The growth of cognitive science as a field, or at least as a descriptive term, indicates an emerging scientific consensus that many fundamental human capacities require collaborative and interdisciplinary research to make further fundamental headway. Language, as central to our essential humanity as anything is, represents one area in which massive amounts of interdisciplinary research is underway at virtually every research institution in the world.

This paper offers an alternative interpretation for what has been called the defective tense hypothesis, the primacy of aspect hypothesis, or simply the aspect hypothesis in the literature on first and second language acquisition of tense and aspect. The aspect hypothesis states that first and second language learners will initially be influenced by the inherent semantic aspect of verbs or predicates in the acquisition of tense and aspect markers associated with or affixed to these verbs. Our account focuses on the observation that adult native speakers also appear to adhere to this primacy of inherent semantic aspect in the relative quantitative distribution of tense-aspect markers in their speech. We argue that a small set of cognitive operating principles and the notion of prototypicality account for this behavior in learners. Moreover, we argue that these principles are a consequence of how learners and native speakers alike organize information and their perspectives on it in ongoing discourse.

This paper describes a cognitive framework for explaining the acquisition and use of a second language. The framework is based on the identification of two cognitive processing components, called analysis of knowledge and control of processing, that jointly function to develop proficiency in the language. The framework is explained briefly and then applied to five issues in second language acquisition: the similarity of first and second language learning, the starting point for second language acquisition, consciousness, variability, and instruction.

The present paper isolates certain domain-general cognitive processes involved in decision making and examines their instantiations in adult second language acquisition (SLA). After reviewing important differences between mature and immature cognition, I discuss the epistemological categories and concepts that underlie decision making. I then address decision making from the point of view of fallibility—for example, maladaptive biases that mediate learners' decisions—and I suggest that some impediments to success in SLA may be the result of mature domain-general decision making. The heuristic value of research in the area of decision making is emphasized.

This paper examines how the cognitive notion of attention has been employed in SLA and how it is understood in cognitive science. It summarizes recent research on attention from cognitive and neuroscience approaches. Some reformulations of problems raised in SLA research related to attention are proposed. Current research offers detailed ideas about attention and its component processes. These ideas, elaborated theoretically and empirically in cognitive neuroscience, may help untangle some important but difficult issues in SLA. Early, coarse-grained conceptions of attention, such as the limited-capacity metaphor or the automatic versus controlled processing dichotomy, are recast into an integrated human attention system with three separate yet interrelated networks: alertness, orientation, and detection. This finer grained analysis of attention is employed in a model of the role of attention in SLA.

Cognitive science has developed a number of experimental techniques for studying how people learn about sequentially structured stimulus material. We describe these techniques, review findings they have produced, and discuss the findings' relevance for understanding the mastery of syntax during second language learning. Three issues are addressed: (a) the nature or content of what is learned and how it might be represented in the language learner's knowledge base, paying special heed to acquiring abstract rules versus generalizing across stored examples, (b) the role of conscious awareness in syntactic learning, and (c) the role of limited-capacity processing or focal attention in syntactic learning. Care is taken to distinguish between the latter two factors—Focal attention to the task of learning about syntax and conscious awareness of particular syntactic structures are not the same thing and may well play different roles in successful acquisition.

This paper argues that the brain is the seat of cognition, that cognitive processes are neural processes, and that, in the brain, affect and cognition are distinguishable but inseparable. This perspective allows a reconceptualization of the affective filter in terms of the brain's stimulus appraisal system, which interacts with cognition to promote or inhibit second language acquisition. A research strategy is proposed for investigating these ideas.