Computational exploration of the relationship between holistic processing and right hemisphere lateralization in featural and configural recognition tasks

Open URL: http://csjarchive.cogsci.rpi.edu/Proceedings/2011/Holistic processing has long been considered as a property of right hemisphere (RH) processing. Nevertheless, recent studies showed reduced holistic processing and increased RH lateralization in Chinese character recognition expertise, suggesting that these two effects may separate. Through computational modeling, in which we implement a theory of hemispheric asymmetry in perception that posits a low frequency bias in the RH and a high frequency bias in the left hemisphere, we show that when the recognition task relies purely on featural information, holistic processing increases whereas RH lateralization decreases with increasing stimulus similarity; there is a negative correlation between them. In contrast, when the task relies purely on configural information, although RH lateralization negatively correlates with stimulus similarity, holistic processing does not correlate with stimulus similarity; there is a positive correlation between them. This suggests that holistic processing and RH lateralization do not always go together, depending on the task requirements.postprintThe 33rd Annual Meeting of the Cognitive Science Society (CogSci 2011), Boston, MA., 20-23 July 2011. In Proceedings of the 33rd CogSci, 2011, p. 2592-259

Expertise modulates hemispheric asymmetry in holistic processing: evidence from Chinese character processing

Conference Theme: Mind, Technology, and SocietyHolistic processing (HP) has been proposed to be a character-istic of right hemisphere (RH) processing. Here we test this claim using the divided visual field paradigm with Chinese character stimuli. HP is assessed through the composite para-digm, which is commonly used in perceptual expertise re-search. We found that in novice Chinese readers, a standard HP pattern emerged only in the left visual field/RH but not in the right visual field/left hemisphere, consistent with the ana-lytic/holistic hemispheric dichotomy in the literature. However, in expert Chinese readers, neither visual field showed the HP pattern, consistent with the finding that re-duced HP is an expertise maker for Chinese character recog-nition. Thus, the RH does not always employ holistic process-ing; it depends on the perceivers’ experience with the stimuli. This is the first study demonstrating that expertise with a vis-ual object type can modulate hemispheric difference in HP.postprin

Behavioural, Electrophysiological and Neurostimulatory Investigations into Developmental Prosopagnosia

Developmental prosopagnosia (DP) is the difficulty or inability to recognise a face and may affect up to 2.9 percent of the population. There is controversy over whether these impairments are perceptual or memorial in nature, and uncertainty about their stability over time and how to remediate symptoms. In the first stage, a battery of ten tests was assembled to assess a wide range of face recognition skills in DP (n = 11) and compared to a control group (Chapter Two). The majority of DPs showed no signs of impaired face perception but profound face memory deficits. To seek electrophysiological corroboration of these impairments, the DPs (n = 8) were given three behavioural tasks known to elicit specific event related potentials (Chapter Three), assessing face perception (N170), face familiarity (N250r) and semantic access (N400). During the experiment, caloric vestibular stimulation (CVS) was also administered to see if it could reduce symptoms. The tasks revealed intact face perception and impaired accuracy in both memory based tasks, corroborated by an atypical N400. Subtle effects of CVS were observed in all measures of the face familiarity task but not at a level that was clinically relevant. To establish, for the first time, whether the impairments in DP are consistent over time, the effects in Chapter Three were replicated (n = 7)(Chapter Four). A similar pattern emerged and test-retest correlations showed high reliability overtime in the familiarity task but not the semantic access task. This implies that reliable 'diagnosis' of developmental prosopagnosia should be based on judgements of face familiarity and not associated with semantic activity. The beneficial effects of CVS were again present in the N250r behavioural measures and were limited to familiar faces only. This implies that CVS is optimising memory recall for face representations. The source of impairments was consistently shown to be memorial in nature and future studies may wish to explore further divisions of memory in DP such as whether impairments are associated with encoding or recall. The thesis also demonstrates the potential for CVS as both a therapeutic tool and cognitive enhancer, and justify more robust trials investigation

Neural responses in a fast periodic visual stimulation paradigm reveal domain-general visual discrimination deficits in developmental prosopagnosia

