Biology subjects

Read, J.

Publications and source records attributed to Read, J..

18 recordsLinked to original sources

bioRxiv2026

Temporal single-cell profiling of the parabrachial Calca neurons reveals molecular dynamics driving nociplastic pain

Parabrachial Calca neurons are necessary for chronic pain and sufficient to drive nociplastic pain in mice, but how they sustain a pain state that outlasts its trigger is unknown. We performed temporal single-cell mRNA sequencing of the parabrachial nucleus (PBN) across the onset, chronic, and recovery phases of Calca neuron-driven tactile allodynia, using fixed-tissue profiling and reference-atlas registration to track molecularly defined populations over time. Activation broadly induced immediate-early genes, after which Calca neurons displayed changes in expression of genes that affect signaling and synaptic plasticity, with bidirectional changes that mirrored the onset and resolution of allodynia. The gene encoding brain-derived neurotrophic factor (Bdnf) remained persistently elevated in the chronic phase. BDNF infusion in the PBN prolonged allodynia, whereas blockade of its receptor (TrkB) attenuated it, and inactivating the Bdnf gene in Calca neurons abolished their hyperexcitability, attenuated allodynia, and relieved pain in a migraine model. These observations pinpoint BDNF as a driver of persistent nociplastic pain.

neuroscience↗

bioRxiv2026

Repetition-controllable gain-managed nonlinear fiber amplifier enables ultrashort, multiphoton imaging with reduced photodamage

1.We report a repetition-controllable gain-managed nonlinear fiber amplifier (GMNA) that delivers near-infrared 50-fs pulses with pulse energies up to 150 nJ and a widely tunable repetition rate from 1-20 MHz, while maintaining stable pulse quality across the full range. Using this source, we demonstrate label-free multiphoton imaging--including metabolic autofluorescence (2PF/3PF), second/third-harmonic generation, and Simultaneous Label-free Autofluorescence Multiharmonic (SLAM) microscopy imaging--across live cells, human lung spheroids, and hard tissues. We further assess the impact of laser repetition rate on photodamage at fixed pulse energy, supported by preliminary measurements indicating lower damage at lower repetition rate. Collectively, the compact architecture and repetition-rate agility of the GMNA enable real-time optimization of imaging speed, depth, and sample safety for advanced biological microscopy.

biophysics↗

bioRxiv2025

Motivational trade-offs as evidence for sentience in bees: a critique

Establishing if insects feel pain can have far-reaching consequences for insect husbandry, commercial pollination and scientific research. Research in this field therefore requires careful experiments and strong evidence. One important criterion proposed for measuring insect sentience is the ability to show a motivational trade-off, in which "the negative value of a noxious or threatening stimulus is weighed (traded-off) against the positive value of an opportunity for reward". A recent paper investigated motivational trade-offs in bumblebees and concluded that bees can trade-off heat against high sugar rewards. In this paper, we develop a signal detection model to highlight which features would be key to supporting the argument that motivational trade-offs are evidence of the capacity for experiencing pain. We then re-analyse the data from the original paper and find several limitations. Our own re-analysis finds no support for the final conclusions made by the paper. We therefore provide recommendations for future studies investigating the ability of insects to feel pain.

animal behavior and cognition↗

bioRxiv2025

Light Impact on Thalamo-Cortical Connectivity During an Executive Cognitive Task: Effects of Time of Day and Specificities of Teenagers

BackgroundLight affects not only vision but also attention, alertness, and cognition, primarily through intrinsically photosensitive retinal ganglion cells sensitive to blue-wavelength light. While previous research has shown that light influences brain regional activity, its impact on brain connectivity remains unclear. MethodsUsing 7-Tesla fMRI, this study examined how light illuminance modulates canonical left-lateralized verbal thalamo-prefrontal-parietal network connectivity during an auditory executive task. Fifty-five participants, including young adults (19-30 y, 23 Females: scanned in the morning or evening) and adolescents (15-18 y, 6 Females: scanned only in the evening), were studied. ResultsWe first found that across all the groups, moderate blue-enriched light strengthened parietal-to-frontal connectivity, while low-illuminance orange light enhanced thalamus-to-parietal connectivity. When focusing on time-of-day differences in young adults, we found that higher-illuminance blue-enriched light strengthened thalamus-to-prefrontal connectivity in the morning compared to the evening. When focusing on developmental stages differences, during the evening session only, we observe that moderate blue-enriched light enhanced thalamus-to-parietal connectivity in adolescents compared to young adults. ConclusionThese findings reinforce the view that the thalamus plays a key role in mediating the impact of light on cognition and the impact of light depends on the context of light administration, i.e. with timing and age.

