Publications

Abstract

How do object perception and action interact at a neural level? Here we test the hypothesis that perceptual
features, processed by the ventral visuoperceptual stream, are used as priors by the dorsal visuomotor stream to
specify goal-directed grasping actions. We present three main findings, which were obtained by combining
time-resolved transcranial magnetic stimulation and kinematic tracking of grasp-and-rotate object manipulations,
in a group of healthy human participants (N 22). First, the extrastriate body area (EBA), in the ventral stream,
provides an initial structure to motor plans, based on current and desired states of a grasped object and of the
grasping hand. Second, the contributions of EBA are earlier in time than those of a caudal intraparietal region
known to specify the action plan. Third, the contributions of EBA are particularly important when desired and
current object configurations differ, and multiple courses of actions are possible. These findings specify the
temporal and functional characteristics for a mechanism that integrates perceptual processing with motor
planning.

Abstract

In their analysis of methods that participants use to manage the realization of practical courses of action, Kendrick and Drew (2016/this issue) focus on cases of assistance, where the need to be addressed is Self’s, and Other lends a helping hand. In our commentary, we point to other forms of cooperative engagement that are ubiquitously recruited in interaction. Imperative requests characteristically expect compliance on the grounds of Other’s already established commitment to a wider and shared course of actions. Established commitments can also provide the engine behind recruitment sequences that proceed nonverbally. And forms of cooperative engagement that are well glossed as assistance can nevertheless be demonstrably oriented to established commitments. In sum, we find commitment to shared courses of action to be an important element in the design and progression of certain recruitment sequences, where the involvement of Other is best defined as contribution. The commentary highlights the importance of interdependent orientations in the organization of cooperation. Data are in German, Italian, and Polish.

Abstract

Perceptual correlates of Turkish word stress and their contribution to lexical access were studied using the mismatch negativity (MMN) component in event-related potentials (ERPs). The MMN was expected to indicate if segmentally identical Turkish words were distinguished on the sole basis of prosodic features such as fundamental frequency (f0), spectral emphasis (SE), and duration. The salience of these features in lexical access was expected to be reflected in the amplitude of MMN responses. In a multi-deviant oddball paradigm, neural responses to changes in f0, SE, and duration individually, as well as to all three features combined, were recorded for words and pseudowords presented to 14 native speakers of Turkish. The word and pseudoword contrast was used to differentiate language-related effects from acoustic-change effects on the neural responses. First and in line with previous findings, the overall MMN was maximal over frontal and central scalp locations. Second, changes in prosodic features elicited neural responses both in words and pseudowords, confirming the brain's automatic response to any change in auditory input. However, there were processing differences between the prosodic features, most significantly in f0: While f0 manipulation elicited a slightly right-lateralized frontally-maximal MMN in words, it elicited a frontal P3a in pseudowords. Considering that P3a is associated with involuntary allocation of attention to salient changes, the manipulations of f0 in the absence of lexical processing lead to an intentional evaluation of pitch change. f0 is therefore claimed to be lexically specified in Turkish. Rather than combined features, individual prosodic features differentiate language-related effects from acoustic-change effects. The present study confirms that segmentally identical words can be distinguished on the basis of prosodic information alone, and establishes the salience of f0 in lexical access.

Abstract

Like that of many other Germanic languages, the stress system of Swedish has mainly undergone phonological analysis. Recently, however, researchers have begun to recognize the central role of morphology in these systems. Similar to the lexical specification of tonal accent, the Swedish stress system is claimed to be morphologically determined and morphemes are thus categorized as prosodically specified and prosodically unspecified. Prosodically specified morphemes bear stress information as part of their lexical representations and are classified as tonic (i.e., lexically stressed), pretonic and posttonic, whereas prosodically unspecified morphemes receive stress through a phonological rule that is right-edge oriented, but is sensitive to prosodic specification at that edge. The presence of prosodic specification is inferred from vowel quality and vowel quantity; if stress moves elsewhere, vowel quality and quantity change radically in phonologically stressed morphemes, whereas traces of stress remain in lexically stressed morphemes. The present study is the first to investigate whether stress is a lexical property of Swedish morphemes by comparing mismatch negativity (MMN) responses to vowel quality and quantity changes in phonologically stressed and lexically stressed words. In a passive oddball paradigm, 15 native speakers of Swedish were presented with standards and deviants, which differed from the standards in formant frequency and duration. Given that vowel quality and quantity changes are associated with morphological derivations only in phonologically stressed words, MMN responses are expected to be greater in phonologically stressed words than in lexically stressed words that lack such an association. The results indicated that the processing differences between phonologically and lexically stressed words were reflected in the amplitude and topography of MMN responses. Confirming the expectation, MMN amplitude was greater for the phonologically stressed word than for the lexically stressed word and showed a more widespread topographic distribution. The brain did not only detect vowel quality and quantity changes but also used them to activate memory traces associated with derivations. The present study therefore implies that morphology is directly involved in the Swedish stress system and that changes in phonological shape due to stress shift cue upcoming stress and potential addition of a morpheme.