Visual Processing Demands Research Articles

The interplay of perceptual processing demands and practice in modulating voluntary and involuntary motor responses.

Understanding how sensory processing demands affect the ability to ignore task-irrelevant, loud auditory stimuli (LAS) during a task is key to performance in dynamic environments. For example, tennis players must ignore crowd noise to perform optimally. We investigated how practice affects this ability by examining the effects of delivering LASs during preparatory phase of an anticipatory timing (AT) task on the voluntary and reflexive responses in two conditions: lower and higher visual processing loads. Twenty-four participants (mean age = 23.1, 11 females) completed the experiment. The AT task involved synchronizing a finger abduction response with the last visual stimulus item in a sequence of four Gabor grating patches briefly flashed on screen. The lower demand condition involved only this task, and the higher demand condition required processing the orientations of the patches to report changes in the final stimulus item. Our results showed that higher visual processing demands affected the release of voluntary actions, particularly in the first block of trials. When the perceptual load was lower, responses were released earlier by the LAS compared to the high-load condition. Practice reduced these effects largely, but high perceptual load still led to earlier action release in the second block. In contrast, practice led to more apparent facilitation of eyeblink latency in the second block. These findings indicate that a simple perceptual load manipulation can impact the execution of voluntary motor actions, particularly for inexperienced participants. They also suggest distinct movement preparation influences on voluntary and involuntary actions triggered by acoustic stimuli.

Visual stimulation by extensive visual media consumption can be beneficial for motor learning

In this randomized controlled intervention trial, we investigated whether intense visual stimulation through television watching can enhance visual information processing and motor learning performance. 74 healthy young adults were trained in a motor skill with visual information processing demands while being accommodated in a controlled environment for five days. The experimental manipulation (n = 37) consisted of prolonged television watching (i.e., 8 h/day, + 62.5% on average) to induce intense exposure to visual stimulation. The control group (n = 37) did not consume visual media. The groups were compared by motor learning performance throughout the study as well as pre/post visual attention parameters and resting-state network connectivity in functional MRI. We found that the intervention group performed significantly better in the motor learning task (+ 8.21% (95%-CI[12.04, 4.31], t(70) = 4.23, p < 0.001) while showing an increased capacity of visual short-term memory (+ 0.254, t(58) = − 3.19, p = 0.002) and increased connectivity between visual and motor-learning associated resting-state networks. Our findings suggest that the human brain might enter a state of accentuated visuomotor integration to support the implementation of motor learning with visual information processing demands if challenged by ample input of visual stimulation. Further investigation is needed to evaluate the persistence of this effect regarding participants exposed to accustomed amounts of visual media consumption.Clinical Trials Registration: This trial was registered in the German Clinical Trials Register/Deutsches Register klinischer Studien (DRKS): DRKS00019955.

Lexical and sublexical cortical tuning for print revealed by Steady-State Visual Evoked Potentials (SSVEPs) in early readers.

There are multiple levels of processing relevant to reading that vary in their visual, sublexical, and lexical orthographic processing demands. Segregating distinct cortical sources for each of these levels has been challenging in EEG studies of early readers. To address this challenge, we applied recent advances in analyzing high-density EEG using Steady-State Visual Evoked Potentials (SSVEPs) via data-driven Reliable Components Analysis (RCA) in a group of early readers spanning from kindergarten to second grade. Three controlled stimulus contrasts-familiar words versus unfamiliar pseudofonts, familiar words versus pseudowords, and pseudowords versus nonwords-were used to isolate coarse print tuning, lexical processing, and sublexical orthography-related processing, respectively. First, three overlapping yet distinct neural sources-left vOT, dorsal parietal, and primary visual cortex were revealed underlying coarse print tuning. Second, we segregated distinct cortical sources for the other two levels of processing: lexical fine tuning over occipito-temporal/parietal regions; sublexical orthographic fine tuning over left occipital regions. Finally, exploratory group analyses based on children's reading fluency suggested that coarse print tuning emerges early even in children with limited reading knowledge, while sublexical and higher-level lexical processing emerge only in children with sufficient reading knowledge. RESEARCH HIGHLIGHTS: Cognitive processes underlying coarse print tuning, sublexical, and lexical fine tuning were examined in beginning readers. Three overlapping yet distinct neural sources-left ventral occipito-temporal (vOT), left temporo-parietal, and primary visual cortex-were revealed underlying coarse print tuning. Responses to sublexical orthographic fine tuning were found over left occipital regions, while responses to higher-level linguistic fine tuning were found over occipito-temporal/parietal regions. Exploratory group analyses suggested that coarse print tuning emerges in children with limited reading knowledge, while sublexical and higher-level linguistic fine tuning effects emerge in children with sufficient reading knowledge.

