Prediction of Individual Melodic Contour Processing in Sensory Association Cortices From Resting State Functional Connectivity.

Event-related potentials, heart period, and brain-heart responses during a threat of shock oddball task: Replicability and 6-month-reliability.

Connecting brain responsivity and real-world risk taking: Strengths and limitations of current methodological approaches

The role of socioeconomic status in shaping associations between sensory association cortex and prefrontal structure and implications for executive function.

Sensory Pathways and Emotional Context for Action in Primate Prefrontal Cortex

Individual differences in brain responses to cigarette-related cues and pleasant stimuli in young smokers

*Department of Neurology, Medical College of Wisconsin, Milwaukee, Wisconsin, U.S.A.; †University Hospital Gent, Gent, Belgium; ‡Departments of Diagnostic Radiology and Neurosurgery, Yale University, New Haven, Connecticut; §Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania; Clinical Epilepsy Section, National Institutes of Health, Bethesda, Maryland; ¶Department of Radiology, Mayo Clinic, Rochester, Minnesota; and **Department of Neurology, Medical College of Georgia, Augusta, Georgia, U.S.A.

SUMMARYNeuronal oscillations are suggested to play an important role in auditory working memory (WM), but their contribution to content-specific representations has remained unclear. Here, we measure magnetoencephalography during a retro-cueing task with parametric ripple-sound stimuli, which are spectrotemporally similar to speech but resist non-auditory memory strategies. Using machine learning analyses, with rigorous between-subject cross-validation and non-parametric permutation testing, we show that memorized sound content is strongly represented in phase-synchronization patterns between subregions of auditory and frontoparietal cortices. These phase-synchronization patterns predict the memorized sound content steadily across the studied maintenance period. In addition to connectivity-based representations, there are indices of more local, “activity silent” representations in auditory cortices, where the decoding accuracy of WM content significantly increases after task-irrelevant “impulse stimuli.” Our results demonstrate that synchronization patterns across auditory sensory and association areas orchestrate neuronal coding of auditory WM content. This connectivity-based coding scheme could also extend beyond the auditory domain.

Chemically defined feedback connections from infragranular layers of sensory association cortices in the rat

Auditory Brain Development in Children With Hearing Loss – Part One

Recently, only little is known about the cortical activity of tactile sensation for the dominant and subdominant hand. The objective of this study was to investigate the hemodynamic response of human's cortical brain to tactile sensation to compare the dominant and subdominant hand. Ten healthy adults, 25-35 ages, were enrolled. A 45 channel near-infrared spectroscopy system was used to measure brain responses and a solenoid resonance actuator was utilized to stimulate tactile sensation. The results showed that for the hemodynamic response to both hands on tactile stimulation, the corresponding primary sensory cortex and supplementary motor area were commonly activated, but the tactile stimuli of the subdominant hand induced broader areas of cortical activation than that of the dominant hand. Thus, broad brain areas, including the primary motor cortex and sensory association cortex, were activated by tactile stimulation in subdominant hand. These results suggest that there are differences in brain responses to tactile stimulation of the dominant and subdominant hand, which may reflect the importance of neural adaptability and efficiency for tactile sensation of the hand dominance.

Infants are sensitive to the distributional characteristics of the speech they hear, and perception can be altered by the distributional properties of language input. Infants listening to languages with distinct distributional properties show altered perception at the age of 6 months based on learning from ambient language input. Perception can also be altered in the laboratory by manipulating the distributional characteristics of speech in a 2-min exposure. However, the brain mechanisms underlying this learning are not well understood. Here we used MEG to explore the neural processes involved in on-line distributional learning. We examined brain responses to ambiguous speech sounds that straddle a /ba-wa/ speech continuum. Infants were tested longitudinally at 2 and 6 months of age not only to assess whether effects of experience can be documented between 2 and 6 months, but also to determine whether individual differences in brain response can predict future language growth. Our results show that differences in the magnitude of the brain response to ambiguous speech sounds in brain regions involved in auditory speech processing, motor planning, and attention change from 2- to 6-months-of- age. Moreover, we found that individual differences in these regions predict language growth up to 27 months of age.

Do Sensory Cortices Process More than One Sensory Modality during Perceptual Judgments?

A comprehensive understanding of the neural mechanisms of cognitive function requires an understanding of how neural representations are transformed across different scales of neural organization: from within local microcircuits to across different brain areas. However, the neural transformations within the local microcircuits are poorly understood. Particularly, the role that two main cell classes of neurons in cortical microcircuits (i.e. pyramidal neurons and interneurons) have in auditory behaviour and cognition remains unknown. In this study, we tested the hypothesis that pyramidal cells and interneurons in the auditory cortex play a differential role in auditory categorization. To test this hypothesis, we recorded single-unit activity from the auditory cortex of rhesus monkeys while they categorized speech sounds. Based on the spike-waveform shape, a neuron was classified as either a narrow-spiking putative interneuron or a broad-spiking putative pyramidal neuron. We found that putative interneurons and pyramidal neurons in the auditory cortex differentially coded category information: interneurons were more selective for auditory categories than pyramidal neurons. These differences between cell classes may be an essential property of the neural computations underlying auditory categorization within the microcircuitry of the auditory cortex.

Long-term memory integrates the multimodal information acquired through perception into unified concepts, supporting object recognition, thought, and language. While some theories of human cognition have considered concepts to be abstract symbols, recent functional neuroimaging evidence has supported an alternative theory: that concepts are multimodal representations associated with the sensory and motor systems through which they are acquired. However, few studies have examined the effects of cortical lesions on the sensory and motor associations of concepts. We tested the hypothesis that individuals with disease in auditory association cortex would have difficulty processing concepts with strong sound associations (e.g., thunder). Human participants with the logopenic variant of primary progressive aphasia (lvPPA) performed a recognition task on words with strong associations in three modalities: Sound, Sight, and Manipulation. LvPPA participants had selective difficulty on Sound words relative to other modalities. Structural MRI analysis in lvPPA revealed gray matter atrophy in auditory association cortex, as defined functionally in a separate BOLD fMRI study of healthy adults. Moreover, lvPPA showed reduced gray matter density in the region of auditory association cortex that healthy participants activated when processing the same Sound words in a separate BOLD fMRI experiment. Finally, reduced gray matter density in this region in lvPPA directly correlated with impaired performance on Sound words. These findings support the hypothesis that conceptual memories are represented in the sensory and motor association cortices through which they are acquired.

Sound Categories Are Represented as Distributed Patterns in the Human Auditory Cortex