Implicit acquisition of grammars with crossed and nested non-adjacent dependencies: investigating the push-down stack model

A recent hypothesis in empirical brain research on language is that the fundamental difference between animal and human communication systems is captured by the distinction between finite-state and more complex phrase-structure grammars, such as context-free and context-sensitive grammars. However, the relevance of this distinction for the study of language as a neurobiological system has been questioned and it has been suggested that a more relevant and partly analogous distinction is that between non-adjacent and adjacent dependencies. Online memory resources are central to the processing of non-adjacent dependencies as information has to be maintained across intervening material. One proposal is that an external memory device in the form of a limited push-down stack is used to process non-adjacent dependencies. We tested this hypothesis in an artificial grammar learning paradigm where subjects acquired non-adjacent dependencies implicitly. Generally, we found no qualitative differences between the acquisition of non-adjacent dependencies and adjacent dependencies. This suggests that although the acquisition of non-adjacent dependencies requires more exposure to the acquisition material, it utilizes the same mechanisms used for acquiring adjacent dependencies. We challenge the push-down stack model further by testing its processing predictions for nested and crossed multiple non-adjacent dependencies. The push-down stack model is partly supported by the results, and we suggest that stack-like properties are some among many natural properties characterizing the underlying neurophysiological mechanisms that implement the online memory resources used in language and structured sequence processing.     

Odor memory: Review and analysis

We critically review the cognitive literature on olfactory memory and identify the similarities and differences between odor memory and visual-verbal memory. We then analyze this literature using criteria from a multiple memory systems approach to determine whether olfactory memory can be considered to be a separate memory system. We conclude that olfactory memory has a variety of important distinguishing characteristics, but that more data are needed to confer this distinction. We suggest methods for the study of olfactory memory that should make a resolution on the separate memory system hypothesis possible while simultaneously advancing a synthetic understanding of olfaction and cognition.     

Affect is a form of cognition: A neurobiological analysis

In this paper, we suggest that affect meets the traditional definition of "cognition" such that the affect-cognition distinction is phenomenological, rather than ontological. We review how the affect-cognition distinction is not respected in the human brain, and discuss the neural mechanisms by which affect influences sensory processing. As a result of this sensory modulation, affect performs several basic "cognitive" functions. Affect appears to be necessary for normal conscious experience, language fluency, and memory. Finally, we suggest that understanding the differences between affect and cognition will require systematic study of how the phenomenological distinction characterising the two comes about, and why such a distinction is functional.     

Childhood amnesia and distinctions between forms of memory: A comment on Wood, Brown, and Felton

Recently, Wood and his colleagues (1989) presented a case of childhood amnesia as evidence against the distinction between declarative and procedural memory that has sometimes been applied to human amnesia. Their argument was based on the observation that their patient showed some progress in school over the years, i.e., acquired some declarative knowledge, despite severely impaired day-to-day memory ability. We briefly review their case, together with a carefully studied second case of childhood amnesia not mentioned by Wood et al. Their argument is wrong in several ways. First, the utility of the declarative/procedural distinction for amnesia, or the utility of any other distinction between memory systems, depends on whether or not one kind of memory is impaired selectively, not on the severity of the impairment. In particular there is no requirement that one kind of memory be totally absent. Second, they have not provided the data necessary to support their argument; namely, data showing that the amount of declarative knowledge accumulated during years in school was better than would have been expected given the capacity for moment-to-moment or day-to-day memory. Indeed, the patient's moment-to-moment memory ability is better than represented, and the patient's progress in school was abnormally slow. Third, it is not clear that academic achievement scores provide a direct measure of declarative memory abilities (skill learning and recovery of function may also have contributed). We conclude that the evidence from childhood amnesia is fully consistent with the proposal that amnesia reflects a selective impairment in the formation of long-term declarative memory.     

Passive and active processes in visuo-spatial memory: double dissociation in developmental learning disabilities

The distinction between passive and active visuo-spatial memory has been useful to interpret various pattern of deficits reported in individual differences studies. However, this interpretation raises the issue of task difficulty, since active tasks could be failed simply because more complex and the corresponding deficit could reflect a reduced capacity of the system. We describe two children with Nonverbal Learning Disability whose performance provides evidence of a dissociation between passive and active memory processes. One of the children showed a selective impairment in passive tasks and performed flawlessly in active tasks, whereas the second child displayed the opposite pattern. These data suggest that a qualitative difference between passive and active processes does exist and that differences in performance do not reflect a lower/higher level of task difficulty. Further, these data underlie the importance of formulating theoretical models of visuo-spatial memory including both material-related (i.e., visual vs spatial) and process-related (i.e., passive vs active) distinctions.     

