The sensitivity and specificity of a diagnostic test of sequence-space synesthesia

People with sequence-space synaesthesia (SSS) report stable visuo-spatial forms corresponding to numbers, days and months (amongst others). This type of synaesthesia has intrigued scientists for over 130 years but the lack of an agreed upon tool for assessing it has held back research on this phenomenon. The present study builds on previous tests by measuring the consistency of spatial locations that is known to discriminate controls from synaesthetes. We document, for the first time, the sensitivity and specificity of such a test and suggest a diagnostic cut-off point for discriminating between the groups based on the area bounded by different placement attempts with the same item

Survival of the Synesthesia Gene: Why Do People Hear Colors and Taste Words?

This Unsolved Mystery reviews the biological evidence for why synesthesia, a condition in which stimuli presented through one modality spontaneously evoke sensations in an unrelated modality, may have been conserved in the population

Plasma Dynamics

Contains research objectives and summary of research on nineteen research projects split into five sections.National Science Foundation (Grant ENG75-06242-A01)U.S. Energy Research and Development Administration (Contract E(11-1)-2766)U.S. Air Force - Office of Scientific Research (Grant AFOSR-77-3143)U.S. Energy Research and Development Administration (Contract EY-76-C2-02-3070.*000

The temperature independence of interaction strength in a sit-and-wait predator

The strength of interactions between consumers and their resources has important implications for the overall structure and function of food webs. These interactions can change with warming, depending on the foraging mode of the predator. Theory predicts that warming increases foraging velocity in ectotherms, but in a sit-and-wait predator that has zero velocity when foraging, the interaction strength should be temperature independent. Using the protist Urocentrum turbo and the sit-and- wait copepod Orthocyclops modestus, we tested this prediction by measuring dynamic interaction strengths (effect of a predator on prey population growth rate) and by estimating the parameters of a functional response. Both of these metrics were consistent with the prediction that interaction strength is temperature independent in a sit-and-wait predator. Our results indicate that there may be considerable variability in how warming alters foraging interactions, and estimating the overall effects of climate change on food webs may require consideration of the distribution of foraging strategies and the potential asymmetries that arise with interactions that involve different strategies

Motor-sensory recalibration modulates perceived simultaneity of cross-modal events atdifferent distances

A popular model for the representation of time in the brain posits the existence of a single, central clock. In that framework, temporal distortions in perception are explained by contracting or expanding time over a given interval. We here present evidence for an alternative account, one which proposes multiple independent timelines coexisting within the brain and stresses the importance of motor predictions and causal inferences in constructing our temporal representation of the world. Participants judged the simultaneity of a beep and flash coming from a single source at different distances. The beep was always presented at a constant delay after a motor action, while the flash occurred at a variable delay. Independent shifts in the implied timing of the auditory stimulus towards the motor action (but not the visual stimulus) provided evidence against a central-clock model. Additionally, the hypothesis that the time between action and delayed effect is compressed (known as intentional binding) seems unable to explain our results: firstly, because actions and effects can perceptually reverse, and secondly because the recalibration of simultaneity remains even after the participant’s intentional actions are no longer present. Contrary to previous reports, we also find that participants are unable to use distance cues to compensate for the relatively slower speed of sound when audio-visual events are presented in depth. When a motor act is used to control the distal event, however, adaptation to the delayed auditory signal occurs and subjective cross-sensory synchrony is maintained. These results support the hypothesis that perceptual timing derives from and is calibrated by our motor interactions with the world