The ability to detect faces in images is of critical ecological significance. It is a pre-requisi... more The ability to detect faces in images is of critical ecological significance. It is a pre-requisite for other important face perception tasks such as person identification, gender classification and affect analysis. Here we address the question of how the visual system classifies images into face and non-face patterns. We focus on face detection in impoverished images, which allow us to explore information thresholds required for different levels of performance. Our experimental results provide lower bounds on image resolution needed for reliable discrimination between face and non-face patterns and help characterize the nature of facial representations used by the visual system under degraded viewing conditions. Specifically, they enable an evaluation of the contribution of luminance contrast, image orientation and local context on face-detection performance.
Neural Information Processing Systems, Jan 3, 2001
A key question in neuroscience is how to encode sensory stimuli such as images and sounds. Motiva... more A key question in neuroscience is how to encode sensory stimuli such as images and sounds. Motivated by studies of response properties of neurons in the early cortical areas, we propose an encoding scheme that dispenses with absolute measures of signal intensity or contrast and uses, instead, only local ordinal measures. In this scheme, the structure of a signal is represented by a set of equalities and inequalities across adjacent regions. In this paper, we focus on characterizing the fidelity of this representation strategy. We develop a regularization approach for image reconstruction from ordinal measures and thereby demonstrate that the ordinal representation scheme can faithfully encode signal structure. We also present a neurally plausible implementation of this computation that uses only local update rules. The results highlight the robustness and generalization ability of local ordinal encodings for the task of pattern classification.
Face perception is a critical social ability and identifying its neural correlates is important f... more Face perception is a critical social ability and identifying its neural correlates is important from both basic and applied perspectives. In EEG recordings, faces elicit a distinct electrophysiological signature, the N170, which has a larger amplitude and shorter latency in response to faces compared to other objects. However, determining the face specificity of any neural marker for face perception hinges on finding an appropriate control stimulus. We used a novel stimulus set consisting of 300 images that spanned a continuum between random patches of natural scenes and genuine faces, in order to explore the selectivity of face-sensitive ERP responses with a modelbased parametric stimulus set. Critically, our database contained "false alarm" images that were misclassified as faces a computational face-detection system and varied in their image-level similarity to real faces. High-density (128-channel) event-related potentials (ERPs) were recorded while 23 adult subjects viewed all 300 images in random order, and determined whether each image was a face or non-face. The goal of our analyses was to determine the extent to which a gradient of sensitivity to face-like structure was evident in the ERP signal. Traditional waveform analyses revealed that the N170 component over occipitotemporal electrodes was larger in amplitude for faces compared to all non-faces, even those that were high in image similarity to faces, suggesting strict selectivity for veridical face stimuli. By contrast, single-trial classification of the entire waveform measured at the same sensors revealed that misclassifications of non-face patterns as faces increased with image-level similarity to faces. These results suggest that individual components may exhibit steep selectivity, but integration of multiple waveform features may afford graded information regarding stimulus appearance.
Objective-Many blind children in the developing world are unable to obtain timely treatment due t... more Objective-Many blind children in the developing world are unable to obtain timely treatment due to lack of financial and medical resources. Can public health programs that identify and treat such children several years after the onset of blindness enhance their quality of life? The notion that visual development is subject to an early 'critical period' argues against this possibility. However, there are inadequate empirical data from humans on this issue. To address this need, we examined the quality of life of children living in India and who were treated for early-onset blindness (before one year of age), due to cataracts or corneal opacities.
Some theories have proposed that autistic individuals have difficulty learning predictive relatio... more Some theories have proposed that autistic individuals have difficulty learning predictive relationships. We tested this hypothesis using a serial reaction time task in which participants learned to predict the locations of a repeating sequence of target locations. We conducted a large-sample online study with 61 autistic and 71 neurotypical adults. The autistic group had slower overall reaction times, but demonstrated sequence-specific learning equivalent to the neurotypical group, consistent with other findings of typical procedural memory in autism. The neurotypical group, however, made significantly more prediction-related errors early in the experiment when the stimuli changed from repeated sequences to random locations, suggesting certain limited behavioural differences in the learning or utilization of predictive relationships for autistic adults.
