Neurocognitive Informatics Manifesto.

Informatics studies all aspects of the structure of natural and artificial information systems. Theoretical and abstract approaches to information have made great advances, but human information processing is still unmatched in many areas, including information management, representation and understanding. Neurocognitive informatics is a new, emerging field that should help to improve the matching of artificial and natural systems, and inspire better computational algorithms to solve problems that are still beyond the reach of machines. In this position paper examples of neurocognitive inspirations and promising directions in this area are given

Semantic memory

The Encyclopedia of Human Behavior, Second Edition is a comprehensive three-volume reference source on human action and reaction, and the thoughts, feelings, and physiological functions behind those actions

Mapping visual symbols onto spoken language along the ventral visual stream.

Reading involves transforming arbitrary visual symbols into sounds and meanings. This study interrogated the neural representations in ventral occipitotemporal cortex (vOT) that support this transformation process. Twenty-four adults learned to read 2 sets of 24 novel words that shared phonemes and semantic categories but were written in different artificial orthographies. Following 2 wk of training, participants read the trained words while neural activity was measured with functional MRI. Representational similarity analysis on item pairs from the same orthography revealed that right vOT and posterior regions of left vOT were sensitive to basic visual similarity. Left vOT encoded letter identity and representations became more invariant to position along a posterior-to-anterior hierarchy. Item pairs that shared sounds or meanings, but were written in different orthographies with no letters in common, evoked similar neural patterns in anterior left vOT. These results reveal a hierarchical, posterior-to-anterior gradient in vOT, in which representations of letters become increasingly invariant to position and are transformed to convey spoken language information

Symbolizing Number: fMRI investigations of the semantic, auditory, and visual correlates of Hindu-Arabic numerals

Humans are born with a sensitivity to numerical magnitude. In literate cultures, these numerical intuitions are associated with a symbolic notation (e.g..Hindu-Arabic numerals). While a growing body of neuroscientific research has been conducted to elucidate commonalities between symbolic (e.g. Hinud-Arabic numerals) and non-symbolic (e.g. arrays of objects) representations, relatively little is known about the neural correlates specific to the symbolic processing of numerical magnitude. To address this, I conducted the three fMRI experiments contained within this thesis to characterize the neuroanatomical correlates of the auditory, visual, audiovisual, and semantic processing of numerical symbols. In Experiment 1, the neural correlates of symbolic and non-symbolic number were contrasted to reveal that the left angular and superior temporal gyri responded specifically to numerals, while the right posterior superior parietal lobe only responded to non-symbolic arrays. Moreover, the right intraparietal sulcus (IPS) was activated by both formats. The results reflect divergent encoding pathways that converge upon a common representation across formats. In Experiment 2, the neural response to Hindu-Arabic numerals and Chinese numerical ideographs was recorded in individuals who could read both notations and a control group who could read only the numerals. A between-groups contrast revealed semantic processing of ideographs in the right IPS, while asemantic visual processing was found in the left fusiform gyrus. In contrast to the ideographs, the semantic processing of numerals was associated with left IPS activity. The role of these brain regions in the semantic and asemantic representation of numerals is discussed. In Experiment 3, the neural response of the visual, auditory, and audiovisual processing of numerals and letters was measured. The regions associated with visual and auditory responses to letters and numerals were highly similar. In contrast, the audiovisual response to numerals recruited a region of the right supramarginal gyrus, while the audiovisual letters activated left visual regions. In addition, an effect of congruency in the audiovisual pairs was comparable across numeral-number name pairs and letter-letter name pairs, but absent in letter-speech sound pairs. Taken together, these three experiments provide new insights into how the brain processes numerical symbols at different levels of description

Automatic Top-Down Processing Explains Common Left Occipito-Temporal Responses to Visual Words and Objects

Previous studies have demonstrated that a region in the left ventral occipito-temporal (LvOT) cortex is highly selective to the visual forms of written words and objects relative to closely matched visual stimuli. Here, we investigated why LvOT activation is not higher for reading than picture naming even though written words and pictures of objects have grossly different visual forms. To compare neuronal responses for words and pictures within the same LvOT area, we used functional magnetic resonance imaging adaptation and instructed participants to name target stimuli that followed briefly presented masked primes that were either presented in the same stimulus type as the target (word–word, picture–picture) or a different stimulus type (picture–word, word–picture). We found that activation throughout posterior and anterior parts of LvOT was reduced when the prime had the same name/response as the target irrespective of whether the prime-target relationship was within or between stimulus type. As posterior LvOT is a visual form processing area, and there was no visual form similarity between different stimulus types, we suggest that our results indicate automatic top-down influences from pictures to words and words to pictures. This novel perspective motivates further investigation of the functional properties of this intriguing region