TuressonLH2012 3 HK Turesson NK Logothetis KL Hoffman 2012-11-00 47 109 19438 19443 Proceedings of the National Academy of Sciences of the United States of America Object perception and categorization can occur so rapidly that behavioral responses precede or co-occur with the firing rate changes in the object-selective neocortex. Phase coding could, in principle, support rapid representation of object categories, whereby the first spikes evoked by a stimulus would appear at different phases of an oscillation, depending on the object category. To determine whether object-selective regions of the neo-cortex demonstrate phase coding, we presented images of faces and objects to two monkeys while recording local field potentials (LFP) and single unit activity from object-selective regions in the upper bank superior temporal sulcus. Single units showed preferred phases of firing that depended on stimulus category, emerging with the initiation of spiking responses after stimulus onset. Differences in phase of firing were seen below 20 Hz and in the gamma and high-gamma frequency ranges. For all but the <20-Hz cluster, phase differences remained category-specific even when controlling for stimulus-locked activity, revealing that phase-specific firing is not a simple consequence of category-specific differences in the evoked responses of the LFP. In addition, we tested for firing rate-to-phase conversion. Category-specific differences in firing rates accounted for 30–40% of the explained variance in phase occurring at lower frequencies (<20 Hz) during the initial response, but was limited (<20% of the explained variance) in the 30- to 60-Hz frequency range, suggesting that gamma phase-of-firing effects reflect more than evoked LFP and firing rate responses. The present results are consistent with theoretical models of rapid object processing and extend previous observations of phase coding to include object-selective neocortex. no notspecified http://www.kyb.tuebingen.mpg.de/ published 5 15017 15421 BartlettOLH2011 3 AM Bartlett S Ovaysikia NK Logothetis KL Hoffman 2011-12-00 5 31 18423 18432 Journal of Neuroscience Saccadic eye movements (SEMs) are the primary means of gating visual information in primates and strongly influence visual perception. The active exploration of the visual environment (“active vision”) via SEMs produces suppression during saccades and enhancement afterward (i.e., during fixation) in occipital visual areas. In lateral temporal lobe visual areas, the influence, if any, of eye movements is less well understood, despite the necessity of these areas for forming coherent percepts of objects. The upper bank of the superior temporal sulcus (uSTS) is one such area whose sensitivity to SEMs is unknown. We therefore examined how saccades modulate local field potentials (LFPs) in the uSTS of macaque monkeys while they viewed face and nonface object stimuli. LFP phase concentration increased following fixation onset in the alpha (8–14 Hz), beta (14–30 Hz), and gamma (30–60 Hz) bands and was distinct from the image-evoked response. Furthermore, near-coincident onsets of fixation and image presentation—like those occurring in active vision—led to enhanced responses through greater phase concentration in the same frequency bands. Finally, single-unit activity was modulated by the phase of alpha, beta, and gamma oscillations, suggesting that the observed phase-locking influences spike timing in uSTS. Previous research implicates phase concentration in these frequency bands as a correlate of perceptual performance (Womelsdorf et al., 2006; Bosman et al., 2009). Together, these results demonstrate sensitivity to eye movements in an object-processing region of the brain and represent a plausible neural basis for the enhancement of object processing during active vision. no notspecified http://www.kyb.tuebingen.mpg.de/ published 9 15017 15421 5842 3 KL Hoffman NK Logothetis 2009-02-00 1515 364 321 329 Philosophical Transactions of the Royal Society of London B Learning about the world through our senses constrains our ability to recognise our surroundings. Experience shapes perception. What is the neural basis for object recognition and how are learning-induced changes in recognition manifested in neural populations? We consider first the location of neurons that appear to be critical for object recognition, before describing what is known about their function. Two complementary processes of object recognition are considered: discrimination among diagnostic object features and generalization across non-diagnostic features. Neural plasticity appears to underlie the development of discrimination and generalization for a given set of features, though tracking these changes directly over the course of learning has remained an elusive task. no notspecified http://www.kyb.tuebingen.mpg.de/ published 8 15017 15421 5837 3 KL Hoffman AA Ghanzafar I Gauthier NK Logothetis 2008-03-00 2 1 1 8 Frontiers in Systems Neuroscience Auditory and visual signals often occur together, and the two sensory channels are known to infl uence each other to facilitate perception. The neural basis of this integration is not well understood, although other forms of multisensory infl uences