Infants' fast saccades in the gap paradigm and development of visual attention

The saccadic reaction times (SRTs) in the overlap, no-overlap, and gap conditions of 2.5- to 12-month-old infants and adults were measured. In the overlap condition, the SRTs of younger infants were over 600 ms longer than those of older infants, whereas the SRTs in the gap condition of the younger infants were 300–350 ms, much faster than reported hitherto, and were shortened only by about 100 ms. The results indicate that the oculo-motor system and attention process for disengagement in the gap condition mature earlier than the attention process for disengagement in the overlap condition.     

Amplitude Scaling Compensates for Serial Delays in Correcting Eye and Arm Movements

Spatial and metrical parameters of the eye and arm movements made by human subjects (N = 7) in response to visual targets that were stepped unexpectedly either once (single step) or twice (double step) were studied. For the double-step, the displacement of a visual target was decreased or increased in amplitude at intervals before and during a movement. Provided the second target step occurred more than 100 ms before the onset of movement, the amplitude of the subjects' first response was altered in the direction of the new target location. But this amplitude scaling was not always sufficient to reach the new target location, and a second corrective response was required. The latency in producing this second response was greatly increased above reaction time latencies of movements to single-step targets, especially when the target change occurred 100 ms or more before movement onset. These findings suggest that even though serial processing limitations delay the production of a second corrective response, continuous parallel processing of visual information enables the amplitude of the first response to be altered with minimal delay. This enables some degree of real-time continuous control by the visuomotor control system.     

内源性眼跳与注意转移关系研究述评

视觉选择过程中既存在外显的眼跳行为,也包含内隐的注意转移,两者对于视觉目标的加工都有促进作用。近二十年来出现大量关于二者关系的研究,多数研究者发现眼跳和注意转移存在密切联系。内源性眼跳是个体根据目标或意愿主动发起的眼跳,对人类生存具有重大意义。本文系统回顾了视觉加工领域中对于内源性眼跳与空间注意转移关系问题的探讨及其研究成果,分别从行为研究和神经心理学研究两个方面阐述了该领域的研究进展并作出简要评价及展望。     

Local vs. global covert visual attention: Are two states necessary? Comment on Liechty et al., 2003

Liechty, Pieters, and Wedel (2003) report an eye-tracking experiment that is taken to support the distinction between two states of covert visual attention: local versus global. We discuss several logical problems with this dichotomy and their experiment, and then provide an alternate account of their data using a model, E-Z Reader, that requires only a single attention state.We thank Keith Rayner and two anonymous reviewers for comments on an earlier version of this paper.     

I don’t know where to look: the impact of intolerance of uncertainty on saccades towards non-predictive emotional face distractors

Attentional bias to uncertain threat is associated with anxiety disorders. Here we examine the extent to which emotional face distractors (happy, angry and neutral) and individual differences in intolerance of uncertainty (IU), impact saccades in two versions of the “follow a cross” task. In both versions of the follow the cross task, the probability of receiving an emotional face distractor was 66.7%. To increase perceived uncertainty regarding the location of the face distractors, in one of the tasks additional non-predictive cues were presented before the onset of the face distractors and target. We did not find IU to impact saccades towards non-cued face distractors. However, we found IU, over Trait Anxiety, to impact saccades towards non-predictive cueing of face distractors. Under these conditions, IU individuals’ eyes were pulled towards angry face distractors and away from happy face distractors overall, and the speed of this deviation of the eyes was determined by the combination of the cue and emotion of the face. Overall, these results suggest a specific role of IU on attentional bias to threat during uncertainty. These findings highlight the potential of intolerance of uncertainty-based mechanisms to help understand anxiety disorder pathology and inform potential treatment targets.     

