Attention alters certainty but not appearance

Does paying attention to a stimulus change its appearance or merely influence the decision mechanisms involved in reporting it? Recently we proposed an uncertainty stealing hypothesis in which subjects, when uncertain about a perceptual comparison between a cued and uncued stimulus, tend to disproportionately choose the cued stimulus. The result is a psychometric function that mimics the results that would be measured if attention actually changed the appearance of the cued stimulus. In the present study, we measure uncertainty explicitly. In three separate experiments, subjects judged the relative appearance of two Gabor patches that differed in contrast. In the first two experiments, subjects performed a comparative judgment, reporting which stimulus had the higher contrast. In the third experiment, subjects performed an equality judgment, reporting whether the two stimuli had the same or different contrast. In the first comparative judgment experiment and in the equality judgment experiment, one of the two stimuli was pre-cued by an exogenous cue. In the second comparative judgment experiment, a decision bias was explicitly introduced: one stimulus was followed by a post-cue and the subjects were instructed, when uncertain, to choose the cued target. In all three experiments, subjects also indicated whether or not they were certain about each response. The results reveal that in the pre-cue comparative judgment, attention shifted the subjects’ uncertainty and made subjects more likely to report that the cued stimulus had higher contrast. In the post-cue biased comparative judgment, subjects also were more likely to report that the cued stimulus had higher contrast, but without a shift in uncertainty. In the equality judgment, attention did not affect the contrast judgment, and the subjects’ uncertainty remained aligned with their decision. We conclude that attention does not alter appearance but rather manipulates subjects’ uncertainty and decision mechanisms.

EXPRESS: How the size of exogenous attentional cues alters visual performance: from response gain to contrast gain

The normalization model of attention (NMoA) predicts that the attention gain pattern is mediated by changes in the size of the attentional field and stimuli. However, existing studies have not measured gain patterns when the relative sizes of stimuli are changed. To investigate the NMoA, the present study manipulated the attentional field size, namely, the exogenous cue size. Moreover, we assessed whether the relative rather than the absolute size of the attentional field matters, either by holding the target size constant and changing the cue size (experiments 1-3) or by holding the cue size constant and changing the target size (experiment 4), in a spatial cueing paradigm of psychophysical procedures. The results show that the gain modulations changed from response gain to contrast gain when the precue size changed from small to large relative to the target size (experiments 1-3). Moreover, when the target size was once again made larger than the precue size, there was still a change in response gain (experiment 4). These results suggest that the size of exogenous cues plays an important role in adjusting the attentional field and that relative changes rather than absolute changes to exogenous cue size determine gain modulation. These results are consistent with the prediction of the NMoA and provide novel insights into gain modulations of visual selective attention.

Exogenous Bimodal Cues Attenuate Age-Related Audiovisual Integration

Previous studies have demonstrated that exogenous attention decreases audiovisual integration (AVI); however, whether the AVI is different when exogenous attention is elicited by bimodal and unimodal cues and its aging effect remain unclear. To clarify this matter, 20 older adults and 20 younger adults were recruited to conduct an auditory/visual discrimination task following bimodal audiovisual cues or unimodal auditory/visual cues. The results showed that the response to all stimulus types was faster in younger adults compared with older adults, and the response was faster when responding to audiovisual stimuli compared with auditory or visual stimuli. Analysis using the race model revealed that the AVI was lower in the exogenous-cue conditions compared with the no-cue condition for both older and younger adults. The AVI was observed in all exogenous-cue conditions for the younger adults (visual cue > auditory cue > audiovisual cue); however, for older adults, the AVI was only found in the visual-cue condition. In addition, the AVI was lower in older adults compared to younger adults under no- and visual-cue conditions. These results suggested that exogenous attention decreased the AVI, and the AVI was lower in exogenous attention elicited by bimodal-cue than by unimodal-cue conditions. In addition, the AVI was reduced for older adults compared with younger adults under exogenous attention.

On Why Objects Appear Smaller in the Visual Periphery

An object appears smaller in the periphery than in the center of the visual field. In two experiments ( N = 24), we demonstrated that visuospatial attention contributes substantially to this perceptual distortion. Participants judged the size of central and peripheral target objects after a transient, exogenous cue directed their attention to either the central or the peripheral location. Peripheral target objects were judged to be smaller following a central cue, whereas this effect disappeared completely when the peripheral target was cued. This outcome suggests that objects appear smaller in the visual periphery not only because of the structural properties of the visual system but also because of a lack of spatial attention.