Eye-hand coordination during online reach corrections is task dependent.

To produce accurate movements, the human motor system needs to deal with errors that can occur due to inherent noise, changes in the body, or disturbances in the environment. Here, we investigated the temporal coupling of rapid corrections of the eye and hand in response to a change in visual target location during the movement. In addition to a "classic" double-step task in which the target stepped to a new position, participants performed a set of modified double-step tasks in which the change in movement goal was indicated by the appearance of an additional target, or by a spatial or symbolic cue. We found that both the absolute correction latencies of the eye and hand and the relative eye-hand correction latencies were dependent on the visual characteristics of the target change, with increasingly longer latencies in tasks that required more visual and cognitive processing. Typically, the hand started correcting slightly earlier than the eye, especially when the target change was indicated by a symbolic cue, and in conditions where visual feedback of the hand position was provided during the reach. Our results indicate that the oculomotor and limb-motor system can be differentially influenced by processing requirements of the task and emphasize that temporal eye-hand coupling is flexible rather than rigid.NEW & NOTEWORTHY Eye movements support hand movements in many situations. Here, we used variations of a double-step task to investigate temporal coupling of corrective hand and eye movements in response to target displacements. Correction latency coupling depended on the visual and cognitive processing demands of the task. The hand started correcting before the eye, especially when the task required decoding a symbolic cue. These findings highlight the flexibility and task dependency of eye-hand coordination.

Stroke-induced alteration in multi-layer information transmission of cortico-motor system during elbow isometric contraction modulated by myoelectric-controlled interfaces

Objective. Human movement is a complex process requiring information transmission in inter-cortical, cortico-muscular and inter-muscular networks. Though motor deficits after stroke are associated with impaired networks in the cortico-motor system, the mechanisms underlying these networks are to date not fully understood. The purpose of this study is to investigate the changes in information transmission of the inter-cortical, cortico-muscular and inter-muscular networks after stroke and the effect of myoelectric-controlled interface (MCI) dimensionality on such information transmission in each network. Approach. Fifteen healthy control subjects and 11 post-stroke patients were recruited to perform elbow tracking tasks within different dimensional MCIs in this study. Their electromyography (EMG) and functional near-infrared spectroscopy (fNIRS) signals were recorded simultaneously. Transfer entropy was used to analyse the functional connection that represented the information transmission in each network based on the fNIRS and EMG signals. Main results. The results found that post-stroke patients showed the increased inter-cortical connection versus healthy control subjects, which might be attributed to cortical reorganisation to compensate for motor deficits. Compared to healthy control subjects, a lower strength cortico-muscular connection was found in post-stroke patients due to the reduction of information transmission following a stroke. Moreover, the increased MCI dimensionality strengthened inter-cortical, cortico-muscular and inter-muscular connections because of higher visual information processing demands. Significance. These findings not only provide a comprehensive overview to evaluate changes in the cortico-motor system due to stroke, but also suggest that increased MCI dimensionality may serve as a useful rehabilitation tool for boosting information transmission in the cortico-motor system of post-stroke patients.

