Does gaze perception facilitate overt orienting?

Recent studies have demonstrated the facilitation of responses to peripheral targets cued by the direction of the gaze of a face. However, in the absence of data from an eye tracker, it has been unclear to what extent these effects are due to the participants making small saccades in response to the cue that bring them closer to the congruent location of the cued targets. We used an eye tracker to show that while such cue-driven saccades occur, they do not account for the main cueing effects observed. Additionally, by using the same general paradigm as has previously been used with infants, we suggest that different mechanisms underlie eye gaze cueing effects in infants and adults.     

Inhibition of return in children and adolescents

Inhibition of return (IOR), slowed responding to targets at a cued location after attention is removed from this location, has been shown to occur both in adults and in infants. To explore suggestion that the timecourse of IOR depends on factors that might affect the efficiency with which attention is removed from the cued location, we compared the performance of young children (5-10-year-olds, N=49, M=8 years, 4 months) to older children and adolescents (11-17-year-olds, N=61, M=14 years) in single and double cue procedures. Cue-target interval was varied to measure the timecourse of IOR in this within-subjects localization task. Whereas no IOR was found in the young group unless a double cue procedure was used, in the older group, we found IOR at all intervals with the double cue procedure and the typical crossover pattern, with early facilitation followed by inhibition in the single cue procedure.     

Object- and location-based inhibition of return in younger and older adults

When a cued object moves to new spatial coordinates, inhibition of return (IOR) with younger adults is found at the original cued location (location-based IOR) and at the current location of the object (object-based IOR). Older adults, however, show only location-based IOR. To determine whether this pattern of results represents a general age-related deficit in object-based IOR, the authors used static displays in which the placeholders (i.e., objects) were either present (location-based IOR+object-based IOR) or absent (location-based IOR only). Both age groups showed location-based IOR, but the older adults failed to show object-based IOR, consistent with age-related differences in visual pathways.     

Unmasking the inhibition of return phenomenon

Conventional wisdom holds that a nonpredictive peripheral cue produces a biphasic response time (RT) pattern: early facilitation at the cued location, followed by an RT delay at that location. The latter effect is called inhibition of return (IOR). In two experiments, we report that IOR occurs at a cued location far earlier than was previously thought, and that it is distinct from attentional orienting. In Experiment 1, IOR was observed early (i.e., within 50 msec) at the cued location, when the cue predicted that a detection target would occur at another location. In Experiment 2, this early IOR effect was demonstrated to occur for target detection, but not for target identification. We conclude that previous failures to observe early IOR at a cued location may have been due to attention being directed to the cued location and thus “masking” IOR.     

Unmasking the inhibition of return phenomenon.

Conventional wisdom holds that a nonpredictive peripheral cue produces a biphasic response time (RT) pattern: early facilitation at the cued location, followed by an RT delay at that location. The latter effect is called inhibition of return (IOR). In two experiments, we report that IOR occurs at a cued location far earlier than was previously thought, and that it is distinct from attentional orienting. In Experiment 1, IOR was observed early (i.e., within 50 msec) at the cued location, when the cue predicted that a detection target would occur at another location. In Experiment 2, this early IOR effect was demonstrated to occur for target detection, but not for target identification. We conclude that previous failures to observe early IOR at a cued location may have been due to attention being directed to the cued location and thus "masking" IOR.     

The neural correlates of orienting to walking direction in 6‐month‐old infants: An ERP study

The ability to detect social signals represents a first step to enter our social world. Behavioral evidence has demonstrated that 6‐month‐old infants are able to orient their attention toward the position indicated by walking direction, showing faster orienting responses toward stimuli cued by the direction of motion than toward uncued stimuli. The present study investigated the neural mechanisms underpinning this attentional priming effect by using a spatial cueing paradigm and recording EEG (Geodesic System 128 channels) from 6‐month‐old infants. Infants were presented with a central point‐light walker followed by a single peripheral target. The target appeared randomly at a position either congruent or incongruent with the walking direction of the cue. We examined infants' target‐locked event‐related potential (ERP) responses and we used cortical source analysis to explore which brain regions gave rise to the ERP responses. The P1 component and saccade latencies toward the peripheral target were modulated by the congruency between the walking direction of the cue and the position of the target. Infants' saccade latencies were faster in response to targets appearing at congruent spatial locations. The P1 component was larger in response to congruent than to incongruent targets and a similar congruency effect was found with cortical source analysis in the parahippocampal gyrus and the anterior fusiform gyrus. Overall, these findings suggest that a type of biological motion like the one of a vertebrate walking on the legs can trigger covert orienting of attention in 6‐month‐old infants, enabling enhancement of neural activity related to visual processing of potentially relevant information as well as a facilitation of oculomotor responses to stimuli appearing at the attended location.     