How Goal Cue and Motor Activity Modulate Working Memory Performance in Preschoolers?

Working memory (WM) development is considered as a major source of cognitive development. Nevertheless, preschoolers are well known for their poor performance in WM tasks. We suggested that this poor performance results from goal neglect, which would hamper the setting of maintenance strategies. Previous studies have shown that preschoolers’ WM performance can be improved in particular contexts, such as game situation because it can provide cues to support goal maintenance (Bertrand & Camos, 2015; Istomina, 1975). The present experiment aimed at disentangling the effect of two types of cues, exogenous and endogenous, in 5- to 7-year-old children's recall performance. Based on previous findings, a shopping stall was used as exogenous cue and walking played the role of an endogenous cue. The shopping stall provides an exogenous cue because it helps maintaining the goal, i.e., why children had to memorize the series of fruits and vegetables, while walking can provide an endogenous cue as the end of the walk coincides with recall time. Contrary to our hypotheses, we did not observe any improvement of WM performance in conditions with the shopping stall as potential goal cue whereas a detrimental effect of walking was observed in all age groups. We proposed that the latter effect resulted from the distracting of attention from attention-based maintenance activities, and that preschoolers' poor WM performance is not fundamentally due to goal neglect.

Interactions between target location and reward size modulate the rate of microsaccades in monkeys

We have studied how rewards modulate the occurrence of microsaccades by manipulating the size of an expected reward and the location of the cue that sets the expectations for future reward. We found an interaction between the size of the reward and the location of the cue. When monkeys fixated on a cue that signaled the size of future reward, the frequency of microsaccades was higher if the monkey expected a large vs. a small reward. When the cue was presented at a site in the visual field that was remote from the position of fixation, reward size had the opposite effect: the frequency of microsaccades was lower when the monkey was expecting a large reward. The strength of pursuit initiation also was affected by reward size and by the presence of microsaccades just before the onset of target motion. The gain of pursuit initiation increased with reward size and decreased when microsaccades occurred just before or after the onset of target motion. The effect of the reward size on pursuit initiation was much larger than any indirect effects reward might cause through modulation of the rate of microsaccades. We found only a weak relationship between microsaccade direction and the location of the exogenous cue relative to fixation position, even in experiments where the location of the cue indicated the direction of target motion. Our results indicate that the expectation of reward is a powerful modulator of the occurrence of microsaccades, perhaps through attentional mechanisms.

The pupillary light response reflects exogenous attention and inhibition of return

Here we show that the pupillary light response reflects exogenous (involuntary) shifts of attention and inhibition of return. Participants fixated in the center of a display that was divided into a bright and a dark half. An exogenous cue attracted attention to the bright or dark side of the display. Initially, the pupil constricted when the bright, as compared to the dark side of the display was cued, reflecting a shift of attention towards the exogenous cue. Crucially, this pattern reversed about one second after cue presentation. This later-occurring, relative dilation (when the bright side was cued) reflected disengagement from the previously attended location, analogous to the behavioral phenomenon of inhibition of return. Indeed, we observed a strong correlation between 'pupillary inhibition' and behavioral inhibition of return. We conclude that the pupillary light response is a complex eye movement that reflects how we selectively parse and interpret visual input.

The pupillary light response reflects exogenous attention and inhibition of return

Here we show that the pupillary light response reflects exogenous (involuntary) shifts of attention and inhibition of return. Participants fixated in the center of a display that was divided into a bright and a dark half. An exogenous cue attracted attention to the bright or dark side of the display. Initially, the pupil constricted when the bright, as compared to the dark side of the display was cued, reflecting a shift of attention towards the exogenous cue. Crucially, this pattern reversed about one second after cue presentation. This later-occurring, relative dilation (when the bright side was cued) reflected disengagement from the previously attended location, analogous to the behavioral phenomenon of inhibition of return. Indeed, we observed a strong correlation between 'pupillary inhibition' and behavioral inhibition of return. We conclude that the pupillary light response is a complex eye movement that reflects how we selectively parse and interpret visual input.