Papers by Anjan Chatterjee
Patients with schizophrenia (SZ) often make aberrant cause and effect inferences in non-social an... more Patients with schizophrenia (SZ) often make aberrant cause and effect inferences in non-social and social situations. Likewise, patients may perceive cause-and-effect relationships abnormally as a result of an alteration in the physiology of perception. The neural basis for dysfunctions in causality judgements in the context of both physical motion and social motion is unknown. The current study used functional magnetic resonance imaging (fMRI) to investigate a group of patients with SZ and a group of control subjects performing judgements of causality on animated collision sequences (launch-events, Michotte, 1963) and comparable "social" motion stimuli. In both types of animations, similar motion trajectories of the affected object were configured, using parametrical variations of space (angle deviation) and time (delay). At the behavioural level, SZ patients made more physical and less social causal judgements than control subjects, and their judgements were less influenced by motion attributes (angle/time delay). In the patients group, fMRI revealed greater BOLD-responses, during both physical and social causality judgements (group × task interaction), in the left inferior frontal gyrus (L.IFG). Across conditions (main effect), L.IFG-interconnectivity with bilateral occipital cortex was reduced in the patient group. This study provides the first insight into the neural correlates of altered causal judgements in SZ. Patients with SZ tended to over-estimate physical and under-estimate social causality. In both physical and social contexts, patients are influenced less by motion parameters (space and time) than control subjects. Imaging findings of L.IFG-disconnectivity and task-related hyper-activation in the patient group could indicate common dysfunctions in the neural activations needed to integrate external cue-information (space/time) with explicit (top-down) cause-effect judgements of object motions in physical and social settings.
Proceedings of the National Academy of Sciences, 2013
On average, we urban dwellers spend about 90% of our time indoors, and share the intuition that t... more On average, we urban dwellers spend about 90% of our time indoors, and share the intuition that the physical features of the places we live and work in influence how we feel and act. However, there is surprisingly little research on how architecture impacts behavior, much less on how it influences brain function. To begin closing this gap, we conducted a functional magnetic resonance imaging study to examine how systematic variation in contour impacts aesthetic judgments and approach-avoidance decisions, outcome measures of interest to both architects and users of spaces alike. As predicted, participants were more likely to judge spaces as beautiful if they were curvilinear than rectilinear. Neuroanatomically, when contemplating beauty, curvilinear contour activated the anterior cingulate cortex exclusively, a region strongly responsive to the reward properties and emotional salience of objects. Complementing this finding, pleasantness-the valence dimension of the affect circumplex-accounted for nearly 60% of the variance in beauty ratings. Furthermore, activation in a distributed brain network known to underlie the aesthetic evaluation of different types of visual stimuli covaried with beauty ratings. In contrast, contour did not affect approach-avoidance decisions, although curvilinear spaces activated the visual cortex. The results suggest that the well-established effect of contour on aesthetic preference can be extended to architecture. Furthermore, the combination of our behavioral and neural evidence underscores the role of emotion in our preference for curvilinear objects in this domain. neuroaesthetics | design | curvature | habitat theory
Preference for luminance histogram regularities in natural scenes
Vision research, Jan 11, 2015
Natural scene luminance distributions typically have positive skew, and for single objects, there... more Natural scene luminance distributions typically have positive skew, and for single objects, there is evidence that higher skew is a correlate (but not a guarantee) of glossiness. Skewness is also relevant to aesthetics: preference for glossy single objects (with high skew) has been shown even in infants, and skewness is a good predictor of fruit freshness. Given that primate vision appears to efficiently encode natural scene luminance variation, and given evidence that natural scene regularities may be a prerequisite for aesthetic perception in the spatial domain, here we ask whether humans in general prefer natural scenes with more positively skewed luminance distributions. If humans generally prefer images with the higher-order regularities typical of natural scenes and/or shiny objects, we would expect this to be the case. By manipulating luminance distribution skewness (holding mean and variance constant) for individual natural images, we show that in fact preference varies inve...
Brain : a journal of neurology, Jan 31, 2015
Sir, In their letter concerning our recent report, Drs Zeighami and Moustafa discuss several prev... more Sir, In their letter concerning our recent report, Drs Zeighami and Moustafa discuss several previous studies investigating the functions of the ventral and dorsal striatum and the dissociation between action-value and stimulus-value learning. They note that in light of much of this previous work, our findings regarding Patient XG-who suffered bilateral lesions to dorsal striatum and is impaired at stimulus-value but not action-value learning-are quite surprising. We could not agree more, and had undertaken our studies of Patient XG with the hypothesis that he would be impaired at both forms of learning. We think this surprise reinforces the complementary and converging evidence that lesion studies in humans can provide. Functional MRI and single-unit recording have shown that dorsal striatum might contribute to action-value learning, but our study suggests that dorsal striatum is not necessary for action-value learning, at least in humans.
Levetiracetam in the treatment of paroxysmal kinesiogenic choreoathetosis
Movement disorders : official journal of the Movement Disorder Society, 2002
Anticonvulsants are frequently used in the treatment of paroxysmal kinesiogenic choreoathetosis (... more Anticonvulsants are frequently used in the treatment of paroxysmal kinesiogenic choreoathetosis (PKC). Although they are often extremely effective in eliminating paroxysmal movements, short- and long-term side-effects may limit their use in young patients. Levetiracetam (Keppra), a novel antiepileptic drug approved for the treatment of partial seizures is well tolerated in patients with epilepsy. We report on the use of levetiracetam in the treatment of PKC. Levetiracetam was effective in eliminating paroxysmal events and should be considered as an alternative to standard antiepileptic medications in this disorder.
A Distributed Representation of Verb Knowledge
The neural basis of visuospatial analogical reasoning
Spatial Attention to Color and Shape Following Right Brain Damage
Parietal Cortex and Inhibition of Return
Pitch Affects Estimates of Space but not Vice Versa
FUNCTIONAL-SIGNIFICANCE OF THE POWER FUNCTION IN UNILATERAL NEGLECT
VISUAL-ATTENTION, TROXLER FADING, AND THE FRONTAL AND PARIETAL CORTICES
SPATIAL CHARACTERISTICS OF THEMATIC ROLES
HMPAO SPECT IDENTIFIES CORTICAL DIASCHISIS EFFECTS OF WHITE-MATTER LESIONS IN DEMENTIA
A BRIEF NEUROPSYCHOLOGICAL INSTRUMENT FOR THE ASSESSMENT OF SEVERELY IMPAIRED ALZHEIMERS PATIENTS
Further studies validating the severe mini-mental state examination for use in severely impaired Alzheimer's patients
Cobalamine deficiency-Reply
Weight judgment and extinction
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Papers by Anjan Chatterjee