Ian Fiebelkorn

University of Rochester Medical Center | URMC · Department of Neuroscience

Selective attention enhances behaviorally important information and suppresses distracting information. Research on the neural basis of selective attention has largely focused on sensory enhancement, with less focus on sensory suppression. Enhancement and suppression can operate through a push-pull relationship that arises from competitive interact...

Selective attention1 is characterized by alternating states associated with either attentional sampling or attentional shifting, helping to prevent functional conflicts by isolating function-specific neural activity in time.2,3,4,5 We hypothesized that such rhythmic temporal coordination might also help to prevent representational conflicts during...

Even during sustained attention, enhanced processing of attended stimuli waxes and wanes rhythmically, with periods of enhanced and relatively diminished visual processing (and subsequent target detection) alternating at 4 or 8 Hz in a sustained visual attention task. These alternating attentional states occur alongside alternating dynamical states...

Selective attention includes alternating states associated with either attentional sampling or attentional shifting, helping to avoid functional conflicts by isolating function-specific neural activity in time. We hypothesized that such rhythmic temporal coordination might also help to avoid representational conflicts during working memory. Multipl...

Recent research indicates periodicity in attention-related sampling and switching, with some of the initial findings coming from behavioral studies. Brookshire [Brookshire, G. Putative rhythms in attentional switching can be explained by aperiodic temporal structure. Nat Hum Behav. 2022], points out that widely used approaches to testing for rhythm...

Recent evidence suggests that visual attention alternately samples two behaviorally relevant objects at approximately 4Hz, rhythmically shifting between the objects. Whether similar attentional rhythms exist in other sensory modalities, however, is not yet clear. We therefore adapted and extended an established paradigm to investigate visual and po...

Recent research suggests that environmental sampling is a fundamentally rhythmic process (Benedetto, Morrone, & Tomassini, 2019; Fiebelkorn & Kastner, 2019; Schroeder, Wilson, Radman, Scharfman, & Lakatos, 2010). In primates, both attention-related sampling and exploratory eye movements are seemingly shaped by theta-band activity (3–8 Hz) in the la...

Even during sustained attention, enhanced processing of attended stimuli waxes and wanes rhythmically, with periods of enhanced and relatively diminished visual processing (and hit rates) alternating at 4 or 8 Hz in a sustained visual attention task. These alternating attentional states occur alongside alternating dynamical states, in which lateral...

There has been little evidence linking changes in spiking activity that occur prior to a spatially predictable target (i.e., prior to target selection) to behavioral outcomes, despite such preparatory changes being widely assumed to enhance the sensitivity of sensory processing. We simultaneously recorded from frontal and parietal nodes of the atte...

While research in previous decades demonstrated a link between the pulvinar nucleus of the thalamus and visual selective attention, the pulvinar's specific functional role has remained elusive. However, methodological advances in electrophysiological recordings in non-human primates, including simultaneous recordings in multiple brain regions, have...

There has been little evidence linking changes in spiking activity that occur prior to a spatially predictable target (i.e., prior to target selection) to behavioral outcomes, despite such preparatory changes being widely assumed to enhance the sensitivity of sensory processing. We simultaneously recorded from frontal and parietal nodes of the atte...

Spatial attention is comprised of neural mechanisms that boost sensory processing at a behaviorally relevant location while filtering out competing information. The present review examines functional specialization in the network of brain regions that directs such preferential processing. This attention network includes both cortical (e.g., frontal...

The functional role of the pulvinar, with its widespread cortical connectivity, has remained elusive. In this issue of Neuron, Jaramillo et al. (2019) provide a computational roadmap for how the pulvinar might influence various cognitive behaviors across multiple large-scale networks.

Spatial attention is discontinuous, sampling behaviorally relevant locations in theta-rhythmic cycles (3–6 Hz). Underlying this rhythmic sampling are intrinsic theta oscillations in frontal and parietal cortices that provide a clocking mechanism for two alternating attentional states that are associated with either engagement at the presently atten...

Recent evidence has demonstrated that environmental sampling is a fundamentally rhythmic process. Both perceptual sensitivity during covert spatial attention and the probability of overt exploratory movements are tethered to theta-band activity (3–8 Hz) in the attention network. The fronto-parietal part of this network is positioned at the nexus of...

Spatial attention is discontinuous, sampling behaviorally relevant locations in theta-rhythmic cycles (3-6 Hz). Underlying this rhythmic sampling are intrinsic theta oscillations in frontal and parietal cortices that provide a clocking mechanism for two alternating attentional states that are associated with either engagement at the presently atten...

Classic studies of spatial attention assumed that its neural and behavioral effects were continuous over time. Recent behavioral studies have instead revealed that spatial attention leads to alternating periods of heightened or diminished perceptual sensitivity. Yet, the neural basis of these rhythmic fluctuations has remained largely unknown. We s...

Classic models of attention suggest that sustained neural firing constitutes a neural correlate of sustained attention. However, recent evidence indicates that behavioral performance fluctuates over time, exhibiting temporal dynamics that closely resemble the spectral features of ongoing, oscillatory brain activity. Therefore, it has been proposed...

The brain directs its limited processing resources through various selection mechanisms, broadly referred to as attention. Spatial selection, one such mechanism, is sometimes likened to a spotlight, continuously highlighting regions of the visual scene for preferential processing. Evidence suggests that the operation of this spotlight is linked, at...

Even simple tasks rely on information exchange between functionally distinct and often relatively distant neuronal ensembles. Considerable work indicates oscillatory synchronization through phase alignment is a major agent of inter-regional communication. In the brain, different oscillatory phases correspond to low- and high-excitability states. Op...

