Roger B Tootell

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Verified

Roger verified their affiliation via an institutional email.

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• Ph. D.
• Professor (Associate) at Harvard Medical School

Introduction Amblyopia is a developmental disorder associated with reduced performance in visually guided tasks, including binocular navigation within natural environments. To help understand the underlying neurological disorder, we used fMRI to test the impact of amblyopia on the functional organization of scene-selective cortical areas, including...

Regulation of interpersonal distance or “personal space” (PS; the space near the body into which others cannot intrude without eliciting discomfort) is a largely unconscious channel of non-verbal social communication used by many species including humans. PS abnormalities have been observed in neuropsychiatric illnesses, including schizophrenia. Ho...

We employed high-resolution fMRI to distinguish the impacts of anisometropia and strabismus amblyopia on the evoked ocular dominance (OD) response. Sixteen amblyopic participants (eight females) plus eight individuals with normal vision (one female), participated in this study for whom we measured the difference between the response to stimulation...

Advances in the spatiotemporal resolution and field-of-view of neuroimaging tools are driving mesoscale studies for translational neuroscience. On October 10, 2023, the Center for Mesoscale Mapping (CMM) at the Massachusetts General Hospital (MGH) Athinoula A. Martinos Center for Biomedical Imaging and the Massachusetts Institute of Technology (MIT...

Amblyopia is a developmental disorder associated with reduced performance in visually guided tasks, including binocular navigation within natural environments. To help understand the underlying neurological disorder, we used fMRI to test the impact of amblyopia on the functional organization of scene-selective cortical areas, including the posterio...

Current models of scene processing in the human brain include three scene-selective areas: the parahippocampal place area (or the temporal place areas), the restrosplenial cortex (or the medial place area), and the transverse occipital sulcus (or the occipital place area). Here, we challenged this model by showing that at least one other scene-sele...

Current models of scene processing in the human brain include three scene-selective areas: the Parahippocampal Place Area (or the temporal place areas; PPA/TPA), the restrosplenial cortex (or the medial place area; RSC/MPA) and the transverse occipital sulcus (or the occipital place area; TOS/OPA). Here, we challenged this model by showing that at...

Current models of scene processing in the human brain include three scene-selective areas: the Parahippocampal Place Area (or the temporal place areas; PPA/TPA), the restrosplenial cortex (or the medial place area; RSC/MPA) and the transverse occipital sulcus (or the occipital place area; TOS/OPA). Here, we challenged this model by showing that at...

We employed high-resolution functional MRI (fMRI) to distinguish the impacts of anisometropia and strabismus (the two most frequent causes of amblyopia) on the evoked ocular dominance (OD) response. Sixteen amblyopic participants (8 females), comprising 8 individuals with strabismus, 7 with anisometropia, 1 with deprivational amblyopia, along with...

Current models of scene processing in human brain include three scene-selective areas: the Parahippocampal Place Area (or the temporal place areas; PPA/TPA), the restrosplenial cortex (or the medial place area; RSC/MPA) and the transverse occipital sulcus (or the occipital place area; TOS/OPA). Here, we challenged this simplistic model by showing t...

Current models of scene processing in human brain include three scene-selective areas: the Parahippocampal Place Area (or the temporal place areas; PPA/TPA), the restrosplenial cortex (or the medial place area; RSC/MPA) and the transverse occipital sulcus (or the occipital place area; TOS/OPA). Here, we challenged this simplistic model by showing t...

Current models of scene processing in the human brain include three scene-selective areas: the Parahippocampal Place Area (or the temporal place areas; PPA/TPA), the restrosplenial cortex (or the medial place area; RSC/MPA) and the transverse occipital sulcus (or the occipital place area; TOS/OPA). Here, we challenged this model by showing that at...

Current models of scene processing in the human brain include three scene-selective areas: the Parahippocampal Place Area (or the temporal place areas; PPA/TPA), the restrosplenial cortex (or the medial place area; RSC/MPA) and the transverse occipital sulcus (or the occipital place area; TOS/OPA). Here, we challenged this model by showing that at...