We investigated selective impairments of visual identity discrimination in developmental prosopagnosia (DP), using a fast periodic identity oddball stimulation paradigm with electroencephalography (EEG). In Experiment 1, neural responses to unfamiliar face identity changes were strongly attenuated for individuals with DP as compared to Control participants, to the same extent for upright and inverted faces. This reduction of face identity discrimination responses, which was confirmed in Experiment 2, provides direct evidence for deficits in the visual processing of unfamiliar facial identity in DP. Importantly, Experiment 2 demonstrated that DPs showed attenuated neural responses to identity oddballs not only with face images, but also with non-face images (cars). This result strongly suggests that rapid identity-related visual processing impairments in DP are not restricted to faces, but also affect familiar classes of non-face stimuli. Visual discrimination deficits in DP do not appear to be face-specific. To account for these findings, we propose a new account of DP as a domain-general deficit in rapid visual discrimination

The Psychological Correlates of Asymmetric Cerebral Activation

This study examined the psychological correlates of asymmetric cerebral activation as measured by electroencephalograph (EEG) recordings. Five content areas were investigated in the context of EEG asymmetry: hierarchical visual processing, creative potential, mood, personality, and EEG asymmetry, and the effect of a mood induction procedure on cognition and EEG asymmetry. Undergraduate participants completed two experimental sessions separated by two to three weeks. Participants completed a comprehensive set of emotion, personality, and creative potential measures, a cognitive task assessing individual differences in hierarchical visual processing. and a short form of the Rorschach inkblot test. Additionally. each participant underwent either a happy or a sad mood induction procedure to examine the effects of mood on verbal and spatial fluency tasks and EEG asymmetry. EEG was measured in frontal, central. and parietal locations. The primary findings regarding the psychometrics of EEG asymmetry suggested that a large proportion of participants show relatively stable EEG asymmetry across two to three weeks. The results failed to replicate previous research suggesting a relationship between hierarchical visual analysis and mood using a Global-Local task. The results also failed to support the hypothesis that the Rorschach could be used as a measure of hierarchical visual analysis. However, Minor Detail location responses on the Rorschach correlated positively with negative affect and negatively with positive affect. Regarding creativity, the Rorschach was found to be a viable means of assessing individual differences in primary process cognition using the Regressive Imagery Dictionary (Martindale, 1975). Additionally, the results partially supported Martindale\u27s (1 999) hypothesis that creative people show greater right-hemisphere activation. No support was found for the hypothesized relationships between frontal activation asymmetry and mood or personality. Regarding the effect of mood on verbal and spatial fluency, no support was found for the hypothesis that happy moods increase verbal fluency and decrease spatial fluency or that sad moods increase spatial tluency and decrease verbal fluency. Happy and sad mood also did not have a significant effect on EEG asymmetry in the predicted directions. The results are discussed in terms of the status of recent research on EEG asymmetry and its relation to cognition, creativity, emotion and personality

Towards a unified understanding of lateralized vision:A large-scale study investigating principles governing patterns of lateralization using a heterogeneous sample

While functional lateralization of the human brain has been a widely studied topic in the past decades, few studies to date have gone further than investigating lateralization of single, isolated processes. With the present study, we aimed to arrive at a more unified view by investigating lateralization patterns in face and word processing, and associated lower-level visual processing. We tested a large and heterogeneous participant group, and used a number of tasks that had been shown to produce replicable indices of lateralized processing of visual information of different types and complexity. Following Bayesian statistics, group-level analyses showed the expected right hemisphere (RH) lateralization for face, global form, low spatial frequency processing, and spatial attention, and left hemisphere (LH) lateralization for visual word and local feature processing. Compared to right-handed individuals, lateralization patterns of left-handed and especially those who are RH-dominant for language deviated from this 'typical' pattern. Our results support the notion that face and word processes come to be lateralized to homologue areas of the two hemispheres, under influence of the RHand LH-specializations in global form, local feature, and low and high spatial frequency processing. As such, we present a more unified understanding of lateralized vision, providing evidence for the input asymmetry and causal complementarity principles of lateralized visual information processing. The absence of correlations between spatial attention and lateralization of the other processes supports the notion of their independent lateralization, conform the statistical complementarity principle. (C) 2020 The Author(s). Published by Elsevier Ltd