Task-irrelevant emotional faces impair response adjustments in a double-step saccade task

Cognitive control enables us to adjust behaviours according to task demands, and emotion influences the cognitive control. We examined how task-irrelevant emotional stimuli impact the ability to inhibit a prepared response and then programme another appropriate response. In the study, either a single target or two sequential targets appeared after emotional face images (positive, neutral, and negative). Subjects were required to freely viewed the emotional faces and make a saccade quickly upon target onset, but inhibit their initial saccades and redirect gaze to the second target if it appeared. We found that subjects were less successful at inhibiting their initial saccades as the inter-target delay increased. Emotional faces further reduced their inhibition ability with a longer delay, but not with a shorter delay. When subjects failed to inhibit the initial saccade, the longer delay produced longer intersaccadic interval. Especially, positive faces lengthened the intersaccadic interval with a longer delay. These results showed mere presence of emotional stimuli influences gaze redirection by impairing the ability to cancel a prepared saccade and delaying the programming of a corrective saccade. Therefore, we propose that the modulation of response adjustment exerted by emotional faces is related to the stage of initial response programming.     

Eye Movements, Cognitive Processes, and Reading

Itisveryclearthateyemovementdatahavebeenextremelyinfluentialinshapingwhatamodelofskilledreadingshouldbelike[1,2].Eyemovementdatahavealsoyieldedvaluableinsightsconcerningthemostappropriatewaystoteachreading[3,4].Giv鄄enthatmyownresearchhasinvolvedtheuseofeyemovementdataformanyyears,Iamoftenaskedwhatthemostsignificantfindingsthathaveemergedfromourlab.Inthisarticle,IwillfocusonwhatIviewtobethemostimportantfindingsanddevelopmentsfromtheresearchthatwehavedoneoverthisextended30yearperiod.Becauseou…     

内源性眼跳前的空间注意转移

采用线运动错觉(illusory line motion)测量的单任务范式,以色块为眼跳提示刺激,用三个实验对内源性眼跳前是否存在空间注意转移进行了探讨。实验一要求被试将眼睛跳往提示刺激处,通过对线运动错觉的分析确定该条件下的空间注意转移规律;实验二要求被试在将视线保持在注视点处的条件下判断目标色块是否出现,以探明线运动错觉是否受对目标色块前注意阶段加工的影响;实验三要求被试将眼睛跳往提示刺激的对侧,分析眼跳位置与提示刺激空间方位的一致性对空间注意转移的影响。获得以下主要结果：(1)内源性眼跳前存在注意转移;(2)在视线保持在注视点处的条件下,注意未受对提示刺激前注意加工的引导;(3)眼跳目标位置与提示目标位置的空间一致性对眼跳前空间注意转移无显著影响。     

Neurophysiology and neuroanatomy of reflexive and volitional saccades: evidence from studies of humans

This review provides a summary of the contributions made by human functional neuroimaging studies to the understanding of neural correlates of saccadic control. The generation of simple visually guided saccades (redirections of gaze to a visual stimulus or pro-saccades) and more complex volitional saccades require similar basic neural circuitry with additional neural regions supporting requisite higher level processes. The saccadic system has been studied extensively in non-human (e.g., single-unit recordings) and human (e.g., lesions and neuroimaging) primates. Considerable knowledge of this system’s functional neuroanatomy makes it useful for investigating models of cognitive control. The network involved in pro-saccade generation (by definition largely exogenously-driven) includes subcortical (striatum, thalamus, superior colliculus, and cerebellar vermis) and cortical (primary visual, extrastriate, and parietal cortices, and frontal and supplementary eye fields) structures. Activation in these regions is also observed during endogenously-driven voluntary saccades (e.g., anti-saccades, ocular motor delayed response or memory saccades, predictive tracking tasks and anticipatory saccades, and saccade sequencing), all of which require complex cognitive processes like inhibition and working memory. These additional requirements are supported by changes in neural activity in basic saccade circuitry and by recruitment of additional neural regions (such as prefrontal and anterior cingulate cortices). Activity in visual cortex is modulated as a function of task demands and may predict the type of saccade to be generated, perhaps via top-down control mechanisms. Neuroimaging studies suggest two foci of activation within FEF - medial and lateral - which may correspond to volitional and reflexive demands, respectively. Future research on saccade control could usefully (i) delineate important anatomical subdivisions that underlie functional differences, (ii) evaluate functional connectivity of anatomical regions supporting saccade generation using methods such as ICA and structural equation modeling, (iii) investigate how context affects behavior and brain activity, and (iv) use multi-modal neuroimaging to maximize spatial and temporal resolution.