The characterization of cortical myelination is essential for the study of structure-function relationships in the human brain. However, knowledge about cortical myelination is largely based on post-mortem histology, which generally renders direct comparison to function impossible. The repeating pattern of pale-thin-pale-thick stripes of cytochrome...

Personal space is the space around the body that people prefer to maintain between themselves and unfamiliar others. Intrusion into a given person's personal space evokes discomfort and an urge to move away. Physiological studies in non-human primates suggest that defensive responses to intruding stimuli involve the parietal cortex. We hypothesized...

Personal space is the distance that people tend to maintain from others during daily life in a largely unconscious manner. For humans, personal space-related behaviors represent one form of non-verbal social communication, similar to facial expressions and eye contact. Given that the changes in social behavior and experiences that occurred during t...

The characterization of cortical myelination is essential for the study of structure-function relationships in the human brain. However, knowledge about cortical myelination is largely based on post mortem histology, which shows conflicting results depending on the staining method used, and generally renders direct comparison to function impossible...

Personal space (PS) is the distance that people prefer to maintain between themselves and unfamiliar others. Intrusion into the PS evokes discomfort, and an urge to move further apart. Behavioral aspects of PS regulation have been well studied, but the brain mechanisms underlying PS have not. Here we hypothesized that PS processing involves a known...

Personal space has been defined as “the area individuals maintain around themselves into which others cannot intrude without arousing discomfort”. However, the precise relationship between discomfort (or arousal) responses as a function of distance from an observer remains incompletely understood. Also the mechanisms involved in recognizing conspec...

Typically, people maintain a certain distance from others (personal space) during daily life, in a largely automatic, unconscious manner. However during the COVID-19 pandemic, social distancing recommendations led to deliberate expansions of personal space outside of intimate social circles. In the laboratory, personal space preferences are quite s...

Background Attachment, or affiliative bonding among conspecifics, is thought to involve neural mechanisms underlying behavioral responses to threat and reward -related social signals. However, attachment-oriented responses may also rely on basic sensorimotor processes. One sensorimotor system that may play a role in attachment is the parietofrontal...

Background Associative learning and memory processes, including the generalization of previously learned associations, may be altered in schizophrenia. Deficits in schizophrenia in stimulus generalization, one of the simpliest forms of memory, could interfere with the ability to efficiently categorize related, similar information, potentially leadi...

In humans, visual stimuli can be perceived across an enormous range of light levels. Evidence suggests that different neural mechanisms process different subdivisions of this range. For instance, in the retina, stimuli presented at very low (scotopic) light levels activate rod photoreceptors, whereas cone photoreceptors are activated relatively mor...

In humans, visual stimuli can be perceived across an enormous range of light levels. Evidence suggests that different neural mechanisms process different subdivisions of this range. For instance, in the retina, stimuli presented at very low (scotopic) light levels activate rod photoreceptors, whereas cone photoreceptors are activated relatively mor...

Human perception is more 'global' when stimuli are viewed within the lower (rather than the upper) visual field. This phenomenon is typically considered as a 2-D phenomenon, likely due to differential neural processing within dorsal vs. ventral cortical areas, that represent lower vs. upper visual fields, respectively. Here we test a novel hypothes...

Since the discovery of the BOLD effect, detection of ocular dominance columns (ODCs) in primary visual cortex (V1) served as a benchmark for high-precision functional magnetic resonance imaging (fMRI) (Menon et al., 1997; Dechent and Frahm 2000; Cheng et al., 2001; Yacoub et al., 2007). Although gradient-echo (GE) echo-planar imaging (EPI) is often...

Despite GE-EPI being the method of choice in most fMRI applications, their use in high-resolution acquisitions is questioned due to their inherent sensitivity to large draining veins [1]. To examine the effective spatial resolution limits of GE-EPI, it is necessary to measure physiological structures in the human brain with known spatial extent suc...

