Suzanne R. Jongman

Sustained attention in language production: An individual differences investigation

Whereas it has long been assumed that most linguistic processes underlying language production happen automatically, accumulating evidence suggests that these processes do require some form of attention. Here we investigated the contribution of sustained attention: the ability to maintain alertness over time. In Experiment 1, participants’ sustained attention ability was measured using auditory and visual continuous performance tasks. Subsequently, employing a dual-task procedure, participants described pictures using simple noun phrases and performed an arrow-discrimination task while their vocal and manual response times (RTs) and the durations of their gazes to the pictures were measured. Earlier research has demonstrated that gaze duration reflects language planning processes up to and including phonological encoding. The speakers’ sustained attention ability correlated with the magnitude of the tail of the vocal RT distribution, reflecting the proportion of very slow responses, but not with individual differences in gaze duration. This suggests that sustained attention was most important after phonological encoding. Experiment 2 showed that the involvement of sustained attention was significantly stronger in a dual-task situation (picture naming and arrow discrimination) than in simple naming. Thus, individual differences in maintaining attention on the production processes become especially apparent when a simultaneous second task also requires attentional resources.

Entrainment to an auditory signal: Is attention involved?

Many natural auditory signals, including music and language, change periodically. The effect of such auditory rhythms on the brain is unclear however. One widely held view, dynamic attending theory, proposes that the attentional system entrains to the rhythm and increases attention at moments of rhythmic salience. In support, 2 experiments reported here show reduced response times to visual letter strings shown at auditory rhythm peaks, compared with rhythm troughs. However, we argue that an account invoking the entrainment of general attention should further predict rhythm entrainment to also influence memory for visual stimuli. In 2 pseudoword memory experiments we find evidence against this prediction. Whether a pseudoword is shown during an auditory rhythm peak or not is irrelevant for its later recognition memory in silence. Other attention manipulations, dividing attention and focusing attention, did result in a memory effect. This raises doubts about the suggested attentional nature of rhythm entrainment. We interpret our findings as support for auditory rhythm perception being based on auditory-motor entrainment, not general attention entrainment.

Picture naming in typically developing and language-impaired children: the role of sustained attention.

BACKGROUND Children with specific language impairment (SLI) have problems not only with language performance but also with sustained attention, which is the ability to maintain alertness over an extended period of time. Although there is consensus that this ability is impaired with respect to processing stimuli in the auditory perceptual modality, conflicting evidence exists concerning the visual modality. AIMS To address the outstanding issue whether the impairment in sustained attention is limited to the auditory domain, or if it is domain-general. Furthermore, to test whether childrens sustained attention ability relates to their word-production skills. METHODS & PROCEDURES Groups of 7-9 year olds with SLI (N = 28) and typically developing (TD) children (N = 22) performed a picture-naming task and two sustained attention tasks, namely auditory and visual continuous performance tasks (CPTs). OUTCOMES & RESULTS Children with SLI performed worse than TD children on picture naming and on both the auditory and visual CPTs. Moreover, performance on both the CPTs correlated with picture-naming latencies across developmental groups. CONCLUSIONS & IMPLICATIONS These results provide evidence for a deficit in both auditory and visual sustained attention in children with SLI. Moreover, the study indicates there is a relationship between domain-general sustained attention and picture-naming performance in both TD and language-impaired children. Future studies should establish whether this relationship is causal. If attention influences language, training of sustained attention may improve language production in children from both developmental groups.

The interplay between selective and nonselective inhibition during single word production

The present study investigated the interplay between selective inhibition (the ability to suppress specific competing responses) and nonselective inhibition (the ability to suppress any inappropriate response) during single word production. To this end, we combined two well-established research paradigms: the picture-word interference task and the stop-signal task. Selective inhibition was assessed by instructing participants to name target pictures (e.g., dog) in the presence of semantically related (e.g., cat) or unrelated (e.g., window) distractor words. Nonselective inhibition was tested by occasionally presenting a visual stop-signal, indicating that participants should withhold their verbal response. The stop-signal was presented early (250 ms) aimed at interrupting the lexical selection stage, and late (325 ms) to influence the word-encoding stage of the speech production process. We found longer naming latencies for pictures with semantically related distractors than with unrelated distractors (semantic interference effect). The results further showed that, at both delays, stopping latencies (i.e., stop-signal RTs) were prolonged for naming pictures with semantically related distractors compared to pictures with unrelated distractors. Taken together, our findings suggest that selective and nonselective inhibition, at least partly, share a common inhibitory mechanism during different stages of the speech production process.

To plan or not to plan: Does planning for production remove facilitation from associative priming?

Theories of conversation propose that in order to have smooth transitions from one turn to the next, speakers already plan their response while listening to their interlocutor. Moreover, it has been argued that speakers align their linguistic representations (i.e. prime each other), thereby reducing the processing costs associated with concurrent listening and speaking. In two experiments, we assessed how identity and associative priming from spoken words onto picture naming were affected by a concurrent speech planning task. In a baseline (no name) condition, participants heard prime words that were identical, associatively related, or unrelated to target pictures presented two seconds after prime onset. Each prime was accompanied by a non-target picture and followed by its recorded name. The participant did not name the non-target picture. In the plan condition, the participants first named the non-target picture, instead of listening to the recording, and then the target. In Experiment 1, where the plan- and no-plan conditions were tested between participants, priming effects of equal strength were found in the plan and no-plan condition. In Experiment 2, where the two conditions were tested within participants, the identity priming effect was maintained, but the associative priming effect was only seen in the no-plan but not in the plan condition. In this experiment, participant had to decide at the onset of each trial whether or not to name the non-target picture, rendering the task more complex than in Experiment 1. These decision processes may have interfered with the processing of the primes. Thus, associative priming can take place during speech planning, but only if the cognitive load is not too high.