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52
The Speed of Sight
, 2001
"... Macaque monkeys were presented with continuous rapid serial visual presentation (RSVP) sequences of unrelated naturalistic images at rates of 14-222 msec/image, while neurons that responded selectively to complex patterns (e.g., faces) were recorded in temporal cortex. Stimulus selectivity was prese ..."
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Cited by 94 (6 self)
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Macaque monkeys were presented with continuous rapid serial visual presentation (RSVP) sequences of unrelated naturalistic images at rates of 14-222 msec/image, while neurons that responded selectively to complex patterns (e.g., faces) were recorded in temporal cortex. Stimulus selectivity was preserved for 65% of these neurons even at surprisingly fast presentation rates (14 msec/image or 72 images/sec). Five human subjects were asked to detect or remember images under equivalent conditions. Their performance in both tasks was above chance at all rates (14-111 msec/image). The performance of single neurons was comparable to that of humans and responded in a similar way to changes in presentation rate. The implications for the role of temporal cortex cells in perception are discussed.
The Simultaneous Type, Serial Token Model of Temporal Attention and Working Memory
- Psychological Review
, 2007
"... A detailed description of the simultaneous type, serial token (ST 2) model is presented. ST 2 is a model of temporal attention and working memory that encapsulates 5 principles: (a) M. M. Chun and M. C. Potter’s (1995) 2-stage model, (b) a Stage 1 salience filter, (c) N. G. Kanwisher’s (1987, 1991) ..."
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Cited by 75 (18 self)
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A detailed description of the simultaneous type, serial token (ST 2) model is presented. ST 2 is a model of temporal attention and working memory that encapsulates 5 principles: (a) M. M. Chun and M. C. Potter’s (1995) 2-stage model, (b) a Stage 1 salience filter, (c) N. G. Kanwisher’s (1987, 1991) types–tokens distinction, (d) a transient attentional enhancement, and (e) a mechanism for associating types with tokens called the binding pool. The authors instantiate this theoretical position in a connectionist implementation, called neural-ST 2, which they illustrate by modeling temporal attention results focused on the attentional blink (AB). They demonstrate that the ST 2 model explains a spectrum of AB findings. Furthermore, they highlight a number of new temporal attention predictions arising from the ST 2 theory, which are tested in a series of behavioral experiments. Finally, the authors review major AB models and theories and compare them with ST 2.
A quantitative theory of immediate visual recognition
- PROG BRAIN RES
, 2007
"... Human and non-human primates excel at visual recognition tasks. The primate visual system exhibits a strong degree of selectivity while at the same time being robust to changes in the input image. We have developed a quantitative theory to account for the computations performed by the feedforward p ..."
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Cited by 47 (14 self)
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Human and non-human primates excel at visual recognition tasks. The primate visual system exhibits a strong degree of selectivity while at the same time being robust to changes in the input image. We have developed a quantitative theory to account for the computations performed by the feedforward path in the ventral stream of the primate visual cortex. Here we review recent predictions by a model instantiating the theory about physiological observations in higher visual areas. We also show that the model can perform recognition tasks on datasets of complex natural images at a level comparable to psychophysical measurements on human observers during rapid categorization tasks. In sum, the evidence suggests that the theory may provide a framework to explain the first 100–150 ms of visual object recognition. The model also constitutes a vivid example of how computational models can interact with experimental observations in order to advance our understanding of a complex phenomenon. We conclude by suggesting a number of open questions, predictions, and specific experiments for visual physiology and psychophysics.
Spike-based strategies for rapid processing
- NEURAL NETWORKS
, 2001
"... Most experimental and theoretical studies of brain function assume that neurons transmit information as a rate code, but recent studies on the speed of visual processing impose temporal constraints that appear incompatible with such a coding scheme. Other coding schemes that use the pattern of spik ..."
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Cited by 37 (4 self)
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Most experimental and theoretical studies of brain function assume that neurons transmit information as a rate code, but recent studies on the speed of visual processing impose temporal constraints that appear incompatible with such a coding scheme. Other coding schemes that use the pattern of spikes across a population a neurons may be much more efficient. For example, since strongly activated neurons tend to fire first, one can use the order of firing as a code. We argue that Rank Order Coding is not only very efficient, but also easy to implement in biological hardware: neurons can be made sensitive to the order of activation of their inputs by including a feed-forward shunting inhibition mechanism that progressively desensitizes the neuronal population during a wave of afferent activity. In such a case, maximum activation will only be produced when the afferent inputs are activated in the order of their synaptic weights.
The representation of information about faces in the temporal and frontal lobes
- Neuropsychologia
, 2006
"... frontal lobes ..."
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Visual awareness and the detection of fearful faces
- Emotion
, 2005
"... A commonly held view is that emotional stimuli are processed independently of awareness. Here, the authors parametrically varied the duration of a fearful face target stimulus that was backward masked by a neutral face. The authors evaluated awareness by characterizing behavioral performance using r ..."
