Matteo Lisi

Royal Holloway, University of London | RHUL · Department of Psychology

Saccades are rapid eye movements that orient the visual axis toward objects of interest to allow their processing by the central, high-acuity retina. Our ability to collect visual information efficiently relies on saccadic accuracy, which is limited by a combination of uncertainty in the location of the target and motor noise. It has been observed...

Humans can meaningfully express their confidence about uncertain events. Normatively, these beliefs should correspond to Bayesian probabilities. However, it is unclear whether the normative theory provides an accurate description of the human sense of confidence, partly because the self-report measures used in most studies hinder quantitative compa...

Perceptual decisions often require the integration of noisy sensory evidence over time. This process is formalized with sequential sampling models, where evidence is accumulated up to a decision threshold before a choice is made. Although intuition suggests that decision formation must precede the preparation of a motor response (i.e., the action u...

Previous studies suggest that associations between numbers and space are mediated by shifts of visuospatial attention along the horizontal axis. In this study, we investigated the effect of vertical shifts of overt attention, induced by optokinetic stimulation (OKS) and monitored through eye-tracking, in two tasks requiring explicit (number compari...

Experiences of war and displacement can have profound effects on children's affective development and mental health, although the mechanism(s) underlying these effects remain unknown. This study investigated the link between early adversity and attention to affective stimuli using a free‐viewing eye‐tracking paradigm with Syrian refugee (n = 31, Ma...

Probes flashed within a moving frame are dramatically displaced (Ozkan et al, 2021; Wong & Mack, 1981). The effect is much larger than that seen on static or moving probes (induced motion, Duncker, 1929; Wallach et al, 1978). These flashed probes are often perceived with the separation they have in frame coordinates -- a 100% effect. Here we explor...

The double-drift illusion produces a large deviation in perceived direction that strongly dissociates physical position from perceived position. Surprisingly, saccades do not seem to be affected by the illusion (Lisi & Cavanagh, 2015). When targeting a double-drift stimulus, the saccade system is driven by retinal rather than perceived position. He...

Background: Child maltreatment is associated with poorer social functioning and increased risk of mental health problems in adolescence and adulthood, but the processes underlying these associations remain unclear. Although crucial for establishing and maintaining relationships, trust judgements have not been experimentally investigated in childre...

In visual detection tasks confidence ratings are typically less useful for discriminating correct rejections from misses (that is, correct vs wrong ‘signal absent’ decisions) than they are for discriminating hits from false alarms (correct vs wrong ‘signal present’ decisions). While signal detection theory (SDT) can account for this asymmetry by po...

Previous studies suggest that associations between numbers and space are mediated by shifts of visuospatial attention along the horizontal axis. In this study, we investigated the effect of vertical shifts of overt attention, induced by optokinetic stimulation (OKS) and monitored through eye-tracking, in two tasks requiring explicit (number compari...

Early adversity and trauma can have profound effects on children’s affective development and mental health outcomes. Interventions that improve mental health and socioemotional development are essential to mitigate these effects. We conducted a pilot study examining whether a reading-based program ( We Love Reading ) improves emotion recognition an...

Does conscious perception occur during initial sensory processing, or does it arise later in a supra modal fashion? If conscious access truly depends on supra modal processes, we may be able to induce "asensory perception", where only the semantic features of a meaningful stimulus are accessed, untied to its sensory attributes. Here we tested this...

Importance Many ophthalmology appointments have been converted to telemedicine assessments. The use of a printed vision chart for ophthalmology telemedicine appointments that can be used by people who are excluded from digital testing has yet to be validated. Objectives To evaluate the repeatability of visual acuity measured using the Home Acuity...

Objectives: to develop and validate a simple paper vision test (the Home Acuity Test or HAT) for ophthalmology telemedicine appointments, which can be used by people who are digitally excluded. Design: Bland Altman analysis of the HAT chart, compared to the last measured visual acuity on a standard clinical test. Setting: Routine outpatient ophthal...

Eyeblinks cause disruption of visual input that generally goes unnoticed. It is thought that the brain uses active suppression to prevent awareness of the gaps, but it is unclear how suppression would affect the perception of dynamic events when visual input changes across the blink. Here, we addressed this question by studying the perception of mo...