neuroscience↗

bioRxiv2024

Cortical Excitability is Affected by Light Exposure- Distinct Effects in Adolescents and Young Adults

Light, particularly blue-wavelength light exerts a broad range of non-image forming (NIF) effects including the stimulation of cognition and alertness and the regulation of mood, sleep and circadian rhythms. However, its underlying brain mechanisms are not fully elucidated. Likewise, whether adolescents show a different NIF sensitivity to light compared to adults is not established. Here, we investigated whether cortical excitability, a basic aspect of brain function that depends on sleep-wake regulation, is affected by blue light and whether the effect is similar in young adults and adolescents. We used transcranial magnetic stimulation coupled to high-density electroencephalography (TMS-EEG) in healthy young adults (N=13, 24.2 {+/-} 3.4 y) and in adolescents (N=15, 16.9 {+/-} 1.1 y). Our results showed that, in young adults, blue light affected cortical excitability following an apparent inverted-U relationship, while adolescents cortical excitability was not significantly different under blue light compared to orange light. In addition, although light did not affect performance on a visuomotor vigilance task completed during the TMS-EEG recordings, cortical excitability was positively correlated to task performance in both age groups. This study provides valuable insights into the complex interplay between light, cortical excitability, and behavior. Our findings highlight the role of age in NIF effects of light, suggesting that brain responses to light differ during developmental periods.

neuroscience↗

bioRxiv2024

Decipher: A computational pipeline to extract context-specific mechanistic insights from single-cell profiles

The advent of single-cell profiling technologies has revolutionized our understanding of the cellular and molecular states that underpin disease. However, current computational tools struggle to recover both known and novel mechanistic insights at distinct layers of biological regulation. Here, we present Decipher, a novel computational pipeline that builds integrated cell signalling networks from single-cell profiles in a context-specific, data-driven manner and identifies the key cellular and molecular events that drive disease. We benchmarked Decipher against existing tools and found it could recover known, experimentally determined cytokine signalling pathways, whilst maintaining the flexibility to detect novel pathways and context-specific effects. Notably, Decipher produces global cell-to-cell signalling maps that are interpretable. We utilised Decipher to unveil the cellular and molecular mechanisms driving a novel population of inflammatory monocytes enriched with interferon stimulated genes that is markedly increased in frequency following secondary immunization with the Pfizer-BioNTech COVID-19 mRNA vaccine. Finally, we employed Decipher to interrogate regulon profiles from covid-19 patients with mild versus severe disease, and we found that progression to severe disease was associated with a loss of interferon signalling transcription factors (Irf7, Irf9, STAT1, STAT2) and a gain of factors that drive inflammation and cellular stress responses (NFkB, HIF-1a, ATF3, ATF4). Taken together, our findings demonstrate that Decipher can decode signalling pathways and report on ligand-receptor mediated transcription factor-target gene networks that underlie processes in homeostasis, disease, and cellular responses to therapies. We present Decipher as an invaluable new tool for the discovery of novel therapeutic targets and the development of new medicines.

bioinformatics↗

bioRxiv2024

Effect of alcohol on the speed of shifting endogenous and exogenous attention

The study aimed to investigate to what extent acute moderate doses of alcohol affect the speed of endogenous versus exogenous attentional shift times. Subjects viewed an array of 10 moving clocks and reported the time a clock indicated when cued. Target clocks were indicated by peripheral or central cues, including conditions of pre-cuing. This allowed assessing shift times when attention was pre-allocated, when peripheral cues triggered exogenous attention shifts, and when central cues triggered endogenous attention shifts. Each subject participated in 2 sessions (alcohol/placebo), whereby the order of drug intake was counterbalanced across subjects, and subjects were blinded to conditions. Confirming previous results, we show that pre-cuing resulted in the fastest shift times, followed by exogenous cuing, with endogenous attentional shifts being slowest. Alcohol increased attentional shift times across all 3 conditions compared to placebo. Thus, the detrimental effects of alcohol on attentional shift times did not depend on the type of attention probed.

neuroscience↗

bioRxiv2024

Exposure to light supresses the activity of the medial and superior amygdala during emotional processing

