Browsing by keyword "Cognition and Perception"
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Cognitive testing for dementia is adversely affected by administration in a foreign locationBACKGROUND: It is colloquially considered that cognitive tests can be adversely affected by administration in a foreign location. However, a definitive demonstration of this is lacking in the literature. To determine whether or not this is the case, we compared the results of cognitive testing in a familiar versus foreign environment by single test administrator of individuals diagnosed with Alzheimer's disease randomized to placebo in a multi-site clinical study. FINDINGS: Cognitive tests were administered to 6 long-term residents of an assisted living facility at their residence (the "Familiar" cohort). The identical tests were administered to a newly admitted resident and to 2 community-dwelling individuals who drove to the administrator's office for the first time (the "Foreign" cohort). Secondary testing was administered 3 months later at the same respective locations. Caregivers of participants completed reports of mood, behavior and activities of daily living. The Familiar cohort performed equally well at both visits. The Foreign cohort performed significantly worse than the Familiar cohort at baseline. They improved statistically, and matched Familiar cohort performance, by their second visit. Caregiver reports for both cohorts were unchanged between visits. CONCLUSIONS: These findings support the notion that a foreign location can adversely affect performance on cognitive tests, and therefore support cognitive testing in a familiar location.
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Gaze patterns during identity and emotion judgments in hearing adults and deaf users of American Sign LanguageDeaf individuals rely on facial expressions for emotional, social, and linguistic cues. In order to test the hypothesis that specialized experience with faces can alter typically observed gaze patterns, twelve hearing adults and twelve deaf, early-users of American Sign Language judged the emotion and identity of expressive faces (including whole faces, and isolated top and bottom halves), while accuracy and fixations were recorded. Both groups recognized individuals more accurately from top than bottom halves, and emotional expressions from bottom than top halves. Hearing adults directed the majority of fixations to the top halves of faces in both tasks, but fixated the bottom half slightly more often when judging emotion than identity. In contrast, deaf adults often split fixations evenly between the top and bottom halves regardless of task demands. These results suggest that deaf adults have habitual fixation patterns that may maximize their ability to gather information from expressive faces.
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"Look who's talking!" Gaze Patterns for Implicit and Explicit Audio-Visual Speech Synchrony Detection in Children With High-Functioning AutismConversation requires integration of information from faces and voices to fully understand the speaker's message. To detect auditory-visual asynchrony of speech, listeners must integrate visual movements of the face, particularly the mouth, with auditory speech information. Individuals with autism spectrum disorder may be less successful at such multisensory integration, despite their demonstrated preference for looking at the mouth region of a speaker. We showed participants (individuals with and without high-functioning autism (HFA) aged 8-19) a split-screen video of two identical individuals speaking side by side. Only one of the speakers was in synchrony with the corresponding audio track and synchrony switched between the two speakers every few seconds. Participants were asked to watch the video without further instructions (implicit condition) or to specifically watch the in-synch speaker (explicit condition). We recorded which part of the screen and face their eyes targeted. Both groups looked at the in-synch video significantly more with explicit instructions. However, participants with HFA looked at the in-synch video less than typically developing (TD) peers and did not increase their gaze time as much as TD participants in the explicit task. Importantly, the HFA group looked significantly less at the mouth than their TD peers, and significantly more at non-face regions of the image. There were no between-group differences for eye-directed gaze. Overall, individuals with HFA spend less time looking at the crucially important mouth region of the face during auditory-visual speech integration, which is maladaptive gaze behavior for this type of task.
