Complex Perception Research Articles

Effects of linguistic context and noise type on speech comprehension.

Understanding speech in background noise is an effortful endeavor. When acoustic challenges arise, linguistic context may help us fill in perceptual gaps. However, more knowledge is needed regarding how different types of background noise affect our ability to construct meaning from perceptually complex speech input. Additionally, there is limited evidence regarding whether perceptual complexity (e.g., informational masking) and linguistic complexity (e.g., occurrence of contextually incongruous words) interact during processing of speech material that is longer and more complex than a single sentence. Our first research objective was to determine whether comprehension of spoken sentence pairs is impacted by the informational masking from a speech masker. Our second objective was to identify whether there is an interaction between perceptual and linguistic complexity during speech processing. We used multiple measures including comprehension accuracy, reaction time, and processing effort (as indicated by task-evoked pupil response), making comparisons across three different levels of linguistic complexity in two different noise conditions. Context conditions varied by final word, with each sentence pair ending with an expected exemplar (EE), within-category violation (WV), or between-category violation (BV). Forty young adults with typical hearing performed a speech comprehension in noise task over three visits. Each participant heard sentence pairs presented in either multi-talker babble or spectrally shaped steady-state noise (SSN), with the same noise condition across all three visits. We observed an effect of context but not noise on accuracy. Further, we observed an interaction of noise and context in peak pupil dilation data. Specifically, the context effect was modulated by noise type: context facilitated processing only in the more perceptually complex babble noise condition. These findings suggest that when perceptual complexity arises, listeners make use of the linguistic context to facilitate comprehension of speech obscured by background noise. Our results extend existing accounts of speech processing in noise by demonstrating how perceptual and linguistic complexity affect our ability to engage in higher-level processes, such as construction of meaning from speech segments that are longer than a single sentence.

ClustML: A measure of cluster pattern complexity in scatterplots learnt from human-labeled groupings

Visual quality measures (VQMs) are designed to support analysts by automatically detecting and quantifying patterns in visualizations. We propose a new VQM for visual grouping patterns in scatterplots, called ClustML, which is trained on previously collected human subject judgments. Our model encodes scatterplots in the parametric space of a Gaussian Mixture Model and uses a classifier trained on human judgment data to estimate the perceptual complexity of grouping patterns. The numbers of initial mixture components and final combined groups quantify visual cluster patterns in scatterplots. It improves on existing VQMs, first, by better estimating human judgments on two-Gaussian cluster patterns and, second, by giving higher accuracy when ranking general cluster patterns in scatterplots. We use it to analyze kinship data for genome-wide association studies, in which experts rely on the visual analysis of large sets of scatterplots. We make the benchmark datasets and the new VQM available for practical use and further improvements.

Investigating the effects of perceptual complexity versus conceptual meaning on the object benefit in visual working memory.

Previous research has demonstrated greater visual working memory (VWM) performance for real-world objects compared with simple features. Greater amplitudes of the contralateral delay activity (CDA)-a sustained event-related potential measured during the delay period of a VWM task-havealso been noted for meaningful stimuli, despite being thought of as a neural marker of a fixed working memory capacity. The current study aimed to elucidate the factors underlying improved memory performance for real-world objects by isolating the relative contributions of perceptual complexity (i.e., number of visual features) and conceptual meaning (i.e., availability of semantic, meaningful features). Participants (N = 22) performed a lateralized VWM task to test their memory of intact real-world objects, scrambled real-world objects and colours. The CDA was measured during both encoding and WM retention intervals (600-1000 ms and 1300-1700 ms poststimulus onset, respectively), and behavioural performance was estimated by using d' (memory strength in a two-alternative forced choice task). Behavioural results revealed significantly better performance within-subjects for real-world objects relative to scrambled objects and colours, with no difference between colours and scrambled objects. The amplitude of the CDA wasalso largest for intact real-world objects, with no difference in magnitude for scrambled objects and colours, during working memory maintenance. However, during memory encoding, both the colours and intact real-world objects had significantly greater amplitudes than scrambled objects and were comparable in magnitude. Overall, findings suggest that conceptual meaning (semantics) supports the memory benefit for real-world objects.