Preference and visual cognitive processing demands of alphabetic and QWERTY keyboards of individuals with and without brain injury

ABSTRACT Following a severe brain injury (BI), some literate individuals who require augmentative and alternative communication (AAC) strategies to support communication may benefit from the use of onscreen keyboards to generate text. A range of layouts are available to these individuals within specialized communication software. However, a paucity of information is available to describe user preferences, user perceptions, as well as the visual-cognitive processing demands of such layouts. Such information is critical to guide clinical decision-making for keyboard selection and to provide patient-centered services. This study: (a) described the preferences and perceptions of two onscreen keyboard layouts (QWERTY and alphabetic) and (b) used eye-tracking analysis to investigate the visual-cognitive processing demands between these onscreen keyboards for individuals with and without BI. Results indicated participants in both groups held a strong preference for QWERTY keyboard interfaces and had extensive prior experience using the QWERTY keyboard layout on mobile devices. Eye-tracking analysis revealed less visual-cognitive processing demands using a QWERTY keyboard layout for both groups but were only statistically significant for those without BI. Results suggest that use of a keyboard layout that aligns with client preferences and prior experiences (i.e., the QWERTY keyboard for these participants) may lead to increased satisfaction with the communication experience and increased communication efficiency.

The eye-mind wandering link: Identifying gaze indices of mind wandering across tasks.

During mind wandering, visual processing of external information is attenuated. Accordingly, mind wandering is associated with changes in gaze behaviors, albeit findings are inconsistent in the literature. This heterogeneity obfuscates a complete view of the moment-to-moment processing priorities of the visual system during mind wandering. We hypothesize that this observed heterogeneity is an effect of idiosyncrasy across tasks with varying spatial allocation demands, visual processing demands, and discourse processing demands and reflects a strategic, compensatory shift in how the visual system operates during mind wandering. We recorded eye movements and mind wandering (via thought-probes) as 132 college-aged adults completed a battery of 7 short (6 min) tasks with different visual demands. We found that for tasks requiring extensive sampling of the visual field, there were fewer fixations, and, depending on the specific task, fixations were longer and/or more dispersed. This suggests that visual sampling is sparser and potentially slower and more dispersed to compensate for the decreased sampling rate during mind wandering. For tasks that demand centrally focused gaze, mind wandering was accompanied by more exploratory eye movements, such as shorter and more dispersed fixations as well as larger saccades. Gaze behaviors were not reliably associated with mind wandering during a film comprehension task. These findings provide insight into how the visual system prioritizes external information when attention is focused inward and indicates the importance of task demands when assessing the relationship between eye movements, visual processing, and mind wandering. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Enumeration strategy differences revealed by saccade-terminated eye tracking

Brain regions involved in saccadic eye movements partially overlap with a frontoparietal network implicated in encoding numerosities. Eye movement patterns may plausibly reflect strategic scanning behaviours to resolve the open-ended task of efficiently enumerating visual arrays. If so, these patterns may help explain individual differences in enumeration acuity in terms of well-understood visual attention mechanisms. Most enumeration eye-tracking paradigms, however, do not allow for direct manipulation of eye movement behaviours to test these claims. In the current study we terminated trials after a specified number of saccades to systematically probe the time course of enumeration strategies. Fifteen adults (11 naïve, 4 informed) enumerated random dot arrays under three conditions: (1) a novel saccade-terminated design where arrays were visible until one, two or four saccades had occurred; (2) a duration-terminated design where arrays were shown for 250, 500 or 1000 ms; and (3) a response-terminated design where arrays were visible until a response. Participants gave more accurate responses when enumerating saccade-terminated trials despite taking a similar time as in the duration-terminated trials. When participants were informed how trials would terminate, their saccade onset latencies shifted to match task demands. Rotating saccade vectors to align with salient image locations accounted for variability in the orientation of saccade trajectories. These findings (1) show a combination of stimulus-derived visual processing and task-based strategic demands account for enumeration eye movements patterns, (2) validate a novel saccade-contingent trial termination procedure for studying sequences of enumeration eye movements, and (3) highlight the need to include analyses of spatial and temporal eye movement patterns into models of visual enumeration strategies.