have been shown to occur at surprisingly early stages of processing in cortex. Primary visual cortex neurons can show frequency-tuning to auditory stimuli, and auditory cortex responds selectively to certain somatosensory stimuli, supporting the possibility that complex visual signals may modulate early stages of auditory processing. To elucidate which auditory regions, if any, are responsive to complex visual stimuli, we recorded from auditory cortex and the superior temporal sulcus while presenting visual stimuli consisting of various objects, neutral faces, and facial expressions generated during vocalization. Both objects and conspecifi c faces elicited robust fi eld potential responses in auditory cortex sites, but the responses varied by category: both neutral and vocalizing faces had a highly consistent negative component (N100) followed by a broader positive component (P180) whereas object responses were more variable in time and shape, but could be discriminated consistently from the responses to faces. The face response did not vary within the face category, i.e., for expressive vs. neutral face stimuli. The presence of responses for both objects and neutral faces suggests that auditory cortex receives highly informative visual input that is not restricted to those stimuli associated with auditory components. These results reveal selectivity for complex visual stimuli in a brain region conventionally described as non-visual “unisensory” cortex. no notspecified http://www.kyb.tuebingen.mpg.de/ published 7 15017 15421 4671 3 KL Hoffman KM Gothard MC Schmid NK Logothetis 2007-05-00 9 17 766 772 Current Biology The social behavior of both human and nonhuman primates relies on specializations for the recognition of individuals, their facial expressions, and their direction of gaze [1], [2], [3], [4] and [5]. A broad network of cortical and subcortical structures has been implicated in face processing, yet it is unclear whether co-occurring dimensions of face stimuli, such as expression and direction of gaze, are processed jointly or independently by anatomically and functionally segregated neural structures. Awake macaques were presented with a set of monkey faces displaying aggressive, neutral, and appeasing expressions with head and eyes either averted or directed. BOLD responses to these faces as compared to Fourier-phase-scrambled images revealed widespread activation of the superior temporal sulcus and inferotemporal cortex and included activity in the amygdala. The different dimensions of the face stimuli elicited distinct activation patterns among the amygdaloid nuclei. The basolateral amygdala, including the lateral, basal, and accessory basal nuclei, produced a stronger response for threatening than appeasing expressions. The central nucleus and bed nucleus of the stria terminalis responded more to averted than directed-gaze faces. Independent behavioral measures confirmed that faces with averted gaze were more arousing, suggesting the activity in the central nucleus may be related to attention and arousal. no notspecified http://www.kyb.tuebingen.mpg.de/ published 6 15017 15421 4497 3 CD Dahl NK Logothetis KL Hoffman 2007-05-00 1622 274 2069 2076 Proceedings of the Royal Society of London B Despite considerable evidence that neural activity in monkeys reflects various aspects of face perception, relatively little is known about monkeys’ face processing abilities. Two characteristics of face processing observed in humans are a subordinate-level entry point, here, the default recognition of faces at the subordinate, rather than basic, level of categorization, and holistic effects, i.e., perception of facial displays as an integrated whole. The present study used an adaptation paradigm to test whether untrained Rhesus macaques display these hallmarks of face processing. In Experiments 1 and 2, macaques showed greater rebound from adaptation to conspecific faces than to other animals at the individual or subordinate level. In Experiment 3, exchanging only the bottom half of a monkey face produced greater rebound in aligned than in misaligned composites, indicating that for normal, aligned faces, the new bottom half may have influenced perception of the whole face. Scan path analysis supported this assertion: during rebound, fixation to the unchanged eye region was renewed, but only for aligned stimuli. These experiments show that macaques naturally display the distinguishing characteristics of face processing seen in humans, and provide the first clear demonstration that holistic information guides scan paths for conspecific faces. no notspecified http://www.kyb.tuebingen.mpg.de//fileadmin/user_upload/files/publications/Dahl_4497[0].pdf published 7 15017 15421 3361 3 AA Ghazanfar JX Maier KL Hoffman NK Logothetis 2005-05-00 20 25 5004 5012 Journal of Neuroscience In the social world, multiple sensory channels are used concurrently to facilitate communication. Among human and nonhuman primates, faces and voices are the primary means of transmitting social signals (Adolphs, 2003; Ghazanfar and Santos, 2004). Primates recognize the correspondence between species-specific facial and vocal expressions (Massaro, 1998; Ghazanfar and Logothetis, 