The impact of perceptual complexity on road crossing decisions in younger and older adults

Cognitive abilities decline with healthy ageing which can have a critical impact on day-to-day activities. One example is road crossing where older adults (OAs) disproportionally fall victim to pedestrian accidents. The current research examined two virtual reality experiments that investigated how the complexity of the road crossing situation impacts OAs (N = 19, ages 65–85) and younger adults (YAs, N = 34, ages 18–24) with a range of executive functioning abilities (EFs). Overall, we found that OAs were able to make safe crossing decisions, and were more cautious than YAs. This continued to be the case in high cognitive load situations. In these situations, safe decisions were associated with an increase in head movements for participants with poorer attention switching than participants with better attention switching suggesting these groups developed compensation strategies to continue to make safe decisions. In situations where participants had less time to make a crossing decision all participants had difficulties making safe crossing decisions which was amplified for OAs and participants with poorer EFs. Our findings suggest more effort should be taken to ensure that road crossing points are clear of visual obstructions and more speed limits should be placed around retirement or care homes, neither of which are legislated for in the UK and Australia.

Null effect of perceived drum pattern complexity on the experience of groove.

There is a broad consensus in groove research that the experience of groove, understood as a pleasurable urge to move in response to music, is to some extent related to the complexity of the rhythm. Specifically, music with medium rhythmic complexity has been found to motivate greater urge to move compared to low or high complexity music (inverted-U hypothesis). Studies that confirmed the inverted-U hypothesis usually based their measure of complexity on the rhythmic phenomenon of syncopation, where rhythms with more and/or stronger syncopation are considered to be more complex than less syncopated rhythms. However, syncopation is not the same as complexity and represents only one rhythmic device that makes music complex. This study attempts the verification of the inverted-U hypothesis independently from syncopation. It uses a new stimulus set of forty idiomatic popular music drum patterns whose perceptual complexity was measured experimentally in a previous study. The current study reports the results of a listening experiment with n = 179 participants, in which the inverted-U hypothesis was not confirmed. Complexity did not have any significant effect on listeners' urge to move (p = 834). Results are discussed in the context of the psychological model of musical groove, which offers a nuance to this null result: simple drum patterns motivate listeners to dance because they convey metric clarity; complex patterns invite dancing because they are interesting. Yet, overall, the urge to move does not seem to depend on complexity, at least in the case of idiomatic drum patterns that are typically encountered in the Western popular music repertoire.

Unveiling the influence of task-relevance of emotional faces on behavioral reactions in a multi-face context using a novel Flanker-Go/No-go task

Recent research indicates that emotional faces affect motor control only when task-relevant. However, these studies utilized a single-face presentation, which does not accurately mirror real-life situations wherein we frequently engage with multiple individuals simultaneously. To overcome this limitation, we gave 40 participants two versions of a novel Flanker-Go/No-go task, where we presented three-face stimuli with a central target and two task-irrelevant flankers that could be congruent or incongruent with the target for valence and gender. In the Emotional Discrimination Task (EDT), participants had to respond to fearful or happy targets and refrain from moving with neutral ones. In the Gender Discrimination Task (GDT), the same images were shown, but participants had to respond according to the target's gender. In line with previous studies, we found an effect of valence only in EDT, where fearful targets increased reaction times and omission error rates compared to happy faces. Notably, the flanker effect, i.e., slower and less accurate responses in incongruent than congruent conditions, was not found. This likely stems from the higher perceptual complexity of faces than that of stimuli traditionally used in the Eriksen Flanker task (letters or signs), leading to a capacity limit in face feature processing.

Generative visual common sense: Testing analysis-by-synthesis on Mondrian-style image.

The well-known Mondrian-style images, aside from being aesthetically amusing, also reflect the core principles of human vision in their viewing experience. First, when we see a Mondrian-style image consisting only of a grid and primary colors, we may automatically interpret its causal history such that it was generated by recursively partitioning a blank scene. Second, the image we observe is open to many possible ways of partitioning, and their probabilities of dominating the interpretation can be captured by a probabilistic distribution. Moreover, the causal interpretation of a Mondrian-style image can emerge almost spontaneously, not being tailored to any specific task. Using Mondrian-style images as a case study, we demonstrate the generative nature of human vision by showing that a Bayesian model based upon an image-generation task can support a wide range of visual tasks with little retraining. Our model, learned from human-synthesized Mondrian-style images, could predict human performance in the perceptual complexity ranking, capture the transmission stability when images were iteratively passed among participants, and pass a visual Turing test. Our results collectively show that human vision is causal such that we interpret an image from the angle of how it was generated. The success of generalization with little retraining suggests that generative vision constitutes a type of common sense that supports a wide range of tasks of different natures. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Investigating the effects of perceptual complexity versus conceptual meaning on the neural correlates of visual working memory

Investigating the effects of perceptual complexity versus conceptual meaning on the neural correlates of visual working memory

Dissociating affective and perceptual effects of schematic faces on attentional scope.