The generalization of conditioned fear responses has been shown to decrease as a function of perceptual similarity. However, generalization may also extend beyond the perceptual discrimination threshold, ostensibly due to contributions from processes other than perception. Currently the neural mechanisms that mediate perceptual and non-perceptual a...

Multiple color-selective areas have been described in visual cortex, in both humans and non-human primates. In macaques, hue-selective columns have been reported in several areas. In V2, it has been proposed that such hue-selective columns are mapped so as to mirror the order of wavelength through the visible spectrum, within thin-type stripes. Oth...

Using ultra-high field fMRI makes in vivo examinations of columnar and laminar structures in the human cerebral cortex feasible. However, it is still under debate which acquisition technique is optimal for high-resolution fMRI. Typical acquisition protocols at lower field strengths use GE-EPI , which possesses high BOLD sensitivity but lacks specif...

Magnocellular versus parvocellular (M-P) streams are fundamental to the organization of macaque visual cortex. Segregated, paired M-P streams extend from retina through LGN into V1. TheMstream extends further into area V5/MT, and parts of V2. However, elsewhere in visual cortex, it remains unclear whether M-P-derived information (1) becomes intermi...

Background: Generalization from previous experiences allows us to evaluate the affective value of novel events. A breakdown of this fundamental ability may lead to incorrect attributions of affective value that could give rise to psychotic symptoms. To examine this hypothesis, we tested whether the generalization of conditioned fear responses is ab...

When visual objects are located in the lower visual field, human observers perceive objects to be nearer than their real physical location. Conversely, objects in the upper visual field are viewed farther than their physical location. This bias may be linked to the statistics of natural scenes, and perhaps the ecological relevance of objects in the...

In fMRI studies, human lateral occipital (LO) cortex is thought to respond selectively to images of objects, compared with nonobjects. However, it remains unresolved whether all objects evoke equivalent levels of activity in LO, and, if not, which image features produce stronger activation. Here, we used an unbiased parametric texture model to pred...

[This corrects the article DOI: 10.1016/j.nicl.2015.07.008.].

Unlabelled: In nonhuman primates (NHPs), secondary visual cortex (V2) is composed of repeating columnar stripes, which are evident in histological variations of cytochrome oxidase (CO) levels. Distinctive "thin" and "thick" stripes of dark CO staining reportedly respond selectively to stimulus variations in color and binocular disparity, respectiv...

This article focuses on the perception and neural mechanisms of ‘normal’ color vision in humans and related nonhuman primates, with special focus on color processing in the visual cortex. Where relevant, we also describe degraded and/or different types of color vision, in different clinical populations and species, respectively.

Here we propose that earlier-demonstrated details in the primate visual cortical map may account for an otherwise puzzling (and problematic) finding in the current human fMRI literature. Specifically, the well-known regions LO and MT(+) reportedly overlap in the human cortical visual map, when those two regions are localized using standard stimulus...

Schizophrenia is associated with subtle abnormalities in day-to-day social behaviors, including a tendency in some patients to “keep their distance” from others in physical space. The neural basis of this abnormality, and related changes in social functioning, is unknown. Here we examined, in schizophrenic patients and healthy control subjects, the...

Previous studies have attributed multiple diverse roles to the posterior superior temporal cortex (STC), both visually driven and cognitive, including part of the default mode network (DMN). Here, we demonstrate a unifying property across this multimodal region. Specifically, the lateral intermediate (LIM) portion of STC showed an unexpected featur...

Retinotopic organization is a ubiquitous property of lower-tier visual cortical areas in human and nonhuman primates. In macaque visual cortex, the retinotopic maps extend to higher-order areas in the ventral visual pathway, including area TEO in the inferior temporal (IT) cortex. Distinct regions within IT cortex are also selective to specific obj...

Cutting-edge research on the visual cognition of scenes, covering issues that include spatial vision, context, emotion, attention, memory, and neural mechanisms underlying scene representation. For many years, researchers have studied visual recognition with objects—single, clean, clear, and isolated objects, presented to subjects at the center of...

