Bianca Bromberger

The differentiation of iconic and metaphoric gestures: Common and unique integration processes

Recent research on the neural integration of speech and gesture has examined either gesture in the context of concrete [iconic (IC) gestures] or abstract sentence content [metaphoric (MP) gestures]. However, there has not yet been a direct comparison of the processing of both gesture types. This study tested the theory that left posterior temporal and inferior frontal brain regions are each uniquely involved in the integration of IC and MP gestures. During fMRI‐data acquisition, participants were shown videos of an actor performing IC and MP gestures and associated sentences. An isolated gesture (G) and isolated sentence condition (S) were included to separate unimodal from bimodal effects at the neural level. During IC conditions, we found increased activity in the left posterior middle temporal gyrus and its right hemispheric homologue. The same regions in addition to the left inferior frontal gyrus (IFG) were activated during MP conditions in contrast to the isolated conditions (G&S). These findings support the hypothesis that there are distinct integration processes for IC and MP gestures. In line with recent claims of the semantic unification theory, there seems to be a division between perceptual‐matching processes within the posterior temporal lobe and higher‐order relational processes within the IFG. Hum Brain Mapp, 2011.

The Assessment of Art Attributes

Neuropsychological investigations of art production and perception have the potential to offer critical insight into the biology of visual aesthetics. Thus far, however, investigations of art production in patients have been limited to anecdotal observations and investigations of art perception are non-existent. Progress in the field is hampered by the lack of an adequate instrument to provide basic quantification of artwork attributes. Motivated by the need to move neuropsychology of art beyond the fascinating anecdote, we present the Assessment of Art Attributes (AAA). The AAA is an instrument designed to assess six formal-perceptual and six conceptual-representational attributes using 24 paintings from the Western canon. Both artistically naïve and experienced participants were given the AAA. We found high degrees of agreement in the assessment of these attributes in both groups and few differences between the groups. We expect that the AAAs componential and quantitative approach will be useful in advancing neuropsychological studies as well as any investigations in which style and content of art works need to be quantified and compared.

Language, perception, and the schematic representation of spatial relations

Schemas are abstract nonverbal representations that parsimoniously depict spatial relations. Despite their ubiquitous use in maps and diagrams, little is known about their neural instantiation. We sought to determine the extent to which schematic representations are neurally distinguished from language on the one hand, and from rich perceptual representations on the other. In patients with either left hemisphere damage or right hemisphere damage, a battery of matching tasks depicting categorical spatial relations was used to probe for the comprehension of basic spatial concepts across distinct representational formats (words, pictures, and schemas). Left hemisphere patients underperformed right hemisphere patients across all tasks. However, focused residual analyses using voxel-based lesion-symptom mapping (VLSM) suggest that (1) left hemisphere deficits in the representation of categorical spatial relations are difficult to distinguish from deficits in naming these relations and (2) the right hemisphere plays a special role in extracting schematic representations from richly textured pictures.

The Right Hemisphere in Esthetic Perception

Little about the neuropsychology of art perception and evaluation is known. Most neuropsychological approaches to art have focused on art production and have been anecdotal and qualitative. The field is in desperate need of quantitative methods if it is to advance. Here, we combine a quantitative approach to the assessment of art with modern voxel-lesion-symptom-mapping methods to determine brain–behavior relationships in art perception. We hypothesized that perception of different attributes of art are likely to be disrupted by damage to different regions of the brain. Twenty participants with right hemisphere damage were given the Assessment of Art Attributes, which is designed to quantify judgments of descriptive attributes of visual art. Each participant rated 24 paintings on 6 conceptual attributes (depictive accuracy, abstractness, emotion, symbolism, realism, and animacy) and 6 perceptual attributes (depth, color temperature, color saturation, balance, stroke, and simplicity) and their interest in and preference for these paintings. Deviation scores were obtained for each brain-damaged participant for each attribute based on correlations with group average ratings from 30 age-matched healthy participants. Right hemisphere damage affected participants’ judgments of abstractness, accuracy, and stroke quality. Damage to areas within different parts of the frontal parietal and lateral temporal cortices produced deviation in judgments in four of six conceptual attributes (abstractness, symbolism, realism, and animacy). Of the formal attributes, only depth was affected by inferior prefrontal damage. No areas of brain damage were associated with deviations in interestingness or preference judgments. The perception of conceptual and formal attributes in artwork may in part dissociate from each other and from evaluative judgments. More generally, this approach demonstrates the feasibility of quantitative approaches to the neuropsychology of art.

