Open Access Publications

@article{romagnano_dynamic_2024,

title = {Dynamic brain communication underwriting face pareidolia},

author = {Valentina Romagnano and Julian Kubon and Alexander N. Sokolov and Andreas J. Fallgatter and Christoph Braun and Marina A. Pavlova},

url = {https://www.pnas.org/doi/full/10.1073/pnas.2401196121},

doi = {10.1073/pnas.2401196121},

year  = {2024},

date = {2024-04-01},

urldate = {2024-05-09},

journal = {Proceedings of the National Academy of Sciences},

volume = {121},

number = {16},

pages = {e2401196121},

abstract = {Face pareidolia is a tendency to seeing faces in nonface images that reflects high tuning to a face scheme. Yet, studies of the brain networks underwriting face pareidolia are scarce. Here, we examined the time course and dynamic topography of gamma oscillatory neuromagnetic activity while administering a task with nonface images resembling a face. Images were presented either with canonical orientation or with display inversion that heavily impedes face pareidolia. At early processing stages, the peaks in gamma activity (40 to 45 Hz) to images either triggering or not face pareidolia originate mainly from the right medioventral and lateral occipital cortices, rostral and caudal cuneus gyri, and medial superior occipital gyrus. Yet, the difference occurred at later processing stages in the high-frequency range of 80 to 85 Hz over a set of the areas constituting the social brain. The findings speak rather for a relatively late neural network playing a key role in face pareidolia. Strikingly, a cutting-edge analysis of brain connectivity unfolding over time reveals mutual feedforward and feedback intra- and interhemispheric communication not only within the social brain but also within the extended large-scale network of down- and upstream regions. In particular, the superior temporal sulcus and insula strongly engage in communication with other brain regions either as signal transmitters or recipients throughout the whole processing of face-pareidolia images.},

note = {Publisher: Proceedings of the National Academy of Sciences},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{wang_mesoscale_2024,

title = {Mesoscale organization of ventral and dorsal visual pathways in macaque monkey revealed by 7T fMRI},

author = {Jianbao Wang and Xiao Du and Songping Yao and Lihui Li and Hisashi Tanigawa and Xiaotong Zhang and Anna Wang Roe},

url = {https://www.sciencedirect.com/science/article/pii/S0301008224000200},

doi = {10.1016/j.pneurobio.2024.102584},

issn = {0301-0082},

year  = {2024},

date = {2024-02-01},

urldate = {2024-02-06},

journal = {Progress in Neurobiology},

pages = {102584},

abstract = {In human and nonhuman primate brains, columnar (mesoscale) organization has been demonstrated to underlie both lower and higher order aspects of visual information processing. Previous studies have focused on identifying functional preferences of mesoscale domains in specific areas; but there has been little understanding of how mesoscale domains may cooperatively respond to single visual stimuli across dorsal and ventral pathways. Here, we have developed ultrahigh-field 7T fMRI methods to enable simultaneous mapping, in individual macaque monkeys, of response in both dorsal and ventral pathways to single simple color and motion stimuli. We provide the first evidence that anatomical V2 cytochrome oxidase-stained stripes are well aligned with fMRI maps of V2 stripes, settling a long-standing controversy. In the ventral pathway, a systematic array of paired color and luminance processing domains across V4 was revealed, suggesting a novel organization for surface information processing. In the dorsal pathway, in addition to high quality motion direction maps of MT, MST and V3A, alternating color and motion direction domains in V3 are revealed. As well, submillimeter motion domains were observed in peripheral LIPd and LIPv. In sum, our study provides a novel global snapshot of how mesoscale networks in the ventral and dorsal visual pathways form the organizational basis of visual objection recognition and vision for action.},

keywords = {PROPixx, VPixxProgram},

pubstate = {published},

tppubtype = {article}

}

@article{doherty_atypical_2024,

title = {Atypical cortical networks in children at high-genetic risk of psychiatric and neurodevelopmental disorders},

author = {Joanne L. Doherty and Adam C. Cunningham and Samuel J. R. A. Chawner and Hayley M. Moss and Diana C. Dima and David E. J. Linden and Michael J. Owen and Marianne B. M. Bree and Krish D. Singh},

