What makes words sound similar?

Although similarity plays an important role in accounts of language processing, there are surprisingly few direct empirical studies of the phonological similarity between words, and it is therefore not clear whether similarity comparisons between words involve processes similar to those involved in other cognitive domains. In five experiments, participants chose which of two monosyllabic pseudo-words sounded more similar to a target pseudo-word. Our results are generally consistent with the structural alignment theory of comparisons between complex mental representations, suggesting that phonological word similarity parallels similarity involving other kinds of information including visual objects and scenes, events, and word meanings. We use our results to test new metrics of word similarity, and identify predictions for future similarity research both in the domain of word sounds and in other cognitive domains.     

The Chemnitz LogAnalyzer: A tool for analyzing data from hypertext navigation research

Computer-based studies usually produce log files as raw data. These data cannot be analyzed adequately with conventional statistical software. The Chemnitz LogAnalyzer provides tools for quick and comfortable visualization and analyses of hypertext navigation behavior by individual users and for aggregated data. In addition, it supports analogous analyses of questionnaire data and reanalysis with respect to several predefined orders of nodes of the same hypertext. As an illustration of how to use the Chemnitz LogAnalyzer, we give an account of one study on learning with hypertext. Participants either searched for specific details or read a hypertext document to familiarize themselves with its content. The tool helped identify navigation strategies affected by these two processing goals and provided comparisons, for example, of processing times and visited sites. Altogether, the Chemnitz LogAnalyzer fills the gap between log files as raw data of Web-based studies and conventional statistical software.     

The Vienna comparative cognition technology (VCCT): An innovative operant conditioning system for various species and experimental procedures

This article describes a laboratory system for running learning experiments in operant chambers with various species. It is based on a modern version of a classical learning chamber for operant conditioning, the so-called ??Skinner box??. Rather than constituting a stand-alone unit, as is usually the case, it is an integrated part of a comprehensive technical solution, thereby eliminating a number of practical problems that are frequently encountered in research on animal learning and behavior. The Vienna comparative cognition technology combines modern computer, stimulus presentation, and reinforcement technology with flexibility and user-friendliness, which allows for efficient, widely automatized across-species experimentation, and thus makes the system appropriate for use in a broad range of learning tasks.     

Similarity-based asymmetries in perceptual matching

Asymmetries, where response times differ depending on the order of two stimuli, have been widely used to explore fundamental aspects of perceptual processing. Given how much is made of asymmetries in the study of perception there has been surprisingly little research into the cognitive mechanisms that may underlie why comparing two objects in isolation depends on the order of presentation. In visual search, for example, asymmetries are typically attributed to fundamental processing characteristics as opposed to the inherent relation between two stimuli. However, one possible explanation for asymmetries found in perceptual processing is that similarity is important in the task and it is similarity itself that is asymmetric. In the current paper, we use a stimulus set for which the transformational account of similarity predicts asymmetries based on differences in transformational complexity. Using the fine-grained measure of reaction time we show that directional differences in transformation distance successfully predict asymmetries in the speed of matching two stimuli in sequence. The results are discussed in relation to the role of transformations in perceptual identification more generally, and how transformations could be revealing about how objects are compared in other experimental contexts where objects are compared directionally (e.g., visual search).     

Learning and development of embodied numerosity

Recent empirical evidence indicates that seemingly abstract numerical cognitions are rooted in sensory and bodily experiences. In particular in finger counting finger-based representations reflect a specific case of embodied cognition, we termed embodied numerosity. Furthermore, we suggest that finger-based representations should be considered a distinct representation of number (magnitude) and argue that this representation is activated automatically whenever we encounter a number. We discuss in what way such a theoretical framework can account for the associations of fingers and numbers observed so far. In the final part, we evaluate whether the concept of embodied numerosity should be generalized beyond finger-based representations with particular focus on whether bodily-sensory experiences (such as moving the whole body along the mental number line) may corroborate numerical capabilities. In a series of intervention studies, we consistently observed more pronounced training effects for our embodied numerosity trainings for different age groups, different digital media, different number ranges, and different control conditions. Taken together, we conclude that embodied representations of number (magnitude) exist, are not limited to finger-based representations, and influence number processing in a systematic and functional way that can be used to foster the efficiency of numerical trainings.     

Memory for time and place contributes to enhanced confidence in memories for emotional events

Emotion strengthens the subjective sense of remembering. However, these confidently remembered emotional memories have not been found be more accurate for some types of contextual details. We investigated whether the subjective sense of recollecting negative stimuli is coupled with enhanced memory accuracy for three specific types of central contextual details using the remember/know paradigm and confidence ratings. Our results indicate that the subjective sense of remembering is indeed coupled with better recollection of spatial location and temporal context, but not higher memory accuracy for colored dots placed in the conceptual center of negative and neutral scenes. These findings show that the enhanced subjective recollective experience for negative stimuli reliably indicates objective recollection for spatial location and temporal context, but not for other types of details, whereas for neutral stimuli, the subjective sense of remembering is coupled with all the types of details assessed. Translating this finding to flashbulb memories, we found that, over time, more participants correctly remembered the location where they learned about the terrorist attacks on 9/11 than any other canonical feature. Likewise, participants' confidence was higher in their memory for location versus other canonical features. These findings indicate that the strong recollective experience of a negative event corresponds to an accurate memory for some kinds of contextual details but not for other kinds. This discrepancy provides further evidence that the subjective sense of remembering negative events is driven by a different mechanism than the subjective sense of remembering neutral events.