Feature Selection Methods for Zero-Shot Learning of Neural Activity.

Dimensionality poses a serious challenge when making predictions from human neuroimaging data. Across imaging modalities, large pools of potential neural features (e.g.

Semantic attributes are encoded in human electrocorticographic signals during visual object recognition.

Non-invasive neuroimaging studies have shown that semantic category and attribute information are encoded in neural population activity. Electrocorticography (ECoG) offers several advantages over non-invasive approaches, but the degree to which semantic attribute information is encoded in ECoG responses is not known. We recorded ECoG while patients named objects from 12 semantic categories and then trained high-dimensional encoding models to map semantic attributes to spectral-temporal features of the task-related neural responses.

Conceptual knowledge representation: A cross-section of current research.

How is conceptual knowledge encoded in the brain? This special issue of Cognitive Neuropsychology takes stock of current efforts to answer this question through a variety of methods and perspectives. Across this work, three questions recur, each fundamental to knowledge representation in the mind and brain. First, what are the elements of conceptual representation? Second, to what extent are conceptual representations embodied in sensory and motor systems? Third, how are conceptual representations shaped by context, especially linguistic context? In this introductory article we provide relevant background on these themes and introduce how they are addressed by our contributing authors.

Attentional and Contextual Priors in Sound Perception.

Behavioral and neural studies of selective attention have consistently demonstrated that explicit attentional cues to particular perceptual features profoundly alter perception and performance. The statistics of the sensory environment can also provide cues about what perceptual features to expect, but the extent to which these more implicit contextual cues impact perception and performance, as well as their relationship to explicit attentional cues, is not well understood. In this study, the explicit cues, or attentional prior probabilities, and the implicit cues, or contextual prior probabilities, associated with different acoustic frequencies in a detection task were simultaneously manipulated.

Mental encoding and neural decoding of abstract cognitive categories: a commentary and simulation.

The premise of Multi-Voxel Pattern Analysis (MVPA) of functional Magnetic Resonance Image (fMRI) data is that mental encodings or states give rise to patterns of neural activation, which in turn, give rise to patterns of blood-oxygen level dependent (BOLD) responses distributed across sets of voxels. Statistical learning algorithms can then be used to detect relationships between mental encodings and BOLD responses, typically through pattern classification. Amongst many other applications, this technique has been used to evidence abstract category representation in an assortment of brain areas and across a range of cognitive domains.

What does the right hemisphere know about phoneme categories?

Innate auditory sensitivities and familiarity with the sounds of language give rise to clear influences of phonemic categories on adult perception of speech. With few exceptions, current models endorse highly left-hemisphere-lateralized mechanisms responsible for the influence of phonemic category on speech perception, based primarily on results from functional imaging and brain-lesion studies. Here we directly test the hypothesis that the right hemisphere does not engage in phonemic analysis.

Brain-behavior relationships in reading acquisition are modulated by socioeconomic factors.

Functional neuroimaging may provide insights into the achievement gap in reading skill commonly observed across socioeconomic status (SES). Brain activation during reading tasks is known to be associated with individual differences in children's phonological language skills. By selecting children of equivalent phonological skill, yet diverse socioeconomic backgrounds, we use functional magnetic resonance imaging (fMRI) to demonstrate that a child's experience, as operationalized by SES, can systematically modulate the relationship between phonological language skills and reading-related brain activity in left fusiform and perisylvian regions.

Two brain pathways for attended and ignored words.

The dependency of word processing on spare attentional resources has been debated for several decades. Recent research in the study of selective attention has emphasized the role of task load in determining the fate of ignored information. In parallel to behavioral evidence, neuroimaging data show that the activation generated by unattended stimuli is eliminated in task-relevant brain regions during high attentional load tasks.