url = {https://www.nature.com/articles/s41386-023-01628-x},

doi = {10.1038/s41386-023-01628-x},

issn = {1740-634X},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-04},

journal = {Neuropsychopharmacology},

volume = {49},

number = {2},

pages = {368–376},

abstract = {Although many genetic risk factors for psychiatric and neurodevelopmental disorders have been identified, the neurobiological route from genetic risk to neuropsychiatric outcome remains unclear. 22q11.2 deletion syndrome (22q11.2DS) is a copy number variant (CNV) syndrome associated with high rates of neurodevelopmental and psychiatric disorders including autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD) and schizophrenia. Alterations in neural integration and cortical connectivity have been linked to the spectrum of neuropsychiatric disorders seen in 22q11.2DS and may be a mechanism by which the CNV acts to increase risk. In this study, magnetoencephalography (MEG) was used to investigate electrophysiological markers of local and global network function in 34 children with 22q11.2DS and 25 controls aged 10–17 years old. Resting-state oscillatory activity and functional connectivity across six frequency bands were compared between groups. Regression analyses were used to explore the relationships between these measures, neurodevelopmental symptoms and IQ. Children with 22q11.2DS had altered network activity and connectivity in high and low frequency bands, reflecting modified local and long-range cortical circuitry. Alpha and theta band connectivity were negatively associated with ASD symptoms while frontal high frequency (gamma band) activity was positively associated with ASD symptoms. Alpha band activity was positively associated with cognitive ability. These findings suggest that haploinsufficiency at the 22q11.2 locus impacts short and long-range cortical circuits, which could be a mechanism underlying neurodevelopmental and psychiatric vulnerability in this high-risk group.},

note = {Number: 2 

Publisher: Nature Publishing Group},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{fakche_perceptual_2024,

title = {Perceptual Cycles Travel Across Retinotopic Space},

author = {Camille Fakche and Laura Dugué},

url = {https://doi.org/10.1162/jocn_a_02075},

doi = {10.1162/jocn_a_02075},

issn = {0898-929X},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-16},

journal = {Journal of Cognitive Neuroscience},

volume = {36},

number = {1},

pages = {200–216},

abstract = {Visual perception waxes and wanes periodically over time at low frequencies (theta: 4–7 Hz; alpha: 8–13 Hz), creating “perceptual cycles.” These perceptual cycles can be induced when stimulating the brain with a flickering visual stimulus at the theta or alpha frequency. Here, we took advantage of the well-known organization of the visual system into retinotopic maps (topographic correspondence between visual and cortical spaces) to assess the spatial organization of induced perceptual cycles. Specifically, we tested the hypothesis that they can propagate across the retinotopic space. A disk oscillating in luminance (inducer) at 4, 6, 8, or 10 Hz was presented in the periphery of the visual field to induce perceptual cycles at specific frequencies. EEG recordings verified that the brain responded at the corresponding inducer frequencies and their first harmonics. Perceptual cycles were assessed with a concurrent detection task—target stimuli were displayed at threshold contrast (50% detection) at random times during the inducer. Behavioral results confirmed that perceptual performance was modulated periodically by the inducer at each frequency. We additionally manipulated the distance between the target and the inducer (three possible positions) and showed that the optimal phase, that is, moment of highest target detection, shifted across target distance to the inducer, specifically when its flicker frequency was in the alpha range (8 and 10 Hz). These results demonstrate that induced alpha perceptual cycles travel across the retinotopic space in humans at a propagation speed of 0.3–0.5 m/sec, consistent with the speed of unmyelinated horizontal connections in the visual cortex.},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{marshall_representation_2024,

title = {The representation of priors and decisions in the human parietal cortex},

author = {Tom R. Marshall and Maria Ruesseler and Laurence T. Hunt and Jill X. O’Reilly},

url = {https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002383},

doi = {10.1371/journal.pbio.3002383},

issn = {1545-7885},

year  = {2024},

date = {2024-01-01},

urldate = {2024-02-01},

journal = {PLOS Biology},

volume = {22},

number = {1},

pages = {e3002383},

abstract = {Animals actively sample their environment through orienting actions such as saccadic eye movements. Saccadic targets are selected based both on sensory evidence immediately preceding the saccade, and a “salience map” or prior built-up over multiple saccades. In the primate cortex, the selection of each individual saccade depends on competition between target-selective cells that ramp up their firing rate to saccade release. However, it is less clear how a cross-saccade prior might be implemented, either in neural firing or through an activity-silent mechanism such as modification of synaptic weights on sensory inputs. Here, we present evidence from magnetoencephalography for 2 distinct processes underlying the selection of the current saccade, and the representation of the prior, in human parietal cortex. While the classic ramping decision process for each saccade was reflected in neural firing rates (measured in the event-related field), a prior built-up over multiple saccades was implemented via modulation of the gain on sensory inputs from the preferred target, as evidenced by rapid frequency tagging. A cascade of computations over time (initial representation of the prior, followed by evidence accumulation and then an integration of prior and evidence) provides a mechanism by which a salience map may be built up across saccades in parietal cortex. It also provides insight into the apparent contradiction that inactivation of parietal cortex has been shown not to affect performance on single-trials, despite the presence of clear evidence accumulation signals in this region.},

note = {Publisher: Public Library of Science},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{minarik_optimal_2023,

