Optokinetic stimulation affects temporal estimation in healthy humans

Recovery from auditory and visual neglect after optokinetic stimulation with pursuit eye movements – Transient modulation and enduring treatment effects

BackgroundPatients with right hemisphere damage are often unaware of, inattentive to and fail to interact with stimuli on their left side. This disorder, called hemispatial neglect, is a major source of disability. Inducing leftward ocular pursuit by optokinetic stimulation (OKS) relieves some of the signs of unilateral neglect. However, it is difficult to provide patients with a continuously moving background that is required for OKS. We studied whether OKS projected onto a see-through head-mounted display (HMD) would help treat neglect.Methods14 patients with neglect after cerebral infarction performed line bisections on a computer screen, both with and without OKS that was either delivered by the HMD or on the same screen that was displaying the lines that were to be bisected.ResultsThe line bisection performances were significantly different in the four conditions (P < 0.001). The post hoc analyses indicated that the rightward deviation observed in the control conditions on the line bisection tasks without OKS, improved significantly with the use OKS in both the HMD and screen conditions (α < 0.05). The results between the screen and HMD conditions were also different (α < 0.05). The OKS in the HMD condition corrected patients’ rightward deviation more toward the actual midline than did the OKS provided during the screen condition.ConclusionsOKS projected onto the see-through HMD improved hemispatial neglect. The development of a portable device may aid in the treatment of neglect.

One of the less-noticed arguments associated with urban-space perception while moving is the pedestrians' subjective time perception. Indeed, in many cases, the pedestrians' perception of the time needed to travel a distance is shorter or longer than the actual time. The main objective of this paper—which has been neglected by many urban designers—is to determine the effect of the physical-spatial structure of a built environment on the pedestrians' perception of time. It is hypothesized that different spatial configurations and physical structures can have specific effects on the observer's subjective perception of time, while moving in an urban space.Since this study needed to examine different types of physical-spatial structures from a time perspective, while preventing the possible involvement of other non-physical factors that affect people's time estimates, real urban environments received limited use in this study. Instead, the researchers used a virtual-reality technique to maximize the similarity between the observers' perceived conditions and the real environment. This makes it possible to make dynamic and continuous changes to the physical-spatial variables under study in a semi-real context, and to control other variables affecting the time variable. In addition, to achieve a systematic and logical review, the researchers analyzed the effects of the physical-spatial structures in nine defined simulated tests on pedestrians' subjective time perception. The results supported the hypothesis of a logical relationship between certain physical-spatial configurations and the observer's subjective time perception while moving in an urban space. The logical relationships between the nine configurations studied in this paper were presented as part of the study’s practical results.

Product configurators have been important enablers of customised product design. In a configuration process, customers need to specify the attribute choices that best satisfy their needs. A combination of customer decisions then informs the desired product. Psychology and information retrieval researchers have acknowledged that time is an important factor in measuring customer satisfaction with decision-making process. Some recent studies have also shown that the subjective perception of time is an even more relevant measure of customer satisfaction. However, it remains unclear what factors are most significant in affecting a person's subjective perception of time. This study investigates the relationship between people's experience with the on-line configuration process and their subjective perceptions of the time involved. Empirical experiments are designed to answer the relevant research questions. The experiment's results show that two factors, namely the difficulty of the task and the customers' motivation to process information, both significantly affect customers' perceptions of time. We also find that customers' perceptions of time are significantly correlated with their satisfaction with the configured products, and that perceived time is moderately correlated with satisfaction with the configuration process.

Signatures of Subjective Time Perception in the ERP During Stimulus Encoding

Growing evidence suggests that mental calculation might involve movements of attention along a spatial representation of numerical magnitude. Addition and subtraction on nonsymbolic numbers (numerosities) seem to induce a “momentum” effect, and have been linked to distinct patterns of neural activity in cortical regions subserving attention and eye movements. We investigated whether mental arithmetic on symbolic numbers, a cornerstone of abstract mathematical reasoning, can be affected by the manipulation of overt spatial attention induced by optokinetic stimulation (OKS). Participants performed additions or subtractions of auditory two-digit numbers during horizontal (experiment 1) or vertical OKS (experiment 2), and eye movements were concurrently recorded. In both experiments, the results of addition problems were underestimated, whereas results of subtractions were overestimated (a pattern that is opposite to the classic Operational Momentum effect). While this tendency was unaffected by OKS, vertical OKS modulated the occurrence of decade errors during subtractions (i.e., fewer during downward OKS and more frequent during upward OKS). Eye movements, on top of the classic effect induced by OKS, were affected by the type of operation during the calculation phase, with subtraction consistently leading to a downward shift of gaze position and addition leading to an upward shift. These results highlight the pervasive nature of spatial processing in mental arithmetic. Furthermore, the preeminent effect of vertical OKS is in line with the hypothesis that the vertical dimension of space–number associations is grounded in universal (physical) constraints and, thereby, more robust than situated and culture-dependent associations with the horizontal dimension.

Although omission and substitution errors in neglect dyslexia (ND) patients have always been considered as different manifestations of the same acquired reading disorder, recently, we proposed a new dual mechanism model. While omissions are related to the exploratory disorder which characterizes unilateral spatial neglect (USN), substitutions are due to a perceptual integration mechanism. A consequence of this hypothesis is that specific training for omission-type ND patients would aim at restoring the oculo-motor scanning and should not improve reading in substitution-type ND. With this aim we administered an optokinetic stimulation (OKS) to two brain-damaged patients with both USN and ND, MA and EP, who showed ND mainly characterized by omissions and substitutions, respectively. MA also showed an impairment in oculo-motor behavior with a non-reading task, while EP did not. The two patients presented a dissociation with respect to their sensitivity to OKS, so that, as expected, MA was positively affected, while EP was not. Our results confirm a dissociation between the two mechanisms underlying omission and substitution reading errors in ND patients. Moreover, they suggest that such a dissociation could possibly be extended to the effectiveness of rehabilitative procedures, and that patients who mainly omit contralesional-sided letters would benefit from OKS.

