Cochlea to categories: The spatiotemporal dynamics of semantic auditory representations.

How does the auditory system categorize natural sounds? Here we apply multimodal neuroimaging to illustrate the progression from acoustic to semantically dominated representations. Combining magnetoencephalographic (MEG) and functional magnetic resonance imaging (fMRI) scans of observers listening to naturalistic sounds, we found superior temporal responses beginning ∼55 ms post-stimulus onset, spreading to extratemporal cortices by ∼100 ms. Early regions were distinguished less by onset/peak latency than by functional properties and overall temporal response profiles.

The Nature of Illusions: A New Synthesis Based on Verifiability.

This overview discusses the nature of perceptual illusions with particular reference to the theory that illusions represent the operation of a sensory code for which there is no meaningful ground truth against which the illusory percepts can be compared, and therefore there are no illusions as such. This view corresponds to the Bayesian theory that "illusions" reflect unusual aspects of the core strategies of adapting to the natural world, again implying that illusions are simply an information processing characteristic. Instead, it is argued that a more meaningful approach to the field that we call illusions is the Ebbinghaus approach of comparing the illusory percept with a ground truth that is directly verifiable as aberrant by the observer in the domain of the illusory phenomenology (as opposed to relying on the authority of other experts).

Quantitative Digitography Measures Motor Symptoms and Disease Progression in Parkinson's Disease.

Background: Assessment of motor signs in Parkinson's disease (PD) requires an in-person examination. However, 50% of people with PD do not have access to a neurologist. Wearable sensors can provide remote measures of some motor signs but require continuous monitoring for several days.

Perceptual learning with dichoptic attention tasks improves attentional modulation in V1 and IPS and reduces interocular suppression in human amblyopia.

Long-term and chronic visual suppression to the non-preferred eye in early childhood is a key factor in developing amblyopia, as well as a critical barrier to treat amblyopia. To explore the relationship between selective visual attention and amblyopic suppression and its role in the success of amblyopic training, we used EEG source-imaging to show that training human adults with strabismic and anisometropic amblyopia with dichoptic attention tasks improved attentional modulation of neural populations in the primary visual cortex (V1) and intraparietal sulcus (IPS). We also used psychophysics to show that training reduced interocular suppression along with visual acuity and stereoacuity improvements.

Ocular neovascularization following hypoxic ischemic encephalopathy.

We present the findings of 2 children with neonatal hypoxic ischemic encephalopathy (HIE), who demonstrated ocular neovascularization at birth. While the cerebral effects of HIE have been well described, ocular effects have not. Our cases, combined with recent published laboratory research, demonstrate that significant ocular effects may accompany HIE.

Do we enjoy what we sense and perceive? A dissociation between aesthetic appreciation and basic perception of environmental objects or events.

This integrative review rearticulates the notion of human aesthetics by critically appraising the conventional definitions, offerring a new, more comprehensive definition, and identifying the fundamental components associated with it. It intends to advance holistic understanding of the notion by differentiating aesthetic perception from basic perceptual recognition, and by characterizing these concepts from the perspective of information processing in both visual and nonvisual modalities. To this end, we analyze the dissociative nature of information processing in the brain, introducing a novel local-global integrative model that differentiates aesthetic processing from basic perceptual processing.

Brain trauma impacts retinal processing: photoreceptor pathway interactions in traumatic light sensitivity.

Background: Concussion-induced light sensitivity, or traumatic photalgia, is a lifelong debilitating problem for upwards of 50% of mild traumatic brain injury (mTBI) cases, though of unknown etiology. We employed spectral analysis of electroretinographic (ERG) responses to assess retinal changes in mTBI as a function of the degree of photalgia.

Methods: The design was a case-control study of the changes in the ERG waveform as a function of level of light sensitivity in individuals who had suffered incidents of mild traumatic brain injury.

From the Lab to People's Home: Lessons from Accessing Blind Participants' Interactions via Smart Glasses in Remote Studies.

Researchers have adopted remote methods, such as online surveys and video conferencing, to overcome challenges in conducting in-person usability testing, such as participation, user representation, and safety. However, remote user evaluation on hardware testbeds is limited, especially for blind participants, as such methods restrict access to observations of user interactions. We employ smart glasses in usability testing with blind people and share our lessons from a case study conducted in blind participants' homes ( = 12), where the experimenter can access participants' activities via dual video conferencing: a third-person view via a laptop camera and a first-person view via smart glasses worn by the participant.

Self-Regulation of Seat of Attention Into Various Attentional Stances Facilitates Access to Cognitive and Emotional Resources: An EEG Study.

This study provides evidence supporting the operation of a novel cognitive process of a somatic seat of attention, or ego-center, whose somatic location is under voluntary control and that provides access to differential emotional resources. Attention has typically been studied in terms of what it is directed toward, but it can also be associated with a localized representation in the body image that is experienced as the source or seat of attention-an aspect that has previously only been studied by subjective techniques. Published studies of this phenomenon under terms such as egocenter or self-location suggest that the seat of attention can be situated in various ways within the experienced body, resulting in what are here referred to as different attentional stances.

Perception and Appreciation of Tactile Objects: The Role of Visual Experience and Texture Parameters.