title = {Optimal parameters for rapid (invisible) frequency tagging using MEG},

author = {Tamas Minarik and Barbara Berger and Ole Jensen},

url = {https://www.sciencedirect.com/science/article/pii/S1053811923005402},

doi = {10.1016/j.neuroimage.2023.120389},

issn = {1053-8119},

year  = {2023},

date = {2023-11-01},

urldate = {2024-01-31},

journal = {NeuroImage},

volume = {281},

pages = {120389},

abstract = {Frequency tagging has been demonstrated to be a useful tool for identifying representational-specific neuronal activity in the auditory and visual domains. However, the slow flicker (<30 Hz) applied in conventional frequency tagging studies is highly visible and might entrain endogenous neuronal oscillations. Hence, stimulation at faster frequencies that is much less visible and does not interfere with endogenous brain oscillatory activity is a promising new tool. In this study, we set out to examine the optimal stimulation parameters of rapid frequency tagging (RFT/RIFT) with magnetoencephalography (MEG) by quantifying the effects of stimulation frequency, size and position of the flickering patch. Rapid frequency tagging using flickers above 50 Hz results in almost invisible stimulation which does not interfere with slower endogenous oscillations; however, the signal is weaker as compared to tagging at slower frequencies so certainty over the optimal parameters of stimulation delivery are crucial. The here presented results examining the frequency range between 60 Hz and 96 Hz suggest that RFT induces brain responses with decreasing strength up to about 84 Hz. In addition, even at the smallest flicker patch (2°) focally presented RFT induces a significant and measurable oscillatory brain signal (steady state visual evoked potential/field, SSVEP/F) at the stimulation frequency (66 Hz); however, the elicited response increases with patch size. While focal RFT presentation elicits the strongest response, off-centre presentations do generally mainly elicit a measureable response if presented below the horizontal midline. Importantly, the results also revealed considerable individual differences in the neuronal responses to RFT stimulation. Finally, we discuss the comparison of oscillatory measures (coherence and power) and sensor types (planar gradiometers and magnetometers) in order to achieve optimal outcomes. Based on our extensive findings we set forward concrete recommendations for using rapid frequency tagging in human cognitive neuroscience investigations.},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{taveras-cruz_threshold_2023,

title = {Threshold versus intensity curves measured with a new high-brightness display system},

author = {Yesenia Taveras-Cruz and Rhea T. Eskew Jr.},

url = {https://doi.org/10.1167/jov.23.11.71},

doi = {10.1167/jov.23.11.71},

issn = {1534-7362},

year  = {2023},

date = {2023-09-01},

urldate = {2023-12-21},

journal = {Journal of Vision},

volume = {23},

number = {11},

pages = {71},

abstract = {Classical threshold vs. intensity (tvi) curves were measured using optical systems and were generally limited to increment test stimuli and relatively simple spatial patterns. Modern displays provide more flexibility in terms of stimuli spatial profiles but are usually dim enough that there may be rod intrusion when measuring cone responses. Here we describe a high-brightness display system and present tvi’s for increment and decrement achromatic tests. The system consists of a PROPixx three-chip DLP LED color projector (VPixx Technologies, Saint-Bruno, Canada) controlled via a Datapixx display driver, with 12-bit digital to analog conversion per RGB channel. Light from the projector is collected in a large diameter lens and focused on high gain rear projection screen. Retinal illuminance of the background may be varied in three ways: (a) varying the mean current supplied to the LEDs from the controller (adjustable in software); (b) using calibrated neutral density filters mounted near the eye; and (c) changing the midpoint of the RGB channels in software (e.g., making the white background as R=G=B=0.1 instead of 0.5). Method (c) is made easier by the fact that the PROPixx “gamma curve” is linear, which also means that no RGB bits are lost to gamma correction. We will show thresholds for achromatic tests on a white background varying from 0.56 to 4.03 log trolands, with preliminary results suggesting differences in the tvi curves between the increment and decrement tests.},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{taveras-cruz_increment_2023,

title = {Increment and decrement threshold vs. intensity curves for achromatic and L-cone tests.},