Striemer and Danckert (2010a) suggest that prism adaptation (PA) has beneficial effects primarily on spatial attention and the motor components of neglect, and that the direct effects on visual neglect are insignificant. The main support for their influential hypothesis (e.g.,

Deficits of position sense, unilateral neglect and optokinetic stimulation

Time perception plays a fundamental role in human perceptual and motor activities, and can be influenced by various factors, such as selective attention and arousal. However, little is known about the influence of individual alerting efficiency on perceived duration. In this study, we explored this question by running two experiments. The Attentional Networks Test was used to evaluate individual differences in alerting efficiency in each experiment. Temporal bisection (Experiment 1) and time generalization task (Experiment 2) were used to explore the participants’ perception of duration. The results indicated that subjects in the high alerting efficiency group overestimated interval durations and estimated durations more accurately compared with subjects in the low alerting efficiency group. The two experiments showed that the sensitivity of time was not influenced by individual alerting efficiency. Based on previous studies and current findings, we infer that individual differences in alerting efficiency may influence time perception through modulating the latency of the attention-controlled switch and the speed of the peacemaker within the framework of the internal clock model.

Solving arithmetic problems has been shown to induce shifts of spatial attention, subtraction problems orienting attention to the left side, and addition problems to the right side of space. At the neurofunctional level, the activations elicited by the solving of arithmetical problems resemble those elicited by horizontal eye movements. Whether overt orientation of attention (i.e., eye movements) can be linked to the solving procedure is, however, still under debate. In the present study, we used optokinetic stimulation (OKS) to trigger automatic eye movements to orient participants' overt attention to the right or to the left of their visual field while they were solving addition or subtraction problems. The results show that, in comparison to leftward OKS and a control condition, rightward OKS facilitates the solving of addition problems that necessitate a carrying procedure. Subtraction solving was unaffected by leftward or rightward OKS. These results converge with previous findings to show that attentional shifts are functionally related to mental arithmetic processing.

e22123Background: Perception of time strongly correlates with people’s current emotional state. The aim of this study was to investigate the association between subjective perception of time and le...

The paper presents a variant of the methodological technique to express diagnostics of peculiarities of temporal perception and person's attitude to time. The article presents the approbation results of “Temporal modality of life fulfillment questionnaire”, which allow to define ones' relation to time, time direction, time expansion, saturation by events, differentiation, and structure systems. The questionnaire consists of statements with closed type answers. The scales are based on the following characteristics: past, present, future, positive relationship, negative relationship, real representation of time, emotional (seeming) representation of time. We present the results of psychometric testing of our method. The paper discusses the results of a pilot study using the developed questionnaire. The participants of the research are first year students of bachelor, specialist and master programs. The study was conducted on TSU students in 2021. The sample size is 145 students (25 males, 120 females). We evaluated the questionnaire scales structure with exploratory factor analysis. Three factors were found. Factor 1 is the “Emotional fixation on events” scale. Scale scores demonstrate emotional relation to a time, devotion to illusory time perception. Factor 2 is the “Time of life-fulfilment realization” scale. Scale scores demonstrate time realization. It includes plans structuring, activity effectiveness estimation, experience accounting, realistic time perception. Factor 3 is the “Modal estimates balance” scale. Scale scores demonstrate present time perception wholeness. Time satisfaction allows to estimate ones subjective successfulness in time. Construct validity, conducted by correlation analysis with F. Zimbardo's questionnaire (ZTPI), shows convergence between time constructs, which allow concluding that author's questionnaire could be used for temporal time perception studies. Based on the results we argue the verification of “Temporal modality of life fulfillment” questionnaire and further studies of its reliability.

In today’s fast-paced society, time often feels like it’s slipping away more quickly than ever before. The constant stream of information, rapid technological advancements, and visual overload from screens have all contributed to a heightened sense of urgency and acceleration in daily life. This modern experience raises questions about how the pace of society interacts with our subjective perception of time. Visual stimuli, particularly in environments saturated with motion, advertisements, and digital content, play a significant role in shaping how fast or slow we feel time is passing. As our world speeds up visually, our sense of time may follow. Understanding the relationship between visual stimuli and time perception has broad implications for areas like design, virtual reality, and cognitive psychology, revealing how our sensory experiences shape our sense of time.

The effect of an olfactory stimulation on the perception of time was investigated through two different experiments based on temporal bisection tasks. In experiment 1, the durations to be classified as either short or long were centered on 400 ms while in Experiment 2 there were centered on 2000 ms. The participants were different in the two experiments (36 subjects in each one). In each experiment, half of the subjects learnt the anchor durations when smelling an unpleasant odor (decanoic acid) and the other half when smelling no odor. After the learning phase, both groups were tested with and without odor. The results showed opposite effects depending on the duration range. The subjects underestimated the time in the presence of the unpleasant odor in the short duration range while they overestimated it in the long duration range. The results have been discussed in the framework of the pacemaker-counter clock model and a potential emotional effect induced by the odor on the subjective time perception has also been considered.