Uni- and multisensory contextual boundaries in encoding, recognition and memory for temporal order

We experience our daily lives as an ongoing series of impressions, but we cognitively process those impressions as segmented events. Segmentation is based on contextual changes, such as spatial environment, moment in time or social surrounding, which are used as event boundaries that associate experiences from different contexts to different event models. However, event segmentation affects perceptual and mnemonic processing depending on the temporal proximity of experiences to event boundaries. Most event segmentation studies have used unisensory visual or auditory contexts, of which the visual modality is overrepresented. In this study, we directly compared the effect of unisensory vs. multisensory boundaries on event segmentation. Participants encoded lists of visual objects while changes in unisensory (audio or visual) or multisensory (audiovisual) context changes occurred at a regular interval. We assessed the effect of contextual changes on an encoding task and two memory tasks for perceptual recognition and temporal order of encoded objects. We found that audio and audiovisual contexts resulted in longer encoding times than the visual context. Contextual changes impaired recognition memory for boundary items and impaired temporal order memory for item pairs crossing a boundary, but these effects did not differ between unisensory and multisensory contexts. Our findings suggest that the sensory modality of event boundaries modulated perceptual but not mnemonic event processing, and provide further understanding in how we segment our experiences in perception and memory.

Evidence for suffix cohesion in French

ABSTRACT In a language, suffix cohesion refers to the fact that suffixed words behave phonologically as simple or complex units depending on the suffix they are built with. This article uncovers a previously undescribed pattern of suffix cohesion in French, where words suffixed with vowel- and glide-initial suffixes behave phonologically like simple units (e.g. fêtiez [fet-je] ‘you partied’) and words built with other consonant-initial suffixes behave phonologically like complex units (e.g. fêterez [fɛt-ʁe] ‘you will party’). The evidence comes from a reassessment of well-known data on [ə]–[ɛ] stem alternations and from an acoustic study of [e]–[ɛ] and [o]–[ɔ] alternations in suffixed words as pronounced by 10 speakers living in the Paris area. The suffix’s phonological shape is found to provide the best account of the data among a set of factors that have been argued to be relevant to suffix cohesion in other languages (in particular resyllabification). The French pattern has important theoretical implications for theories of suffix cohesion as it is not prosodically conditioned. An alternative analysis in terms of paradigm uniformity is proposed, where suffixed words are treated as complex units phonologically if the suffix’s phonological shape facilitates the perceptual recognition of the base corresponding to the suffixed word’s stem.

Seeking Salience

Chapter 2 explores the role played by categorization processing in perceptual recognition and introduces a diagnostic recognition framework for engaging art derived from a biased competition model for selective attention. The environment is replete with information. Perceptual systems are limited capacity cognitive systems. Perceptual systems are by their very nature, therefore, selective. In ordinary contexts, task demands and general world knowledge are used to direct attention to task-salient features of the environment. In artistic contexts these task demands are constrained by shared knowledge of different categories of art which serve as recipes to direct attention to minimal sets of diagnostic compositional features that carry the content of a work. Neurophysiological evidence demonstrates that these psychological processes not only guide attention, but also shape perception. This in turn entails that psychology and neuroscience can contribute to an understanding of how an artwork carries and conveys its artistically salient content.

An Eye-Tracking Evaluation of Gauge Shapes in Process Control

Operators monitor gauge shapes in control room displays to maintain the status of the refinery control process within normal limits. To test if shapes currently used by operators are effectively designed, two experiments were conducted to test the effectiveness of individual shapes in a Visual Thesaurus toolkit for comprehension and change detection. Moreover, eye tracking technology was used to investigate basic perceptual recognition behaviors of each Visual Thesaurus shape for comprehension and change detection. Thirty-one students from Pennsylvania State University participated in this experiment. It was found that pupil size could be used to track the cognitive load of participants. Correctness was also measured but it was not as sensitive as pupil size, as it did not capture a difference in the effectiveness of shapes.

Selective Involvement of Superior Frontal Cortex During Working Memory for Shapes

A spatial/nonspatial functional dissociation between the dorsal and ventral visual pathways is well established and has formed the basis of domain-specific theories of prefrontal cortex (PFC). Inconsistencies in the literature regarding prefrontal organization, however, have led to questions regarding whether the nature of the dissociations observed in PFC during working memory are equivalent to those observed in the visual pathways for perception. In particular, the dissociation between dorsal and ventral PFC during working memory for locations versus object identities has been clearly present in some studies but not in others, seemingly in part due to the type of objects used. The current study compared functional MRI activation during delayed-recognition tasks for shape or color, two object features considered to be processed by the ventral pathway for perceptual recognition. Activation for the shape-delayed recognition task was greater than that for the color task in the lateral occipital cortex, in agreement with studies of visual perception. Greater memory-delay activity was also observed, however, in the parietal and superior frontal cortices for the shape than for the color task. Activity in superior frontal cortex was associated with better performance on the shape task. Conversely, greater delay activity for color than for shape was observed in the left anterior insula and this activity was associated with better performance on the color task. These results suggest that superior frontal cortex contributes to performance on tasks requiring working memory for object identities, but it represents different information about those objects than does the ventral frontal cortex.