Hemispheric Laterality and Cognitive Style

The purpose of the present study was to determine the nature and degree of relationship between cerebral hemispheric style and several traditional dimensions of cognitive style. A large battery of laterality preference, cognitive style, verbal and nonverbal ability, and selected additional tests was administered to 97 (52 female, 45 male) right-handed undergraduate volunteers, with subsequent analysis of relationships among the measures by simple correlation, factor analysis, and multiple regression methods. Laterality measures included the Zenhausern, Verbalizer-Visualizer Questionnaire, and a lateral eye movement observation measure. Data analyses utilized individual laterality test scores as well as a composite laterality index. Eleven cognitive style tests were administered, including measures of field independence, distractibility, complexity, flexibility, and other dimensions. Additional tests administered included measures of verbal and visual synthesizing ability, anxiety, repression-sensitization, and social desirability. The main findings of the study were as follows: (1) Intercorrelations of the cognitive style measures were generally very low, ranging from .00 to -.54; (2) Only one cognitive style factor reliably emerged, accounting for about 10% of the common cognitive style test variance. This factor was called Open vs. Closed-Mindedness and was defined primarily by Dogmatism, Rigidity, and Ambiguity Tolerance scores; (3) Maximum multiple prediction of individual and composite laterality scores from individual cognitive style tests, cognitive style factor scores, and additional scores accounted for 11% to 25% of laterality variance; (4) Sex differences were nonsignificant on all measures with the following exceptions: Females performed the Stroop Test more quickly, were narrower categorizers on the Category Width Scale, and obtained higher trait anxiety scores than males. General conclusions drawn were that hemispheric and cognitive style, as measured in the present study, are largely unrelated, and that individuals manifest considerable diversity in cognitive style. The findings caution against oversimplification and overgeneralization in reference to both hemispheric and cognitive style and their interrelationship. Low intercorrelations of measures within both domains do call into question the adequacy of available tests of these constructs and suggest the need for further test development based upon current neuropsychological knowledge

Beyond Shape: How You Learn about Objects Affects How They Are Represented in Visual Cortex

Background: Experience can alter how objects are represented in the visual cortex. But experience can take different forms. It is unknown whether the kind of visual experience systematically alters the nature of visual cortical object representations. Methodology/Principal Findings: We take advantage of different training regimens found to produce qualitatively different types of perceptual expertise behaviorally in order to contrast the neural changes that follow different kinds of visual experience with the same objects. Two groups of participants went through training regimens that required either subordinate-level individuation or basic-level categorization of a set of novel, artificial objects, called ‘‘Ziggerins’’. fMRI activity of a region in the right fusiform gyrus increased after individuation training and was correlated with the magnitude of configural processing of the Ziggerins observed behaviorally. In contrast, categorization training caused distributed changes, with increased activity in the medial portion of the ventral occipito-temporal cortex relative to more lateral areas. Conclusions/Significance: Our results demonstrate that the kind of experience with a category of objects can systematically influence how those objects are represented in visual cortex. The demands of prior learning experience therefore appear t

Running head featural composites and lineups: "What big teeth you have" - Red Riding Hood and the face recognition failure : the effects of isolated featural and configural composite construction and recognition accuracy

Includes abstract.Includes bibliographical references.When a crime is committed, law enforcement typically relies on the testimony of an eyewitness. However, eyewitness testimony is often susceptible to contamination. Eyewitnesses are usually required to construct a composite of the perpetrator. Research has suggested that eyewitnesses who construct composites are more likely to misidentify the target in a later recognition task (Comish, 1987; Wells, Charman, & Olson, 2005; Yu & Geiselman, 1993). This hampering effect may occur because composite programs utilise a featural selection strategy, which is in opposition to configural and holistic processing that is used when faces are encoded