author = {Yesenia Taveras-Cruz and Aanya Sehgal and Jr. Rhea T. Eskew},

url = {https://doi.org/10.1167/jov.23.9.5729},

doi = {10.1167/jov.23.9.5729},

issn = {1534-7362},

year  = {2023},

date = {2023-08-01},

urldate = {2023-12-21},

journal = {Journal of Vision},

volume = {23},

number = {9},

pages = {5729},

abstract = {The desensitization of the visual system as a function of the increasing luminance of a background field yields threshold vs. intensity (tvi) curves, classically measured using increment tests. Here we use a new, high-brightness display system to measure both increment and decrement thresholds. Our display system is based upon a PROPixx three-chip DLP LED color projector (VPixx Technologies, Saint-Bruno, Canada), with light from the projector collected into a field lens and focused onto a high gain rear projection screen. This display combines the brightness of traditional optical systems with the flexibility of control provided by modern displays; in particular, it is simple to use the silent substitution method to isolate single cone types. Here we report tvi curves for achromatic and (L-)ong wavelength sensitive cone isolating tests, measured using method of adjustment. Selected thresholds were verified with a spatial, two-alternative forced-choice procedure. The adapting background was white, with luminances ranging from 0.6 to 4.0 log Trolands (a maximum near 3200 cd/m2, bleaching about 1/3 of the L and M cone pigment). Our observers are slightly more sensitive to decrements than increments (about 0.1 log units), for both achromatic and L-cone tests, and to L-cone tests than to achromatic tests (about 0.6 log cone contrast units), over the entire adapting range. Both increment and decrement thresholds follow the Stiles template, approximating Weber’s law except at the lowest adapting levels. The achromatic tvi’s, for both increment and decrement tests, are, on average, slightly steeper than the L-cone tvi’s. In addition, decrement tvi’s are steeper than the increment tvi’s, indicating greater effects of light adaptation for the decrements, which may be due to differences in the effects of light adaptation in ON and OFF pathways.},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{marijan_role_2023,

title = {The Role of Prediction During Continuous Visual Tracking in 3D Environments},

author = {Aleksandra Marijan and Clara Mestre and T Rowan Candy and Kathryn Bonnen},

url = {https://doi.org/10.1167/jov.23.9.5601},

doi = {10.1167/jov.23.9.5601},

issn = {1534-7362},

year  = {2023},

date = {2023-08-01},

urldate = {2023-12-21},

journal = {Journal of Vision},

volume = {23},

number = {9},

pages = {5601},

abstract = {In everyday life, prediction plays a critical role in ocular motor target tracking. The ocular motor system employs a mixture of saccades and smooth pursuit across version and vergence eye movements to successfully follow objects as they move in the world. However, these eye movements are most often studied in isolation, saccades separate from smooth pursuit, version separate from vergence. Here we examined the perception/prediction of motion trajectories and how different types of eye movements are employed to coordinate the ocular motor tracking of those targets. Eye movements were recorded with an Eyelink 1000 (SR Research) at 500 Hz. The stimuli were presented using a PROPixx projector (VPixx Technologies) and an active circular polarizer, with subjects wearing passive circular polarizing glasses. The screen was set at a viewing distance of 70 cm. Cartoon images of angular size 2.2° moved with horizontal trajectories (initiating version eye movements) or motion-in-depth trajectories (initiating convergence and divergence). The motion trajectories in the predictable condition were sinusoids of varying amplitudes (5, 10 and 20 cm) and temporal frequencies (.25, .5, and 1 Hz). The unpredictable trajectories were smoothed Brownian random walks in position (sigma = 0.1 cm, 0.2 cm, and 0.3 cm). We measured the number of saccades across all conditions. In the horizontal motion condition, there were systematic increases in the number of saccades with increasing trajectory amplitudes and temporal frequency. For the motion-in-depth condition, participants made similar numbers of saccades regardless of the trajectory amplitude and frequency. There were no consistent differences between saccade behavior in the predictable vs. unpredictable conditions. A cross-correlogram analysis of the unpredictable trajectory condition revealed a longer latency (µ=77ms},

keywords = {3DPolarizer, PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{levi_sensory_2023,

title = {Sensory and Choice Responses in MT Distinct from Motion Encoding},

author = {Aaron J. Levi and Yuan Zhao and Il Memming Park and Alexander C. Huk},

url = {https://www.jneurosci.org/content/43/12/2090},

doi = {10.1523/JNEUROSCI.0267-22.2023},

issn = {0270-6474, 1529-2401},

year  = {2023},

date = {2023-03-01},

urldate = {2023-12-21},

journal = {Journal of Neuroscience},

volume = {43},

number = {12},

pages = {2090–2103},

abstract = {The macaque middle temporal (MT) area is well known for its visual motion selectivity and relevance to motion perception, but the possibility of it also reflecting higher-level cognitive functions has largely been ignored. We tested for effects of task performance distinct from sensory encoding by manipulating subjects' temporal evidence-weighting strategy during a direction discrimination task while performing electrophysiological recordings from groups of MT neurons in rhesus macaques (one male, one female). This revealed multiple components of MT responses that were, surprisingly, not interpretable as behaviorally relevant modulations of motion encoding, or as bottom-up consequences of the readout of motion direction from MT. The time-varying motion-driven responses of MT were strongly affected by our strategic manipulation—but with time courses opposite the subjects' temporal weighting strategies. Furthermore, large choice-correlated signals were represented in population activity distinct from its motion responses, with multiple phases that lagged psychophysical readout and even continued after the stimulus (but which preceded motor responses). In summary, a novel experimental manipulation of strategy allowed us to control the time course of readout to challenge the correlation between sensory responses and choices, and population-level analyses of simultaneously recorded ensembles allowed us to identify strong signals that were so distinct from direction encoding that conventional, single-neuron-centric analyses could not have revealed or properly characterized them. Together, these approaches revealed multiple cognitive contributions to MT responses that are task related but not functionally relevant to encoding or decoding of motion for psychophysical direction discrimination, providing a new perspective on the assumed status of MT as a simple sensory area. 