Attention maintenance training: Are young drivers getting better or being more strategic?

Young drivers are particularly poor at maintaining attention to the forward roadway where imminent hazards may occur. Existing training programs such as FOrward Concentration and Attention Learning (FOCAL) have been shown to improve young drivers’ attention maintenance performance. The current study examines two competing hypotheses for the effectiveness of FOCAL: 1) Drivers disregard the secondary task to focus on maintaining attention, or 2) FOCAL improves drivers’ multitasking ability on the driving and the secondary tasks. FOCAL- and placebo-trained drivers navigated through four distinct scenarios in a driving simulator. During each scenario, they were asked to perform a secondary task interacting with a mock in-vehicle navigation system. Results showed that FOCAL improved driver attention maintenance performance and, surprisingly, their secondary task performance. These results suggest the possibility that FOCAL in fact increases not only their ability to maintain their attention to the forward roadway but also a drivers’ multitasking performance. Future works should use a variety of in-vehicle tasks with different visual processing demands to determine the generalizability of the current finding.

Processing capacity for moving objects in artificial worlds

Substantial research over the last 30 years of vision science has illuminated how we understand a dynamic world. Studies of ensemble processing tell us what kinds of motion, like linear translation and global optic flow, can be easily used by human vision perceive coherent object trajectories and estimate time-to-contact (Whitney & Leib, 2018; Van den Berg, 1992). Studies of multiple object tracking tell us how we use information to know that a given object is the same one over space and time (Flombaum, 2009; Scimeca & Franconeri, 2014). Every one of these studies has been inspired by the dynamic natural world that the visual system evolved in. But we also spend several hours daily immersed in artificial worlds that use moving displays for information. Dynamic data visualizations, map transformations, and diagrams are used for data analysis, navigation, and education. These dynamic displays are comprised of multiple dynamic objects that, across domains, demand many of the same visual processing capacities we have long studied in the lab. Empirically determining when these dynamic displays are (and aren’t) effective allows us a fresh scenario for understanding how we process dynamic scenes, while at the same time allowing research outputs to inspire interventions to help create more effective displays for students, scientists, and the general public. We present a theory-driven analysis of these displays and the visual processing demands they invoke. We show that visual processing capacities in perception and attention (ensemble processing, tracking object individuals and groups) are what help us see patterns in artificial displays, and that we fail to see patterns when processing capacity is exceeded. Visualizations that defy categorization within this framework can uncover new basic research directions. This domain presents use-inspired basic research by vision scientists to test visual thinking in the constructed, dynamic displays of everyday visual experience.

Tapping the Full Potential? Jumping Performance of Volleyball Athletes in Game-Like Situations

Background: One key issue in elite interactive team sports is the simultaneous execution of motor actions (e.g., dribbling a ball) and perceptual-cognitive tasks (e.g., visually scanning the environment for action choices). In volleyball, one typical situation is to prepare and execute maximal block jumps after multiple-options decision-making and concurrent visual tracking of the ongoing game dynamics to find an optimal blocking location. Based on resource-related dual- and multi-tasking theories simultaneous execution of visual-cognitive and motor tasks may interfere with each other. Therefore, the aim of this study was to investigate whether volleyball-specific perceptual-cognitive demands (i.e., divided attention, decision making) affect blocking performance (i.e., jumping performance and length of the first step after the ready-block-position) compared to relatively isolated jumping performance.Methods: Twenty-two elite volleyball players (1st – 3rd German league) performed block jumps in front of a net construction in a single-task condition (ST) and in two perceptual (-cognitive) dual-task conditions including a dual-task low (DT_L; presenting a picture of an opponent attack on a screen) and a dual-task high condition (DT_H; presenting videos of an offensive volleyball set play with a two-alternative choice).Results: The results of repeated-measures ANOVAs showed a significant effect of conditions on jumping performance [F(2,42) = 33.64, p < 0.001, ηp2 = 0.62] and on the length of the first step after the ready-block-position [F(2,42) = 7.90, p = 0.001, ηp2 = 0.27). Post hoc comparisons showed that jumping performance in DT_H (p < 0.001) and DT_L (p < 0.001) was significantly lower than in ST. Also, length of the first step after the ready-block-position in DT_H (p = 0.005) and DT_L (p = 0.028) was significantly shorter than in ST.Conclusion: Our findings suggest that blocking performance (i.e., jumping height, length of the first step) decreases in elite volleyball players when a perceptual (-cognitive) load is added. Based on the theory of Wickens (2002), this suggests a resource overlap between visual-processing demands for motor performance and for tracking the dynamics of the game. Interference with the consequence of dual-task related performance costs can therefore also be found in elite athletes in their specific motor expert domain.