Recent results suggest that autistic individuals find it challenging to temporally coordinate the... more Recent results suggest that autistic individuals find it challenging to temporally coordinate their actions with predictable external cues, as indicated, for instance, by lower accuracy in synchronizing finger taps to an auditory metronome compared with their non-autistic peers. However, it is not yet clear whether these difficulties are driven primarily by motor or perceptual impairments. We recruited autistic and non-autistic participants for an online study which tested both finger tapping synchronization and continuation as well as purely perceptual (non-motoric) rhythmic timing. We fractionated each participant’s synchronization results into several individual-specific parameters representing error correction, motor noise, and internal time-keeper noise, and also investigated error-correcting responses to small timing perturbations in metronome timing. Contrary to previous work, we did not find strong evidence for reduced tapping error correction. However, we found compelling e...
The training data distribution is often biased towards objects in certain orientations and illumi... more The training data distribution is often biased towards objects in certain orientations and illumination conditions. While humans have a remarkable capability of recognizing objects in out-of-distribution (OoD) orientations and illuminations, Deep Neural Networks (DNNs) severely suffer in this case, even when large amounts of training examples are available. In this paper, we investigate three different approaches to improve DNNs in recognizing objects in OoD orientations and illuminations. Namely, these are (i) training much longer after convergence of the in-distribution (InD) validation accuracy, i.e., late-stopping, (ii) tuning the momentum parameter of the batch normalization layers, and (iii) enforcing invariance of the neural activity in an intermediate layer to orientation and illumination conditions. Each of these approaches substantially improves the DNN's OoD accuracy (more than 20% in some cases). We report results in four datasets: two datasets are modified from the MNIST and iLab datasets, and the other two are novel (one of 3D rendered cars and another of objects taken from various controlled orientations and illumination conditions). These datasets allow to study the effects of different amounts of bias and are challenging as DNNs perform poorly in OoD conditions. Finally, we demonstrate that even though the three approaches focus on different aspects of DNNs, they all tend to lead to the same underlying neural mechanism to enable OoD accuracy gains -individual neurons in the intermediate layers become more selective to a category and also invariant to OoD orientations and illuminations. We anticipate this study to be a basis for further improvement of deep neural networks' OoD generalization performance, which is highly demanded to achieve safe and fair AI applications.
In the Dot task, children and adults involuntarily compute an avatar’s visual perspective, which ... more In the Dot task, children and adults involuntarily compute an avatar’s visual perspective, which has been interpreted as automatic Theory of Mind. We conducted three experiments in India, testing newly sighted children (N=5; all girls), neurotypical children (ages 5-10; N=90; 38 girls) and adults (N=30; 18 women) in a highly simplified version of the Dot task. No evidence of automatic perspective-taking was observed, although all groups revealed perspective-taking costs. A newly sighted child and the youngest children in our sample also showed an egocentric bias, which disappeared by age 10. Responding to recent work on what Theory of Mind tasks actually measure, we conclude that the standard Dot task relies so heavily on Executive Control that the alleged evidence of automatic Theory of Mind might simply reveal perspective switching costs.
2019 Computing in Cardiology Conference (CinC), 2019
Defined as the ability of the nervous systems to reduce their response over repeated stimulation,... more Defined as the ability of the nervous systems to reduce their response over repeated stimulation, habituation inflects its parameters in terms of frequency, intensity, recovery and anticipation of responses. Although its concepts have developed from the study of the Central Nervous System (CNS) in processing stimuli at the cortical level, we aim at defining habituation from an autonomic point of view, via heart rate and heart rate variability assessments. To this extent, by using a point-process approach, we devise a novel Autonomic Reactivity Function (ARF) describing the time-varying Autonomic Nervous System (ANS) response in terms of intensity and anticipation, whose reduction (or increment) over repeated stimuli can be ascribed to habituating (or sensitizating) patterns. We tested the mathematical formalization of such metrics in both neurotypical subjects and children with autism spectrum disorder. By eliciting autonomic responses via multisensory stimulation, we collected electrocardiography (ECG) signals, pulled ARFs out from them and performed the Persons coefficient between autonomic habituation metrics and participants sensory profiles and disorder severeness. Results show a relevant positive correlation with Short Sensory Profile (SSP-2) questionnaire (60%) and with Autism Diagnostic Observation Schedule (ADOS-2) questionnaire (76%).
