RESUMEN
A left visual field (LVF) bias in perceptual judgments, response speed, and discrimination accuracy has been reported in humans. Cognitive factors, such as visual spatial attention, are known to modulate or even eliminate this bias. We investigated this problem by recording pupillometry together with functional magnetic resonance imaging (fMRI) in a cued visual spatial attention task. We observed that (i) the pupil was significantly more dilated following attend-right than attend-left cues, (ii) the task performance (e.g. reaction time [RT]) did not differ between attend-left and attend-right trials, and (iii) the difference in cue-related pupil dilation between attend-left and attend-right trials was inversely related to the corresponding difference in RT. Neuroscientically, correlating the difference in cue-related pupil dilation with the corresponding cue-related fMRI difference yielded activations primarily in the right hemisphere, including the right intraparietal sulcus and the right ventrolateral prefrontal cortex. These results suggest that (i) there is an asymmetry in visual spatial attention control, with the rightward attention control being more effortful than the leftward attention control, (ii) this asymmetry underlies the reduction or the elimination of the LVF bias, and (iii) the components of the attentional control networks in the right hemisphere are likely part of the neural substrate of the observed asymmetry in attentional control.
Asunto(s)
Señales (Psicología) , Campos Visuales , Humanos , Mapeo Encefálico , Atención/fisiología , Tiempo de Reacción/fisiología , Percepción Espacial/fisiología , Estimulación Luminosa , Lateralidad Funcional/fisiologíaRESUMEN
Young infants learn about the world by overtly shifting their attention to perceptually salient events. In adults, attention recruits several brain regions spanning the frontal and parietal lobes. However, it is unclear whether these regions are sufficiently mature in infancy to support attention and, more generally, how infant attention is supported by the brain. We used event-related functional magnetic resonance imaging (fMRI) in 24 sessions from 20 awake behaving infants 3 mo to 12 mo old while they performed a child-friendly attentional cuing task. A target was presented to either the left or right of the infant's fixation, and offline gaze coding was used to measure the latency with which they saccaded to the target. To manipulate attention, a brief cue was presented before the target in three conditions: on the same side as the upcoming target (valid), on the other side (invalid), or on both sides (neutral). All infants were faster to look at the target on valid versus invalid trials, with valid faster than neutral and invalid slower than neutral, indicating that the cues effectively captured attention. We then compared the fMRI activity evoked by these trial types. Regions of adult attention networks activated more strongly for invalid than valid trials, particularly frontal regions. Neither behavioral nor neural effects varied by infant age within the first year, suggesting that these regions may function early in development to support the orienting of attention. Together, this furthers our mechanistic understanding of how the infant brain controls the allocation of attention.
Asunto(s)
Atención , Desarrollo Infantil , Lóbulo Frontal/fisiología , Mapeo Encefálico , Lóbulo Frontal/diagnóstico por imagen , Humanos , Lactante , Recién Nacido , Imagen por Resonancia Magnética/métodos , Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/fisiologíaRESUMEN
Focusing attention is a key cognitive skill, but how the gaze of others affects engaged attention remains relatively unknown. We investigated if participants' attentional bias toward a location is modulated by the number of people gazing toward or away from it. We presented participants with a nonpredictive directional cue that biased attention towards a specific location. Then, any number of four stimulus faces turned their gaze toward or away from the attended location. When all the faces looked at the attended location participants increased their commitment to it, and response time to targets at that location were speeded. When most or all of the faces looked away from the attended location, attention was withdrawn, and response times were slowed. This study reveals that the gaze of others can penetrate one's ability to focus attention, which in turn can be both beneficial and costly to one's responses to events in the environment.
Asunto(s)
Sesgo Atencional , Atención , Señales (Psicología) , Fijación Ocular , Humanos , Tiempo de ReacciónRESUMEN
A novel, salient stimulus, even though it is not related to a concurrent goal-directed behavior, powerfully captures people's attention. While this stimulus-driven attentional capture has long been presumed to take place in a purely bottom-up or automatic manner, growing evidence shows that a number of top-down factors modulate the stimulus-driven capture of attention. Recent studies pointed out the cue presentation frequency is such a factor; the capture of attention by a salient, task-irrelevant cue increased as its presentation frequency decreased. Expanding these studies, we investigated how the modulatory effect of the cue frequency differs depending on the level of competition between multiple stimuli. As results, we found that an infrequently presented cue exerted stronger capture effect than a frequently presented cue, either in the presence or in the absence of distractors. Importantly, in the absence of distractors, performance difference elicited by the frequently present cue was due to non-attentional sensory artifacts or decisional noise. However, the same frequent cue evoked genuine attentional effect when multiple distractors accompanied the target, evoking stimulus-driven competition. Taken together, these results demonstrate that the effect of attentional cue is modulated by cue frequency, and this modulation is also affected by stimulus-driven competition.