A psychophysiological and driving performance evaluation of focal and ambient visual processing demands in simulated driving

Research has focused little on the ambient and focal visual channels within which driving and side-task information can be processed. In the current experiment, for the purpose of demonstrating differentiation of focal and ambient visual processing attentional demands on driving performance and physiological response, subjects participated in a dual-task driving simulation that contained focal and ambient components. We hypothesized that ambient demands would not have any effects on driving performance or physiological response, whereas the focal-side-task would cause a deterioration in driving performance and specific changes in physiological response. Support for these hypotheses would provide evidence that focal visual processing is attention demanding, whereas the processing of ambient visual information is not.Some results suggest that ambient visual information was processed pre-attentively, whereas focal visual information requires attentional resources to be processed. Driving performance deteriorated and changes in physiological response occurred when the focal side-task was added to driving, but not when the ambient side-task was added. However, we failed to see predicted changes in driving performance and physiological response as the demands of the focal and ambient components of the driving simulation varied. The results of the current study suggest that a differentiation in attention demands between focal and ambient vision does exist, but that further research is needed to better understand the nature and practical consequences of the differentiation.

Gunslinger Effect and Müller-Lyer Illusion: Examining Early Visual Information Processing for Late Limb-Target Control.

The multiple process model contends that there are two forms of online control for manual aiming: impulse regulation and limb-target control. This study examined the impact of visual information processing for limb-target control. We amalgamated the Gunslinger protocol (i.e., faster movements following a reaction to an external trigger compared with the spontaneous initiation of movement) and Müller-Lyer target configurations into the same aiming protocol. The results showed the Gunslinger effect was isolated at the early portions of the movement (peak acceleration and peak velocity). Reacted aims reached a longer displacement at peak deceleration, but no differences for movement termination. The target configurations manifested terminal biases consistent with the illusion. We suggest the visual information processing demands imposed by reacted aims can be adapted by integrating early feedforward information for limb-target control.

The structure of inter-individual differences in visual ability: Evidence from the general population and synaesthesia

This study considers how inter-individual differences in visual ability are structured. Visual ability could be a single entity (along the lines of general intelligence, or ‘g’), or could be structured according to major anatomical or physiological pathways (dorsal v. ventral streams; magno- v. parvo-cellular systems); or may be a finer-grained mosaic of abilities. To test this, we employed seven visual psychophysical tests (generating 16 measures) on a large (100+) sample of neurotypical participants. A Varimax-rotated PCA (Principal Component Analysis) revealed a two-factor solution that broadly corresponds to a high and low spatial frequency division (consistent with a magno/parvo distinction). Over and above this, two measures (temporal order judgments; gain in contrast sensitivity) correlated with most others, and loaded on both factors, suggesting that they tap broad visual processing demands. These analyses open up further possibilities for exploring the genetic and neuroscientific foundations of differences in visual ability. The tests were also run on a group of individuals with different types of visually-based synaesthesia, given that previous research have suggested they possess a distinct profile of visual abilities. Synaesthesia was linked to enhanced processing of colour and shape/curvature information (amongst others), that may relate to differences in V4 in this group. In conclusion, individual differences in vision are both striking and meaningful, despite our difficulty to imagine seeing the world any differently.