SIGNIFICANCE STATEMENT This study extends understanding of the middle temporal (MT) area beyond its representation of visual motion. Combining multineuron recordings, population-level analyses, and controlled manipulation of task strategy, we exposed signals that depended on changes in temporal weighting strategy, but did not manifest as feedforward effects on behavior. This was demonstrated by (1) an inverse relationship between temporal dynamics of behavioral readout and sensory encoding, (2) a choice-correlated signal that always lagged the stimulus time points most correlated with decisions, and (3) a distinct choice-correlated signal after the stimulus. These findings invite re-evaluation of MT for functions outside of its established sensory role and highlight the power of experimenter-controlled changes in temporal strategy, coupled with recording and analysis approaches that transcend the single-neuron perspective.},

note = {Publisher: Society for Neuroscience 

Section: Research Articles},

keywords = {DATAPixx, PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{seijdel_rapid_2023,

title = {Rapid invisible frequency tagging (RIFT): a promising technique to study neural and cognitive processing using naturalistic paradigms},

author = {Noor Seijdel and Tom R Marshall and Linda Drijvers},

url = {https://doi.org/10.1093/cercor/bhac160},

doi = {10.1093/cercor/bhac160},

issn = {1047-3211},

year  = {2023},

date = {2023-03-01},

urldate = {2024-01-31},

journal = {Cerebral Cortex},

volume = {33},

number = {5},

pages = {1626–1629},

abstract = {Frequency tagging has been successfully used to investigate selective stimulus processing in electroencephalography (EEG) or magnetoencephalography (MEG) studies. Recently, new projectors have been developed that allow for frequency tagging at higher frequencies (>60 Hz). This technique, rapid invisible frequency tagging (RIFT), provides two crucial advantages over low-frequency tagging as (i) it leaves low-frequency oscillations unperturbed, and thus open for investigation, and ii) it can render the tagging invisible, resulting in more naturalistic paradigms and a lack of participant awareness. The development of this technique has far-reaching implications as oscillations involved in cognitive processes can be investigated, and potentially manipulated, in a more naturalistic manner.},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{ferrante_statistical_2023,

title = {Statistical Learning of Distractor Suppression Downregulates Prestimulus Neural Excitability in Early Visual Cortex},

author = {Oscar Ferrante and Alexander Zhigalov and Clayton Hickey and Ole Jensen},

url = {https://www.jneurosci.org/content/43/12/2190},

doi = {10.1523/JNEUROSCI.1703-22.2022},

issn = {0270-6474, 1529-2401},

year  = {2023},

date = {2023-03-01},

urldate = {2024-01-31},

journal = {Journal of Neuroscience},

volume = {43},

number = {12},

pages = {2190–2198},

abstract = {Visual attention is highly influenced by past experiences. Recent behavioral research has shown that expectations about the spatial location of distractors within a search array are implicitly learned, with expected distractors becoming less interfering. Little is known about the neural mechanism supporting this form of statistical learning. Here, we used magnetoencephalography (MEG) to measure human brain activity to test whether proactive mechanisms are involved in the statistical learning of distractor locations. Specifically, we used a new technique called rapid invisible frequency tagging (RIFT) to assess neural excitability in early visual cortex during statistical learning of distractor suppression while concurrently investigating the modulation of posterior alpha band activity (8–12 Hz). Male and female human participants performed a visual search task in which a target was occasionally presented alongside a color-singleton distractor. Unbeknown to the participants, the distracting stimuli were presented with different probabilities across the two hemifields. RIFT analysis showed that early visual cortex exhibited reduced neural excitability in the prestimulus interval at retinotopic locations associated with higher distractor probabilities. In contrast, we did not find any evidence of expectation-driven distractor suppression in alpha band activity. These findings indicate that proactive mechanisms of attention are involved in predictive distractor suppression and that these mechanisms are associated with altered neural excitability in early visual cortex. Moreover, our findings indicate that RIFT and alpha band activity might subtend different and possibly independent attentional mechanisms. 