According to a recent influential proposal, several phenotypic features of autism spectrum disord... more According to a recent influential proposal, several phenotypic features of autism spectrum disorder (ASD) may be accounted for by differences in predictive skills between individuals with ASD and neurotypical individuals. In this systematic review, we describe results from 47 studies that have empirically tested this hypothesis. We assess the results based on two observable aspects of prediction: learning a pairing between an antecedent and a consequence and responding to an antecedent in a predictive manner. Taken together, these studies suggest distinct differences in both predictive learning and predictive response. Studies documenting differences in learning predictive pairings indicate challenges in detecting such relationships especially when predictive features of an antecedent have low salience or consistency, and studies showing differences in habituation and perceptual adaptation suggest low‐level predictive processing differences in ASD. These challenges may account for t...
Journal of Autism and Developmental Disorders, 2020
It is estimated that nearly 90% of children on the autism spectrum exhibit sensory atypicalities.... more It is estimated that nearly 90% of children on the autism spectrum exhibit sensory atypicalities. What aspects of sensory processing are affected in autism? Although sensory processing can be studied along multiple dimensions, two of the most basic ones involve examining instantaneous sensory responses and how the responses change over time. These correspond to the dimensions of 'sensitivity' and 'habituation'. Results thus far have indicated that autistic individuals do not differ systematically from controls in sensory acuity/sensitivity. However, data from studies of habituation have been equivocal. We have studied habituation in autism using two measures: galvanic skin response (GSR) and magnetoencephalography (MEG). We report data from two independent studies. The first study, was conducted with 13 autistic and 13 age-matched neurotypical young adults and used GSR to assess response to an extended metronomic sequence. The second study involved 24 participants (12 with an ASD diagnosis), different from those in study 1, spanning the pre-adolescent to young adult age range, and used MEG.
Journal of Autism and Developmental Disorders, 2020
Autism is strongly associated with sensory processing difficulties. We investigate sensory habitu... more Autism is strongly associated with sensory processing difficulties. We investigate sensory habituation, given its relevance for understanding important phenotypic traits like hyper-and hypo-sensitivities. We collected electroencephalography data from 22 neuro-typical(NT) and 13 autistic(ASD) children during the presentation of visual and auditory sequences of repeated stimuli. Our data show that the ASD children have significantly reduced habituation relative to the NT children for both auditory and visual stimuli. These results point to impaired habituation as a modality-general phenomenon in ASD. Additionally, the rates of habituation are correlated with several clinical scores associated with competence along diverse phenotypic dimensions. These data suggest that the sensory difficulties in autism are likely to be associated with reduced habituation and are related to clinical symptomology.
F1000 - Post-publication peer review of the biomedical literature, 2009
There is growing consensus that the summed activity of multiple nodes of a distributed cortical n... more There is growing consensus that the summed activity of multiple nodes of a distributed cortical network supports face recognition in humans, including "core" ventral occipito-temporal cortex (VOTC) regions [1-3], as well as "extended" regions outside VOTC . Surprisingly, many individuals with congenital prosopagnosia -a lifelong impairment in face processing [6-9] --exhibit normal BOLD activation in the "core" VOTC regions [10] (but see ). Interestingly, these same individuals evince a reduction in the structural integrity of the white matter tracts connecting VOTC to anterior temporal and frontal cortices which form part of the "extended" face network. These findings suggest that the profound impairment in congenital prosopagnosia may arise not from a dysfunction of the core VOTC areas per se but from a failure to propagate signals between the intact VOTC and the extended nodes of the network. Here, using the fMR adaptation paradigm with famous and unknown faces, we show that individuals with congenital prosopagnosia evince normal adaptation effects in VOTC, indicating sensitivity to facial identity, but, unlike controls, show no differential activation for familiar versus unknown faces outside VOTC, particularly in the precuneus/posterior cingulate cortex and the anterior paracingulate cortex. These results indicate that normal BOLD activation in VOTC is insufficient to subserve intact face recognition, and support the hypothesis that disrupted information propagation between VOTC and the extended face processing network underlies the functional impairment in congenital prosopagnosia. prosopagnosia; face processing; ventral visual cortex; neural circuit; neurodevelopmental disorders We adopted a rapid event-related fMR adaptation technique, which utilizes the change in the fMRI signal (BOLD) following repeated presentation of images to 'tag' response properties of neurons . Subjects performed a same/different identity judgment on a pair of sequentially
The ability to detect faces in images is of critical ecological significance. It is a pre-requisi... more The ability to detect faces in images is of critical ecological significance. It is a pre-requisite for other important face perception tasks such as person identification, gender classification and affect analysis. Here we address the question of how the visual system classifies images into face and non-face patterns. We focus on face detection in impoverished images, which allow us to explore information thresholds required for different levels of performance. Our experimental results provide lower bounds on image resolution needed for reliable discrimination between face and non-face patterns and help characterize the nature of facial representations used by the visual system under degraded viewing conditions. Specifically, they enable an evaluation of the contribution of luminance contrast, image orientation and local context on face-detection performance.