2003; Izumi and Kojima, 2004), and these visual and auditory channels can be integrated into unified percepts to enhance detection and discrimination. Where and how such communication signals are integrated at the neural level are poorly understood. In particular, it is unclear what role "unimodal" sensory areas, such as the auditory cortex, may play. We recorded local field potential activity, the signal that best correlates with human imaging and event-related potential signals, in both the core and lateral belt regions of the auditory cortex in awake behaving rhesus monkeys while they viewed vocalizing conspecifics. We demonstrate unequivocally that the primate auditory cortex integrates facial and vocal signals through enhancement and suppression of field potentials in both the core and lateral belt regions. The majority of these multisensory responses were specific to face/voice integration, and the lateral belt region shows a greater frequency of multisensory integration than the core region. These multisensory processes in the auditory cortex likely occur via reciprocal interactions with the superior temporal sulcus. no notspecified http://www.kyb.tuebingen.mpg.de//fileadmin/user_upload/files/publications/ghazanfar05_JN_3361[0].pdf published 8 15017 15421 4056 2 KL Hoffman I Gauthier Elsevier Amsterdam, Netherlands 2007-02-00 437–445 Evolution of Nervous Systems Faces are processed in similar ways across cultures, and, in many instances, across primate species. Consistent and discrete brain regions are active for processing faces across human subjects, some of which appear to have homologous structures in the nonhuman primate. These behavioral and neural similarities across species suggest that face processing may be the target of evolutionary specialization. Evidence for an innate specialization can be obtained through testing abilities in infants, who have had minimal opportunity for environmental influences. Another strategy for verifying a specialization for face processing would be to compare homologous structures implicated in face processing in human and nonhuman primates. This approach may be particularly fruitful if the functions and developmental constraints of such structures are better understood in the nonhuman primate. Based on evidence from both approaches, we propose a possible neural substrate for one subset of face-processing abilities that may be innate, and describe evidence that still other face-processing skills may be experience expectant or experience dependent. no notspecified http://www.kyb.tuebingen.mpg.de/ published -437 15017 15421 7060 7 AM Bartlett NK Logothetis KL Hoffman San Diego, CA, USA2010-11-00 40th Annual Meeting of the Society for Neuroscience (Neuroscience 2010) Saccadic eye movements (SEMs) are the primary means of actively sampling the visual environment. The effect of saccadic eye movements on the neural processing of visual information has been characterized for retinotopic cortex [1,2], primarily in the forms of saccadic suppression [3]. Whereas previous studies have provided evidence for SEM-related activity in higher-order areas such as IT [4] and the hippocampus [5], we know of no investigation of neural activity in the STS, a region anatomically and functionally implicated in eye movements. To address this issue, we analyzed local field potential (LFP) data recorded from the upper bank superior temporal sulcus (uSTS) of two awake rhesus macaques passively viewing images of faces and non-face objects. As expected, LFP phase and amplitude in different frequency bands were modulated relative to image onset (i.e. image-evoked responses). In addition, responses were modulated relative to fixation onset, and varied based on the delay between image onset and fixation onset, suggesting an interaction between visual-evoked and SEM-evoked responses. To determine whether ‘well-timed’ fixations would lead to greater phase-locking of the evoked response [1] we selected trials in which a fixation was made within 20 ms of image onset (quasi- ‘active vision' condition), and compared responses to trials in which no eye movements were made in the interval -150 to 200 ms relative to image onset ('passive vision' condition). Phase concentration was increased in the alpha and beta frequency bands around the onset time of image-evoked responses in the active compared to passive conditions. In addition, the mean phase across electrode sites became more consistent, resulting in a larger-amplitude population evoked response for active than passive conditions. Our results demonstrate an interaction of sensory and saccadic signals in higher-order visual areas. The modulation observed is consistent with a role for active vision in reducing neural variability, enhancing signal transmission along visual pathways. no notspecified http://www.kyb.tuebingen.mpg.de/ published 0 15017 15421 6284 7 AM Bartlett NK Logothetis KL Hoffman Chicago, IL, USA2009-10-00 39th Annual Meeting of the Society for Neuroscience (Neuroscience 2009) Modulation of neural signals by saccadic eye movements (SEMs) has been reported in various cortical regions involved in visual and auditory perception. This work typically focused on how a SEM-related signal could