SIGNIFICANCE STATEMENT What we experienced in the past affects how we perceive the external world in the future. For example, an annoying flashing light might be better ignored if we know in advance where it usually appears. This ability of extracting regularities from the environment is called statistical learning. In this study, we explore the neuronal mechanisms allowing the attentional system to overlook items that are unequivocally distracting based on their spatial distribution. By recording brain activity using MEG while probing neural excitability with a novel technique called RIFT, we show that the neuronal excitability in early visual cortex is reduced in advance of stimulus presentation for locations where distracting items are more likely to occur.},

note = {Publisher: Society for Neuroscience 

Section: Research Articles},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{weise_involuntary_2023,

title = {Involuntary shifts of spatial attention contribute to distraction—Evidence from oscillatory alpha power and reaction time data},

author = {Annekathrin Weise and Thomas Hartmann and Fabrice Parmentier and Nathan Weisz and Philipp Ruhnau},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/psyp.14353},

doi = {10.1111/psyp.14353},

issn = {1469-8986},

year  = {2023},

date = {2023-01-01},

urldate = {2023-12-21},

journal = {Psychophysiology},

volume = {60},

number = {10},

pages = {e14353},

abstract = {Imagine you are focusing on the traffic on a busy street to ride your bike safely when suddenly you hear the siren of an ambulance. This unexpected sound involuntarily captures your attention and interferes with ongoing performance. We tested whether this type of distraction involves a spatial shift of attention. We measured behavioral data and magnetoencephalographic alpha power during a cross-modal paradigm that combined an exogenous cueing task and a distraction task. In each trial, a task-irrelevant sound preceded a visual target (left or right). The sound was usually the same animal sound (i.e., standard sound). Rarely, it was replaced by an unexpected environmental sound (i.e., deviant sound). Fifty percent of the deviants occurred on the same side as the target, and 50% occurred on the opposite side. Participants responded to the location of the target. As expected, responses were slower to targets that followed a deviant compared to a standard. Crucially, this distraction effect was mitigated by the spatial relationship between the targets and the deviants: responses were faster when targets followed deviants on the same versus different side, indexing a spatial shift of attention. This was further corroborated by a posterior alpha power modulation that was higher in the hemisphere ipsilateral (vs. contralateral) to the location of the attention-capturing deviant. We suggest that this alpha power lateralization reflects a spatial attention bias. Overall, our data support the contention that spatial shifts of attention contribute to deviant distraction.},

note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/psyp.14353},

keywords = {DATAPixx2, PROPixx, RESPONSEPixxMRI, SOUNDPixx},

pubstate = {published},

tppubtype = {article}

}

@article{szekely_comparison_2022,

title = {Comparison of human foveal contrast sensitivity during walking and standing},

author = {Brian Szekely and Bharath Shankar and Paul MacNeilage},

url = {https://doi.org/10.1167/jov.22.14.4329},

doi = {10.1167/jov.22.14.4329},

issn = {1534-7362},

year  = {2022},

date = {2022-12-01},

urldate = {2023-12-21},

journal = {Journal of Vision},

volume = {22},

number = {14},

pages = {4329},

abstract = {Prior studies comparing human contrast sensitivity during walking and standing have reported poorer contrast sensitivity during walking (Benjamin et al 2017; Cao & Haendel 2019). Here we present preliminary evidence suggesting that human foveal contrast sensitivity may be improved during walking compared to standing despite increased retinal image motion of the target. Ten human subjects judged the orientation (+/-45 deg) of Gabor targets (textasciitilde11 cpd, 4° diameter, 32 msec duration) presented in the center of a projection screen (ProPixx-Vpixx) against a grey background at a distance of textasciitilde1.75 m in an otherwise darkened room. The contrast of the Gabor targets was fixed at a level that was previously determined to yield textasciitilde79% correct responses for each subject during standing. The timing of target presentation was randomized relative to the previous response and there was no fixation point. In a counterbalanced design, the mean percent correct was significantly better (p=0.04) during walking on a treadmill at 1.3 m/s (83±7%) than during standing (75±9%). Eye, head, and heel movements were tracked (EyeLink 2, Optitrack) and used to estimate viewing distance, retinal image motion, and timing of stimulus presentation relative to the locomotor stride cycle. Average viewing distance was nearer (and spatial frequency lower) during walking than standing (1.79 vs 1.68 m; 11.2 vs 10.5 cpd), but mean retinal image motion was increased during walking (1.84±3.23°/s) compared to standing (0.23±1.33), with the greatest retinal image motion (and least percent correct) during the heel-strike phase. Pending experiments to better control for differences in viewing distance and pupil dilation between standing and walking, this result may indicate enhanced dynamic visual acuity during walking that allows overcoming visual perturbations introduced by active movement.},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{brickwedde_application_2022,

title = {Application of rapid invisible frequency tagging for brain computer interfaces},

author = {Marion Brickwedde and Yulia Bezsudnova and Anna Kowalczyk and Ole Jensen and Alexander Zhigalov},

