Putting lexical constraints in context into the visual-world paradigm

Prior eye-tracking studies of spoken sentence comprehension have found that the presence of two potential referents, e.g., two frogs, can guide listeners toward a Modifier interpretation of Put the frog on the napkin… despite strong lexical biases associated with Put that support a Goal interpretation of the temporary ambiguity (Tanenhaus, M. K., Spivey-Knowlton, M. J., Eberhard, K. M. & Sedivy, J. C. (1995). Integration of visual and linguistic information in spoken language comprehension. Science, 268, 1632–1634; Trueswell, J. C., Sekerina, I., Hill, N. M. & Logrip, M. L. (1999). The kindergarten-path effect: Studying on-line sentence processing in young children. Cognition, 73, 89–134). This pattern is not expected under constraint-based parsing theories: cue conflict between the lexical evidence (which supports the Goal analysis) and the visuo-contextual evidence (which supports the Modifier analysis) should result in uncertainty about the intended analysis and partial consideration of the Goal analysis. We reexamined these put studies (Experiment 1) by introducing a response time-constraint and a spatial contrast between competing referents (a frog on a napkin vs. a frog in a bowl). If listeners immediately interpret on the… as the start of a restrictive modifier, then their eye movements should rapidly converge on the intended referent (the frog on something). However, listeners showed this pattern only when the phrase was unambiguously a Modifier (Put the frog that’s on the…). Syntactically ambiguous trials resulted in transient consideration of the Competitor animal (the frog in something). A reading study was also run on the same individuals (Experiment 2) and performance was compared between the two experiments. Those individuals who relied heavily on lexical biases to resolve a complement ambiguity in reading (The man heard/realized the story had been…) showed increased sensitivity to both lexical and contextual constraints in the put-task; i.e., increased consideration of the Goal analysis in 1-Referent Scenes, but also adeptness at using spatial constraints of prepositions (in vs. on) to restrict referential alternatives in 2-Referent Scenes. These findings cross-validate visual world and reading methods and support multiple-constraint theories of sentence processing in which individuals differ in their sensitivity to lexical contingencies.     

Selection from perceptual and conceptual representations

The lateral prefrontal cortex has been implicated in a wide variety of functions that guide our behavior, and one such candidate function is selection. Selection mechanisms have been described in several domains spanning different stages of processing, from visual attention to response execution. Here, we consider two such mechanisms: selecting relevant information from the perceptual world (e.g., visual selective attention) and selecting relevant information from conceptual representations (e.g., selecting a specific attribute about an object from long-term memory). Although the mechanisms involved in visual selective attention have been well characterized, much less is known about the latter case of selection. In this article, we review the relevant literature from the attention domain as a springboard to understanding the mechanisms involved in conceptual selection.     

Neuroanatomically separable effects of imageability and grammatical class during single-word comprehension

The present study characterizes the neural correlates of noun and verb imageability and addresses the question of whether components of the neural network supporting word recognition can be separately modified by variations in grammatical class and imageability. We examined the effect of imageability on BOLD signal during single-word comprehension of nouns and verbs. Subjects made semantic similarity judgments while undergoing functional magnetic resonance imaging (fMRI). Nouns and verbs were matched on imageability, and imageability varied continuously within a grammatical category. We observed three anatomically separable effects: a main effect of grammatical class, a main effect of imageability, and an imageability by grammatical class cross-over interaction. The left superior parietal lobule and a region in the left fusiform responded similarly to increases in noun and verb imageability; the left superior temporal gyrus showed greater activity for verbs than nouns after imageability was matched across grammatical class; and, in both the left middle temporal gyrus and the left inferior frontal lobe, a decrease in noun but not verb imageability resulted in higher BOLD signal. The presence of reliable and anatomically separable main effects of both imageability and grammatical class renders unlikely the hypothesis that previously reported dissociations between nouns and verbs can be dismissed as imageability effects. However, some regions previously thought to respond to grammatical class or imageability instead respond to the interaction of these variables.     

Perceptual and conceptual sources of priming on a word generation task

Repetition of any number of cognitive processes can facilitate subsequent performance (i.e., repetition priming). In this study, we explored several candidate mechanisms that could account for repetition priming on a word generation task. In Experiment 1, we examined whether repetition of semantic processing is necessary for priming on this task. In Experiment 2, we examined whether repetition of semantic processing is sufficient for priming on this task. In both experiments, we additionally examined the effect of changing the specific nature of the semantic retrieval task (i.e., from visual to functional, and vice versa) on performance. The results from these experiments indicated that repetition of semantic processing is both necessary and sufficient to produce a facilitation effect on the word generation task. However, semantic processing of the same attribute does not need to be repeated for facilitation effects to occur. Implications of these findings for theories of the representation and retrieval of semantic knowledge are discussed.     

Approach, avoidance, and inhibition: Personality traits predict cognitive control abilities

The extent to which approach and avoidance personality trait sensitivities are associated with specific cognitive control abilities as well as with verbal and nonverbal domains remains unclear. In the current study, we investigated whether approach and avoidance trait sensitivities predict performance on verbal and nonverbal versions of the Stroop task, which taps the specific cognitive control ability of inhibiting task-irrelevant information. The findings from the current study indicate that whereas approach (specifically, Extraversion) sensitivity was predictive of verbal Stroop performance, avoidance (specifically, Behavioral Inhibition System) sensitivity was predictive of nonverbal Stroop performance. These results provide novel evidence suggestive of the integration of motivational personality traits and the ability to inhibit task-irrelevant information in a domain-specific fashion.