Selective attention,diffused attention,and the development of categorization

How do people learn categories and what changes with development? The current study attempts to address these questions by focusing on the role of attention in the development of categorization. In Experiment 1, participants (adults, 7-year-olds, and 4-year-olds) were trained with novel categories consisting of deterministic and probabilistic features, and their categorization and memory for features were tested. In Experiment 2, participants’ attention was directed to the deterministic feature, and in Experiment 3 it was directed to the probabilistic features. Attentional cueing affected categorization and memory in adults and 7-year-olds: these participants relied on the cued features in their categorization and exhibited better memory of cued than of non-cued features. In contrast, in 4-year-olds attentional cueing affected only categorization, but not memory: these participants exhibited equally good memory for both cued and non-cued features. Furthermore, across the experiments, 4-year-olds remembered non-cued features better than adults. These results coupled with computational simulations provide novel evidence (1) pointing to differences in category representation and mechanisms of categorization across development, (2) elucidating the role of attention in the development of categorization, and (3) suggesting an important distinction between representation and decision factors in categorization early in development. These issues are discussed with respect to theories of categorization and its development.     

A cognitive neuroscience account of posttraumatic stress disorder and its treatment

Recent research in the areas of animal conditioning, the neural systems underlying emotion and memory, and the effect of fear on these systems is reviewed. This evidence points to an important distinction between hippocampally-dependent and non-hippocampally-dependent forms of memory that are differentially affected by extreme stress. The cognitive science perspective is related to a recent model of posttraumatic stress disorder, dual representation theory, that also posits separate memory systems underlying vivid reexperiencing versus ordinary autobiographical memories of trauma. This view is compared with other accounts in the literature of traumatic memory processes in PTSD, and the contrasting implications for therapy are discussed.     

Behavioural evidence for separating components within visuo-spatial working memory

Several different sources of evidence support the idea that visuo-spatial working memory can be segregated into separate cognitive subsystems. However, the nature of these systems remains unclear. Recently we reported data from neurological patients suggesting that information about visual appearance is retained in a different subsystem from information about spatial location. In this paper we report latency data from neurologically intact participants showing an experimental double dissociation between memory for appearance and memory for location. This was achieved by use of a selective dual task interference technique. This pattern provides evidence supporting the segregation of visuo-spatial memory between two systems, one of which supports memory for stimulus appearance and the other which supports memory for spatial location.     

Using an Individual Differences Approach to Examine Two Distinct Types of Suggestibility Effects

Two studies were conducted to examine relations between suggestibility effects studied in two commonly used research paradigms and a group of individual difference factors that have been theoretically linked to eyewitness suggestibility. In Study 1, we examined relations between the immediate acceptance of misinformation as measured by errors on misleading questions and individual differences in conformity, agreeableness, imagery ability, and memory. As predicted, the immediate acceptance of misinformation was associated with conformity but was not related to imagery ability. In Study 2, we examined relations between delayed retrieval errors produced during a classic misinformation paradigm and the same set of individual difference factors. Consistent with our predictions, delayed misinformation retrieval errors were related to imagery ability but were not related to conformity or agreeableness. Taken together, this predicted pattern of results across the two studies provides some preliminary evidence for an emerging distinction between these two types of suggestibility effects. Underlying theoretical, methodological, and practical issues related to the assessment of suggestibility effects are discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

Memory systems of the brain: a brief history and current perspective

The idea that memory is composed of distinct systems has a long history but became a topic of experimental inquiry only after the middle of the 20th century. Beginning about 1980, evidence from normal subjects, amnesic patients, and experimental animals converged on the view that a fundamental distinction could be drawn between a kind of memory that is accessible to conscious recollection and another kind that is not. Subsequent work shifted thinking beyond dichotomies to a view, grounded in biology, that memory is composed of multiple separate systems supported, for example, by the hippocampus and related structures, the amygdala, the neostriatum, and the cerebellum. This article traces the development of these ideas and provides a current perspective on how these brain systems operate to support behavior.     