url = {https://www.sciencedirect.com/science/article/pii/S0165027022002527},

doi = {10.1016/j.jneumeth.2022.109726},

issn = {0165-0270},

year  = {2022},

date = {2022-12-01},

urldate = {2024-01-31},

journal = {Journal of Neuroscience Methods},

volume = {382},

pages = {109726},

abstract = {Background 

Brain-computer interfaces (BCI) based on steady-state visual evoked potentials (SSVEPs/SSVEFs) are among the most commonly used BCI systems. They require participants to covertly attend to visual objects flickering at specified frequencies. The attended location is decoded online by analysing the power of neuronal responses at the flicker frequency. 

New method 

We implemented a novel rapid invisible frequency-tagging technique, utilizing a state-of-the-art projector with refresh rates of up to 1440 Hz. We flickered the luminance of visual objects at 56 and 60 Hz, which was invisible to participants but produced strong neuronal responses measurable with magnetoencephalography (MEG). The direction of covert attention, decoded from frequency-tagging responses, was used to control an online BCI PONG game. 

Results 

Our results show that seven out of eight participants were able to play the pong game controlled by the frequency-tagging signal, with average accuracies exceeding 60 %. Importantly, participants were able to modulate the power of the frequency-tagging response within a 1-second interval, while only seven occipital sensors were required to reliably decode the neuronal response. 

Comparison with existing methods 

In contrast to existing SSVEP-based BCI systems, rapid frequency-tagging does not produce a visible flicker. This extends the time-period participants can use it without fatigue, by avoiding distracting visual input. Furthermore, higher frequencies increase the temporal resolution of decoding, resulting in higher communication rates. 

Conclusion 

Using rapid invisible frequency-tagging opens new avenues for fundamental research and practical applications. In combination with novel optically pumped magnetometers (OPMs), it could facilitate the development of high-speed and mobile next-generation BCI systems.},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{sharp_spatial_2022,

title = {Spatial Attention Tunes Temporal Processing in Early Visual Cortex by Speeding and Slowing Alpha Oscillations},

author = {Poppy Sharp and Tjerk Gutteling and David Melcher and Clayton Hickey},

url = {https://www.jneurosci.org/content/42/41/7824},

doi = {10.1523/JNEUROSCI.0509-22.2022},

issn = {0270-6474, 1529-2401},

year  = {2022},

date = {2022-10-01},

urldate = {2023-12-21},

journal = {Journal of Neuroscience},

volume = {42},

number = {41},

pages = {7824–7832},

abstract = {The perception of dynamic visual stimuli relies on two apparently conflicting perceptual mechanisms: rapid visual input must sometimes be integrated into unitary percepts but at other times must be segregated or parsed into separate objects or events. Though they have opposite effects on our perceptual experience, the deployment of spatial attention benefits both operations. Little is known about the neural mechanisms underlying this impact of spatial attention on temporal perception. Here, we record magnetoencephalography (MEG) in male and female humans to demonstrate that the deployment of spatial attention for the purpose of segregating or integrating visual stimuli impacts prestimulus oscillatory activity in retinotopic visual brain areas where the attended location is represented. Alpha band oscillations contralateral to an attended location are therefore faster than ipsilateral oscillations when stimuli appearing at this location will need to be segregated, but slower in expectation of the need for integration, consistent with the idea that α frequency is linked to perceptual sampling rate. These results demonstrate a novel interaction between temporal visual processing and the allocation of attention in space. 

SIGNIFICANCE STATEMENT Our environment is dynamic and visual input therefore varies over time. To make sense of continuously changing information, our visual system balances two complementary processes: temporal segregation in order to identify changes, and temporal integration to identify consistencies in time. When we know that a circumstance requires use of one or the other of these operations, we are able to prepare for this, and this preparation can be tracked in oscillatory brain activity. Here, we show how this preparation for temporal processing can be focused spatially. When we expect to integrate or segregate visual stimuli that will appear at a specific location, oscillatory brain activity changes in visual areas responsible for the representation of that location. In this way, spatial and temporal mechanisms interact to support adaptive, efficient perception.},

note = {Publisher: Society for Neuroscience 

Section: Research Articles},

keywords = {PROPixx, RESPONSEPixxMRI},

pubstate = {published},

tppubtype = {article}

}

@article{goddard_magnetoencephalography_2022,

title = {Magnetoencephalography contrast adaptation reflects perceptual adaptation},