The brain mechanisms through which changes in season and light exposure modulate mood may involve different nuclei of the amygdala. We aimed to test this hypothesis using 7 Tesla functional magnetic resonance imaging in 29 healthy young adults. We first considered time-of-year changes in activity that are related to the slow change in photoperiod. We find that the response to emotional stimuli of selected medial and superior nuclei of the amygdala peaked around the start of winter or increased with worse mood status. We further assessed how alternating short exposures to light of different illuminance acutely affected the regional activity of the amygdala. We show that the same areas showed a linear reduction of activity when exposed to increasing light illuminance, specifically when processing emotional stimuli. Importantly, the impact of light on part of these nuclei peaked around the start of summer or decreased with worse mood. These findings provide new evidence that humans show seasonality and that, for mood, it involves parts of the amygdala. The results bring novel insights into the mechanisms that underlie the long-term and acute impact of light on mood and that may contribute to the benefits of light therapy in the treatment of mood disorders.

neuroscience↗

bioRxiv2023

Regional response to light illuminance across the human hypothalamus

Light exerts multiple non-image-forming biological effects on physiology including the stimulation of alertness and cognition. However, the subcortical circuitry underlying the stimulating impact of light is not established in humans. We used 7 Tesla functional magnetic resonance imaging to assess the impact of variations in light illuminance on the regional activity of the hypothalamus while healthy young adults (N=26; 16 women; 24.3 {+/-} 2.9y) were completing two auditory cognitive tasks. We find that, during both the executive and emotional tasks, higher illuminance triggered an activity increase over the posterior part of the hypothalamus, which includes part of the tuberomamillary nucleus and the posterior part of the lateral hypothalamus. In contrast, increasing illuminance evoked a decrease in activity over the anterior and ventral parts of the hypothalamus, encompassing notably the suprachiasmatic nucleus and another part of the tuberomammillary nucleus. Critically, the performance of the executive task was improved under higher illuminance and was negatively correlated with the activity of the posterior hypothalamus area. These findings reveal the distinct local dynamics of different hypothalamus regions that underlie the impact of light on cognition.

neuroscience↗

bioRxiv2023

Physically stressed bees expect less reward in an active choice judgement bias test

Emotion-like states in animals are commonly assessed using judgment bias tests, which measure responses to ambiguous information. A few studies have recently used these tests to argue for the presence of emotion-like states in insects. However, the results from most of these studies could have other explanations, including changes in motivation and attention. To control for these explanations, we therefore developed a novel judgment bias test, requiring bumblebees to make an active choice indicating their interpretation of ambiguous stimuli. Bumblebees were trained to associate high or low rewards, delivered in two different reward chambers, with distinct colors. Two groups of bees were then physically stressed by shaking or trapping, while the third group served as a control. We subsequently presented the bees with ambiguous colors between the two learnt colors and noted which reward chamber they chose. When presented with ambiguous colors, stressed bees were less likely than control bees to enter the reward chamber previously associated with high reward. We modelled bee behavior using signal detection and drift diffusion models and showed that control bees and stressed bees were, respectively, more likely to respond optimistically and pessimistically to ambiguous cues. The signal detection model further showed that the behavior of stressed bees was explained by a reduction in their prior expectation of high rewards. Our findings thus provide strong evidence for emotion-like states in bees and suggest that their stress-induced pessimistic behavior is explained by a reduced expectation of higher rewards.

animal behavior and cognition↗

bioRxiv2021

A Computational Model of Stereoscopic Prey Capture inPraying Mantises

We present a simple model which can account for the stereoscopic sensitivity of praying mantis predatory strikes. The model consists of a single "disparity sensor": a binocular neuron sensitive to stereoscopic disparity and thus to distance from the animal. The model is based closely on the known behavioural and neurophysiological properties of mantis stereopsis. The monocular inputs to the neuron reflect temporal change and are insensitive to contrast sign, making the sensor insensitive to interocular correlation. The monocular receptive fields have a excitatory centre and inhibitory surround, making them tuned to size. The disparity sensor combines inputs from the two eyes linearly, applies a threshold and then an exponent output nonlinearity. The activity of the sensor represents the model mantiss instantaneous probability of striking. We integrate this over the stimulus duration to obtain the expected number of strikes in response to moving targets with different stereoscopic distance, size and vertical disparity. We optimised the parameters of the model so as to bring its predictions into agreement with our empirical data on mean strike rate as a function of stimulus size and distance. The model proves capable of reproducing the relatively broad tuning to size and narrow tuning to stereoscopic distance seen in mantis striking behaviour. The model also displays realistic responses to vertical disparity. Most surprisingly, although the model has only a single centre-surround receptive field in each eye, it displays qualitatively the same interaction between size and distance as we observed in real mantids: the preferred size increases as prey distance increases beyond the preferred distance. We show that this occurs because of a stereoscopic "false match" between the leading edge of the stimulus in one eye and its trailing edge in the other; further work will be required to find whether such false matches occur in real mantises. This is the first image-computable model of insect stereopsis, and reproduces key features of both neurophysiology and striking behaviour.