Neural correlates for aesthetic appraisal of pictograph and its referent: An fMRI study

As one kind of language symbols, pictograph has a graphical structure based on its referential object. Are the aesthetic qualities of these referential objects reflected in the cognitive and neural processing of the font structure of pictographs? In this present study, participants performed aesthetic judgments on both pictographs and their referential object images whilst acquiring fMRI data. Square luminance judgment was served as baseline to control for activity in motor brain regions associated with the key responses. Behavioral results showed both font structures of pictographs and their corresponding object images which refer to beautiful objects were rated significantly higher on beauty than those refer to ugly objects. Functional MRI revealed regions of occipital lobe, frontal lobe and inferior orbitofrontal cortex (OFC) that were commonly activated for pictographs and object images referring to beautiful objects in the direct contrasts between beautiful judgment and luminance judgment. Moreover, only the aesthetic judgments of beauty for the pictographs but not the object images elicited activation of motor areas, which implied relevant embodied experience was elicited during the aesthetic perception of novel pictographs. In contrast, activities associated with pictographs referring to ugly objects were limited to visual processing regions of the bilateral inferior occipital gyri, which could be due to the intentions of avoiding ugly or aversive stimulus. In addition, object images were associated with broader recruitment in cortical areas than pictographs, likely due to the increased visual processing demands for the more visually complex object images. These findings indicate that aesthetic perceptions for the font structures of pictographs were derived from their referential objects, which could arouse a similar sense of beauty supported by common neural mechanisms with other aesthetic objects.

B-31 * Problem Solving Weaknesses in Children with Nonverbal Learning Differences

Objective: Children with discrepancies between verbal comprehension and visual-perceptual reasoning often have nonverbal learning differences (NVLD). Research suggests they have difficulty with hypothesis generation and problem solving, processing information differently. We hypothesized children with positive VCI-PRI discrepancy would demonstrate fluid problem solving difficulties as measured by novel, executive functioning tasks on the Delis Kaplan Executive Function System (D-KEFS). Method: Participants include 43 children who received neuropsychological evaluation within a private practice setting over 2 years. The data includes both males (67%) and females, ranging from ages 6 to 16 years (M = 10.47, SD = 3.07). Participants were administered the Wechsler Intelligence Scale for Children (WISC-IV) and select subtests of the D-KEFS. The discrepancy between the Verbal Comprehension Index (VCI) and Perceptual Reasoning Index (PRI) was calculated as a measure of nonverbal weaknesses. Results: A bivariate correlational design was used to assess the relationship between executive functioning and VCI-PRI discrepancy. A medium, negative correlation was found between VCI-PRI discrepancy and the Twenty Questions Initial Abstraction subtest score (D-KEFS), (r = −.435, n = 22, p = .043). Conclusion(s): Overall the data presented supports the hypothesis that NVLD are associated with fluid problem solving on novel tasks. Specifically, this negative relationship highlights unique difficulties integrating verbal and visual perceptual processing demands in children with NVLD.

Reading in Devanagari: Insights from functional neuroimaging.