Attention allocation to positive and negative stimuli differs. For example, the flanker-interference asymmetry describes a pattern of results on flanker tasks using emotional stimuli, where a typical flanker-interference effect is observed for positive targets but not for negative targets. There are two dominant explanations for the flanker-interference asymmetry. According to the emotion-first explanation, negative targets are preferentially processed to facilitate the processing of potentially threatening stimuli. In contrast, feature-first explanations argue that the asymmetry results from differences in perceptual complexity between positive and negative stimuli. Three experiments used schematic emotional faces in a flanker task to directly compare these explanations. To manipulate the perceptual complexity of the stimuli, an enclosing circle was present on half of the trials. In all three experiments, reaction times showed the expected flanker-interference asymmetry, but the pattern was not influenced by the presence of the circle. However, event-related potentials showed that perceptual complexity influenced both the structural encoding and evaluative processing of the faces in the N170 and P3b time windows. These results suggest that both perceptual complexity and emotional valence play an important role in the processing of schematic emotional faces, but that emotional valence may have a stronger effect at evaluative stages of processing. Other findings show that the enclosing circle may alter the perceived emotional expression of neutral faces. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Temozolomide treatment inhibits spontaneous motivation for exploring a complex object in mice: A potential role of adult hippocampal neurogenesis in "curiosity".

Intrinsic exploratory biases are an innate motivation for exploring certain types of stimuli or environments over others, and they may be associated with cognitive, emotional, and even personality-like traits. However, their neurobiological basis has been scarcely investigated. Considering the involvement of the hippocampus in novelty recognition and in spatial and pattern separation tasks, this work researched the role of adult hippocampal neurogenesis (AHN) in intrinsic exploratory bias for a perceptually complex object in mice. Spontaneous object preference tasks revealed that both male and female C57BL/6J mice showed a consistent unconditioned preference for exploring "complex"-irregular-objects over simpler ones. Furthermore, increasing objects' complexity resulted in an augmented time of object exploration. In a different experiment, male mice received either vehicle or the DNA alkylating agent temozolomide (TMZ) for 4 weeks, a pharmacological treatment that reduced AHN as evidenced by immunohistochemistry. After assessment in a behavioral test battery, the TMZ-treated mice did not show any alterations in general exploratory and anxiety-like responses. However, when tested in the spontaneous object preference task, the TMZ-treated mice did not display enhanced exploration of the complex object, as evidenced both by a reduced exploration time-specifically for the complex object-and a lack of preference for the complex object over the simple one. This study supports a novel role of AHN in intrinsic exploratory bias for perceptual complexity. Moreover, the spontaneous complex object preference task as a rodent model of "curiosity" is discussed.

Long-term memory enhances object retention in visual working memory independently from perceptual complexity

Long-term memory enhances object retention in visual working memory independently from perceptual complexity

Scene Complexity Captures the Detail Trace of Visual Episodic Memory

Memory research has established that human observers use schemas, mental constructs that represent scene elements and relationships between those elements, as the basis for encoding information into visual episodic memory. Newly developed computational methods now allow the extraction of this schema information from the human observer via two-dimensional maps known as Visual Memory Schema (VMS) maps (Kyle-Davidson, Bors & Evans, 2019). VMS maps reveal which regions in a scene image are responsible for a human recalling that scene. VMS Maps are highly consistent among observers and are not explained solely by computational saliency models or eye-fixations. However, previous work also suggests that humans, in addition to schemas, retain rich detail of the scene, and the presence of that detailed information aids in later recognition of the same. Findings show that scenes considered to be more detailed (scenes with man-made elements) are remembered better than less detailed scenes (natural scene). Similarly, images that have detail removed (compared to a source image) appear less memorable than images that maintain the original detail (Baddeley & Evans, 2019). We investigated whether perceptual image complexity could stand as an analogue for the detail trace in visual memory, exploring how the complexity of an image relates to that image's memorability. Our approach was to conduct a behavioural experiment gathering two-dimensional complexity information from humans for a scene dataset that already has corresponding schema information (VMS Maps), which allowed us to explore complexity and memorability from a two-dimensional perspective. Next, we trained a neural network to predict complexity scores, and investigate this relationship for another scene memory dataset, now comparing the predicted complexity scores with ground truth memory for the images. The findings indicate that both extracted, and predicted perceptual complexity of the scene, relates to how well observers remember that same scene.