Spatiotemporal distribution of facilitation and inhibition of return arising from the reflexive orienting of covert attention

Currently, there is debate regarding both the spatial and temporal relationship between facilitation and inhibition of return (IOR) components of attention, as observed on the covert orienting of visual attention task (COVAT). These issues were addressed in a series of experiments where the spatial and temporal relationships between cue and target were manipulated. Facilitation occurred only when the stimulus onset asynchrony (SOA) was short and there was temporal overlap between cue and target. IOR occurred only when SOA was long and there was no temporal overlap between cue and target. Facilitation encompassed the cued location and all locations between the cue and fixation, whereas IOR arose for the entire cued hemifield. These findings suggest that the facilitation and IOR found on COVATs that use noninformative peripheral cues are separable and stimulus-driven processes.     

The spatial distribution of inhibition of return

Inhibition of return (IOR) refers to the finding that response times (RTs) are typically slower for targets at previously attended (cued) locations than for targets at novel (uncued) locations. Although previous research has indicated that IOR may spread beyond a cued location, the present study is the first to examine the spatial distribution of IOR with high spatial resolution over a large portion of the central visual field. This was done by using a typical IOR procedure (cue, delay, target) with 4 cue locations and 441 target locations (each separated by 1° of visual angle). The results indicate that IOR spreads beyond the cued location to affect the cued hemifield. However, the cues also produced a gradient of RTs throughout the visual field, with inhibition in the cued hemifield gradually giving way to facilitation in the hemifield opposite the cue.     

Evidence from a response choice task reveals a selection bias in the attentional cueing paradigm

In a typical attentional cueing paradigm, irrelevant peripheral cues produce early facilitation (fast responses) followed by later inhibition (slow responses) to cued locations. Here we examine whether cues not only influence the speed with which responses are produced, but also impact or bias which location is ultimately selected as requiring a response. Specifically, can cues influence not only the speed with which we respond but also influence the behavior produced? To examine this question, a choice localization task was used in which no targets were presented, and subjects were asked to choose which effector (left hand, right hand) to use in response to a centrally presented tone. Thus, following either a left or right peripheral cue, and then a central tone, subjects were free to respond with either their left or right hand. Early facilitation and later inhibition with this choice procedure were found in both response times and the proportion of responses to the cued and uncued locations. These results suggest that there are processes which initially bias response selection toward cued locations and then subsequently bias response selection away from cued locations.     

Grabbing attention without knowing: Automatic capture of attention by subliminal spatial cues

The present study shows that an abrupt onset cue that is not consciously perceived can cause attentional facilitation followed by inhibition at the cued location. The observation of this classic biphasic effect of facilitation followed by inhibition of return (IOR) suggests that the subliminal cue captured attention in a purely exogenous way. Since IOR is not observed following endogenous shifts of spatial attention, but is observed following exogenous, stimulus-driven shifts of spatial attention, it is unlikely that top-down control settings or other non-attentional effects played a role. The current findings are interpreted in terms of a neurobiological model of visual awareness.     

Spatial distribution of visual attention: Perceptual sensitivity and response latency

Studies of the spatial distribution of visual attention have shown that attentional facilitation monotonically decreases in a graded fashion with increasing distance from an attended location. However, reaction time (RT) measures have typically shown broader gradients than have signal detection (SD) measures of perceptual sensitivity. It is not clear whether these differences have arisen because the stages of information processing indexed by RT measures are different from those indexed by SD measures, or whether these differences are due to methodological confounds in the SD studies. In the present set of experiments, the spatial distribution of attention was studied by using a luminance detection task in an endogenous cuing paradigm that was designed to permit accurate calculations of SD and RT measures for targets at cued and uncued locations. Subjects made target-present/absent decisions at one of six possible cued or uncued upper visual hemifield locations on each trial. The results from three experiments suggest that the differences between broad and focal attentional distributions are not the result of different stages of information processing indexed by RT measures as opposed to SD measures. Rather, the differing distributions appear to reflect variations in attentional allocation strategies induced by the perceptual requirements typical of RT paradigms as opposed to SD paradigms. These findings support numerous prior studies showing that spatial attention affects perceptual sensitivity and that the strategic allocation of attention is a highly flexible process.     