Keeping track of where we are: Spatial working memory in navigation

Spatial working memory (WM) seems to include two types of spatial information: locations and relations. However, this distinction has been based on small-scale tasks. Here, we used a virtual navigation paradigm to examine whether WM for locations and relations applies to the large-scale spatial world. We found that navigators who successfully learned two routes and also integrated them were superior at maintaining multiple locations and multiple relations in WM. However, over the entire spectrum of navigators, WM for spatial relations, but not locations, was specifically predictive of route integration performance. These results lend further support to the distinction between these two forms of spatial WM and point to their critical role in individual differences in navigation proficiency.     

Quantifier comprehension in corticobasal degeneration

In this study, we investigated patients with focal neurodegenerative diseases to examine a formal linguistic distinction between classes of generalized quantifiers, like "some X" and "less than half of X." Our model of quantifier comprehension proposes that number knowledge is required to understand both first-order and higher-order quantifiers. The present results demonstrate that corticobasal degeneration (CBD) patients, who have number knowledge impairments but little evidence for a deficit understanding other aspects of language, are impaired in their comprehension of quantifiers relative to healthy seniors, Alzheimer's disease (AD) and frontotemporal dementia (FTD) patients [F(3,77)=4.98; p<.005]. Moreover, our model attempts to honor a distinction in complexity between classes of quantifiers such that working memory is required to comprehend higher-order quantifiers. Our results support this distinction by demonstrating that FTD and AD patients, who have working memory limitations, have greater difficulty understanding higher-order quantifiers relative to first-order quantifiers [F(1,77)=124.29; p<.001]. An important implication of these findings is that the meaning of generalized quantifiers appears to involve two dissociable components, number knowledge and working memory, which are supported by distinct brain regions.     

Spatial Semantics,Cognition, and Their Interaction: A Comparative Study of Spatial Categorization in English and Korean

This study has two goals. First, we present much‐needed empirical linguistic data and systematic analyses on the spatial semantic systems in English and Korean, two languages that have been extensively compared to date in the debate on spatial language and spatial cognition. We conduct our linguistic investigation comprehensively, encompassing the domains of tight‐ and loose‐fit as well as containment and support relations. The current analysis reveals both cross‐linguistic commonalities and differences: From a common set of spatial features, each language highlights a subset of those features for its principal categorization, and those primary features are importantly different between English and Korean: English speakers categorize events predominantly by containment and support relations (and do so with prepositions), whereas Korean speakers categorize them by tight‐fit and loose‐fit relations (and do so with verbs), with a further distinction of containment and support within the loose‐fit relation. The analysis also shows that the tight‐fit domain is more cross‐linguistically diverse in categorization than is the loose‐fit domain. Second, we test the language data against the nonlinguistic categorization results reported in Choi and Hattrup (2012). The results show a remarkable degree of convergence between the patterns predicted from the current linguistic analysis and those found in C&H's nonlinguistic study and thus provide empirical and strong evidence for an influence of language on nonlinguistic spatial cognition. At the same time, the study reveals areas where the two systems closely interact with each other as well as those where one is independent from the other. Taking both parts of the study together, we identify the specific roles that language and spatial perception/cognition play in spatial categorization.     

Preservation of categorical knowledge in Alzheimer's disease: A computational account

Abstract

The distinction between knowledge of specific exemplars and knowledge of their general categories is central to much theorising on the nature of semantic memory. The dissociation between exemplar and category knowledge observed in Alzheimer's Disease (AD) would appear to support this distinction, and to suggest that different neural systems are involved in the representation of exemplar and category knowledge. We review the evidence for preserved category knowledge in the semantic memory impairment of AD, and propose an alternative interpretation, according to which category and exemplar knowledge are both represented in the same distributed neural substrate. The relative preservation of category knowledge is a consequence of the greater frequency, and hence greater robustness, of the representation of attributes shared by all or most members of a category, compared to exemplar-unique attributes. We test and confirm the computational adequacy of this hypothesis in two computer simulations.     