This exploratory study was designed to examine the effects of visual experience and specific texture parameters on both discriminative and aesthetic aspects of tactile perception. To this end, the authors conducted two experiments using a novel behavioral (ranking) approach in blind and (blindfolded) sighted individuals. Groups of congenitally blind, late blind, and (blindfolded) sighted participants made relative stimulus preference, aesthetic appreciation, and smoothness or softness judgment of two-dimensional (2D) or three-dimensional (3D) tactile surfaces through active touch.

Higher Visual Function Deficits in Children With Cerebral Visual Impairment and Good Visual Acuity.

In clinical practice Cerebral Visual Impairment (CVI) is typically diagnosed by observation of abnormal visually guided behaviors which indicate higher visual function deficits (HVFDs) suggesting abnormal brain development or brain damage in a child with a suitable clinical history. HVFDs can occur even in the presence of good visual acuity and may remain undiagnosed the good visual acuity does not prompt further investigation. This leads to a lack of understanding of the child's visual perceptual difficulties.

Differential Effects of Pathological Beta Burst Dynamics Between Parkinson's Disease Phenotypes Across Different Movements.

Resting state beta band (13-30 Hz) oscillations represent pathological neural activity in Parkinson's disease (PD). It is unknown how the peak frequency or dynamics of beta oscillations may change among fine, limb, and axial movements and different disease phenotypes. This will be critical for the development of personalized closed loop deep brain stimulation (DBS) algorithms during different activity states.

The Interstitial Pathways as the Substrate of Consciousness: A New Synthesis.

This paper considers three classes of analyses of the nature of consciousness: abstract theories of the functional organization of consciousness, and concrete proposals as to the neural substrate of consciousness, while providing a rationale for contesting non-neural and transcendental conceptualizations of consciousness. It indicates that abstract theories of the dynamic core of consciousness have no force unless they are grounded in the physiology of the brain, since the organization of dynamic systems, such as the Sun, could equally well qualify as conscious under such theories. In reviewing the wealth of studies of human consciousness since the mid-20th century, it concludes that many proposals for the particular neural substrate of consciousness are insufficient in various respects, but that the results can be integrated into a novel scheme that consciousness extends through a subcortical network of interlaminar structures from the brainstem to the claustrum.

Motion Processing Deficits in Children With Cerebral Visual Impairment and Good Visual Acuity.

Purpose: We sought to characterize neural motion processing deficits in children with cerebral visual impairment (CVI) who have good visual acuity using an objective, quantifiable method (steady-state visual evoked potentials [SSVEPs]).

Methods: We recorded SSVEPs in response to three types of visual motion - absolute motion and more complex relative and rotary motion, comparing them to form-related vernier and contour responses. We studied a group of 31 children with CVI diagnosed via detailed clinical examinations and 28 age-matched healthy controls.

Cartography as Spatial Representation: A new assessment of the competing advantages and drawbacks across fields of science.

The history of cartography has been marked by the endless search for the perfect form for the representation of the information on a spherical surface manifold into the flat planar format of the printed page or computer screen. Dozens of cartographic formats have been proposed over the centuries from ancient Greek times to the present. This is an issue not just for the mapping of the globe, but in all fields of science where spherical entities are found.

Lack of progression of beta dynamics after long-term subthalamic neurostimulation.

Objective: To investigate the progression of neural and motor features of Parkinson's disease in a longitudinal study, after washout of medication and bilateral subthalamic nucleus deep brain stimulation (STN DBS).

Methods: Participants with clinically established Parkinson's disease underwent bilateral implantation of DBS leads (18 participants, 13 male) within the STN using standard functional frameless stereotactic technique and multi-pass microelectrode recording. Both DBS leads were connected to an implanted investigative sensing neurostimulator (Activa™ PC + S, Medtronic, PLC).

Mental Visualization in the Cerebellum: Rapid Non-motor Learning at Sub-Lobular and Causal Network Levels.

It is generally understood that the main role of the cerebellum is in movement planning and coordination, but neuroimaging has led to striking findings of its involvement in many aspects of cognitive processing. Mental visualization is such a cognitive process, extensively involved in learning and memory, artistic and inventive creativity, etc. Here, our aim was to conduct a multidimensional study of cerebellar involvement in the non-motor cognitive tasks.

Neuroplasticity and Crossmodal Connectivity in the Normal, Healthy Brain.

Objective: Neuroplasticity enables the brain to establish new crossmodal connections or reorganize old connections which are essential to perceiving a multisensorial world. The intent of this review is to identify and summarize the current developments in neuroplasticity and crossmodal connectivity, and deepen understanding of how crossmodal connectivity develops in the normal, healthy brain, highlighting novel perspectives about the principles that guide this connectivity.

Methods: To the above end, a narrative review is carried out.

Excitatory Contribution to Binocular Interactions in Human Visual Cortex Is Reduced in Strabismic Amblyopia.

Binocular summation in strabismic amblyopia is typically reported as being absent or greatly reduced in behavioral studies and is thought to be because of a preferential loss of excitatory interactions between the eyes. Here, we studied how excitatory and suppressive interactions contribute to binocular contrast interactions along the visual cortical hierarchy of humans with strabismic and anisometropic amblyopia in both sexes, using source-imaged steady-state visual evoked potentials (SSVEP) over a wide range of relative contrast between the two eyes. Dichoptic parallel grating stimuli modulated at unique temporal frequencies in each eye allowed us to quantify spectral response components associated with monocular inputs (self-terms) and the response components because of interaction of the inputs of the two eyes [intermodulation (IM) terms].