5,807 research outputs found

    Neural differentiation is moderated by age in scene- but not face-selective cortical regions

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    The aging brain is characterized by neural dedifferentiation, an apparent decrease in the functional selectivity of category-selective cortical regions. Age-related reductions in neural differentiation have been proposed to play a causal role in cognitive aging. Recent findings suggest, however, that age-related dedifferentiation is not equally evident for all stimulus categories and, additionally, that the relationship between neural differentiation and cognitive performance is not moderated by age. In light of these findings, in the present experiment, younger and older human adults (males and females) underwent fMRI as they studied words paired with images of scenes or faces before a subsequent memory task. Neural selectivity was measured in two scene-selective (parahippocampal place area (PPA) and retrosplenial cortex (RSC)] and two face-selective [fusiform face area (FFA) and occipital face area (OFA)] regions using both a univariate differentiation index and multivoxel pattern similarity analysis. Both methods provided highly convergent results, which revealed evidence of age-related reductions in neural dedifferentiation in scene-selective but not face-selective cortical regions. Additionally, neural differentiation in the PPA demonstrated a positive, age-invariant relationship with subsequent source memory performance (recall of the image category paired with each recognized test word). These findings extend prior findings suggesting that age-related neural dedifferentiation is not a ubiquitous phenomenon, and that the specificity of neural responses to scenes is predictive of subsequent memory performance independently of age

    Discovering Gender Differences in Facial Emotion Recognition via Implicit Behavioral Cues

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    We examine the utility of implicit behavioral cues in the form of EEG brain signals and eye movements for gender recognition (GR) and emotion recognition (ER). Specifically, the examined cues are acquired via low-cost, off-the-shelf sensors. We asked 28 viewers (14 female) to recognize emotions from unoccluded (no mask) as well as partially occluded (eye and mouth masked) emotive faces. Obtained experimental results reveal that (a) reliable GR and ER is achievable with EEG and eye features, (b) differential cognitive processing especially for negative emotions is observed for males and females and (c) some of these cognitive differences manifest under partial face occlusion, as typified by the eye and mouth mask conditions.Comment: To be published in the Proceedings of Seventh International Conference on Affective Computing and Intelligent Interaction.201

    Age differences in encoding-related alpha power reflect sentence comprehension difficulties

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    When sentence processing taxes verbal working memory, comprehension difficulties arise. This is specifically the case when processing resources decline with advancing adult age. Such decline likely affects the encoding of sentences into working memory, which constitutes the basis for successful comprehension. To assess age differences in encoding-related electrophysiological activity, we recorded the electroencephalogram from three age groups (24, 43, and 65 years). Using an auditory sentence comprehension task, age differences in encoding-related oscillatory power were examined with respect to the accuracy of the given response. That is, the difference in oscillatory power between correctly and incorrectly encoded sentences, yielding subsequent memory effects (SME), was compared across age groups. Across age groups, we observed an age-related SME inversion in the alpha band from a power decrease in younger adults to a power increase in older adults. We suggest that this SME inversion underlies age-related comprehension difficulties. With alpha being commonly linked to inhibitory processes, this shift may reflect a change in the cortical inhibition–disinhibition balance. A cortical disinhibition may imply enriched sentence encoding in younger adults. In contrast, resource limitations in older adults may necessitate an increase in cortical inhibition during sentence encoding to avoid an information overload. Overall, our findings tentatively suggest that age-related comprehension difficulties are associated with alterations to the electrophysiological dynamics subserving general higher cognitive functions

    Minding the manner: attention to motion events in Turkish-Dutch early bilinguals

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    Languages differ in the way motion events are encoded. In satellite-framed languages, motion verbs typically encode manner, while in verb-framed languages, path. We investigated the ways in which satellite-framed Dutch and verb-framed Turkish co-determine one’s attention to motion events in early bilinguals. In an EEG oddball paradigm, Turkish–Dutch bilinguals (n = 25) and Dutch controls (n = 27) watched short video clips of motion events, followed by a still picture that matched the preceding video in four ways (oddball design: 10% full match, 10% manner match, 10% endpoint match, and 70% full mismatch). We found that both groups showed similar oddball P300 effects, associated with task-related attention. Group differences were revealed in a late positivity (LP): The endpoint-match elicited a larger LP than the manner-match in the bilinguals, which may reflect language-driven attention. Our results indicate that cross-linguistic manner encoding difference impacts attention at a later stage

    Minding the manner: attention to motion events in Turkish–Dutch early bilinguals

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    Languages differ in the way motion events are encoded. In satellite-framed languages, motion verbs typically encode manner, while in verb-framed languages, path. We investigated the ways in which satellite-framed Dutch and verb-framed Turkish co-determine one’s attention to motion events in early bilinguals. In an EEG oddball paradigm, Turkish–Dutch bilinguals (n = 25) and Dutch controls (n = 27) watched short video clips of motion events, followed by a still picture that matched the preceding video in four ways (oddball design: 10% full match, 10% manner match, 10% endpoint match, and 70% full mismatch). We found that both groups showed similar oddball P300 effects, associated with task-related attention. Group differences were revealed in a late positivity (LP): The endpoint-match elicited a larger LP than the manner-match in the bilinguals, which may reflect language-driven attention. Our results indicate that cross-linguistic manner encoding difference impacts attention at a later stage

    Culture shapes how we look at faces

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    Background: Face processing, amongst many basic visual skills, is thought to be invariant across all humans. From as early as 1965, studies of eye movements have consistently revealed a systematic triangular sequence of fixations over the eyes and the mouth, suggesting that faces elicit a universal, biologically-determined information extraction pattern. Methodology/Principal Findings: Here we monitored the eye movements of Western Caucasian and East Asian observers while they learned, recognized, and categorized by race Western Caucasian and East Asian faces. Western Caucasian observers reproduced a scattered triangular pattern of fixations for faces of both races and across tasks. Contrary to intuition, East Asian observers focused more on the central region of the face. Conclusions/Significance: These results demonstrate that face processing can no longer be considered as arising from a universal series of perceptual events. The strategy employed to extract visual information from faces differs across cultures

    Change blindness: eradication of gestalt strategies

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    Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task
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