视觉工作记忆中特征绑定关系的记忆机制

弱客体理论认为, 视觉工作记忆系统是由众多特征存储的子系统组成, 不同纬度的特征独立存储在相应的有限容量的子系统中, 相互之间不会竞争记忆资源。而对于特征之间绑定关系的记忆存在不同的观点。一种观点认为绑定关系的记忆需要注意维持, 因此绑定关系的记忆会占用到特征记忆的资源; 另一种观点认为绑定关系的记忆是自动发生的, 不需要注意的维持。本实验的目的是探究特征绑定关系的记忆是否是自动发生的。在实验中, 我们设计了两种任务, 一种任务是只记忆颜色, 另一种任务是记忆颜色跟位置及其之间的绑定关系, 并测试分析视觉工作记忆相关的ERP成分CDA。结果发现两种任务条件下的CDA波幅之间没有显著差异, 说明视觉工作记忆中的特征绑定是自动发生的。     

Gestalt and feature-intensive processing: Toward a unified model of human information processing

“Cognitive asynchrony theory,” recently developed in research on aging and memory, implies a functional distinction between the processing of “feature-intensive” items, those with numerous identifiable features, and the processing of images which are relatively sparse in such features and are handled in a more wholistic, “gestalt” manner. The present experiments addressed the question of whether such a distinction exists outside the realms of memory in which it has thus far been addressed. The present work used mental rotation as a model system. Consistent with the predictions of this model, Experiment 1 showed that feature-intensive figures required significantly more time to rotate than did gestalt figures, even though angles of rotation were the same. Experiment 2 demonstrated that feature-intensive processing may involve verbally-accessible semantic systems to a greater degree than is the case with “gestalt” items. Experiment 3 identified significant practice effects of feature-intensive stimuli on the processing of gestalt stimuli, but not the reverse. The results of these experiments indicate that the “gestalt/feature-intensive” processing distinction extends to mental rotation as well as to memory. Implications for the nature of mental representation of verbal and visual materials are discussed.     

Gestalt and feature-intensive processing: Toward a unified model of human information processing

“Cognitive asynchrony theory,” recently developed in research on aging and memory, implies a functional distinction between the processing of “feature-intensive” items, those with numerous identifiable features, and the processing of images which are relatively sparse in such features and are handled in a more wholistic, “gestalt” manner. The present experiments addressed the question of whether such a distinction exists outside the realms of memory in which it has thus far been addressed. The present work used mental rotation as a model system. Consistent with the predictions of this model, Experiment 1 showed that feature-intensive figures required significantly more time to rotate than did gestalt figures, even though angles of rotation were the same. Experiment 2 demonstrated that feature-intensive processing may involve verbally-accessible semantic systems to a greater degree than is the case with “gestalt” items. Experiment 3 identified significant practice effects of feature-intensive stimuli on the processing of gestalt stimuli, but not the reverse. The results of these experiments indicate that the “gestalt/feature-intensive” processing distinction extends to mental rotation as well as to memory. Implications for the nature of mental representation of verbal and visual materials are discussed.     

A unitary signal-detection model of implicit and explicit memory

Do dissociations imply independent systems? In the memory field, the view that there are independent implicit and explicit memory systems has been predominantly supported by dissociation evidence. Here, we argue that many of these dissociations do not necessarily imply distinct memory systems. We review recent work with a single-system computational model that extends signal-detection theory (SDT) to implicit memory. SDT has had a major influence on research in a variety of domains. The current work shows that it can be broadened even further in its range of application. Indeed, the single-system model that we present does surprisingly well in accounting for some key dissociations that have been taken as evidence for independent implicit and explicit memory systems.     

Visual short-term memory always requires general attention

The role of attention in visual memory remains controversial; while some evidence has suggested that memory for binding between features demands no more attention than does memory for the same features, other evidence has indicated cognitive costs or mnemonic benefits for explicitly attending to bindings. We attempted to reconcile these findings by examining how memory for binding, for features, and for features during binding is affected by a concurrent attention-demanding task. We demonstrated that performing a concurrent task impairs memory for as few as two visual objects, regardless of whether each object includes one or more features. We argue that this pattern of results reflects an essential role for domain-general attention in visual memory, regardless of the simplicity of the to-be-remembered stimuli. We then discuss the implications of these findings for theories of visual working memory.