Characterising and dissecting human perception of scene complexity

Humans can effortlessly assess the complexity of the visual stimuli they encounter. However, our understanding of how we do this, and the relevant factors that result in our perception of scene complexity remain unclear; especially for the natural scenes in which we are constantly immersed. We introduce several new datasets to further understanding of human perception of scene complexity. Our first dataset (VISC-C) contains 800 scenes and 800 corresponding two-dimensional complexity annotations gathered from human observers, allowing exploration for how complexity perception varies across a scene. Our second dataset, (VISC-CI) consists of inverted scenes (reflection on the horizontal axis) with corresponding complexity maps, collected from human observers. Inverting images in this fashion is associated with destruction of semantic scene characteristics when viewed by humans, and hence allows analysis of the impact of semantics on perceptual complexity. We analysed perceptual complexity from both a single-score and a two-dimensional perspective, by evaluating a set of calculable and observable perceptual features based upon grounded psychological research (clutter, symmetry, entropy and openness). We considered these factors’ relationship to complexity via hierarchical regressions analyses, tested the efficacy of various neural models against our datasets, and validated our perceptual features against a large and varied complexity dataset consisting of nearly 5000 images. Our results indicate that both global image properties and semantic features are important for complexity perception. We further verified this by combining identified perceptual features with the output of a neural network predictor capable of extracting semantics, and found that we could increase the amount of explained human variance in complexity beyond that of low-level measures alone. Finally, we dissect our best performing prediction network, determining that artificial neurons learn to extract both global image properties and semantic details from scenes for complexity prediction. Based on our experimental results, we propose the “dual information” framework of complexity perception, hypothesising that humans rely on both low-level image features and high-level semantic content to evaluate the complexity of images.

Simultaneous Detection of Loop-Closures and Changed Objects

Loop-closure detection (LCD) in large non-stationary environments remains an important challenge in robotic visual simultaneous localization and mapping (vSLAM). To reduce computational and perceptual complexity, it is helpful if a vSLAM system has the ability to perform image change detection (ICD). Unlike previous applications of ICD, time-critical vSLAM applications cannot assume an offline background modeling stage, or rely on maintenance-intensive background models. To address this issue, we introduce a novel maintenance-free ICD framework that requires no background modeling. We demonstrate that LCD can be reused as the main process for ICD with minimal extra cost. Based on these concepts, we develop a novel vSLAM component that enables simultaneous LCD and ICD. ICD experiments based on challenging cross-season LCD scenarios validate the efficacy of the proposed method.

Perceptual and response factors in the gradual onset continuous performance tasks.

Using a novel gradual onset continuous performance task (gradCPT), recent research has uncovered a brain network of the sustained attention ability, demonstrating marked individual differences. Yet much about the cognitive processes that support performance on the gradCPT remains unknown. Here, we tested the importance of response inhibition and perceptual discrimination in the gradCPT. Participants monitored a continuous stream of natural scenes from two categories-cities and mountains-with a 9:1 ratio. In separate task blocks, they responded either to the frequent or the rare, yielding a response rate of either 90% or 10%. Performance was much worse, and declined more significantly over time, when the required response rate was higher. To test the role of stimulus onset, separate task blocks presented the scenes either gradually, with adjacent scenes blending into each other (gradCPT), or abruptly, with a single scene visible at a time (abruptCPT). Despite its increased complexity, the gradCPT yielded better performance than the abruptCPT, contradicting the perceptual complexity hypothesis and suggesting a detrimental role of the automaticity of responses to rhythmic stimuli in sustained attention. Further bolstering the role of response inhibition in the gradCPT, participants with superior inhibitory function, as assessed by the "stop-signal" task, did better on the gradCPT. These findings show that response inhibition contributes to the ability to sustain attention, especially in tasks that require frequent and repetitive responses as in assembly-line jobs.

An Approach to Measuring Ship Design Complexity

Understanding different aspects of complexity and measuring them properly are important steps of handling ship design complexity effectively. The main objective of this article is to develop a practical and comprehensive method to measure ship design complexity. In engineering design, complexity is measured today by different indexes and methods. This paper initially explores the applicability of such measures in a ship design context supported by a review of different relevant user-cases. However, it is acknowledged that most of these measurement methods focus on product-related complexity aspects and rarely address or quantify complexities generated by the design process, the organisation of the firm, or the market situation. Therefore, this paper introduces a new and comprehensive model to measure ship design complexity including all these aspects. The model quantifies ship design complexity by means of the following nine different descriptive factors: directional, spatial, decision-making, structural, behavioral, contextual, perceptual, temporal, and technological complexity.