prepare sensory areas for novel incoming visual stimuli following the end of SEMs [1]. In contrast to a low-dimensional timing signal, SEM modulation could convey information about the size and direction of SEMs, which could be useful for predicting what types of visual information to expect based on peripheral vision. Indeed, the local field potential (LFP) from visual areas V4 and TE in monkeys showed SEM modulation that was different for contra- and ipsi-versive horizontal SEMs [2]. In addition, single unit activity in primate auditory cortex is known to be sensitive to eye position in the orbit, as measured during spontaneous and auditory-evoked responses [4]. Our previous results showed that the upper bank superior temporal sulcus (STS) and core and belt auditory cortex (ACx) are modulated by SEMs [3], though it was not clear whether this was only a low-dimensional timing signal, or whether the response was also sensitive to the direction and/or magnitude of the saccade. Because oculomotor brain regions that project to STS and ACx are known to encode saccade amplitude while also controlling contraversive SEMs, we measured the influence of these two saccade metrics on ACx and STS activity in two awake, behaving monkeys during visually- and non-visually- guided SEMs. We analyzed the frequency-specific (spectral) LFP with a combination of Hilbert transforms and the Chronux signal processing toolbox. During SEMs, spectral power in the gamma and very high frequency ranges (60-200Hz) was correlated with the degree of contraversive movement and with overall saccade amplitude. The relationship between high-frequency power and saccade measures was seen in STS and ACx, during both visually-driven and non-visually-driven SEMs. In addition, high-frequency increases in power were often accompanied by decreases of power in the delta band (1-4 Hz). Our results suggest SEM modulation of activity in ACx and STS contains both spatial and temporal information, regardless of whether the SEM is visually-driven. Such a signal could be useful for scale-invariant feature integration, for the trans-saccadic integration of objects in complex scenes, or it may merely be the consequence of the signals conveyed from ipsilateral oculomotor areas. no notspecified http://www.kyb.tuebingen.mpg.de/ published 0 15017 15421 HoffmanTGL2009 7 K Hoffman H Turesson AA Ghazanfar NK Logothetis Salt Lake City, UT, USA2009-03-00 Computational and Systems Neuroscience Meeting (COSYNE 2009) Phase coding - stimulus coding by the timing of spikes with respect to the phase of local oscillations - is an alternative, complementary coding strategy to that of rate coding. One neocortical mechanism for phase coding posits that rhythmic inhibition in the gamma frequency range may interact with stimulus-evoked excitation, producing spikes earlier in an oscillatory cycle for preferred than non-preferred stimuli (Fries et al. 2007). Thus, the enhanced response for preferred stimuli commonly seen in the slowly-evolving rate code may also be coded through differences in spike timing within a single gamma cycle. Theoretically, this would provide a downstream target with a faster readout than would be possible with rate coding. Evidence for phase coding of visual stimuli was demonstrated recently in V1 of the anesthetized macaque (Montemurro et al. 2008), but only for lower frequencies (<12 Hz). Another study of spike-field phase coding in the secondary somatosensory cortex of the awake monkey also failed to find phase coding in the gamma frequency range (Ray et al. 2008). To address the generality and frequency-dependence of phase coding, we tested whether phase coding would be observed in an object-selective brain region in the awake macaque. Two monkeys passively viewed images of faces, clip-art objects, and computer-generated 'greebles' during broadband recordings from the upper bank superior temporal sulcus (STS; N=13 sessions). For all stimulus-responsive single units, trials were grouped according to the stimulus category presented and spiking was compared to the phase of the frequency components of the local field potential on that trial. For the majority of these cells (N=15), the phase at which firing occurred differed across stimulus categories. The category-selective phase differences were most common in two frequency bands: below 20Hz and in the gamma range (60-80Hz). The phase differences were not sustained throughout the image presentation, but rather were limited to roughly the first 200ms following stimulus onset, with no difference in the time course across frequencies. These results suggest that the visual category displayed can be extracted from the oscillatory phase when firing occurs. This holds not only for primary cortical areas known for their precise spike timing, but also for cells in association cortex, such as the upper-bank of the STS. Unlike previous studies, we found evidence of phase coding in the gamma frequency range, suggesting that there may be a regional specificity to the coding strategies used. The superior temporal sulcus receives highly-processed signals from multiple modalities, via projections from widespread cortical areas. As such, cells in STS may be less strictly