neuroscience↗

bioRxiv2020

Sequence evaluation and comparative analysis of novel assays for intact proviral HIV-1 DNA

The HIV proviral reservoir is the major barrier to cure. The predominantly replication-defective proviral landscape makes the measurement of virus that is likely to cause rebound upon ART-cessation challenging. To address this issue, novel assays to measure intact HIV proviruses have been developed. The Intact Proviral DNA Assay (IPDA) is a high-throughput assay that uses two probes to exclude the majority of defective proviruses and determine the frequency of intact proviruses, albeit without sequence confirmation. Quadruplex PCR with four probes (Q4PCR), is a lower-throughput assay that uses limiting dilution long distance PCR amplification followed by qPCR and near-full length genome sequencing (nFGS) to estimate the frequency of sequence-confirmed intact proviruses and provide insight into their clonal composition. To explore the advantages and limitations of these assays, we compared IPDA and Q4PCR measurements from 39 ART-suppressed people living with HIV. We found that IPDA and Q4PCR measurements correlated with one another but frequencies of intact proviral DNA differed by approximately 19-fold. This difference may be in part due to inefficiencies in long distance PCR amplification of proviruses in Q4PCR, leading to underestimates of intact proviral frequencies. In addition, nFGS analysis within Q4PCR explained that some of this difference is explained by proviruses that are classified as intact by IPDA but carry defects elsewhere in the genome. Taken together, this head-to-head comparison of novel intact proviral DNA assays provides important context for their interpretation in studies to deplete the HIV reservoir and shows that together the assays bracket true reservoir size. ImportanceThe Intact Proviral DNA Assay (IPDA) and Quadruplex PCR (Q4PCR) represent major advances in accurately quantifying and characterizing the replication competent HIV reservoir. This study compares the two novel approaches for measuring intact HIV proviral DNA in samples from 39 ART-suppressed people living with HIV, thereby informing ongoing efforts to deplete the HIV reservoir in cure-related trials.

microbiology↗

bioRxiv2020

Target tracking behaviour of the praying mantis Sphrodromantis lineola (Linnaeus) is driven by looming-type motion-detectors.

We designed visual stimuli to characterise the motion-detectors that underlie target tracking behaviour in the mantis. The first was a small, moving, stripy, bug-like target, made by opening a moving, Gabor-filtered window onto an extended, moving, sinewave pattern. The mantis tracked this bug-like target, but the likelihood of tracking the bug depended only on the temporal frequency of its motion. In contrast, optomotor responses to the extended moving sinewave pattern alone depended on both spatial and temporal frequency of the pattern, as expected from classical, correlation-based motion-detectors. In another experiment, we used small moving objects that were made up of chequerboard patterns of randomly arranged dark squares, and found objects with smaller sized chequers were tracked relatively less. Response suppression like this, when the internal detail of an object increases, suggests the presence of lateral inhibition between inputs to the motion-detectors for target tracking. Finally, wide-field motion of a chequerboard background near the target, balanced so no optomotor responses were evoked, suppressed tracking proportionally both to the nearness of the background to the target and to the size its dark chequered squares. Backgrounds with smaller sized squares produced more suppression. This effect has been used as a demonstration of lateral inhibition in detectors for looming-motion and makes their response greatest to an expanding outer edge, an image produced by an approaching object. Our findings point to a new role for a looming-type motion-detector in mantis target tracking. We also discuss the suitability of several large lobula-complex neurons for this role.Summary Statement Lateral inhibition shown by motion-detectors underlying target tracking by the praying mantis Sphrodromantis lineola (Linnaeus).View Full Text

animal behavior and cognition↗

bioRxiv2019

Social networks with strong spatial embedding generate non-standard epidemic dynamics driven by higher-order clustering