New findings show that corrections for sensory misalignment do not become adult-like until late childhood, whilst sensory integration develops years earlier. This calls for refinement of the theory which posits that to integrate the senses, the developing system must first be calibrated.

Perceptual decisions often require the integration of noisy sensory evidence over time. This process is formalized with sequential sampling models, where evidence is accumulated up to a decision threshold before a choice is made. Although classical accounts grounded in cognitive psychology tend to consider the process of decision formation and the...

Eye blinks cause disruption of visual input that generally goes unnoticed. It is thought that the brain uses active suppression to prevent awareness of the gaps, but it is unclear how suppression would affect the perception of dynamic events, when visual input changes across the blink. Here we addressed this question by studying the perception of m...

Whether humans are optimal decision makers is still a debated issue in the realm of perceptual decisions. Taking advantage of the direct link between an optimal decision-making and the confidence in that decision, we offer a new dual-decisions method of inferring such confidence without asking for its explicit valuation. Our method circumvents the...

Voluntary orienting of spatial attention is typically investigated by visually presented directional cues, which are called predictive when they indicate where the target is more likely to appear. In this study, we investigated the nature of the potential link between cue predictivity (the proportion of valid trials) and the strength of the resulti...

The double-drift stimulus produces a strong shift in apparent motion direction that generates large errors of perceived position. In this study, we tested the effect of attentional load on the perceptual estimates of motion direction and position for double-drift stimuli. In each trial, four objects appeared, one in each quadrant of a large screen,...

The double-drift stimulus (a drifting Gabor with orthogonal internal motion) generates a large discrepancy between its physical and perceived path. Surprisingly, saccades directed to the double-drift stimulus land along the physical, and not perceived, path (Lisi M, Cavanagh P. Curr Biol 25: 2535−2540, 2015). We asked whether memory-guided saccades...

Lo studio dei movimenti oculari è un’importante fonte di informazioni sia per la psicologia e neuropsicologia clinica che per quella sperimentale. Nella prima parte di questo capitolo verranno descritte le differenti tipolo- gie di movimenti oculari e le loro funzioni. Nella seconda parte del capitolo verrà discussa la relazione tra movimenti ocula...

Our visual system allows us to localize objects in the world and plan motor actions toward them. We have recently shown that the localization of moving objects differs between perception and saccadic eye movements (Lisi & Cavanagh, 2015), suggesting different localization mechanisms for perception and action. This finding, however, could reflect a...

Eye blinks cause disruptions to visual input and are accompanied by rotations of the eye ball [1]. Like every motor action, these eye movements are subject to noise and introduce instabilities in gaze direction across blinks [2]. Accumulating errors across repeated blinks would be debilitating for visual performance. Here we show that the oculomoto...

During an eye blink, visual input is disrupted while objects in motion continue to change in position. How does this temporal occlusion affect our ability to accurately perceive motion and time? We carried out two experiments to investigate perception of motion trajectories at the time of a blink. In Experiment 1, we presented participants with a m...

Estimated time contracts or dilates depending on many visual-stimulation attributes (size, speed, etc.). Here we show that when such attributes are jointly modulated so as to respect the rules of perspective, their effect on the perceived duration of moving objects depends on the presence of contextual information about viewing distance. We show th...

Estimated time contracts or dilates depending on many visual-stimulation attributes (size, speed, etc.). Here we show that when such attributes are jointly modulated so as to respect the rules of perspective, their effect on the perceived duration of moving objects depends on the presence of contextual information about viewing distance.We show tha...

Animals (including humans) are able to assess the quality of incoming sensory information and act accordingly while taking decisions. The computations underlying such ability are unclear. If neuronal activity encodes probability distributions over sensory variables, then uncertainty – hence confidence – about their value is explicitly represented a...

The double-drift stimulus leads to a large discrepancy between the physical path of a moving gabor and its perceived direction. Saccades directed to the double-drift stimulus land along the physical, and not perceived, path (Lisi & Cavanagh, 2015). Here we asked whether memory-guided saccades exhibited the same dissociation from perception. We used...