driven by any given sensory input than are cells in early sensory cortical areas. Timing with respect to an internal gamma 'clock' may be one means by which such association areas maintain precise codes, as has been demonstrated previously for other cortical association areas such as the hippocampus (e.g., Buzsaki & Chrobak 1995). The phase coding observed in STS may indicate one role for intrinsic rhythms in the coding of extrinsic - or stimulus-driven - inputs. no notspecified http://www.kyb.tuebingen.mpg.de/ published 0 15017 15421 4572 7 CD Dahl NK Logothetis KL Hoffman Trier, Germany2007-03-00 166 49. Tagung Experimentell Arbeitender Psychologen (TeaP 2007) Despite considerable evidence that neural activity in monkeys reflects various aspects of face perception, relatively little is known about monkeys face processing behaviour. The present study used an adaptation paradigm to test whether untrained Rhesus macaques display two hallmarks of face processing observed in humans, namely, a subordinate entry point, here, the default recognition of faces at the individual level of categorization, and holistic effects, i.e., perception of facial parts as an integrated whole. In Experiment 1, monkeys showed greater rebound from adaptation to conspecific faces than to animals and non-conspecific faces at the subordinate level. In Experiment 2, exchanging only the bottom half of a monkey face produced greater rebound in aligned than in misaligned composites, indicating that for normal, aligned faces, the new bottom half has influenced perception of the whole face. These experiments show that macaques naturally display the distinguishing characteristics of face processing seen in humans. no notspecified http://www.kyb.tuebingen.mpg.de/ published -166 15017 15421 HoffmanGSL2006 7 KL Hoffman KM Gothard MC Schmid NK Logothetis Atlanta, GA, USA2006-10-00 36th Annual Meeting of the Society for Neuroscience (Neuroscience 2006) The amygdala has been associated with the perception of (and responses to) socially-relevant stimuli such as facial expressions, yet the relative roles of the component nuclei are largely unknown. Here, Rhesus macaques passively viewed blocks of faces or Fourier phase-scrambled images while being scanned in a 4.7 T magnet. Stimulus blocks contained the same 12 unfamiliar monkeys displaying one of three expressions (aggressive, neutral, or appeasing) with gaze/head position either directed or averted. Anatomically-defined regions of interest were applied to the eight-segment GE-EPIs (3s TR) acquired at a resolution of 1x1x2mm. The basolateral amygdala nuclei showed greater activation for aggressive than for appeasing expressions, irrespective of gaze, consistent with previous reports of amygdala sensitivity to threatening or fearful stimuli. Significant interactions between basolateral amygdala and temporal lobe neocortical areas were also observed. In contrast, the central nucleus showed greater responsivity to averted gaze, with no significant effects of expression. This unexpected result is nonetheless consistent with skin conductance response profiles in monkeys viewing these same stimuli (Mosher et al., 2006). The distinct response profiles seen in component amygdaloid nuclei may help to reconcile the dual roles attributed to amygdalar function, namely: detection of fearful stimuli and mediation of attentional/orienting responses. no notspecified http://www.kyb.tuebingen.mpg.de/ published 0 15017 15421 4003 7 CD Dahl NK Logothetis KL Hoffman Sarasota, FL, USA2006-06-00 432 6th Annual Meeting of the Vision Sciences Society (VSS 2006) Face perception in humans differs from perception of most objects: faces are recognized at the individual or subordinate level (e.g. Madonna, Collie), whereas objects are recognized at the basic level (e.g. face, dog). Additionally, faces are perceived holistically, i.e. features are not functionally independent. To date, these criteria have yet to be tested in monkeys. Using a dishabituation paradigm borrowed from developmental psychology, rhesus macaques elicited an image or blank square, alternately, by directing gaze towards the monitor, and terminated a stimulus by looking away. After 20 seconds of cummulative stimulus display time, a new image was displayed, constituting the beginning of a dishabituation trial. Image preference is measured as the time spent looking at the new image versus the cummulative display time. In experiment 1, conspecific faces preceded by either another animal or face showed higher preference than those preceded by the mirror-reversed image, demonstrating individuation among monkey faces. In contrast, animals (dogs or birds) did not elicit higher preference when preceded by another same-category exemplar, than when preceded by the mirror-reversed image, demonstrating only basic level differentiation. In experiment 2, composite monkey faces consisting of top and bottom halves were either aligned or misaligned. In dishabituation trials, only the bottom half was replaced. If monkeys perceive faces as wholes, this would cause perception of a new face only in the aligned condition. Indeed, aligned faces elicited greater preference than misaligned faces in dishabituation trials. Thus