Fraser Smith

• PhD
• Associate Professor at University of East Anglia

Neurons, even in the earliest sensory areas of cortex, are subject to a great deal of contextual influence from both within and across modality connections. In the present work, we investigated whether the earliest regions of somatosensory cortex (S1 and S2) would contain content-specific information about visual object categories. We reasoned that...

Human early visual cortex was traditionally thought to process simple visual features such as orientation, contrast and spatial frequency via feed-forward input from the lateral geniculate nucleus [e.g.1]. However, the role of non-retinal influence on early visual cortex is so far insufficiently investigated despite feedback connections greatly out...

Neuronal cortical circuitry comprises feedforward, lateral, and feedback projections, each of which terminates in distinct cortical layers [1-3]. In sensory systems, feedforward processing transmits signals from the external world into the cortex, whereas feedback pathways signal the brain's inference of the world [4-11]. However, the integration o...

Faces transmit a wealth of important social signals. While previous studies have elucidated the network of cortical regions important for perception of facial expression, and the associated temporal components such as the P100, N170 and EPN, it is still unclear how task constraints may shape the representation of facial expression (or other face ca...

Neurons, even in the earliest sensory regions of cortex, are subject to a great deal of contextual influences from both within and across modality connections. Recent work has shown that primary sensory areas can respond to and, in some cases, discriminate stimuli that are not of their target modality: for example, primary somatosensory cortex (SI)...

Perceptual decisions are derived from the combination of priors and sensorial input. While priors are broadly understood to reflect experience/expertise developed over one’s lifetime, the role of perceptual expertise at the individual level has seldom been directly explored. Here, we manipulate probabilistic information associated with a high and l...

Neurons in the primary visual cortex (V1) receive sensory inputs that describe small, local regions of the visual scene and cortical feedback inputs from higher visual areas processing the global scene context. Investigating the spatial precision of this visual contextual modulation will contribute to our understanding of the functional role of cor...

Whilst previous research has linked attenuation of the mu rhythm to the observation of specific visual categories, and even to a potential role in action observation via a putative mirror neuron system, much of this work has not considered what specific type of information might be coded in this oscillatory response when triggered via vision. Here,...

Although humans are considered to be face experts, there is a well-established reliable variation in the degree to which neurotypical individuals are able to learn and recognise faces. While many behavioural studies have characterised these differences, studies that seek to relate the neuronal response to standardised behavioural measures of abilit...

Intelligent manipulation of handheld tools marks a major discontinuity between humans and our closest ancestors. Here we identified neural representations about how tools are typically manipulated within left anterior temporal cortex, by shifting a searchlight classifier through whole-brain real action fMRI data when participants grasped 3D-printed...

Intelligent manipulation of handheld tools marks a major discontinuity between humans and our closest ancestors. Here we identified neural representations about how tools are typically manipulated within left anterior temporal cortex, by shifting a searchlight classifier through whole-brain real action fMRI data when participants grasped 3D-printed...

Studies on low-level visual information underlying pain categorization have led to inconsistent findings. Some show an advantage for low spatial frequency information (SFs) and others a preponderance of mid SFs. This study aims to clarify this gap in knowledge since these results have different theoretical and practical implications, such as how fa...

Most neuroimaging experiments that investigate how tools and their actions are represented in the brain use visual paradigms where tools or hands are displayed as 2D images and no real movements are performed. These studies discovered selective visual responses in occipitotemporal and parietal cortices for viewing pictures of hands or tools, which...

Studies on low-level visual information underlying pain categorization have led to inconsistent findings. Some are showing an advantage for low spatial frequency information (SFs) and others a preponderance of mid SFs. This study aims to clarify this gap in knowledge since these results have different theoretical and practical implications, such as...

Most neuroimaging experiments that investigate how tools and their actions are represented in the brain use visual paradigms where tools or hands are displayed as 2D images and no real movements are performed. These studies discovered selective visual responses in occipito-temporal and parietal cortices for viewing pictures of hands or tools, which...

Face recognition ability is often reported to be a relative strength in Williams syndrome (WS). Yet methodological issues associated with the supporting research, and evidence that atypical face processing mechanisms may drive outcomes ‘in the typical range’, challenge these simplistic characterisations of this important social ability. Detailed in...

Rapidly and accurately processing information from faces is a critical human function that is known to improve with developmental age. Understanding the underlying drivers of this improvement remains a contentious question, with debate continuing as to the presence of early vs. late maturation of face-processing mechanisms. Recent behavioural evide...

Neurons, even in earliest sensory regions of cortex, are subject to a great deal of contextual influences from both within and across modality connections. Recently we have shown that cross-modal connections from vision to primary somatosensory cortex (SI) transmit content-specific information about familiar visual object categories. In the present...

A growing body of evidence suggests that neural pattern reactivation supports successful memory formation across multiple study episodes. Previous studies investigating the beneficial effects of repeated encoding typically presented the same stimuli repeatedly under the same encoding task instructions. In contrast, repeating stimuli in different co...

Rapidly and accurately processing information from faces is a critical human function that is known to improve with developmental age. Understanding the underlying drivers of this improvement remains a contentious question, with debate continuing as to the presence of early vs. late maturation of face processing mechanisms. Recent behavioural evide...

Faces transmit a wealth of important social signals. While previous studies have elucidated the network of cortical regions important for perception of facial expression, and the associated temporal components such as the P100, N170 and EPN, it is still unclear how task constraints may shape the representation of facial expression (or other face ca...