Some directly transmitted human pathogens such as influenza and measles generate sustained exponential growth in incidence, and have a high peak incidence consistent with the rapid depletion of susceptible individuals. Many do not. While a prolonged exponential phase typically arises in traditional disease-dynamic models, current quantitative descriptions of non-standard epidemic profiles are either abstract, phenomenological or rely on highly skewed offspring distributions in network models. Here, we create large socio-spatial networks to represent contact behaviour using human population density data, a previously developed fitting algorithm, and gravity-like mobility kernels. We define a basic reproductive number R0 for this system analogous to that used for compartmental models. Controlling for R0, we then explore networks with a household-workplace structure in which between-household contacts can be formed with varying degrees of spatial correlation, determined by a single parameter from the gravity-like kernel. By varying this single parameter and simulating epidemic spread, we are able to identify how more frequent local movement can lead to strong spatial correlation and thus induce sub-exponential outbreak dynamics with lower, later epidemic peaks. Also, the ratio of peak height to final size was much smaller when movement was highly spatially correlated. We investigate the topological properties of our networks via a generalized clustering coefficient that extends beyond immediate neighbourhoods, identifying very strong correlations between 4th order clustering and non-standard epidemic dynamics. Our results motivate the joint observation of incidence and socio-spatial human behaviour during epidemics that exhibit non-standard incidence patterns. Author SummaryEpidemics are typically described using a standard set of mathematical models that do not capture social interactions or the way those interactions are determined by geography. Here we propose a model that can reflect social networks influenced strongly by the way people travel and we show that they lead to very different epidemic profiles. This type of model will likely be useful for forecasting.

systems biology↗

bioRxiv2018

The neuronal basis of insect stereopsis

A puzzle for neuroscience - and robotics - is how insects achieve surprisingly complex behaviours with such tiny brains1,2. One example is depth perception via binocular stereopsis in the praying mantis, a predatory insect. Praying mantids use stereopsis, the computation of distances from disparities between the two retinas, to trigger a raptorial strike of their forelegs3,4 when prey is within reach. The neuronal basis of this ability is entirely unknown. From behavioural evidence, one view is that the mantis brain must measure retinal disparity locally across a range of distances and eccentricities4-7, very like disparity-tuned neurons in vertebrate visual cortex8. Sceptics argue that this \"retinal disparity hypothesis\" implies far too many specialised neurons for such a tiny brain9. Here we show the first evidence that individual neurons in the praying mantis brain are indeed tuned to specific disparities and eccentricities, and thus locations in 3D-space. This disparity information is transmitted to the central brain by neurons connecting peripheral visual areas in both hemispheres, as well as by a unilateral neuron type. Like disparity-tuned cortical cells in vertebrates, the responses of these mantis neurons are consistent with linear summation of binocular inputs followed by an output nonlinearity10. Additionally, centrifugal neurons project disparity information back from the central brain to early visual areas, possibly for gain modulation or 3D spatial attention. Thus, our study not only proves the retinal disparity hypothesis for insects, it reveals feedback connections hitherto undiscovered in any animal species.

neuroscience↗

bioRxiv2018

Apparent Motion Perception in the Praying Mantis: Psychophysics and Modelling

Apparent motion is the perception of a motion created by rapidly presenting still frames in which objects are displaced in space. Observers can reliably discriminate the direction of apparent motion when inter-frame object displacement is below a certain limit, Dmax. Earlier studies of motion perception in humans found that Dmax scales with spatial element size, interpreting the relationship between the two as linear, and that Dmax appears to be lower-bounded at around 15 arcmin. Here, we run corresponding experiments in the praying mantis Sphodromantis lineola to investigate how Dmax scales with element size. We used moving random chequerboard patterns of varying element and displacement step sizes to elicit the optomotor response, a postural stabilization mechanism that causes mantids to lean in the direction of large-field motion. Subsequently, we calculated Dmax as the displacement step size corresponding to a 50% probability of detecting an optomotor response in the same direction as the stimulus. Our main findings are that mantis Dmax appears to scale as a power-law of element size and that, in contrast to humans, it does not appear to be lower-bounded. We present two models to explain these observations: a simple high-level model based on motion energy in the Fourier domain and a more detailed one based on the Reichardt Detector. The models present complementary intuitive and physiologically-realistic accounts of how Dmax scales with element size in insects.\n\nAuthor SummaryComputer monitors, smart phone screens and other forms of digital displays present a series of still images (frames) in which objects are displaced in small steps, tricking us into perceiving smooth motion. This illusion is referred to as \"apparent motion\", and for it to work effectively the magnitude of each displacement step must be smaller than a certain limit, referred to as Dmax. Previous studies have investigated the relationship between this limit and object size in humans and found that larger objects can be displaced in larger steps without affecting motion perception. In this work, we investigated the same relationship in the praying mantis Sphodromantis lineola by presenting them with moving chequerboard patterns on a computer monitor. Even though motion perception in humans and insects are believed to be explained equally well by the same underlying model, we found that Dmax scales with object size differently in mantids. These results suggest that there may be qualitative differences in how mantids perceive apparent motion compared to humans.