monkeys, like humans, show individuation and holistic processing of conspecific faces. no notspecified http://www.kyb.tuebingen.mpg.de/ published -432 15017 15421 HoffmanGL2005 7 KL Hoffman KM Gothard NK Logotethis Washington, DC, USA2005-11-00 35th Annual Meeting of the Society for Neuroscience (Neuroscience 2005) According to recent studies, both humans and macaques share face-selective brain regions. Among the active regions in the monkey, the anterior STS, and to a lesser degree TE, contain neurons selective to facial expressions and gaze or head direction. Results from human fMRI suggest the STS is sensitive to gaze direction, whereas the amygdala is the hallmark region showing activity for facial affect, particularly negative affect. To clarify which brain regions, if any, may be biased towards the processing of facial expressions or gaze/head direction, we presented blocks of face stimuli or Fourier-phase scrambled images to the awake Rhesus macaque placed in a 4.7 T magnet. The stimulus blocks contained images of the same 12 monkeys, grouped by gaze/head direction (towards or away) and facial expression (aggressive, neutral, or appeasing), for a total of 6 face groups and 6 corresponding scramble groups. Eight-segment GE-EPIs (3s TR) were obtained at a resolution of 1x1x2mm, smoothed with a Gaussian kernel at 2mm FWHM. Regions of face activation from previous reports were subsumed by regions of activation in the present study: large extents of STS were active bilaterally from posterior regions near FST to anterior regions co-extensive with the amygdala. Anterior activation spread over the lip of STS into TE (peak activation for face versus scrambled images, T = 18.38). Aggressive facial expressions produced amygdala activation, whereas appeasing faces activated a patch in area TF. The overall STS face activation, and amygdala activation to aggressive stimuli are consistent with BOLD activity reported in humans; however, the extensive STS activity was, as a whole, not sensitive to gaze or facial expressions. no notspecified http://www.kyb.tuebingen.mpg.de/ published 0 15017 15421 HoffmanGGL2004 7 KL Hoffman AA Ghazanfar I Gauthier NK Logothetis San Diego, CA, USA2004-10-00 34th Annual Meeting of the Society for Neuroscience (Neuroscience 2004) Single unit responses in the lower bank of the superior temporal sulcus and inferotemporal cortex show selectivity for faces and objects; however, the degree of selectivity beyond these unimodal visual areas is not well understood. Simultaneous recordings were collected from electrodes placed in multisensory regions of the upper bank of the superior temporal sulcus (uSTS), and in the lateral belt of auditory cortex, which is heavily interconnected with uSTS. The monkey passively viewed three classes of static images: monkey faces, various clip-art objects, and Greebles, an artificial set of homogeneous stimuli. Electrodes in auditory cortex as well as those in uSTS showed local field potential response profiles which differed for faces than for either Greebles or objects. The ‘face’ response in both recorded regions was characterized by a peak negativity around 100ms after stimulus onset. Multiple- and single-unit activity in uSTS revealed a variety of response selectivities to the three stimulus categories, but the most common was an enhanced response for the face stimuli. Discriminatory responses began as early as 50-70ms after stimulus onset. Taken together, these results indicate that 1. faces and objects elicit differentiable neural responses, even outside of unimodal visual areas, 2. Greeble responses are more closely associated with object than with face responses, and 3. category discrimination can occur at early latencies even in multisensory ‘association’ cortex. no notspecified http://www.kyb.tuebingen.mpg.de/ published 0 HoffmanGGL2004_2 7 K Hoffman A Ghazanfar I Gauthier NK Logothetis Barcelona, Spain2004-06-00 5th International Multisensory Research Forum (IMRF 2004) Behavioral and neural evidence suggests that faces are represented as a distinct class from other objects. Face-selective single unit reponses are most commonly found in unimodal visual areas such as the lower bank of superior temporal sulcus and the contiguous inferotemporal region. We investigated 1) the degree to which such face/object classifications occur beyond unimodal visual areas and 2) whether Greebles, an artificial set of homogeneous stimuli, elicit responses from sites that are also face-responsive. Simultaneous electrode recordings were collected from auditory cortex and the upper bank of the superior temporal sulcus (uSTS). The monkey passively viewed three classes of static images: monkey faces, various clip-art objects, and Greebles. The local field potential (LFP) response to faces was characterized by a peak negativity around 100ms after stimulus onset in both auditory cortex and uSTS. Both regions responded to objects and Greebles; however, their LFPs typically had a longer latency to peak, and a different response profile when compared with the face response. The relationship between the LFP response and spiking activity will also be described. no notspecified http://www.kyb.tuebingen.mpg.de/ published 0 15017 15421