Neural Information Processing Systems, Jan 3, 2001
A key question in neuroscience is how to encode sensory stimuli such as images and sounds. Motiva... more A key question in neuroscience is how to encode sensory stimuli such as images and sounds. Motivated by studies of response properties of neurons in the early cortical areas, we propose an encoding scheme that dispenses with absolute measures of signal intensity or contrast and uses, instead, only local ordinal measures. In this scheme, the structure of a signal is represented by a set of equalities and inequalities across adjacent regions. In this paper, we focus on characterizing the fidelity of this representation strategy. We develop a regularization approach for image reconstruction from ordinal measures and thereby demonstrate that the ordinal representation scheme can faithfully encode signal structure. We also present a neurally plausible implementation of this computation that uses only local update rules. The results highlight the robustness and generalization ability of local ordinal encodings for the task of pattern classification.
Face perception is a critical social ability and identifying its neural correlates is important f... more Face perception is a critical social ability and identifying its neural correlates is important from both basic and applied perspectives. In EEG recordings, faces elicit a distinct electrophysiological signature, the N170, which has a larger amplitude and shorter latency in response to faces compared to other objects. However, determining the face specificity of any neural marker for face perception hinges on finding an appropriate control stimulus. We used a novel stimulus set consisting of 300 images that spanned a continuum between random patches of natural scenes and genuine faces, in order to explore the selectivity of face-sensitive ERP responses with a modelbased parametric stimulus set. Critically, our database contained "false alarm" images that were misclassified as faces a computational face-detection system and varied in their image-level similarity to real faces. High-density (128-channel) event-related potentials (ERPs) were recorded while 23 adult subjects viewed all 300 images in random order, and determined whether each image was a face or non-face. The goal of our analyses was to determine the extent to which a gradient of sensitivity to face-like structure was evident in the ERP signal. Traditional waveform analyses revealed that the N170 component over occipitotemporal electrodes was larger in amplitude for faces compared to all non-faces, even those that were high in image similarity to faces, suggesting strict selectivity for veridical face stimuli. By contrast, single-trial classification of the entire waveform measured at the same sensors revealed that misclassifications of non-face patterns as faces increased with image-level similarity to faces. These results suggest that individual components may exhibit steep selectivity, but integration of multiple waveform features may afford graded information regarding stimulus appearance.
Objective-Many blind children in the developing world are unable to obtain timely treatment due t... more Objective-Many blind children in the developing world are unable to obtain timely treatment due to lack of financial and medical resources. Can public health programs that identify and treat such children several years after the onset of blindness enhance their quality of life? The notion that visual development is subject to an early 'critical period' argues against this possibility. However, there are inadequate empirical data from humans on this issue. To address this need, we examined the quality of life of children living in India and who were treated for early-onset blindness (before one year of age), due to cataracts or corneal opacities.
Some theories have proposed that autistic individuals have difficulty learning predictive relatio... more Some theories have proposed that autistic individuals have difficulty learning predictive relationships. We tested this hypothesis using a serial reaction time task in which participants learned to predict the locations of a repeating sequence of target locations. We conducted a large-sample online study with 61 autistic and 71 neurotypical adults. The autistic group had slower overall reaction times, but demonstrated sequence-specific learning equivalent to the neurotypical group, consistent with other findings of typical procedural memory in autism. The neurotypical group, however, made significantly more prediction-related errors early in the experiment when the stimuli changed from repeated sequences to random locations, suggesting certain limited behavioural differences in the learning or utilization of predictive relationships for autistic adults.