Facial expressions of emotion are signals of high biological value. Whilst recognition of facial expressions has been much studied in central vision, the ability to perceive these signals in peripheral vision has only seen limited research to date, despite the potential adaptive advantages of such perception. In the present experiment, we investiga...

Data (d-prime scores) underlying the main statistical analyses for every participant in each task (recognition & detection) for each combination of emotion and eccentricity. (XLSX)

A network of cortical and sub-cortical regions is known to be important in the processing of facial expression. However, to date no study has investigated whether representations of facial expressions present in this network permit generalization across independent samples of face information (e.g., eye region vs mouth region). We presented partici...

The present experiment used functional magnetic resonance imaging to investigate representational similarity patterns across repeated stimulus encoding with stimuli being presented in different modalities. Twenty adult participants performed a categorization task during the encoding phase, followed by an unexpected recognition-source memory task. D...

Using fMRI decoding techniques we recently demonstrated that early visual cortex contains content-specific information from sounds in the absence of visual stimulation (Vetter, Smith & Muckli, Current Biology, 2014). Here we studied whether the emotional valence of sounds can be decoded in early visual cortex during emotionally ambiguous visual sti...

The receptive fields of V1 neurons are driven by sensory input. V1 neurons are also modulated by cortical feedback, and this can be conceptualised as neuronal "feedback fields". Feedback fields can be investigated in human V1 by performing multivoxel pattern analyses on voxels that respond to an occluded portion of a visual scene. We investigated t...

The spatial precision of cortical feedback to V1 was explored using functional magnetic resonance imaging. Feedback may be local, predicting the image point by point or global, predicting the gist. Images were presented to 12 subjects with the lower right quadrant occluded (Smith & Muckli 2010) and at three different spatially-shifted versions (0/2...

Neurons, even in the earliest sensory areas of cortex, are subject to a large number of contextual influences from both within and across modality connections. In previous work (Smith & Goodale, 2012, ECVP) we have shown that early regions of somatosensory cortex (S1) surprisingly contain content-specific information about visually presented object...

Clark offers a powerful description of the brain as a prediction machine, which offers progress on two distinct levels. First, on an abstract conceptual level, it provides a unifying framework for perception, action, and cognition (including subdivisions such as attention, expectation, and imagination). Second, hierarchical prediction offers progre...

Higher visual areas in the occipitotemporal cortex contain discrete regions for face processing, but it remains unclear if V1 is modulated by top-down influences during face discrimination, and if this is widespread throughout V1 or localized to retinotopic regions processing task-relevant facial features. Employing functional magnetic resonance im...

Background / Purpose: We investigated whether emotional context as communicated through auditory stimulation can influence the activity patterns in early visual cortex. Main conclusion: When viewing an emotionally ambiguous interaction between two point-light walkers, activity patterns in early visual areas are influenced by emotional informat...

Our present understanding of the neural mechanisms and sensorimotor transformations that govern the planning of arm and eye movements predominantly come from invasive parieto-frontal neural recordings in nonhuman primates. While functional MRI (fMRI) has motivated investigations on much of these same issues in humans, the highly distributed and mul...

Primary visual cortex (V1) is often characterized by the receptive field properties of its feed-forward input. Direct thalamo-fugal input to any V1 cell however, is less than 5% (Douglas and Martin, 2007), and much of V1 response variance remains unexplained. We propose that one of the core functions of cortical processing is to predict upcoming ev...

Despite early visual cortex being one of the most intensely studied systems in the brain, the majority of processing variance is still unexplained. Here we show that information from hearing is contained in the activity patterns of early visual cortex, in a content-specific manner, in the absence of visual stimulation and despite an orthogonal work...

Even within the early sensory areas, the majority of the input to any given cortical neuron comes from other cortical neurons. To extend our knowledge of the contextual information that is transmitted by such lateral and feedback connections, we investigated how visually nonstimulated regions in primary visual cortex (V1) and visual area V2 are inf...

Primary visual cortex (area V1) and higher visual areas are reciprocally connected. To understand the nature of this reciprocal processing in more detail, we investigated the importance of area V1 (and its subregions) during complex face categorization tasks. It is generally assumed that gender or expression classification of faces is a complex cog...

We investigated whether contextual auditory information is contained in the neural activity pattern of visual cortex in a category-specific manner. While being blindfolded, subjects were presented with three types of natural sounds: a forest scene (animate/non-human), a talking crowd (animate/human) and traffic noise (inanimate). We used multivaria...

It is well established that animal communication signals have adapted to the evolutionary pressures of their environment. For example, the low-frequency vocalizations of the elephant are tailored to long-range communications, whereas the high-frequency trills of birds are adapted to their more localized acoustic niche. Like the voice, the human fac...

It is well established that animal communication signals have adapted to the evolutionary pressures of their environment. For example, the low-frequency vocalizations of the elephant are tailored to long-range communications, whereas the high-frequency trills of birds are adapted to their more localized acoustic niche. Like the voice, the human fac...

Reverse correlation methods have been widely used in neuroscience for many years and have recently been applied to study the sensitivity of human brain signals (EEG, MEG) to complex visual stimuli. Here we employ one such method, Bubbles (Gosselin, F., Schyns, P.G., 2001. Bubbles: A technique to reveal the use of information in recognition tasks. V...

Is it not ironic that Robert Crease (December 2002 p15) uses Karl Popper's "principle of falsifiability" to find an apparent flaw in the principle itself? Popper's principle implied that a theory cannot be proved right, only wrong. But Crease quotes just one example as apparently conclusive evidence that the principle is unsound – namely, the scien...