Artistic Production Following Brain Damage: A Study of Three Artists

ABSTRACT We know little about the neurologic bases of art production. The idea that the right brain hemisphere is the “artistic brain” is widely held, despite the lack of evidence for this claim. Artists with brain damage can offer insight into these laterality questions. The authors used an instrument called the Assessment of Art Attributes to examine the work of two individuals with left-brain damage and one with right-hemisphere damage. In each case, their art became more abstract and distorted and less realistic. They also painted with looser strokes, less depth and more vibrant colors. No unique pattern was observed following right-brain damage. However, art produced after left-brain damage also became more symbolic. These results show that the neural basis of art production is distributed across both hemispheres in the human brain.

A sinister bias for calling fouls in soccer.

Distinguishing between a fair and unfair tackle in soccer can be difficult. For referees, choosing to call a foul often requires a decision despite some level of ambiguity. We were interested in whether a well documented perceptual-motor bias associated with reading direction influenced foul judgments. Prior studies have shown that readers of left-to-right languages tend to think of prototypical events as unfolding concordantly, from left-to-right in space. It follows that events moving from right-to-left should be perceived as atypical and relatively debased. In an experiment using a go/no-go task and photographs taken from real games, participants made more foul calls for pictures depicting left-moving events compared to pictures depicting right-moving events. These data suggest that two referees watching the same play from distinct vantage points may be differentially predisposed to call a foul.

The specificity of action knowledge in sensory and motor systems

Neuroimaging studies have found that sensorimotor systems are engaged when participants observe actions or comprehend action language. However, most of these studies have asked the binary question of whether action concepts are embodied or not, rather than whether sensory and motor areas of the brain contain graded amounts of information during putative action simulations. To address this question, we used repetition suppression (RS) functional magnetic resonance imaging to determine if functionally-localized motor movement and visual motion regions-of-interest (ROI) and two anatomical ROIs (inferior frontal gyrus, IFG; left posterior middle temporal gyrus, pMTG) were sensitive to changes in the exemplar (e.g., two different people “kicking”) or representational format (e.g., photograph or schematic drawing of someone “kicking”) within pairs of action images. We also investigated whether concrete versus more symbolic depictions of actions (i.e., photographs or schematic drawings) yielded different patterns of activation throughout the brain. We found that during a conceptual task, sensory and motor systems represent actions at different levels of specificity. While the visual motion ROI did not exhibit RS to different exemplars of the same action or to the same action depicted by different formats, the motor movement ROI did. These effects are consistent with “person-specific” action simulations: if the motor system is recruited for action understanding, it does so by activating ones own motor program for an action. We also observed significant repetition enhancement within the IFG ROI to different exemplars or formats of the same action, a result that may indicate additional cognitive processing on these trials. Finally, we found that the recruitment of posterior brain regions by action concepts depends on the format of the input: left lateral occipital cortex and right supramarginal gyrus responded more strongly to symbolic depictions of actions than concrete ones.

Pregnancy-Induced Sensitization Promotes Sex Disparity in Living Donor Kidney Transplantation

The presence of sex disparity in living donor kidney transplantation (LDKT) remains controversial. To determine if women fall behind men in LDKT evaluation, we performed an intention to treat study of 2587 candidates listed for kidney transplant at a single transplant center over 7 years. We found that women and men kidney transplant candidates engaged an equivalent type and number of prospective living donors. However, sex-specific differences in sensitization history and histocompatibility reduced the rate of LDKT for women by 30%. Pregnancy-induced incompatibility with spouse donors was limiting given that spouses were among the individuals most likely to complete donation. Notably, participation in a kidney paired exchange program eliminated sex-based differences in LDKT. Collectively, these data suggest that pregnancy is a formidable biologic barrier for women and contributes uniquely to sex disparity in LDKT. Targeted efforts to improve transplant center participation in paired kidney exchanges may increase sex equity in LDKT.