Recent results suggest that autistic individuals find it challenging to temporally coordinate the... more Recent results suggest that autistic individuals find it challenging to temporally coordinate their actions with predictable external cues, as indicated, for instance, by lower accuracy in synchronizing finger taps to an auditory metronome compared with their non-autistic peers. However, it is not yet clear whether these difficulties are driven primarily by motor or perceptual impairments. We recruited autistic and non-autistic participants for an online study which tested both finger tapping synchronization and continuation as well as purely perceptual (non-motoric) rhythmic timing. We fractionated each participant’s synchronization results into several individual-specific parameters representing error correction, motor noise, and internal time-keeper noise, and also investigated error-correcting responses to small timing perturbations in metronome timing. Contrary to previous work, we did not find strong evidence for reduced tapping error correction. However, we found compelling e...
The training data distribution is often biased towards objects in certain orientations and illumi... more The training data distribution is often biased towards objects in certain orientations and illumination conditions. While humans have a remarkable capability of recognizing objects in out-of-distribution (OoD) orientations and illuminations, Deep Neural Networks (DNNs) severely suffer in this case, even when large amounts of training examples are available. In this paper, we investigate three different approaches to improve DNNs in recognizing objects in OoD orientations and illuminations. Namely, these are (i) training much longer after convergence of the in-distribution (InD) validation accuracy, i.e., late-stopping, (ii) tuning the momentum parameter of the batch normalization layers, and (iii) enforcing invariance of the neural activity in an intermediate layer to orientation and illumination conditions. Each of these approaches substantially improves the DNN's OoD accuracy (more than 20% in some cases). We report results in four datasets: two datasets are modified from the MNIST and iLab datasets, and the other two are novel (one of 3D rendered cars and another of objects taken from various controlled orientations and illumination conditions). These datasets allow to study the effects of different amounts of bias and are challenging as DNNs perform poorly in OoD conditions. Finally, we demonstrate that even though the three approaches focus on different aspects of DNNs, they all tend to lead to the same underlying neural mechanism to enable OoD accuracy gains -individual neurons in the intermediate layers become more selective to a category and also invariant to OoD orientations and illuminations. We anticipate this study to be a basis for further improvement of deep neural networks' OoD generalization performance, which is highly demanded to achieve safe and fair AI applications.
In the Dot task, children and adults involuntarily compute an avatar’s visual perspective, which ... more In the Dot task, children and adults involuntarily compute an avatar’s visual perspective, which has been interpreted as automatic Theory of Mind. We conducted three experiments in India, testing newly sighted children (N=5; all girls), neurotypical children (ages 5-10; N=90; 38 girls) and adults (N=30; 18 women) in a highly simplified version of the Dot task. No evidence of automatic perspective-taking was observed, although all groups revealed perspective-taking costs. A newly sighted child and the youngest children in our sample also showed an egocentric bias, which disappeared by age 10. Responding to recent work on what Theory of Mind tasks actually measure, we conclude that the standard Dot task relies so heavily on Executive Control that the alleged evidence of automatic Theory of Mind might simply reveal perspective switching costs.
2019 Computing in Cardiology Conference (CinC), 2019
Defined as the ability of the nervous systems to reduce their response over repeated stimulation,... more Defined as the ability of the nervous systems to reduce their response over repeated stimulation, habituation inflects its parameters in terms of frequency, intensity, recovery and anticipation of responses. Although its concepts have developed from the study of the Central Nervous System (CNS) in processing stimuli at the cortical level, we aim at defining habituation from an autonomic point of view, via heart rate and heart rate variability assessments. To this extent, by using a point-process approach, we devise a novel Autonomic Reactivity Function (ARF) describing the time-varying Autonomic Nervous System (ANS) response in terms of intensity and anticipation, whose reduction (or increment) over repeated stimuli can be ascribed to habituating (or sensitizating) patterns. We tested the mathematical formalization of such metrics in both neurotypical subjects and children with autism spectrum disorder. By eliciting autonomic responses via multisensory stimulation, we collected electrocardiography (ECG) signals, pulled ARFs out from them and performed the Persons coefficient between autonomic habituation metrics and participants sensory profiles and disorder severeness. Results show a relevant positive correlation with Short Sensory Profile (SSP-2) questionnaire (60%) and with Autism Diagnostic Observation Schedule (ADOS-2) questionnaire (76%).
