How do speakers predict the syntax of a verb from its meaning? Traditional theories posit that syntactically relevant information about semantic arguments consists of a list of thematic roles like "agent", "theme", and "goal", which are linked onto a hierarchy of grammatical positions like subject, object and oblique object. For verbs involving motion, the entity caused to move is defined as the "theme" or "patient" and linked to the object. However, this fails for many common verbs, as in fill water into the glass and cover a sheet onto the bed. In more recent theories verbs’ meanings are multidimensional structures in which the motions, changes, and other events can be represented in separate but connected substructures; linking rules are sensitive to the position of an argument in a particular configuration. The verb’s object would be linked not to the moving entity but to the argument specified as "affected" or caused to change as the main event in the verb’s meaning. The change can either be one of location, resulting from motion in a particular manner, or of state, resulting from accommodating or reacting to a substance. For example, pour specifies how a substance moves (downward in a stream), so its substance argument is the object (pour the water/glass); fill specifies how a container changes (from not full to full), so its stationary container argument is the object (fill the glass/water). The newer theory was tested in three experiments. Children aged 3;4-9;4 and adults were taught made-up verbs, presented in a neutral syntactic context (this is mooping), referring to a transfer of items to a surface or container. Subjects were tested on their willingness to encode the moving items or the surface as the verb’s object. For verbs where the items moved in a particular manner (e.g., zig-zagging), people were more likely to express the moving items as the object; for verbs where the surface changed state (e.g., shape, color, or fullness), people were more likely to express the surface as the object. This confirms that speakers are not confined to labeling moving entities as "themes" or "patients" and linking them to the grammatical object; when a stationary entity undergoes a state change as the result of a motion, it can be represented as the main affected argument and thereby linked to the grammatical object instead.

When it comes to explaining English verbs’ patterns of regular and irregular generalization, single-network theories have difficulty with the former, rule-only theories with the latter process. Linguistic and psycholinguistic evidence, based on observation during experiments and simulations in morphological pattern generation, independently call for a hybrid of the two theories.

How do people recognize an object in different orientations? One theory is that the visual system describes the object relative to a reference frame centered on the object, resulting in a representation that is invariant across orientations. Chronometric data show that this is true only when an object can be identified uniquely by the arrangement of its parts along a single dimension. When an object can only be distinguished by an arrangement of its parts along more than one dimension, people mentally rotate it to a familiar orientation. This finding suggests that the human visual reference frame is tied to egocentric coordinates.

In a recent paper, Chambers and Reisberg (1985) showed that people cannot reverse classical ambiguous figures in imagery (such as the Necker cube, duck/rabbit, or Schroeder staircase). In three experiments, we refute one kind of explanation for this difficulty: that visual images do not contain information about the geometry of a shape necessary for reinterpreting it or that people cannot apply shape classification procedures to the information in imagery. We show, that given suitable conditions, people can assign novel interpretations to ambiguous images which have been constructed out of parts or mentally transformed. For example, when asked to imagine the letter “D” on its side, affixed to the top of the letter “J”, subjects spontaneously report “seeing” an umbrella. We also show that these reinterpretations are not the result of guessing strategies, and that they speak directly to the issue of whether or not mental images of ambiguous figures can be reconstrued. Finally, we show that arguments from the philosophy literature on the relation between images and descriptions are not relevant to the issue of whether images can be reinterpreted, and we suggest possible explanations for why classical ambiguous figures do not spontaneously reverse in imagery.

The acquisition of the passive in English poses a learnability problem. Most transitive verbs have passive forms (e.g., kick/was kicked by), tempting the child to form a productive rule of passivization deriving passive participles from active forms. However, some verbs cannot be passivized (e.g. cost/was cost by). Given that children do not receive negative evidence telling them which strings are ungrammatical, what prevents them from overgeneralizing a productive passive rule to the exceptional verbs (or if they do incorrectly passivize such verbs, how do they recover)? One possible solution is that children are conservative: they only generate passives for those verbs that they have heard in passive sentences in the input. We show that this proposal is incorrect: in children’s spontaneous speech, they utter passive participles that they could not have heard in parental input, and in four experiments in which 3–8-year-olds were taught novel verbs in active sentences, they freely uttered passivized versions of them when describing new events. An alternative solution is that children at some point come to possess a semantic constraint distinguishing passivizable from nonpassivizable verbs. In two of the experiments, we show that children do not have an absolute constraint forbidding them to passivize nonactional verbs of perception or spatial relationships, although they passivize them somewhat more reluctantly than they do actional verbs. In two other experiments, we show that children’s tendency to passivize depends on the mapping between thematic roles and grammatical functions specified by the verb: they selectively resist passivizing made-up verbs whose subjects are patients and whose objects are agents; and they are more likely to passivize spatial relation verbs with location subjects than with theme subjects. These trends are consistent with Jackendoff’s “Thematic Hierarchy Condition” on the adult passive. However, we argue that the constraint on passive that adults obey, and that children approach, is somewhat different: passivizable verbs must have object arguments that are patients, either literally for action verbs, or in an extended abstract sense that individual languages can define for particular classes of nonactional verbs.