Disruption of delayed memory for a sequence of spatial locations following CA1- or CA3-lesions of the dorsal hippocampus

Axon-sparing neurotoxic lesions of CA1 or CA3 were produced in the dorsal hippocampus to test dissociative lesion effects on spatial working memory for sequential items. Rats were required to remember four different sections sequentially presented on a newly devised maze (i.e., Tulum maze) during a study phase. Each section was cued by a unique object that was specifically associated with each location within the section during the study phase. Following a 15-s delay and during the test phase, rats were required to revisit the location within a section randomly chosen among the previously visited sections in the absence of the cued object. Both CA1 and CA3 lesions similarly disrupted accurate relocation of a previously visited place. However, differential effects of the CA1 and CA3 lesions were observed in serial position curves. CA3-lesions disrupted performance for the first three serial positions, but did not disrupt performance for the last serial position (recency). In contrast, CA1-lesions disrupted performance for all serial positions. The results suggest that temporal separation of spatial memory may depend on the conjoint function of CA1 and CA3 of the hippocampus with a disruption of a spatial pattern completion process following CA3 lesions and a disruption of a temporal pattern separation process following a CA1 lesion.     

自我面孔对空间注意的调控：来自Posner空间线索范式的证据

利用Posner的空间线索范式,三个实验意在探寻自我面孔作为特殊的刺激对空间注意的调控作用。在实验一中,自我或者熟悉的面孔作为内源性线索出现在视野中央,通过朝左或者朝右来提示目标出现的位置。在实验二（小图）和实验三（大图）中,自我或熟悉的面孔与目标同时呈现,作为与任务无关的刺激出现在视野的左侧或右侧。实验一的结果发现,与熟悉的面孔相比较,自我面孔产生了更大的提示效应。这意味着当自我面孔与任务相关时,对提示位置易化优于熟悉的面孔。与之相反的是,在实验二和实验三中,自我面孔和熟悉的面孔同样捕获目标位置的空间注意。然而,研究并没有发现自我面孔与熟悉面孔在捕获注意上的差异。这一结果也许暗示着在注意捕获的过程中,面孔效应足够大而掩盖了自我效应的出现。这些发现表明自我面孔之所以是具有特殊性的刺激不仅受感知过程的影响,还依赖于与任务的关系。     

Age-related differences in object- and location-based inhibition of return of attention

Four experiments examined age-related differences in inhibition of return (IOR) of visual attention. Using static stimuli, both young and older adults were slower to detect targets in previously cued objects, showing equivalent IOR. With objects that moved after they had been cued, young adults were slower to detect targets in the cued object (compared with uncued ones), revealing object-based IOR, but older adults were faster to detect targets in such objects, failing to demonstrate object-based IOR. Both age groups were slower to detect targets at the initially cued location (location-based IOR). The results show that age has a differential effect on IOR depending on the frame of reference of the inhibition: Inhibition for objects breaks down with age, but that for location does not. This pattern of results is consistent with the view that there are specific inhibitory deficits in old age.     

Movement versus focusing of visual attention

In two experiments, we investigated the idea that attention moves through visual space in an analog fashion. The spatial distribution of attention was determined by presenting a spatially informative cue and comparing reaction times to targets at cued and uncued locations as a function of the interval from cue onset to target onset (SOA). Facilitation and inhibition were measured by reference to a neutral condition in which the cue provided no spatial information. In the first experiment, we used a central cue (an arrow), and in the second experiment, we used a peripheral cue (a 50-msec flash). With central cue, the facilitatory effects of the cuing were initially equal for all locations on the indicated side of the display, and then decreased for all locations except the one that had been specifically cued. These results are interpreted as being more consistent with "focusing" of an initially broad "beam" of attention than with "movement" of a narrow beam from fixation to the cued location. With peripheral cues, strong facilitation specific to the cued location was manifest as early as 50 msec after cue onset, but this effect decreased with increasing SOA. Inhibition for uncued locations increased with increasing SOA at a rate that generally reflected their distance from the cued location. Taken together, these results reveal important differences between peripheral and central cues in the generation of attentional selectivity, not just in the time-course of events, but also in the nature of the processes involved.     