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Cited by 26 (0 self)
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A commonly held view is that emotional stimuli are processed independently of awareness. Here, the authors parametrically varied the duration of a fearful face target stimulus that was backward masked by a neutral face. The authors evaluated awareness by characterizing behavioral performance using receiver operating characteristic curves from signal detection theory. Their main finding was that no universal objective awareness threshold exists for fear perception. Although several subjects displayed a behavioral pattern consistent with previous reports (i.e., targets masked at 33 ms), a considerable percentage of their subjects (64%) were capable of reliably detecting 33-ms targets. Their findings suggest that considerable information is available even in briefly presented stimuli (possibly as short as 17 ms) to support masked fear detection. Emotional stimuli, such as a picture of a fearful face or an aversive scene, are processed rapidly. For example, when viewing such pictures, subjects exhibit fast, involuntary, autonomic re-sponses (Ohman, Esteves, & Soares, 1995). Under some condi-tions, the processing of emotional stimuli may proceed when the stimuli are outside the focus of attention (Vuilleumier, Armony,
A reevaluation of the electrophysiological correlates of expert object processing
- Journal of Cognitive Neuroscience
, 2006
"... & Subordinate-level object processing is regarded as a hallmark novel exemplars, and exemplars from novel species. Event-of perceptual expertise. However, the relative contribution of related potentials indicated that both basic- and subordinate-subordinate- and basic-level category experience i ..."
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Cited by 24 (5 self)
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& Subordinate-level object processing is regarded as a hallmark novel exemplars, and exemplars from novel species. Event-of perceptual expertise. However, the relative contribution of related potentials indicated that both basic- and subordinate-subordinate- and basic-level category experience in the acquisi- level training enhanced the early N170 component, but only tion of perceptual expertise has not been clearly delineated. In subordinate-level training amplified the later N250 component. this study, participants learned to classify wading birds and owls These results are consistent with models positing separate basic at either the basic (e.g., wading bird, owl) or the subordinate and subordinate learning mechanisms, and, contrary to perspec-(e.g., egret, snowy owl) level. After 6 days of training, behavioral tives attempting to explain visual expertise solely in terms of results showed that subordinate-level but not basic-level train- subordinate-level processing, suggest that expertise enhances ing improved subordinate discrimination of trained exemplars, neural responses of both basic and subordinate processing. &
Neural Mechanisms for Access to Consciousness
- In M. Gazzaniga (Ed.), the Cognitive Neurosciences III
, 2003
"... Introduction: the challenge of a science of consciousness Understanding consciousness has become the ultimate intellectual challenge of this new millennium. Even if philosophers now accept the notion that it is a "real , natural, biological phenomenon literally located in the brain" (Revo ..."
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Cited by 23 (1 self)
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Introduction: the challenge of a science of consciousness Understanding consciousness has become the ultimate intellectual challenge of this new millennium. Even if philosophers now accept the notion that it is a "real , natural, biological phenomenon literally located in the brain" (Revonsuo, 2001), a view in harmony with the neuroscientist conception that "consciousness is entirely caused by neurobiological processes and realized in brain structures" (Changeux, 1983; Crick, 1994; Edelman, 1989), the real issue becomes: how to elaborate a science of consciousness? This challenging problem raises two questions. A first one is how to empirically define experimental paradigms in order to delineate a relevant and ultimately causal relationship between subjective phenomena and objective measurements of neural activity. Cognitive psychologists have now defined a variety of minimal experimental protocols which allow a fair comparison between conscious and non-conscious processing of informa
Invariant visual object recognition: A model, with lighting invariance
- Journal of Physiology - Paris
, 2006
"... How are invariant representations of objects formed in the visual cortex? We describe a neurophysiological and computational approach which focusses on a feature hierarchy model in which invariant representations can be built by self-organizing learning based on the statistics of the visual input. T ..."
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Cited by 21 (6 self)
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How are invariant representations of objects formed in the visual cortex? We describe a neurophysiological and computational approach which focusses on a feature hierarchy model in which invariant representations can be built by self-organizing learning based on the statistics of the visual input. The model can use temporal continuity in an associative synaptic learning rule with a short term memory trace, and/or it can use spatial continuity in Continuous Transformation learning. The model of visual processing in the ventral cortical stream can build representations of objects that are invariant with respect to translation, view, size, and in this paper we show also lighting. The model has been extended to provide an account of invariant representations in the dorsal visual system of the global motion produced by objects such as looming, rotation, and object-based movement. The model has been extended to incorporate topdown feedback connections to model the control of attention by biased competition in for example spatial and object search tasks. The model has also been extended to account for how the visual system can select single objects in complex visual scenes, and how multiple objects can be represented in a scene.
Dissociating local and global levels of perceptuo-motor control in masked priming
- Journal of Experimental Psychology: Human Perception and Performance
, 2006
"... Masked prime stimuli presented near the threshold of conscious awareness affect responses to subsequent targets. The direction of these priming effects depends on the interval between masked prime and target. With short intervals, benefits for compatible trials (primes and targets mapped to the same ..."
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Cited by 13 (3 self)
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Masked prime stimuli presented near the threshold of conscious awareness affect responses to subsequent targets. The direction of these priming effects depends on the interval between masked prime and target. With short intervals, benefits for compatible trials (primes and targets mapped to the same response) and costs for incompatible trials are observed. This pattern reverses with longer intervals. We argue (a) that these effects reflect the initial activation and subsequent self-inhibition of the primed response, and the corresponding inhibition and subsequent disinhibition of the nonprimed response, and (b) that they are generated at dissociable local (within response channels) and global (between channels) levels of motor control. In two experiments, global-level priming effects were modulated by changing the number of response alternatives, whereas local-level effects remained unaffected. These experiments suggest that low-level motor control mechanisms can be successfully decomposed into separable subcomponents, operating at different levels within the motor system.