The nationality benefit: Long-term memory associations enhance visual working memory for color-shape conjunctions

Visual working memory (VWM) is typically found to be severely limited in capacity, but this limitation may be ameliorated by providing familiar objects that are associated with knowledge stored in long-term memory. However, comparing meaningful and meaningless stimuli usually entails a confound, because different types of objects also tend to vary in terms of their inherent perceptual complexity. The current study therefore aimed to dissociate stimulus complexity from object meaning in VWM. To this end, identical stimuli – namely, simple color-shape conjunctions – were presented, which either resembled meaningful configurations (“real” European flags), or which were rearranged to form perceptually identical but meaningless (“fake”) flags. The results revealed complexity estimates for “real” and “fake” flags to be higher than for unicolor baseline stimuli. However, VWM capacity for real flags was comparable to the unicolor baseline stimuli (and substantially higher than for fake flags). This shows that relatively complex, yet meaningful “real” flags reveal a VWM capacity that is comparable to rather simple, unicolored memory items. Moreover, this “nationality” benefit was related to individual flag recognition performance, thus showing that VWM depends on object knowledge.

Perceptual perplexity and parameter parsimony

AbstractThis article reconsiders the concept of a perceptual model of hydrological processes as the first stage to be considered in developing a procedural model for a particular catchment area. While various perceptual models for experimental catchments have been developed, the concept is not widely used in defining or evaluating catchment models. This is, at least in part, because of the evident complexity possible in a perceptual model and the approximate nature of procedural model structures and parameterizations, particularly where there is a requirement for parameter parsimony. A perceptual model for catchments in Cumbria, North‐West England, is developed as an exemplar and illustrated in terms of time varying distribution functions. Two critical questions are addressed: how can perceptual model hypotheses be tested at scales of interest, and how can constraints then be imposed on the basis of qualitative perceptual knowledge in conditioning predictive models? It is suggested that there is value in perceptual information, particularly in thinking about predicting the impacts of future change and that we still have much to learn about moving from observational and perceptual complexity to parsimonious predictability.This article is categorized under:Science of Water > Hydrological ProcessesScience of Water > Methods

The Effects of Repetitive Transcranial Magnetic Stimulation Antidepressant Response on Cold Cognition: A Single-Arm Prospective Longitudinal Study.

PurposeThe cognitive neuropsychological model of depression suggests that the cognitive deficits observed in depressed subjects are the result of attenuated top-down cognitive control resulting in increased bottom-up emotional processing. Remediation of cognitive impairments in cold cognition has been proposed as a valuable treatment for depression. The study aimed to examine the effects of clinical response to repetitive transcranial magnetic stimulation (rTMS) on cold cognition over the course of 8 weeks in medication-refractory depressed subjects.Materials and MethodsTwenty-two medication-refractory depressed subjects received twenty sessions of high-frequency rTMS targeting the left dorsolateral prefrontal cortex, one of the key nodes of the cognitive control network. Cold cognition and antidepressant treatment response were monitored at baseline, week 2, 4 and 8. Clinical response was defined as ≥50% reduction in Montgomery-Åsberg Depression Rating Scale score at week 8. Longitudinal changes in cold cognition were modeled using (generalized) linear mixed models. It was hypothesized that the excitatory effects of rTMS would improve cognition in the domains of executive function, memory, and attention. Additionally, responders were expected to show larger cognitive improvements than nonresponders.ResultsA decrease in median latency was observed on a task that measured executive function, irrespective of treatment response status. Further, responders showed significantly larger improvements in A-Prime (the ability to detect target sequences) on a sustained attention task. Post hoc analysis indicated higher levels of rumination in non-responders.ConclusionOur findings suggest that distractions during tasks with low perceptual complexity affected nonresponders disproportionately possibly due to higher rumination levels. Overall, cold cognition in medication-resistant depressed subjects was minimally affected by rTMS, substantiating the safety of rTMS treatment.LimitationsThe sample size was small, and the study did not include a control group.

Driving Skills of Individuals With and Without Developmental Coordination Disorder (DCD/Dyspraxia).

Learning to drive is a significant event for the transition to adulthood and delay or avoidance may have social, practical, and psychological implications. For those with Developmental Coordination Disorder (DCD/Dyspraxia), driving presents a considerable challenge, and the literature shows that there are differences in driving ability between individuals with and without DCD. The aim of the current research is to further our understanding of the mechanisms underlying the driving experiences of individuals with DCD. Nineteen participants with DCD (10 drivers and 9 non-drivers) and 36 controls (17 drivers and 19 non-drivers) aged 18–57 years took part in this study. Participants completed standardized tests, questionnaires and a driving simulation task designed to measure speed, road positioning, and rate of change of steering in three conditions with increasing perceptual complexity. Results indicate that behaviors for all participants changed as the perceptual demands of the task increased. However, drivers with DCD were more affected than all other groups, driving more slowly, and driving further to the right. These findings illustrate how the impact of both internal and external constraints negatively affect the success of the driving task for individuals with DCD compared to their TD peers.