FACILITATION OF SACCADES TOWARD A COVERTLY ATTENDED LOCATION IN EARLY INFANCY

Abstract— Covert shifts of visual attention may be demonstrated in both adult and infant subjects by facilitation of reaction times to make a saccade to a previously cued location However, this facilitation may be interpreted m terms of a direct effect on the eye movement system in the present experiment, we attempted to train 4-month-old infants to make a saccade in the location opposite from that in which a cue appeared Following such training, we examined the reaction lime to occasional probe targets that appeared in the same location as the cue Infants were faster to respond to a target in this location than they were to respond to it either in the training (expected) location or in baseline trials We interpret the results as providing further evidence for covert shifts of attention m 4-month-old infants, and suggest that the effects of covert shifts of attention on the eye movement system are independent of those from sequence learning     

Localizing the development of covert attention in infants with scalp event-related potentials

This study examined covert shifts of attention in infants aged 14, 20, and 26 weeks of age with scalp-recorded event-related potentials (ERPs). The infants were tested in a spatial cuing procedure. The reaction time to localize the target showed covert attention shifts (e.g., response facilitation or inhibition of return depending on cue-target stimulus onset asynchrony). There was a larger P1 ERP component on the valid trials than on the invalid trials or on the no-cue control trials. Presaccadic ERP potentials in response to the target were larger when it was in the cued location than when it was in uncued locations. There were increases from 14 to 26 weeks of age in the amount of inhibition of return, in the post-target-onset P1 effect, and in the presaccadic ERP potentials. These results suggest that cortical development parallels the development of covert orienting of attention and saccade planning in infants in this age range.     

Facilitation and inhibition caused by the orienting of attention in propositional reasoning tasks

In an attempt to study the orienting of attention in reasoning, we developed a set of propositional reasoning tasks structurally similar to Posner's (1980) spatial cueing paradigm, widely used to study the orienting of attention in perceptual tasks. We cued the representation in working memory of a reasoning premise, observing whether inferences drawn using that premise or a different, uncued one were facilitated, hindered, or unaffected. The results of Experiments 1a, 1b, 1c, and 1d, using semantically (1a-1c) or statistically (1d) informative cues, showed a robust, long-lasting facilitation for drawing inferences from the cued rule. In Experiment 2, using uninformative cues, inferences from the cued rule were facilitated with a short stimulus onset asynchrony (SOA), whereas they were delayed when the SOA was longer, an effect that is similar to the “inhibition of return” (IOR) in perceptual tasks. Experiment 3 used uninformative cues, three different SOAs, and inferential rules with disjunctive antecedents, replicating the IOR-like effect with the long SOAs and, at the short SOA, finding evidence of a gradient-like behaviour of the facilitation effect. Our findings show qualitative similarities to some effects typically observed in the orienting of visual attention, although the tasks did not involve spatial orienting.     

Facilitation and inhibition caused by the orienting of attention in propositional reasoning tasks

In an attempt to study the orienting of attention in reasoning, we developed a set of propositional reasoning tasks structurally similar to Posner's (1980) spatial cueing paradigm, widely used to study the orienting of attention in perceptual tasks. We cued the representation in working memory of a reasoning premise, observing whether inferences drawn using that premise or a different, uncued one were facilitated, hindered, or unaffected. The results of Experiments 1a, 1b, 1c, and 1d, using semantically (1a–1c) or statistically (1d) informative cues, showed a robust, long-lasting facilitation for drawing inferences from the cued rule. In Experiment 2, using uninformative cues, inferences from the cued rule were facilitated with a short stimulus onset asynchrony (SOA), whereas they were delayed when the SOA was longer, an effect that is similar to the “inhibition of return” (IOR) in perceptual tasks. Experiment 3 used uninformative cues, three different SOAs, and inferential rules with disjunctive antecedents, replicating the IOR-like effect with the long SOAs and, at the short SOA, finding evidence of a gradient-like behaviour of the facilitation effect. Our findings show qualitative similarities to some effects typically observed in the orienting of visual attention, although the tasks did not involve spatial orienting.     

Examining inhibition of return with multiple sequential cues in younger and older adults

Studies with younger adults have shown that when multiple peripheral cues are presented sequentially, inhibition of return (IOR) occurs at several locations with the greatest IOR at the most recently cued location and the least at the earliest cued location. The inhibitory ability needed to tag multiple locations requires visuospatial working memory, and it is thought that this type of memory may be vulnerable to the effects of aging. The present experiments examined whether older adults would show less IOR at multiple cued locations than younger adults when placeholders were present (Experiment 1) and absent (Experiment 2). Of interest, in both experiments older adults showed an almost identical pattern of IOR, in both magnitude and number of inhibited locations, to that of younger adults. This finding, in conjunction with research on memory-guided saccades, suggests that there may be a form of visuospatial working memory, specific to oculomotor and visual attention processes, that is relatively resistant to the effects of aging.