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Neural activations during self-related processing in patients with chronic pain and effects of a brief self-compassion training - A pilot studyChronic pain negatively affects psychological functioning including self-perception. Self-compassion may improve self-related functioning in patients with chronic pain but understanding of the neural mechanisms is limited. In this study, twenty patients with chronic low back pain read negative self-related situations and were instructed to be either self-reassuring or self-critical while undergoing fMRI. Patients rated their feelings of self-reassurance and self-criticism during each condition, and brain responses were contrasted with neutral instructions. Trait self-compassion measures (SCS) were also acquired. Brain activations during self-criticism and self-reassurance were localized to prefrontal, self- and emotion-processing areas, such as medial prefrontal cortex, dorsolateral prefrontal cortex (dlPFC), dorsal anterior cingulate cortex and posterior cingulate cortex. Self-reassurance resulted in more widespread and stronger activations relative to self-criticism. Patients then completed a brief self-compassion training (8 contact hours, 2 weeks home practice). Exploratory pre-post comparisons in thirteen patients found that feelings of self-criticism were significantly reduced and brain activations were greater in the anterior insula and prefrontal cortical regions such as dlPFC. Pre-post increases in dlPFC activation correlated with increased self-compassion (SCS), suggesting that early self-compassion skills might primarily target self-criticism via dlPFC upregulation. Future controlled studies on self-compassion training in chronic pain populations should extend these results.
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Sex differences in cognition, emotional reactivity, and motor ability in gonadally-intact middle-aged marmosets (Callithrix jacchus)Sex differences in cognition are well documented. Women outperform men on measures of perceptual speed and verbal abilities, while men outperform women on tests of spatial processing. Robust sex differences also exist in stress responses. However, it is unclear how these sex differences change over time and whether males and females follow different trajectories of age-related cognitive decline. Studies in nonhuman primate models can help resolve this issue. The common marmoset (Callithrix jacchus) is a New World primate with a short lifespan that can perform complex cognitive tasks in computerized settings that are comparable to those used with humans. The present study is part of a longitudinal project aimed at determining whether males and females follow different trajectories of cognitive aging. This report focuses on sex differences at study entry. Thirteen marmosets (7 females), aged 4-6 years were tested on a comprehensive battery of tasks assessing cognitive function, motor skills and emotional reactivity. For cognition, monkeys were initially trained on a simple visual discrimination problem, followed by reversal learning using the Cambridge Neuropsychological Test Automated Battery (CANTAB). They also performed the Hill-and-Valley task as a measure of fine motor skills. To assess emotional reactivity, each marmoset was separated from their colony for 7 hours. Behavioral assessments, which involved recording the occurrence of approximately 25 behaviors, occurred a total of 6 times: immediately before separation, 3 times during separation, immediately after separation, and 24-hr later. No sex difference was found for simple discrimination, but males tended to perform better than females on the reversal learning task. No sex difference was observed in motor skills. During separation from the colony, females were more reactive than males, as indicated by more agitated locomotion, and vocalizations. Together, these findings expand upon previous studies and demonstrate sex differences in reversal learning and emotional reactivity in gonadally-intact middle-aged marmosets. As the study progresses, we should be able to determine the neural correlates of these sex differences and how they may change with aging. Supported by NIH grant AG046266
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Visual field bias in hearing and deaf adults during judgments of facial expression and identityThe dominance of the right hemisphere during face perception is associated with more accurate judgments of faces presented in the left rather than the right visual field (RVF). Previous research suggests that the left visual field (LVF) bias typically observed during face perception tasks is reduced in deaf adults who use sign language, for whom facial expressions convey important linguistic information. The current study examined whether visual field biases were altered in deaf adults whenever they viewed expressive faces, or only when attention was explicitly directed to expression. Twelve hearing adults and 12 deaf signers were trained to recognize a set of novel faces posing various emotional expressions. They then judged the familiarity or emotion of faces presented in the left or RVF, or both visual fields simultaneously. The same familiar and unfamiliar faces posing neutral and happy expressions were presented in the two tasks. Both groups were most accurate when faces were presented in both visual fields. Across tasks, the hearing group demonstrated a bias toward the LVF. In contrast, the deaf group showed a bias toward the LVF during identity judgments that shifted marginally toward the RVF during emotion judgments. Two secondary conditions tested whether these effects generalized to angry faces and famous faces and similar effects were observed. These results suggest that attention to facial expression, not merely the presence of emotional expression, reduces a typical LVF bias for face processing in deaf signers.