According to a recent influential proposal, several phenotypic features of autism spectrum disord... more According to a recent influential proposal, several phenotypic features of autism spectrum disorder (ASD) may be accounted for by differences in predictive skills between individuals with ASD and neurotypical individuals. In this systematic review, we describe results from 47 studies that have empirically tested this hypothesis. We assess the results based on two observable aspects of prediction: learning a pairing between an antecedent and a consequence and responding to an antecedent in a predictive manner. Taken together, these studies suggest distinct differences in both predictive learning and predictive response. Studies documenting differences in learning predictive pairings indicate challenges in detecting such relationships especially when predictive features of an antecedent have low salience or consistency, and studies showing differences in habituation and perceptual adaptation suggest low‐level predictive processing differences in ASD. These challenges may account for t...
Journal of Autism and Developmental Disorders, 2020
It is estimated that nearly 90% of children on the autism spectrum exhibit sensory atypicalities.... more It is estimated that nearly 90% of children on the autism spectrum exhibit sensory atypicalities. What aspects of sensory processing are affected in autism? Although sensory processing can be studied along multiple dimensions, two of the most basic ones involve examining instantaneous sensory responses and how the responses change over time. These correspond to the dimensions of 'sensitivity' and 'habituation'. Results thus far have indicated that autistic individuals do not differ systematically from controls in sensory acuity/sensitivity. However, data from studies of habituation have been equivocal. We have studied habituation in autism using two measures: galvanic skin response (GSR) and magnetoencephalography (MEG). We report data from two independent studies. The first study, was conducted with 13 autistic and 13 age-matched neurotypical young adults and used GSR to assess response to an extended metronomic sequence. The second study involved 24 participants (12 with an ASD diagnosis), different from those in study 1, spanning the pre-adolescent to young adult age range, and used MEG.
Journal of Autism and Developmental Disorders, 2020
Autism is strongly associated with sensory processing difficulties. We investigate sensory habitu... more Autism is strongly associated with sensory processing difficulties. We investigate sensory habituation, given its relevance for understanding important phenotypic traits like hyper-and hypo-sensitivities. We collected electroencephalography data from 22 neuro-typical(NT) and 13 autistic(ASD) children during the presentation of visual and auditory sequences of repeated stimuli. Our data show that the ASD children have significantly reduced habituation relative to the NT children for both auditory and visual stimuli. These results point to impaired habituation as a modality-general phenomenon in ASD. Additionally, the rates of habituation are correlated with several clinical scores associated with competence along diverse phenotypic dimensions. These data suggest that the sensory difficulties in autism are likely to be associated with reduced habituation and are related to clinical symptomology.
F1000 - Post-publication peer review of the biomedical literature, 2009
There is growing consensus that the summed activity of multiple nodes of a distributed cortical n... more There is growing consensus that the summed activity of multiple nodes of a distributed cortical network supports face recognition in humans, including "core" ventral occipito-temporal cortex (VOTC) regions [1-3], as well as "extended" regions outside VOTC . Surprisingly, many individuals with congenital prosopagnosia -a lifelong impairment in face processing [6-9] --exhibit normal BOLD activation in the "core" VOTC regions [10] (but see ). Interestingly, these same individuals evince a reduction in the structural integrity of the white matter tracts connecting VOTC to anterior temporal and frontal cortices which form part of the "extended" face network. These findings suggest that the profound impairment in congenital prosopagnosia may arise not from a dysfunction of the core VOTC areas per se but from a failure to propagate signals between the intact VOTC and the extended nodes of the network. Here, using the fMR adaptation paradigm with famous and unknown faces, we show that individuals with congenital prosopagnosia evince normal adaptation effects in VOTC, indicating sensitivity to facial identity, but, unlike controls, show no differential activation for familiar versus unknown faces outside VOTC, particularly in the precuneus/posterior cingulate cortex and the anterior paracingulate cortex. These results indicate that normal BOLD activation in VOTC is insufficient to subserve intact face recognition, and support the hypothesis that disrupted information propagation between VOTC and the extended face processing network underlies the functional impairment in congenital prosopagnosia. prosopagnosia; face processing; ventral visual cortex; neural circuit; neurodevelopmental disorders We adopted a rapid event-related fMR adaptation technique, which utilizes the change in the fMRI signal (BOLD) following repeated presentation of images to 'tag' response properties of neurons . Subjects performed a same/different identity judgment on a pair of sequentially
Uploads
Papers by Pawan Sinha