Fear generalization is the production of fear responses to a stimulus that is similar—but not identical—to a threatening stimulus. Although prior studies have found that fear generalization magnitudes are qualitatively related to the degree of perceptual similarity to the threatening stimulus, the precise relationship between these two functions ha...

Significance The brain processes visual stimuli along different feature dimensions, including edge orientation, visual motion, and color. To expedite visual processing, cells that process a common visual dimension are often anatomically grouped in cortical columns, patches, and/or areas. Here, we tested the hypothesis that ( i ) image curvature is...

This chapter examines recent fMRI studies that have reported certain low-level preferences/biases in the scene-responsive areas of visual cortex. It looks at selectivity to low-level visual features in the scene-responsive areas specifically in the parahippocampal place area (PPA). Evidence shows that multiple lower-level variables affect the fMRI...

Background / Purpose: Fear generalization in human beings is an adaptive process. However, excessive fear generalization may lead to psychopathological states, such as anxiety. To understand the relationship between perceptual processes and fear generalization, we used a novel Pavlovian conditioning paradigm. We then compared the autonomic and ex...

Fifteen years ago, an intriguing area was found in human visual cortex. This area (the parahippocampal place area [PPA]) was initially interpreted as responding selectively to images of places. However, subsequent studies reported that PPA also responds strongly to a much wider range of image categories, including inanimate objects, tools, spatial...

A parietal-frontal network in primates is thought to support many behaviors occurring in the space around the body, including interpersonal interactions and maintenance of a particular "comfort zone" or distance from other people ("personal space"). To better understand this network in humans, we used functional MRI to measure the responses to movi...

Accurate perception and recognition of objects is a crucial ability for visually dependent organisms such as humans. The visual system must be able to extract a reasonably constant "representation" for all complex visual stimuli despite changes in size, orientation, and illumination. The neural mechanisms underlying this process form the focus of t...

The Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative has focused scientific attention on the necessary tools to understand the human brain and mind. Here, we outline our collective vision for what we can achieve within a decade with properly targeted efforts and discuss likely technological deliverables and neuroscie...

The neural mechanisms underlying the ability to identify and categorize a wide variety of objects effortlessly have been the focus of many studies. Previous studies, especially neuroimaging ones, have typically investigated brain responses to different predefined categories without distinguishing responses to individual object exemplars. Thus, it i...

Three cortical areas (Retro-Splenial Cortex (RSC), Transverse Occipital Sulcus (TOS) and Parahippocampal Place Area (PPA)) respond selectively to scenes. However,their wider role in spatial encoding and their functional connectivity remains unclear. Using fMRI, first we tested the responses of these areas during spatial comparison tasks using dot t...

One of the most remarkable properties of the visual system is the ability to identify and categorize a wide variety of objects effortlessly. However, the underlying neural mechanisms remain elusive. Specifically, the question of how individual object information is represented and intrinsically organized is still poorly understood. To address this...

Recognition is strongly impaired when the normal contrast polarity of faces is reversed. For instance, otherwise-familiar faces become very difficult to recognize when viewed as photographic negatives. Here, we used fMRI to demonstrate related properties in visual cortex: 1) fMRI responses in the human Fusiform Face Area (FFA) decreased strongly (2...

Significance Successful social interaction depends on the ability to recognize others, evaluate their mental states (e.g. intentions, desires, and beliefs), and “read” their emotional states. Here, we show that, in monkeys, damage to the amygdala, a brain structure that is central to the expression of emotion, significantly disrupts the processing...

It has long been known that human vision is more sensitive to contours at cardinal (horizontal and vertical) orientations, compared with oblique orientations; this is the "oblique effect." However, the real-world relevance of the oblique effect is not well understood. Experiments here suggest that this effect is linked to scene perception, via a co...