neuroscience↗

bioRxiv2017

Airway IRF7hi versus IRF7lo molecular response patterns determine clinical phenotypes in children with acute wheezing

Asthma exacerbations are triggered by rhinovirus infections. We employed a systems biology approach to delineate upper airway gene network patterns underlying asthma exacerbation phenotypes in children. Cluster analysis unveiled distinct IRF7hi versus IRF7lo molecular phenotypes, the former exhibiting robust upregulation of Th1/type I interferon responses and the latter an alternative signature marked by upregulation of cytokine and growth factor signalling and downregulation of interferon gamma. The two phenotypes also produced distinct clinical phenotypes. For IRF7lo versus IRF7hi: symptom duration prior to hospital presentation was more than twice as long from initial symptoms (p=0.011) and nearly three times as long for cough (p<0.001); the odds ratio of admission to hospital was increased more than four-fold (p=0.018); and time to recurrence was shorter (p=0.015). In summary, our findings demonstrate that asthma exacerbations in children can be divided into IRF7hi versus IRF7lo phenotypes with associated differences in clinical phenotypes.\n\nAbbreviationsAHR, airway hyperresponsiveness; ARG1, Arginase 1, CSF3, Colony Stimulating Factor 3; CD38, Cluster of Differentiation 38; CD163, Cluster of Differentiation 163; cDCs, conventional (or myeloid) dendritic cells; DDX60, DExD/H-Box Helicase 60; ED, Emergency Department; EGF, Epidermal Growth Factor; ERK, Extracellular signal-Regulated Kinase; FCER1G, Fc Fragment Of IgE Receptor Ig; HMBS, Hydroxymethylbilane Synthase; IFNg, Interferon Gamma; IFNL1, Interferon Lambda 1; IL-1R2, Interleukin 1 Receptor Type 2; IRF7, Interferon Regulatory Factor 7; ISG15, Interferon-stimulated gene 15; MDA5, Melanoma Differentiation-Associated protein 5; MX1, Myxovirus Resistance Protein 1; NAD, nicotinamide adenine dinucleotide; NCR1, Natural cytotoxicity triggering receptor 1; OSM, Oncostatin M; PD-L1, Programmed Death-Ligand 1; PPIA, Peptidylprolyl Isomerase A; PPIB Peptidylprolyl Isomerase B; RSAD2, Radical S-adenosyl methionine domain-containing protein 2; RSV, respiratory syncytial virus; RT-qPCR, quantitative reverse transcription PCR; RV, rhinovirus; sPLA2, secretory Phospholipase A2; TGFb, Transforming Growth Factor beta; THBS1, Thrombospondin 1; TNF, Tumor Necrosis Factor; TLR2, Toll-like Receptor 2.

cell biology↗

bioRxiv2017

Contrast Thresholds Reveal Different Visual Masking Functions In Humans And Praying Mantises

Recently, we showed a novel property of the Hassenstein-Reichardt detector: namely, that insect motion detection can be masked by \"invisible\" noise, i.e. visual noise presented at spatial frequencies to which the animals do not respond when presented as a signal. While this study compared the effect of noise on human and insect motion perception, it used different ways of quantifying masking in two species. This was because the human studies measured contrast thresholds, which were too time-consuming to acquire in the insect given the large number of stimulus parameters examined. Here, we run longer experiments in which we obtained contrast thresholds at just two signal and two noise frequencies. We examine the increase in threshold produced by noise at either the same frequency as the signal, or a different frequency. We do this in both humans and praying mantises (Sphodromantis lineola), enabling us to compare these species directly in the same paradigm. Our results confirm our earlier finding: whereas in humans, visual noise masks much more effectively when presented at the signal spatial frequency, in insects, noise is roughly equivalently effective whether presented at the same frequency or a lower frequency. In both species, visual noise presented at a higher spatial frequency is a less effective mask.\n\nSummary StatementWe here show that despite having similar motion detection systems, insects and humans differ in the effect of low and high spatial frequency noise on their contrast thresholds.

neuroscience↗