Objectives:The current study used functional MRI (fMRI) to obtain a comprehensive understanding of the neural network underlying visual word recognition in Hindi/Devanagari, an alphasyllabic – partly alphabetic and partly syllabic Indian writing system on which little research has hitherto been carried out.Materials and Methods:Sixteen (5F, 11M) neurologically healthy, native Hindi/Devanagari readers aged 21 to 50 named aloud 240 Devanagari words which were either visually linear – had no diacritics or consonant ligatures above or below central plane of text, e.g. फल, वाहन, or nonlinear – had at least one diacritic and/or ligature, e.g. फूल, किरण, and which further included 120 words each of high and low frequency. Words were presented in alternating high and low frequency blocks of 10 words each at 2s/word in a block design, with linear and nonlinear words in separate runs. Word reading accuracy was manually coded, while fMRI images were acquired on a 3T scanner with an 8-channel head-coil, using a T2*-weighted EPI sequence (TR/TE = 2s/35ms).Results:After ensuring high word naming accuracy (M = 97.6%, SD = 2.3), fMRI data analyses (at FDR P < 0.005) revealed that reading Devanagari words elicited robust activations in bilateral occipito-temporal, inferior frontal and precentral regions as well as both cerebellar hemispheres. Other common areas of activation included left inferior parietal and right superior temporal cortices. Primary differences seen between nonlinear and linear word reading networks were in the right temporal areas and cerebellum.Conclusion:Distinct from alphabetic scripts, which are linear in their spatial organization, and recruit a primarily left-lateralized network for word reading, our results revealed a bilateral reading network for Devanagari. We attribute the additional activations in Devanagari to increased visual processing demands arising from the complex visuospatial arrangement of symbols in this ancient script.

The quiet eye without a target: the primacy of visual information processing.

Motor-performance-enhancing effects of long final fixations before movement initiation-a phenomenon called quiet eye (QE)-have repeatedly been demonstrated. Drawing on the information-processing framework, it is assumed that the QE supports information processing revealed by the close link between QE duration and task demands concerning, in particular, response selection and movement parameterization. However, the question remains whether the suggested mechanism also holds for processes referring to stimulus identification. Thus, in a series of 2 experiments, performance in a targeting task was tested as a function of experimentally manipulated visual processing demands as well as experimentally manipulated QE durations. The results support the suggested link because a performance-enhancing QE effect was found under increased visual processing demands only: Whereas QE duration did not affect performance as long as positional information was preserved (Experiment 1), in the full versus no target visibility comparison, QE efficiency turned out to depend on information processing time as soon as the interval falls below a certain threshold (Experiment 2). Thus, the results rather contradict alternative, for example, posture-based explanations of QE effects and support the assumption that the crucial mechanism behind the QE phenomenon is rooted in the cognitive domain.

Language processing in the visual world: Effects of preview, visual complexity, and prediction

This study investigates how people interpret spoken sentences in the context of a relevant visual world by focusing on garden-path sentences, such as Put the book on the chair in the bucket, in which the prepositional phrase on the chair is temporarily ambiguous between a goal and modifier interpretation. In three comprehension experiments, listeners heard these types of sentences (along with disambiguated controls) while viewing arrays of objects. These experiments demonstrate that a classic garden-path effect is obtained only when listeners have a preview of the display and when the visual context contains relatively few objects. Results from a production experiment suggest that listeners accrue knowledge that may allow them to have certain expectations of the upcoming utterance based on visual information. Taken together, these findings have theoretical implications for both the role of prediction as an adaptive comprehension strategy, and for how comprehension tendencies change under variable visual and temporal processing demands.

Ageing and driving: Examining the effects of visual processing demands

► Being able to respond quickly and carry out tasks concurrently are essential for safe driving. ► Elderly have longer response times in comparison with younger groups when driving. ► Older drivers have greater difficulty in responding to the complex visual situations. Being able to respond quickly and carry out tasks concurrently are essential ingredients for safe driving. Both abilities decline with age and thus can compromise driving safety in elderly motorists. We examine this nexus by comparing the performance of a younger adult group (35–45 y) with an older one (+65 y) while completing three dual tasks in a driving simulator: one requiring a simple time reaction response with low visual complexity (Condition 1), another constituting a choice reaction task (Condition 2) and a third simple reaction time task, but with increased visual complexity (Condition 3). There was no significant difference between the two groups in Condition 1. The older group, however, was 27% slower in Condition 2, the choice reaction time task, and 46% slower in Condition 3. There were no differences in error rates for any condition. Future directions in research on ageing and driving abilities as well as the shortcomings of the study are discussed.