luminance), suggesting that oculomotor vector representations originate from featurally-relevant specialized visual modules. Here, we extended this reasoning by behaviorally examining whether the onset latency of saccadic interference elicited by visually complex stimuli is greater than is commonly observed for simple stimuli. We measured human saccade metrics (saccade curvature, endpoint deviations, saccade frequency, error proportion) as a function of time after abrupt distractor onset. Distractors were novel, visually complex, and had to be discriminated from targets to guide saccades. The earliest saccadic interference latency was ~110 ms, considerably longer than previous experiments, suggesting that sensory representations projected into the oculomotor system are gated to allow for sufficient featural processing to satisfy task demands. Surprisingly, initial oculomotor vector representations encoded features, as we manipulated the visual similarity between targets and distractors and observed increased vector modulation response magnitude and duration when the distractor was highly similar to the target. Oculomotor vector modulation was gradually extinguished over the time course of the experiment.

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Task-dependent modulation of SI physiological responses to targets and distractors

Journal of Neurophysiology ◽

10.1152/jn.00385.2012 ◽

2013 ◽

Vol 109 (4) ◽

pp. 1036-1044 ◽

Cited By ~ 8

Author(s):

Elsie Spingath ◽

Hyun-Sug Kang ◽

David T. Blake

Keyword(s):

Time Course ◽

Cortical Plasticity ◽

Task Demands ◽

Neural Responses ◽

Task Condition ◽

Sensory Stimuli ◽

Cortical Implants ◽

Physically Identical ◽

The Relationship ◽

The Brain

Selective attention experimental designs have shown that neural responses to stimuli in primary somatosensory cortex are stronger when the sensory stimuli are task relevant. Other studies have used animals under no task demands for data collection. The relationship between neural responses in the brain during behavior, and while an animal has no task demands, remains underexplored. We trained two animals to perform somatosensory detection for several weeks, followed by somatosensory discrimination for several weeks. Data in response to physically identical stimuli were collected from cortical implants while the animal was under no task demands before each behavioral session and also during that behavioral session. The Fourier spectra of the field potentials during detection or discrimination compared with the no task condition demonstrated suppression of the somatosensory μ-rhythm that is associated with readiness and anticipation of cognitive use of somatosensory and motor inputs. Responses to the task target were stronger during detection and discrimination than in the no task condition. The amplitude normalized time course of the target evoked response was similar in both cases. Evoked responses to the task distractor were not significantly stronger during behavior than in recordings under no task demands. The normalized time course of the distractor responses showed a suppression that peaks 30–35 ms after the onset of the response. The selectivity of this within trial suppression is the same as the selectivity of enduring suppression evident in studies of sensory cortical plasticity, which suggests the same neural process may be responsible for both.

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Flexible neural circuitry in word processing

Behavioral and Brain Sciences ◽

10.1017/s0140525x99411823 ◽

1999 ◽

Vol 22 (2) ◽

pp. 299-300 ◽

Cited By ~ 4

Author(s):

Michael I. Posner ◽

Gregory J. DiGirolamo

Keyword(s):

Blood Flow ◽

Language Processing ◽

Word Processing ◽

Time Course ◽

Right Hemisphere ◽

Neural Circuitry ◽

Task Demands ◽

Language Areas

ERP studies have shown modulation of activation in left frontal and posterior cortical language areas, as well as recruitment of right hemisphere homologues, based on task demands. Furthermore, blood-flow studies have demonstrated changes in the neural circuitry of word processing based on experience. The neural areas and time course of language processing are plastic depending on task demands and experience.

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A comparison of visuomotor cue integration strategies for object placement and prehension

Visual Neuroscience ◽

10.1017/s0952523808080668 ◽

2009 ◽

Vol 26 (1) ◽

pp. 63-72 ◽

Cited By ~ 16

Author(s):

HAL S. GREENWALD ◽

DAVID C. KNILL

Keyword(s):

Motor Control ◽

Visual Cues ◽

Time Course ◽

Three Dimensional ◽

Stimulus Presentation ◽

Task Demands ◽

Cue Integration ◽

Movement Initiation ◽

Initial Stimulus ◽

Integration Strategies

AbstractVisual cue integration strategies are known to depend on cue reliability and how rapidly the visual system processes incoming information. We investigated whether these strategies also depend on differences in the information demands for different natural tasks. Using two common goal-oriented tasks, prehension and object placement, we determined whether monocular and binocular information influence estimates of three-dimensional (3D) orientation differently depending on task demands. Both tasks rely on accurate 3D orientation estimates, but 3D position is potentially more important for grasping. Subjects placed an object on or picked up a disc in a virtual environment. On some trials, the monocular cues (aspect ratio and texture compression) and binocular cues (e.g., binocular disparity) suggested slightly different 3D orientations for the disc; these conflicts either were present upon initial stimulus presentation or were introduced after movement initiation, which allowed us to quantify how information from the cues accumulated over time. We analyzed the time-varying orientations of subjects’ fingers in the grasping task and those of the object in the object placement task to quantify how different visual cues influenced motor control. In the first experiment, different subjects performed each task, and those performing the grasping task relied on binocular information more when orienting their hands than those performing the object placement task. When subjects in the second experiment performed both tasks in interleaved sessions, binocular cues were still more influential during grasping than object placement, and the different cue integration strategies observed for each task in isolation were maintained. In both experiments, the temporal analyses showed that subjects processed binocular information faster than monocular information, but task demands did not affect the time course of cue processing. How one uses visual cues for motor control depends on the task being performed, although how quickly the information is processed appears to be task invariant.

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On the origin of event-related potentials indexing covert attentional selection during visual search: timing of selection by macaque frontal eye field and event-related potentials during pop-out search

Journal of Neurophysiology ◽

10.1152/jn.00549.2012 ◽

2013 ◽

Vol 109 (2) ◽

pp. 557-569 ◽

Cited By ~ 25

Author(s):

Braden A. Purcell ◽

Jeffrey D. Schall ◽

Geoffrey F. Woodman

Keyword(s):

Time Course ◽

Target Selection ◽

Event Related Potentials ◽

Attentional Selection ◽

Task Demands ◽

Frontal Eye Field ◽

Neural Basis ◽

Set Size ◽

Related Potentials ◽

Eye Field

Event-related potentials (ERPs) have provided crucial data concerning the time course of psychological processes, but the neural mechanisms producing ERP components remain poorly understood. This study continues a program of research in which we investigated the neural basis of attention-related ERP components by simultaneously recording intracranially and extracranially from macaque monkeys. Here, we compare the timing of attentional selection by the macaque homologue of the human N2pc component (m-N2pc) with the timing of selection in the frontal eye field (FEF), an attentional-control structure believed to influence posterior visual areas thought to generate the N2pc. We recorded FEF single-unit spiking and local field potentials (LFPs) simultaneously with the m-N2pc in monkeys performing an efficient pop-out search task. We assessed how the timing of attentional selection depends on task demands by direct comparison with a previous study of inefficient search in the same monkeys (e.g., finding a T among Ls). Target selection by FEF spikes, LFPs, and the m-N2pc was earlier during efficient pop-out search rather than during inefficient search. The timing and magnitude of selection in all three signals varied with set size during inefficient but not efficient search. During pop-out search, attentional selection was evident in FEF spiking and LFP before the m-N2pc, following the same sequence observed during inefficient search. These observations are consistent with the hypothesis that feedback from FEF modulates neural activity in posterior regions that appear to generate the m-N2pc even when competition for attention among items in a visual scene is minimal.

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