Recent fMRI studies suggest that cortical face processing extends well beyond the fusiform face area (FFA), including unspecified portions of the anterior temporal lobe. However, the exact location of such anterior temporal region(s), and their role during active face recognition, remain unclear. Here we demonstrate that (in addition to FFA) a smal...

fMRI studies have revealed three scene-selective regions in human visual cortex [the parahippocampal place area (PPA), transverse occipital sulcus (TOS), and retrosplenial cortex (RSC)], which have been linked to higher-order functions such as navigation, scene perception/recognition, and contextual association. Here, we document corresponding (pre...

Previous fMRI studies showed several face-selective areas in human visual cortex, including the Fusiform Face Area (FFA). Following results in macaques, recent fMRI studies also demonstrated face-selective regions in the human anterior temporal lobe (ATFP), which may be involved in higher-level functions such as face recognition. To clarify the con...

Functional magnetic resonance imaging (fMRI) has been used extensively to identify regions in the inferior temporal (IT) cortex that are selective for categories of visual stimuli. However, comparatively little is known about the neuronal responses relative to these fMRI-defined regions. Here, we compared in nonhuman primates the distribution and r...

Traditional studies of neuroanatomical connections require injection of tracer compounds into living brains, then histology of the postmortem tissue. Here, we describe and validate a compound that reveals neuronal connections in vivo, using MRI. The classic anatomical tracer CTB (cholera-toxin subunit-B) was conjugated with a gadolinium-chelate to...

Relative strength of SF selectivity and place selectivity in human PPA. In the left panel, the comparison between normal faces versus normal places revealed the location of FFA and PPA in the averaged map of seven human subjects. This group-averaged activity map is displayed on a ventral view of the averaged inflated cortical surface in the right h...

High-pass-filtered checkerboard images selectively activate PPA. (A and B) An example of middle SF (A) and high SF (B) checkerboards. (C and D) The FFT of middle SF (C) and high SF (D) checkerboards. (E and F) The activity maps for faces versus places (E) and high SF (yellow/red) versus middle SF (cyan/blue) checkerboards (F), in the averaged human...

Region-of-interest analysis of checkerboard data in humans. The bar plot shows the fMRI response to normal, high SF, middle SF, and low SF checkerboard stimuli in FFA and PPA. High SF checkerboards produced the highest fMRI response in PPA (F = 4.15, p < 0.05; ANOVA, Sidak post-hoc test). Error bars indicate one standard error of the mean, based o...

fMRI response to SF-filtered faces. The bar plot shows the percent signal change to normal, high SF, middle SF, and low SF face images in FFA and PPA. High SF faces produced a significantly higher activation in PPA compared to normal, middle SF, and low SF faces (F = 7.65, p < 0.05; ANOVA, Sidak post-hoc test). Error bars indicate one standard erro...

Evidence for mPPA in the subject average, using additional control stimuli. In a separate experiment, we did a blocked-design comparison between places and single faces, objects, and body parts. In each stimulus block, multiple examples of each category were presented. The fMRI activity was measured in three macaque monkeys, and data from all monke...

Comparison between the FFT power spectra of building and face images. In this analysis, we first computed the power spectra of ten building images and ten single face images (images commonly used in a PPA/FFA localizer). The power spectrum of each image was normalized by the power of the DC component. Then the building-versus-face spectral map was...

Topographic representation of preferred SF in early (lower-tier) visual cortex. Each panel shows an activity map on a flattened view of the occipital cortex, oriented in the right-hemisphere format for ease of comparison (left hemisphere from one representative human subject in the top row, and right hemisphere from three other human subjects in th...

The location of mPPA on the inflated cortical surface. The activity map in the left panel shows mPPA and mFFA, based on the comparison between “group photo” faces versus places (see Materials and Methods). The activity map in the right panel shows mPPA and mFFA, based on a blocked-design comparison between large “single” faces (∼15° × 20° in size)...

The PPA response to normal checkerboards. (A and B) An example of the normal (unfiltered) checkerboard (A) and its FFT (B). The gray box around the checkerboard is for illustration purposes only. (C) The activity map for high SF versus normal checkerboards; the high SF checkerboard and its FFT are shown in Figure 3B and 3D. High-pass-filtered check...

