Search results for "Visual Perception"
showing 10 items of 387 documents
Position but not color deviants result in visual mismatch negativity in an active oddball task.
2009
Changes in the visual environment might be detected automatically. This function is provided by the sensory systems and showed, for instance, by the pop-out phenomenon. Automatic change detection is also observable within visual oddball paradigms, where rare changes are introduced in an irrelevant stimulus feature; the detection of deviant stimuli is accompanied by a negative component (so-called visual mismatch negativity) in the human event-related brain potential. In this study, the deviating stimulus feature was embedded in a task-relevant object presented in the focus of attention. With this, visual mismatch negativity was observable only with position deviants presented in the upper v…
Physical Activity from Childhood to Adulthood and Cognitive Performance in Midlife
2019
Introduction: Physical activity (PA) has been suggested to protect against old-age cognitive deficits. However, the independent role of childhood/youth PA for adulthood cognitive performance is unknown. This study investigated the association between PA from childhood to adulthood and midlife cognitive performance. Methods: This study is a part of the Cardiovascular Risk in Young Finns Study. Since 1980, a population-based cohort of 3596 children (age, 3–18 yr) have been followed up in 3- to 9-yr intervals. PA has been queried in all study phases. Cumulative PA was determined in childhood (age, 6–12 yr), adolescence (age, 12–18 yr), young adulthood (age, 18–24 yr), and adulthood (age, 24–37…
The Effects of Hemianopia on Perception of Mutual Gaze
2019
Significance Individuals with left hemianopic field loss (HFL), especially with neglect history, may have greater difficulties than individuals with right HFL in judging the direction of another person's gaze. Purpose Individuals with HFL often show a spatial bias in laboratory-based perceptual tasks. We investigated whether such biases also manifest in a more real-world task, perception of mutual gaze direction, an important, nonverbal communication cue in social interactions. Methods Participants adjusted the eye position of a life-size virtual head on a monitor at a 1-m distance until (1) the eyes appeared to be looking straight at them, or (2) the eyes were perceived to be no longer loo…
Subjective, behavioral, and physiological responses to the rubber hand illusion do not vary with age in the adult phase.
2018
[EN] The Rubber Hand Illusion (RHI) is a perceptual illusion that enables integration of artificial limbs into the body representation through combined multisensory integration. Most previous studies investigating the RHI have involved young healthy adults within a very narrow age range (typically 20-30 years old). The purpose of this paper was to determine the influence of age on the RHI. The RHI was performed on 93 healthy adults classified into three groups of age (20-35 years old, N = 41; 36-60 years old, N = 28; and 61-80 years old, N = 24), and its effects were measured with subjective (Embodiment of Rubber Hand Questionnaire), behavioral (proprioceptive drift), and physiological (cha…
Effects of instruction on acquisition and extinction of electrodermal responses to fear-relevant stimuli.
1977
In the present study we examined the hypothesis that electrodermal responses conditioned to fear-relevant stimuli are insensitive to verbal instructions. In the first experiment, different groups of subjects were conditioned to fear-relevant and fear-irrelevant control stimuli in a long interstimulus interval differential paradigm with shock as the unconditioned stimulus. Then half of the subjects were informed that no more shocks would be presented, and a number of extinction trials followed. The instruction completely abolished responding to fear-irrelevant stimuli, while leaving responses to the fear-relevant stimuli unaffected. In the second experiment, subjects were "conditioned" to fe…
Distraction effects in vision: behavioral and event-related potential indices.
2004
Evidence is presented which shows that slight changes in serially presented visual input can be detected automatically and may result in behavioral distraction. In two experiments, reaction times on a two-alternative, forced-choice duration discrimination task were prolonged in trials where a task-irrelevant change in the location of the stimulus occurred. The P1 and N1 components of the event-related potential were enhanced in such trials. However, electrophysiological and behavioral effects were not affected when the duration discrimination was made more difficult and the N1 amplitude increase and RT prolongation were confined to situations where task-irrelevant location changes were infr…
The Bandwidth of VWM Consolidation Varies With the Stimulus Feature: Evidence From Event-Related Potentials
2018
Our previous work suggests that 2 colors can be consolidated into visual short-term memory (VSTM) in parallel without a loss of memory precision, whereas consolidation of 2 orientations is performed in a strictly serial manner. Those experiments compared VSTM performance for simultaneously and sequentially presented stimuli. However, there is still controversy about whether the bandwidth for consolidation is determined by the type of information. To further investigate this issue, here we measured electroencephalography while participants attempted to consolidate 1, 2 or 4 simultaneously presented colors (Experiment 1) or orientations (Experiment 2) under limited presentation times. We used…
The Development of Perceptual Sensitivity to Second-Order Facial Relations in Children
2010
This study investigated children's perceptual ability to process second-order facial relations. In total, 78 children in three age groups (7, 9, and 11 years) and 28 adults were asked to say whether the eyes were the same distance apart in two side-by-side faces. The two faces were similar on all points except the space between the eyes, which was either the same or different, with various degrees of difference. The results showed that the smallest eye spacing children were able to discriminate decreased with age. This ability was sensitive to face orientation (upright or upside-down), and this inversion effect increased with age. It is concluded here that, despite early sensitivity to conf…
Experimental and methodological factors affecting test-retest reliability of amygdala BOLD responses.
2018
Previous studies reported poor to fair test-retest reliability of amygdala BOLD responses to emotional stimuli. However, these findings are very heterogeneous across and within studies. The present study sought to systematically examine experimental and methodological factors that contribute to this heterogeneity. Forty-six young subjects were scanned twice with a mean test-retest interval of 7 weeks. We compared amygdala reliability across three tasks: A face-matching task, passive viewing of emotional faces, and passive viewing of emotional scenes. We also explored whether extraction of physiological noise can affect the stability of amygdala responses. We assessed test-retest reliability…
Dissociation of emotional processes in response to visual and olfactory stimuli following frontotemporal damage.
2005
Contemporary neuropsychological studies have stressed the widely distributed and multicomponential nature of human affective processes. Here, we examined facial electromyographic (EMG) (zygomaticus and corrugator muscle activity), autonomic (skin conductance and heart rate) and subjective measures of affective valence and arousal in patient TG, a 30 year-old man with left anterior mediotemporal and left orbitofrontal lesions resulting from a traumatic brain injury. Both TG and a normal control group were exposed to hedonically valenced visual and olfactory stimuli. In contrast with control subjects, facial EMG and electrodermal activity in TG did not differentiate among pleasant, unpleasant…