The brain directs its limited processing resources through various selection mechanisms, broadly referred to as attention. The present study investigated the temporal dynamics of two such selection mechanisms: space- and object-based selection. Previous evidence has demonstrated that preferential processing resulting from a spatial cue (i.e., space...

Human and animal neurophysiological studies have shown that the auditory and tactile systems interact both early in time, and early in the cortical processing hierarchy. The question remains as to the functional significance of these multisensory interactions that are observed prior to 100 ms post-stimulus onset in both auditory and tactile cortice...

Findings in animal models demonstrate that activity within hierarchically early sensory cortical regions can be modulated by cross-sensory inputs through resetting of the phase of ongoing intrinsic neural oscillations. Here, subdural recordings evaluated whether phase resetting by auditory inputs would impact multisensory integration processes in h...

Functional networks are comprised of neuronal ensembles bound through synchronization across multiple intrinsic oscillatory frequencies. Various coupled interactions between brain oscillators have been described (e.g., phase-amplitude coupling), but with little evidence that these interactions actually influence perceptual sensitivity. Here, electr...

The frequency of environmental vibrations is sampled by two of the major sensory systems, audition and touch, notwithstanding that these signals are transduced through very different physical media and entirely separate sensory epithelia. Psychophysical studies have shown that manipulating frequency in audition or touch can have a significant cross...

Investigations have traditionally focused on activity in the sensory cortices as a function of their respective sensory inputs. However, converging evidence from multisensory research has shown that neural activity in a given sensory region can be modulated by stimulation of other sensory systems. Both electrophysiology and functional imaging suppo...

Our own work, as well as that of others, has demonstrated the oscillatory nature of visual perception. For example, the phase of ongoing cortical oscillations influences the likelihood of visual-target detection, such that a near-threshold stimulus is more likely to be detected if it occurs during a high-excitability state. Debate persists, however...

Behavioral evidence for an impaired ability to group objects based on similar physical or semantic properties in autism spectrum disorders (ASD) has been mixed. Here, we recorded brain activity from high-functioning children with ASD as they completed a visual-target detection task. We then assessed the extent to which object-based selective attent...

Humans have limited cognitive resources to process the nearly limitless information available in the environment. Endogenous, or 'top-down', selective attention to basic visual features such as color or motion is a common strategy for biasing resources in favor of the most relevant information sources in a given context. Opposing this top-down sepa...

Investigations have traditionally focused on activity in the sensory cortices as a function of their respective sensory inputs. However, converging evidence from multisensory research has shown that neural activity in a given sensory region can be modulated by stimulation of other so-called ancillary sensory systems. Both electrophysiology and func...

Functional networks are comprised of neuronal ensembles bound through synchronization across multiple intrinsic oscillatory frequencies. Various coupled interactions between brain oscillators have been described (e.g., phase–amplitude coupling), but with little evidence that these interactions actually influence perceptual sensitivity. Here, electr...

The simultaneous presentation of a stimulus in one sensory modality often enhances target detection in another sensory modality, but the neural mechanisms that govern these effects are still under investigation. Here, we test a hypothesis proposed in the neurophysiological literature: that auditory facilitation of visual-target detection operates t...

It is well established that sounds can enhance visual-target detection, but the mechanisms that govern these cross-sensory effects, as well as the neural pathways involved, are largely unknown. Here, we tested behavioral predictions stemming from the neurophysiologic and neuroanatomic literature. Participants detected near-threshold visual targets...

Certain features of objects or events can be represented by more than a single sensory system, such as roughness of a surface (sight, sound, and touch), the location of a speaker (audition and sight), and the rhythm or duration of an event (by all three major sensory systems). Thus, these properties can be said to be sensory-independent or amodal....

The brain processes multisensory features of an object (e.g., its sound and shape) in separate cortical regions. A key question is how representations of these features bind together to form a coherent percept (the 'binding problem'). Here we tested the hypothesis that the determination of an object's visuospatial boundaries is paramount to the lin...

Medicaid recipients are disproportionately affected by tobacco-related disease because their smoking prevalence is approximately 53% greater than that of the overall US adult population. This study estimates state-level smoking-attributable Medicaid expenditures. We used state-level and national data and a 4-part econometric model to estimate the f...

Introduction: Medicaid recipients are disproportionately affected by tobacco-related disease because their smoking prevalence is approximately 53% greater than that of the overall US adult population. This study estimates state-level smoking-attributable Medicaid expenditures. Methods: We used state-level and national data and a 4-part econometr...

The spread of attention-related processing across anatomically separated cortical regions plays an important role in the binding of an object's features, both within and across sensory modalities. We presented multiple exemplars of semantically congruent multisensory objects (e.g., dogs with barks) and semantically incongruent multisensory objects...

Standardized methodologies for assessing economic burden of injury at the national or international level do not exist. To measure national incidence, medical costs, and productivity losses of medically treated injuries using the most recent data available in the United States, as a case study for similarly developed countries undertaking economic...

Injuries are one of the most serious public health problems facing the United States today. Through premature death, disability, medical cost and lost productivity, injuries impact the health and welfare of all Americans. Deaths only begin to tell the story. Although many injuries are minor, a large proportion result in fractures, amputations, burn...

To provide state-level estimates of total, Medicare, and Medicaid obesity-attributable medical expenditures. We developed an econometric model that predicts medical expenditures. We used this model and state-representative data to quantify obesity-attributable medical expenditures. Annual U.S. obesity-attributable medical expenditures are estimated...

We use a regression framework and nationally representative data to compute aggregate overweight- and obesity-attributable medical spending for the United States and for select payers. Combined, such expenditures accounted for 9.1 percent of total annual U.S. medical expenditures in 1998 and may have been as high as dollar 78.5 billion (dollar 92.6...