Huber and O'Reilly (2003) proposed that neural habituation aids perceptual processing, separating neural responses to currently viewed objects from recently viewed objects. However, synaptic depression has costs, producing repetition deficits. Prior work confirmed the transition from repetition benefits to deficits with increasing duration of a prime object, but the prediction of enhanced novelty detection was not tested. The current study examined this prediction with a same/different word priming task, using support vector machine (SVM) classification of EEG data, ERP analyses focused on the N400, and dynamic neural network simulations fit to behavioral data to provide a priori predictions of the ERP effects. Subjects made same/different judgements to a response word in relation to an immediately preceding brief target word; prime durations were short (50ms) or long (400ms), and long durations decreased P100/N170 responses to the target word, suggesting that this manipulation increased habituation. Following long duration primes, correct "different" judgments of primed response words increased, evidencing enhanced novelty detection. An SVM classifier predicted trial-bytrial behavior with 66.34% accuracy on held-out data, with greatest predictive power at a time pattern consistent with the N400. The habituation model was augmented with a maintained semantics layer (i.e., working memory) to generate behavior and N400 predictions. A second experiment used responselocked ERPs, confirming the model's assumption that residual activation in working memory is the basis of novelty decisions. These results support the theory that neural habituation enhances novelty detection, and the model assumption that the N400 reflects updating of semantic information in working memory..

The negative compatibility effect (NCE) is the finding of slower reaction times (RTs) to report the direction of a target arrow following a subliminal prime arrow pointed in the same direction. The NCE is commonly thought to reflect automatic response inhibition, and on this assumption, it has recently been used to assess various motor disorders. Here we propose a fundamentally different account of the NCE: one that relates the NCE to a broader class of paradigms that reveal behavioral deficits with repetition priming. We propose that the NCE is a "cognitive aftereffect," as explained with the neural habituation model of Huber and O'Reilly (2003). To identify the underlying perceptual dynamics by reducing the role of response preparation, we developed a novel variant of the NCE task with threshold accuracy rather than RT as the dependent measure. This revealed a transition from positive to negative priming as a function of prime duration, and a second experiment ruled out response priming. The perceptual dynamics of the neural habituation model were fit to these results and then fixed in applying the model to the NCE literature. Application of the model to RTs added a response layer that accumulates response information throughout the trial. With this addition, the model captured results found in the NCE literature that are inconsistent with a response inhibition account. Situations that produce a positive compatibility effect, rather than an NCE, were explained as response priming, whereas NCE effects were explained as a cognitive aftereffect, rooted in perceptual dynamics.

Huber and O'Reilly (2003) proposed that neural habituation aids perceptual processing, separating neural responses to currently viewed objects from recently viewed objects. However, synaptic depression has costs, producing repetition deficits. Prior work confirmed the transition from repetition benefits to deficits with increasing duration of a prime object, but the prediction of enhanced novelty detection was not tested. The current study examined this prediction with a same/different word priming task, using support vector machine (SVM) classification of EEG data, ERP analyses focused on the N400, and dynamic neural network simulations fit to behavioral data to provide a priori predictions of the ERP effects. Subjects made same/different judgements to a response word in relation to an immediately preceding brief target word; prime durations were short (50ms) or long (400ms), and long durations decreased P100/N170 responses to the target word, suggesting that this manipulation increased habituation. Following long duration primes, correct "different" judgments of primed response words increased, evidencing enhanced novelty detection. An SVM classifier predicted trial-bytrial behavior with 66.34% accuracy on held-out data, with greatest predictive power at a time pattern consistent with the N400. The habituation model was augmented with a maintained semantics layer (i.e., working memory) to generate behavior and N400 predictions. A second experiment used responselocked ERPs, confirming the model's assumption that residual activation in working memory is the basis of novelty decisions. These results support the theory that neural habituation enhances novelty detection, and the model assumption that the N400 reflects updating of semantic information in working memory. Introduction:Pyramidal cells exhibit temporary synaptic depression, owing to neurotransmitter depletion, which limits the ability of sending cells to signal receiving cells (Abbott et al. 1997). This reduces postsynaptic activity by an order of magnitude, but many theories of object identification (Riesenhuber and Poggio 1999) do not include this dynamic. Furthermore, these theories do not specify how the visual system resets itself for each new visual input. Huber and O'Reilly (2003) proposed that short-term synaptic depression, which in this context we refer to as neural habituation, exists to solve this temporal parsing problem, allowing unobstructed perception of the current stimulus by suppressing the response of recently identified visual objects; because previously viewed objects are suppressed, any new object is highly salient in comparison. However, if an object is repeated, this suppression may make it difficult to identify that object on its second presentation. Huber and O'Reilly developed an artificial neural network model with synaptic depression to explain such repetition blindness effects. However, the benefits of neural habituation were not previously demonstrated. Using computational modeling, support vector machine (SVM) classifica...

The Negative Compatibility Effect (NCE) is slower reaction times (RTs) to report the direction of a target arrow that follows a matching prime arrow. The cause has been debated, with some studies indicating perception, while others indicate a response effect. We applied the neural habituation model of Huber and O'Reilly (2003) to the NCE, explaining the varied results as reflecting changes in the timing of events. We developed a novel variant of the NCE task, specifying the perceptual dynamics of orientation priming as measured with threshold accuracy. This revealed a transition from positive to negative priming as a function of prime duration, and a second experiment ruled out response priming. The perceptual dynamics of the neural habituation model were fit to these results and the parameter values were fixed in applying the model to the NCE literature. Application of the model to RTs necessitated a response representation that accumulates response information during the trial. Our results indicate that the NCE reflects rapid perceptual priming and slower response priming. Because the accumulation of response information is slow and does not suffer from habituation, the response factor of the prime is a positive effect (lingering response information). In contrast, because perceptual activation is fast and habituates, the perceptual factor can be positive or negative priming depending on the timing of the display sequence. These factors interact with the post-prime mask, which can prime the alternative direction when the mask is a related mask created by combining arrows pointing in both directions.