The double-drift stimulus — a drifting gabor with orthogonal internal motion — produces a dramatic shift of its perceived location but no error in saccades that target it (Lisi & Cavanagh, 2015). In the current study, we used this stimulus within the context of a multiple object tracking task in order to test whether the attention involved in track...

Growing evidence suggests that orienting visual attention in space can influence the processing of numerical magnitude, with leftward orienting speeding up the processing of small numbers relative to larger ones and the converse for rightward orienting. The manipulation of eye movements is a convenient way to direct visuospatial attention, but seve...

It has long been known that the diameter of human pupil enlarges with increasing effort during the execution of a task. This has been observed not only for purely mechanical effort but also for mental effort, as for example the computation of arithmetic problems with different levels of difficulty. Here we show that pupil dilation reflects changes...

Visual processing in the human brain provides the data both for perception and for guiding motor actions. It seems natural that our actions would be directed toward perceived locations of their targets, but it has been proposed that action and perception rely on different visual information [ 1–4 ], and this provocative claim has triggered a long-l...

While the role of selective attention in filtering out irrelevant information has been extensively studied, its characteristics and neural underpinnings when multiple environmental stimuli have to be processed in parallel are much less known. Building upon a dual-task paradigm that induced spatial awareness deficits for contralesional hemispace in...

Observers often do not notice when a visual target is displaced during a saccade (Bridgeman et al., 1975). Instead, if the displacement is repeated on several saccades, the oculomotor system adapts so that saccades land near the displaced target (McLaughlin, 1967). Other disruptions of the visual input may also require a recalibration of gaze. Spec...

We compare how three different systems - saccades, pursuit, and perception - determine the direction of the same moving target. Recent studies suggest that this motion information, although it affects all three systems (saccades, Gellman & Carl, 1991; pursuit, Lisberger, 2010; perceived position, De Valois & De Valois, 1991), might be processed dif...

Recent studies have shown that attentional facilitation lingers at the retinotopic coordinates of a previously attended position after an eye movement. These results are intriguing, since the retinotopic location becomes behaviorally irrelevant once the eyes have moved. Critically, in these studies participants were asked to maintain attention on a...

Many psychophysical studies showed that visual motion can influence the perceived location of stationary stimuli. A classical result is that a stationary aperture filled with a drifting grating appear to be displaced in the direction of motion (De Valois & De Valois, 1991). This illusion also affects the visuomotor system as saccades to static, dri...

Previous studies have shown that number processing can induce spatial biases in perception and action and can trigger the orienting of visuospatial attention. Few studies, however, have investigated how spatial processing and visuospatial attention influences number processing. In the present study, we used the optokinetic stimulation (OKS) techniq...

The brain combines information from different senses to improve performance on perceptual tasks. For instance, auditory processing is enhanced by the mere fact that a visual input is processed simultaneously. However, the sensory processing of one modality is itself subject to diverse influences. Namely, perceptual processing depends on the degree...

Previous studies have shown that number processing involves mechanisms related to visuo-spatial attention orienting. The majority of these studies has revealed the effects of number processing on visuo-spatial attention orienting and on spatially-encoded responses (e.g., left-sided, right-sided). Fewer studies, however, have investi- gated how the...

We studied the modulation of visuospatial awareness—and the resultant asymmetries across visual hemifields—induced by a dual-task manipulation that consumed the attentional resources available for spatial monitoring. Reaction times and detection rates for lateralized, briefly-presented, masked or unmasked visual target(s) were assessed in healthy p...

Covert attention can facilitate visual processing at selected relevant locations, but what happens if the eyes move elsewhere? Recent studies have shown that attentional facilitation lingers at the retinotopic coordinates of the previously attended position after an eye movements (Golomb, Chun and Mazer, 2008 Journal of Neuroscience2810654-62). The...

The posterior parietal cortex (PPC) is fundamental for sensorimotor transformations because it combines multiple sensory inputs and posture signals into different spatial reference frames that drive motor programming. Here, we present a computational model mimicking the sensorimotor transformations occurring in the PPC. A recurrent neural network w...

Growing evidence indicates that planning eye movements and orienting visuospatial attention share overlapping brain mechanisms. A tight link between endogenous attention and eye movements is maintained by the premotor theory, in contrast to other accounts that postulate the existence of specific attention mechanisms that modulate the activity of in...