New SF-filtered place images, generated based on the power spectra of faces and places. (A) First, the power spectra of ten group photo face images and ten place images were obtained, using a 2-D FFT. Then, the power spectra were averaged in each category. The averaged power spectra of faces and places were then converted to a 1-D plot, using rotat...

fMRI response to SF-filtered places. The bar plot shows the percent signal change to high SF and low SF place images in FFA and PPA (see Figure S4B for examples of stimuli). The asterisk denotes a statistically significant difference (t = 3.66, p < 0.01; paired t-test). Error bars indicate one standard error of the mean. PPA showed a higher fMRI re...

The location of high SF activity in PPA, relative to area V8/VO in human maps. The comparison between responses to upper (cyan) and lower (yellow) visual field stimuli revealed area V8/VO in the ventral occipital cortex. This area contained both upper and lower visual field representations. The maps are displayed on a flattened view of human visual...

Classifying natural scenes based on their power spectra. For this classification, we used a large database of indoor and outdoor scenes (the TinyGraz03 dataset: http://www.emt.tugraz.at/~pinz/data/tinygraz03/). This database was originally intended for categorization of scenes from tiny (32 × 32 pixels) images [48]. The authors of the database prov...

Topographic maps of SF sensitivity in macaque visual cortex. The maps show the pattern of activity produced by high SF versus low SF checkerboards. The activity maps are displayed on a flattened view of macaque visual cortex (left hemisphere [LH] and right hemisphere [RH]). The white arrows indicate the high SF activity in the IT cortex, overlappin...

Defining the exact mechanisms by which the brain processes visual objects and scenes remains an unresolved challenge. Valuable clues to this process have emerged from the demonstration that clusters of neurons ("modules") in inferior temporal cortex apparently respond selectively to specific categories of visual stimuli, such as places/scenes. Howe...

How are different object categories organized by the visual system? Current evidence seems to imply that monkeys and humans process object categories in fundamentally different ways. Functional magnetic resonance imaging (fMRI) suggests that humans have a ventral temporal face area, but such evidence is lacking in macaques. Instead, face-responsive...

Psychophysical findings have indicated functional segregation of processing pathways for first-order motion (movement of luminance modulation, LM) and second-order motion (e.g., movement of contrast modulation, CM). However, neural correlates of those pathways are still controversial. To investigate whether there is corresponding anatomical segrega...

Recently we reported that the direction of “invisible” coherent motion was sensitized through repeated presentation. This indicates that in some cases perceptual learning is formed without attention directed specifically at a presented feature (Watanabe, Náñez & Sasaki, 2001; Nature). Here, we examined which stage(s) of visual processing is/are inv...

Watanabe et al (2001, VSS) showed that in MT+ and V3A of humans fMRI signals were higher when the subjects were viewing a global motion flow in a so-called Sekuler display (in which dots moved spatiotemporally locally within a certain range of directions, Williams & Sekuler, 1984) than random motion. In contrast, in V1 no significant difference was...

We investigated the effect of varying the size, speed and eccentricity of moving random textured patterns (RTP) on the motion processing cortical network in the awake macaque monkey. We used contrast-enhanced fMRI (Vanduffel et al., 2001) experiments as well as the 2-DG technique. Both techniques map functional activity in the whole brain, the form...

Recognition is strongly impaired when the normal contrast polarity of faces is reversed. For instance, otherwise-familiar faces become very difficult to recognize when viewed as photographic negatives. Here, we used fMRI to demonstrate related properties in visual cortex: 1) fMRI responses in the human Fusiform Face Area (FFA) decreased strongly (2...

Developmental prosopagnosia (DP) is a condition marked by very poor face recognition ability despite normal vision and absence of brain damage. At the opposite end of the face recognition spectrum, super-recognizers are people who are exceptionally good at recognizing faces (Russell, Duchaine & Nakayama 2009). In previous fMRI studies, subjects wit...