author = {Erin Goddard and Christopher Shooner and Kathy T. Mullen},

url = {https://doi.org/10.1167/jov.22.10.16},

doi = {10.1167/jov.22.10.16},

issn = {1534-7362},

year  = {2022},

date = {2022-09-01},

urldate = {2023-12-21},

journal = {Journal of Vision},

volume = {22},

number = {10},

pages = {16},

abstract = {Contrast adaptation is a fundamental visual process that has been extensively investigated and used to infer the selectivity of visual cortex. We recently reported an apparent disconnect between the effects of contrast adaptation on perception and functional magnetic resonance imaging BOLD response adaptation, in which adaptation between chromatic and achromatic stimuli measured psychophysically showed greater selectivity than adaptation measured using BOLD signals. Here we used magnetoencephalography (MEG) recordings of neural responses to the same chromatic and achromatic adaptation conditions to characterize the neural effects of contrast adaptation and to determine whether BOLD adaptation or MEG better reflect the measured perceptual effects. Participants viewed achromatic, L-M isolating, or S-cone isolating radial sinusoids before adaptation and after adaptation to each of the three contrast directions. We measured adaptation-related changes in the neural response to a range of stimulus contrast amplitudes using two measures of the MEG response: the overall response amplitude, and a novel time-resolved measure of the contrast response function, derived from a classification analysis combined with multidimensional scaling. Within-stimulus adaptation effects on the contrast response functions in each case showed a pattern of contrast-gain or a combination of contrast-gain and response-gain effects. Cross-stimulus adaptation conditions showed that adaptation effects were highly stimulus selective across early, ventral, and dorsal visual cortical areas, consistent with the perceptual effects.},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{petras_information_2021,

title = {Information redundancy across spatial scales modulates early visual cortical processing},

author = {Kirsten Petras and Sanne Oever and Sarang S. Dalal and Valerie Goffaux},

url = {https://www.sciencedirect.com/science/article/pii/S1053811921008867},

doi = {10.1016/j.neuroimage.2021.118613},

issn = {1053-8119},

year  = {2021},

date = {2021-12-01},

urldate = {2024-01-03},

journal = {NeuroImage},

volume = {244},

pages = {118613},

abstract = {Visual images contain redundant information across spatial scales where low spatial frequency contrast is informative towards the location and likely content of high spatial frequency detail. Previous research suggests that the visual system makes use of those redundancies to facilitate efficient processing. In this framework, a fast, initial analysis of low-spatial frequency (LSF) information guides the slower and later processing of high spatial frequency (HSF) detail. Here, we used multivariate classification as well as time-frequency analysis of MEG responses to the viewing of intact and phase scrambled images of human faces to demonstrate that the availability of redundant LSF information, as found in broadband intact images, correlates with a reduction in HSF representational dominance in both early and higher-level visual areas as well as a reduction of gamma-band power in early visual cortex. Our results indicate that the cross spatial frequency information redundancy that can be found in all natural images might be a driving factor in the efficient integration of fine image details.},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{pan_neural_2021,

title = {Neural evidence for lexical parafoveal processing},

author = {Yali Pan and Steven Frisson and Ole Jensen},

url = {https://www.nature.com/articles/s41467-021-25571-x},

doi = {10.1038/s41467-021-25571-x},

issn = {2041-1723},

year  = {2021},

date = {2021-09-01},

urldate = {2024-01-31},

journal = {Nature Communications},

volume = {12},

number = {1},

pages = {5234},

abstract = {In spite of the reduced visual acuity, parafoveal information plays an important role in natural reading. However, competing models on reading disagree on whether words are previewed parafoveally at the lexical level. We find neural evidence for lexical parafoveal processing by combining a rapid invisible frequency tagging (RIFT) approach with magnetoencephalography (MEG) and eye-tracking. In a silent reading task, target words are tagged (flickered) subliminally at 60 Hz. The tagging responses measured when fixating on the pre-target word reflect parafoveal processing of the target word. We observe stronger tagging responses during pre-target fixations when followed by low compared with high lexical frequency targets. Moreover, this lexical parafoveal processing is associated with individual reading speed. Our findings suggest that reading unfolds in the fovea and parafovea simultaneously to support fluent reading.},

note = {Number: 1 

Publisher: Nature Publishing Group},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}

@article{duecker_no_2021,

title = {No Evidence for Entrainment: Endogenous Gamma Oscillations and Rhythmic Flicker Responses Coexist in Visual Cortex},

author = {Katharina Duecker and Tjerk P. Gutteling and Christoph S. Herrmann and Ole Jensen},

url = {https://www.jneurosci.org/lookup/doi/10.1523/JNEUROSCI.3134-20.2021},

doi = {10.1523/JNEUROSCI.3134-20.2021},

issn = {0270-6474, 1529-2401},

year  = {2021},

date = {2021-08-01},

urldate = {2024-01-31},

journal = {The Journal of Neuroscience},

volume = {41},

number = {31},

pages = {6684–6698},

keywords = {PROPixx},

pubstate = {published},

tppubtype = {article}

}