Reduced audiovisual integration in synesthesia – evidence from bimodal speech perception

Recent research suggests synesthesia as a result of a hypersensitive multimodal binding mechanism. To address the question whether multimodal integration is altered in synesthetes in general, grapheme‐colour and auditory‐visual synesthetes were investigated using speech‐related stimulation in two behavioural experiments. First, we used the McGurk illusion to test the strength and number of illusory perceptions in synesthesia. In a second step, we analysed the gain in speech perception coming from seen articulatory movements under acoustically noisy conditions. We used disyllabic nouns as stimulation and varied signal‐to‐noise ratio of the auditory stream presented concurrently to a matching video of the speaker. We hypothesized that if synesthesia is due to a general hyperbinding mechanism this group of subjects should be more susceptible to McGurk illusions and profit more from the visual information during audiovisual speech perception. The results indicate that there are differences between synesthetes and controls concerning multisensory integration – but in the opposite direction as hypothesized. Synesthetes showed a reduced number of illusions and had a reduced gain in comprehension by viewing matching articulatory movements in comparison to control subjects. Our results indicate that rather than having a hypersensitive binding mechanism, synesthetes show weaker integration of vision and audition.     

Contrasting accounts of direction and shape perception in short-range motion: Counterchange compared with motion energy detection

It has long been thought (e.g., Cavanagh & Mather, 1989) that first-order motion-energy extraction via space-time comparator-type models (e.g., the elaborated Reichardt detector) is sufficient to account for human performance in the short-range motion paradigm (Braddick, 1974), including the perception of reverse-phi motion when the luminance polarity of the visual elements is inverted during successive frames. Human observers’ ability to discriminate motion direction and use coherent motion information to segregate a region of a random cinematogram and determine its shape was tested; they performed better in the same-, as compared with the inverted-, polarity condition. Computational analyses of short-range motion perception based on the elaborated Reichardt motion energy detector (van Santen & Sperling, 1985) predict, incorrectly, that symmetrical results will be obtained for the same- and inverted-polarity conditions. In contrast, the counterchange detector (Hock, Schöner, & Gilroy, 2009) predicts an asymmetry quite similar to that of human observers in both motion direction and shape discrimination. The further advantage of counterchange, as compared with motion energy, detection for the perception of spatial shape- and depth-from-motion is discussed.     

Correction to: A psychophysiological investigation of mourning: There are two sides to the story

Motivation and Emotion -     

The social motivation theory of autism

The idea that social motivation deficits play a central role in Autism Spectrum Disorders (ASD) has recently gained increased interest. This constitutes a shift in autism research, which has traditionally focused more intensely on cognitive impairments, such as theory-of-mind deficits or executive dysfunction, and has granted comparatively less attention to motivational factors. This review delineates the concept of social motivation and capitalizes on recent findings in several research areas to provide an integrated account of social motivation at the behavioral, biological and evolutionary levels. We conclude that ASD can be construed as an extreme case of diminished social motivation and, as such, provides a powerful model to understand humans' intrinsic drive to seek acceptance and avoid rejection.     

Guter Eindruck und Persönlichkeitsfragebogen

Ohne ZusammenfassungDie vorliegende Arbeit stellt einen Auszug aus einer Semesterarbeit über Probleme des guten Eindrucks dar, die auf Anregung von Prof. Dr. E. Rausch von H. Gregor im Sommer 1960 dunchgeführt wurde.